WO2020204188A1

WO2020204188A1 - Production method for cyclic olefin copolymer

Info

Publication number: WO2020204188A1
Application number: PCT/JP2020/015411
Authority: WO
Inventors: 多田　智之; 尚幸脇谷; 広行小松
Original assignee: ポリプラスチックス株式会社
Priority date: 2019-04-04
Filing date: 2020-04-03
Publication date: 2020-10-08

Abstract

Provided is a production method for a cyclic olefin copolymer. The production method makes it possible to produce a cyclic olefin copolymer that has a low glass transition temperature (Tg) and excellent workability while also suppressing the generation of polyethylene-like impurities, even when monomers that include norbornene monomers and ethylene are polymerized at a high temperature that is conducive to the generation of polyethylene-like impurities.　According to the present invention, monomers that include norbornene monomers and ethylene are polymerized in the presence of a metallocene catalyst at a temperature of at least 50°C to produce a cyclic olefin copolymer that has a glass transition temperature of no more than 130°C. The pressure at which the ethylene is added to a polymerization vessel is at least 0.3 MPa. The metallocene catalyst has: a ligand that includes a cyclopentadiene ring; and a structure in which a nitrogen atom is bonded to a silicon atom and a transition metal that is in group IV of the periodic table.

Description

Method for Producing Cyclic Olefin Copolymer

The present invention relates to a method for producing a cyclic olefin copolymer containing a structural unit derived from norbornene monomer and a structural unit derived from ethylene.

Cyclic olefin homopolymers and cyclic olefin copolymers have low moisture absorption and high transparency, and are used in various applications including the field of optical materials such as optical disk substrates, optical films, and optical fibers.
As a typical cyclic olefin copolymer, there is a copolymer of cyclic olefin and ethylene, which is widely used as a transparent resin. Since the glass transition temperature of the copolymer of cyclic olefin and ethylene can be changed according to the copolymerization composition of cyclic olefin and ethylene, the copolymer weight in which the glass transition temperature (Tg) is adjusted in a wide temperature range. Copolymerization can be produced (see, for example, Non-Patent Document 1).

For the cyclic olefin copolymer, for example, a low glass transition temperature of 130 ° C. or lower is often desired because it is easy to process various molded products such as films and sheets. Further, in the polymerization for producing a cyclic olefin copolymer having a high glass transition temperature, the activity of the catalyst tends to decrease. Therefore, there is a tendency that the production efficiency of the cyclic olefin copolymer is lowered. Therefore, from this point as well, it is often desired to produce a cyclic olefin copolymer having a low glass transition temperature. In this respect, by increasing the ethylene charging pressure, it is easy to produce a cyclic olefin copolymer having a low glass transition temperature. However, when polymerization is carried out at a high temperature using a highly active catalyst for the purpose of increasing the production efficiency of the cyclic olefin copolymer under the condition of high ethylene charging pressure, polyethylene-like impurities are likely to be generated. When the cyclic olefin copolymer contains polyethylene-like impurities, turbidity occurs when the cyclic olefin copolymer is dissolved in a solvent. As can be understood from such a phenomenon, if the cyclic olefin copolymer contains polyethylene-like impurities, there is a concern that the transparency of the cyclic olefin copolymer may decrease. Therefore, in a general production process for producing a cyclic olefin copolymer having a low glass transition temperature, a process that increases the production cost by filtering and removing insoluble polyethylene-like impurities is required.

The present invention has been made in view of the above problems, and even if a norbornene monomer and a monomer containing ethylene are polymerized at a high temperature at which polyethylene-like impurities are likely to be generated, the formation of polyethylene-like impurities is suppressed. It is an object of the present invention to provide a method for producing a cyclic olefin copolymer capable of efficiently producing a cyclic olefin copolymer having a low glass transition temperature (Tg) and excellent processability.

The present inventors polymerize a monomer containing norbornene monomer and ethylene at a temperature of 50 ° C. or higher in the presence of a metallocene catalyst to obtain a cyclic olefin copolymer having a glass transition temperature of 130 ° C. or lower. At the time of production, the pressure for charging ethylene into the polymerization vessel was set to 0.3 MPa or more, and the ligand containing the cyclopentadiene ring and the nitrogen atom were bonded to the transition metal of Group IV of the periodic table and the silicon atom. We have found that the above-mentioned problems can be solved by using a metallocene catalyst having such a structure, and have completed the present invention. More specifically, the present invention provides the following.

(1) A method for producing a cyclic olefin copolymer containing a structural unit derived from norbornene monomer and a structural unit derived from ethylene and having a glass transition temperature of 130 ° C. or lower.
At least, the norbornene monomer and ethylene are charged as monomers in the polymerization vessel.
Including the polymerization of the monomer in the polymerization vessel in the presence of a metallocene catalyst at a temperature of 50 ° C. or higher.
The pressure of ethylene charged into the polymerization vessel is 0.3 MPa or more.
A production method, wherein the metallocene catalyst has a ligand containing a cyclopentadiene ring and a structure in which a nitrogen atom is bonded to a transition metal of Group IV of the periodic table and a silicon atom.

(2) A DSC curve obtained by measuring a sample of a cyclic olefin copolymer with a differential scanning calorimeter under a nitrogen atmosphere and a heating rate of 20 ° C./min according to the method described in JIS K7121 is obtained. The method for producing a cyclic olefin copolymer according to (1), which does not have a melting point peak derived from a polyethylene-like impurity in the range of 100 ° C. to 140 ° C.

(3) The metallocene catalyst has the following formula (a1):

(In the formula (a1), R ^a1 to R ^a3 are hydrocarbon groups having 1 to 20 carbon atoms which may be the same or different and may contain a hetero atom. R ^a4 is a hydrocarbon group. , A hydrocarbon group or a halogen atom having 1 to 20 carbon atoms which may contain a hetero atom. R ^a1 and R ^a2 are C—Si bond, O—Si bond, Si—Si bond, or N, respectively. -Si bond to a silicon atom. R ^a3 is bonded to a nitrogen atom by a CN bond, an ON bond, a Si—N bond, or an NN bond. Even if R ^a4 contains a hetero atom. In the case of a good hydrocarbon group having 1 to 20 carbon atoms, Ra ⁴ is bonded to the metal atom M by a CM bond. R ^a5 to Ra ⁸ may be independently the same or different, and hydrogen. It is an organic substituent or an inorganic substituent having 1 to 20 carbon atoms which may contain an atom or a hetero atom. Two groups adjacent to each other on the 5-membered ring of R ^a5 to R ^a8 are bonded to each other. M may be Ti, Zr, or Hf.)
The method for producing a cyclic olefin copolymer according to (1) or (2), which is a metallocene compound represented by.

The metallocene compound represented by the formula (a1) is the following formula (a2):

(In the formula (a2), R ^a1 to R ^a4 , and M are the same as those in the formula (a1). R ^a1 to R ^a3 may be independently the same or different, and contain heteroatoms. It may be a hydrocarbon group having 1 to 20 carbon atoms. R ^a4 is a hydrocarbon group or a halogen atom having 1 to 20 carbon atoms which may contain a hetero atom. R ^a1 and Ra ² are. , C—Si bond, O—Si bond, Si—Si bond, or N—Si bond to the silicon atom. ^RA3 is CN bond, ON bond, Si—N bond, or N— It is bonded to a nitrogen atom by an N bond. When R ^a4 is a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, R ^a4 is bonded to a metal atom M by a CM bond. ^a10 and ^Ra11 are organic substituents having 1 to 20 carbon atoms or inorganic substituents, which may be the same or different, and may contain a hydrogen atom and a hetero atom, respectively. P and q. ^Are independently integers from 0 to 4. When R ^a10 and R ^a11 are each plural, the plurality of R ^a10 and R ^a11 may be different groups. Two of the plurality of R ^a10 . group, or when two groups of the plurality of R ^a11 are bonded to adjacent positions on the aromatic ring may also form a ring such two groups are bonded to each other .M is, Ti, Zr , Or Hf.)
The method for producing a cyclic olefin copolymer according to (3), which is a metallocene compound represented by.

(5) The method for producing a cyclic olefin copolymer according to any one of (1) to (4), wherein the transition metal of Group IV of the Periodic Table is Ti.

(6) Any one of (1) to (5), wherein the polymerization is carried out in the presence of a metallocene catalyst, aluminoxane and hindered phenol, or in the presence of a metallocene catalyst, an ionic compound and alkylaluminum. The method for producing a cyclic olefin copolymer according to 1.

According to the present invention, even if a norbornene monomer and a monomer containing ethylene are polymerized at a high temperature at which polyethylene-like impurities are likely to be generated, the glass transition temperature (Tg) is increased while suppressing the formation of polyethylene-like impurities. It is possible to provide a method for producing a cyclic olefin copolymer capable of efficiently producing a cyclic olefin copolymer having low workability and excellent processability.

<< Method for producing cyclic olefin copolymer >>
In the method for producing a cyclic olefin copolymer, a cyclic olefin copolymer containing a structural unit derived from norbornene monomer and a structural unit derived from ethylene and having a glass transition temperature of 130 ° C. or lower is produced.
The manufacturing method is
At least, the norbornene monomer and ethylene are charged as monomers in the polymerization vessel.
It comprises polymerizing the monomer in the polymerization vessel in the presence of a metallocene catalyst at a temperature of 50 ° C. or higher.
Hereinafter, charging the norbornene monomer and ethylene as monomers into the polymerization vessel is also referred to as a charging step. Further, polymerizing the monomer in the polymerization vessel at a temperature of 50 ° C. or higher in the presence of a metallocene catalyst is also referred to as a polymerization step.

The pressure for charging ethylene into the polymerization vessel is 0.3 MPa or more. The charging pressure is a gauge pressure.
The monomer in the polymerization vessel is polymerized at a temperature of 50 ° C. or higher in the presence of a metallocene catalyst.
The metallocene catalyst used for the polymerization has a ligand containing a cyclopentadiene ring and a structure in which a nitrogen atom is bonded to a transition metal of Group IV of the periodic table and a silicon atom.

Generally, when ethylene charged at high pressure and norbornene monomer are copolymerized at a high temperature such as 50 ° C. or higher in the presence of a highly active catalyst, the polymerization of ethylene tends to proceed. Polyethylene-like impurities are likely to be generated.

However, when ethylene charged at high pressure in a reaction vessel and norbornene monomer are polymerized at a high temperature of 50 ° C. or higher, if a metallocene catalyst having the above-mentioned predetermined structure is used, polyethylene-like impurities are generated. It is easy to produce a cyclic olefin copolymer having a low glass transition temperature of 130 ° C. or lower in a good yield while suppressing the above.

<Preparation process>
In the charging step, norbornene monomer and ethylene are charged into the polymerization vessel as monomers. The polymerization vessel may be charged with a norbornene monomer and a monomer other than ethylene as long as the object of the present invention is not impaired. The total of the ratio of the structural units derived from the norbornene monomer and the ratio of the structural units derived from ethylene in the cyclic olefin copolymer is typically 80% by mass or more with respect to all the structural units. Preferably, 95% by mass or more is more preferable. 98% by mass or more is more preferable.

The norbornene monomer and monomers other than ethylene are not particularly limited as long as they can be copolymerized with the norbornene monomer and ethylene. Typical examples of such other monomers include α-olefins. The α-olefin may be substituted with at least one substituent such as a halogen atom.

As the α-olefin, C3 to C12 α-olefins are preferable. The α-olefins of C3 to C12 are not particularly limited, but for example, 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 can be mentioned. Of these, 1-hexene, 1-octene, and 1-decene are preferable.

Ethylene is charged into the polymerization vessel so that the ethylene charging pressure in the polymerization vessel is 0.3 MPa or more. The ethylene charging pressure is preferably 0.4 MPa or more, more preferably 0.5 MPa or more. Increasing the ethylene charging pressure can reduce the amount of catalyst used per produced polymer. Regarding the upper limit, the ethylene charging pressure is, for example, preferably 10 MPa or less, more preferably 5 MPa or less, and even more preferably 3 MPa or less.

A solvent may be charged in the polymerization vessel together with the norbornene monomer and ethylene. The solvent is not particularly limited as long as it does not inhibit the polymerization reaction. Examples of solvents include hydrocarbon solvents such as pentane, hexane, heptane, octane, isooctane, isododecane, mineral oil, cyclohexane, methylcyclohexane, decahydronaphthalene (decalin), benzene, toluene, and xylene, and chloroform, methylene chloride. , Dichloromethane, dichloroethane, and halogenated hydrocarbon solvents such as chlorobenzene.

When the norbornene monomer is charged in the solvent, the lower limit of the concentration of the norbornene monomer is preferably, for example, 0.5% by mass or more, and more preferably 10% by mass or more. As for the upper limit, for example, 50% by mass or less is preferable, and 35% by mass or less is more preferable.

The norbornene monomer will be described below.

[Norbornene monomer]
Examples of the norbornene monomer include norbornene and substituted norbornene, and norbornene is preferable. The norbornene monomer can be used alone or in combination of two or more.

The above-mentioned substituted norbornene is not particularly limited, and examples of the substituent contained in this substituted norbornene include a halogen atom and a monovalent or divalent hydrocarbon group. Specific examples of the substituted norbornene include those represented by the following general formula (I).

(In the formula, R ¹ to R ¹² may be the same or different from each other, and are selected from the group consisting of a hydrogen atom, a halogen atom, and a hydrocarbon group.
R ⁹ and R ¹⁰ and R ¹¹ and R ¹² may be integrated to form a divalent hydrocarbon group.
R ⁹ or R ¹⁰ and R ¹¹ or R ¹² may form a ring with each other.
Further, n indicates 0 or a positive integer.
When n is 2 or more, R ⁵ to R ⁸ may be the same or different in each repeating unit.
However, when n = 0, at least one of R ¹ to R ⁴ and R ⁹ to R ¹² is not a hydrogen atom. )

The substituted norbornene represented by the general formula (I) will be described. R ¹ to R ¹² in the general formula (I) may be the same or different from each other, and are selected from the group consisting of a hydrogen atom, a halogen atom, and a hydrocarbon group.

Specific examples of R ¹ to R ⁸ include hydrogen atoms; halogen atoms such as fluorine, chlorine, and bromine; alkyl groups having 1 to 20 carbon atoms, and the like, which may be different from each other. , Partially different, or all may be the same.

Specific examples of R ⁹ to R ¹² include, for example, a hydrogen atom; a halogen atom such as fluorine, chlorine and bromine; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group such as a cyclohexyl group; a phenyl group and a trill. Substituent or unsubstituted aromatic hydrocarbon groups such as groups, ethylphenyl groups, isopropylphenyl groups, naphthyl groups and anthryl groups; benzyl group, phenethyl group and other alkyl groups substituted with aryl groups and the like. Yes, they may be different, partially different, or all identical.

Specific examples of the case where R ⁹ and R ¹⁰ or R ¹¹ and R ¹² are integrated to form a divalent hydrocarbon group include, for example, an alkylidene group such as an ethylidene group, a propylidene group, and an isopropylidene group. Can be mentioned.

When R ⁹ or R ¹⁰ and R ¹¹ or R ¹² form a ring with each other, the formed ring may be a monocyclic ring, a polycyclic ring, or a polycyclic ring having a crosslink. , It may be a ring having a double bond, or it may be a ring composed of a combination of these rings. Further, these rings may have a substituent such as a methyl group.

Specific examples of the substituted norbornene represented by the general formula (I) include 5-methyl-bicyclo [2.2.1] hepta-2-ene and 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-octadecil-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- Bicyclic olefins such as propenyl-bicyclo [2.2.1] hepta-2-ene;
Tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene (common name: dicyclopentadiene), tricyclo [4.3.0.1 ^2,5 ] deca-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 a partial hydrogenation of these (or cyclopentadiene) Tricyclo [4.4.0.1 ^2,5 ] undeca-3-ene; 5-cyclopentyl-bicyclo [2.2.1] hepta-2-ene, 5-cyclohexyl-bicyclo 3 such as [2.2.1] hepta-2-ene, 5-cyclohexenylbicyclo [2.2.1] hepta-2-ene, 5-phenyl-bicyclo [2.2.1] hepta-2-ene. Cyclic olefin of the ring;
Tetracyclo [4.4.0.1 ^2,5 . ^{17 and 10} ] Dodeca-3-ene (also simply referred to as tetracyclododecene), 8-methyltetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ] Dodeca-3-ene, 8-ethyltetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ] Dodeca-3-ene, 8-methylidenetetracyclo [4.4.0.1 ^2,5 . 17 and ¹⁰ ] Dodeca-3-ene, 8-ethylidenetetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ] Dodeca-3-ene, 8-vinyltetracyclo [4,4.0.1, ^2,5 . 1 ^{7, 10} ] Dodeca-3-ene, 8-propenyl-tetracyclo [4.4.0.1 ^2,5 . ^{17 and 10} ] 4-ring cyclic olefins such as dodeca-3-ene;
8-Cyclopentyl-tetracyclo [4.4.0.1 ^2,5 . 17 and ¹⁰ ] Dodeca-3-ene, 8-cyclohexyl-tetracyclo [4.4.0.1 ^2,5 . 17 and ¹⁰ ] Dodeca-3-ene, 8-cyclohexenyl-tetracyclo [4.4.0.1 ^2,5 . 17 and ¹⁰ ] Dodeca-3-ene, 8-phenyl-cyclopentyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ] Dodeca-3-ene; Tetracyclo [7.4.1 ^3,6 . 0 ^{1,9 1} . 0 ^2,7 ] Tetradeca-4,9,11,13-tetraene (also called 1,4-methano-1,4,4a, 9a-tetrahydrofluorene), tetracyclo [8.4.1, ^4,7 . 0 ^{1,10 1} . 0 ^3,8 ] Pentadeca-5,10,12,14-tetraene (also referred to as 1,4-methano-1,4,4a, 5,10,10a-hexahydroanthracene); pentacyclo [6.6.1. 1 ^{3, 6} . 0 ^2,7 . ^09,14 ] -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-eikosen, heptacyclo [8.7.0.1 ^2,9 . 0 ^3,8 . 1 ^{4, 7} . 0 ^12,17 . 11 ^{13, l6} ] ^-14-eicosene ; polycyclic cyclic olefins such as cyclopentadiene tetramer can be mentioned.

Among them, alkyl-substituted norbornene (for example, bicyclo [2.2.1] hepta-2-ene substituted with one or more alkyl groups) and alkylidene-substituted norbornene (for example, bicyclo substituted with one or more alkylidene groups). [2.2.1] hepta-2-ene) is preferred, 5-ethylidene-bicyclo [2.2.1] hepta-2-ene (common name: 5-ethylidene-2-norbornene, or simply ethylidene norbornene). ) Is particularly preferable.

<Polymerization process>
In the polymerization step, the monomer in the polymerization vessel is polymerized at a temperature of 50 ° C. or higher in the presence of a metallocene catalyst.
As the metallocene catalyst, a catalyst having a ligand containing a cyclopentadiene ring and a structure in which a nitrogen atom is bonded to a transition metal of Group IV of the periodic table and a silicon atom is used. By using such a catalyst, even under conditions where the ethylene charging pressure is high and polymerization is carried out at a high temperature of 50 ° C. or higher, and polyethylene-like impurities are likely to be generated, the formation of polyethylene-like impurities is suppressed and the polymerization is good. A cyclic olefin copolymer can be produced.

In the metallocene catalyst, a substituent may be bonded to the above-mentioned nitrogen atom and silicon atom, but the substituent bonded to the nitrogen atom and the silicon atom is not particularly limited as long as the object of the present invention is not impaired.

As the Group IV transition metal of the periodic table in the metallocene catalyst, Ti, Zr, or Hf is preferable, and Ti is more preferable.

The ligand containing the cyclopentadiene ring contained in the metallocene catalyst will be described in detail as a ligand for the formulas (a1) and (a2) described later.

A preferred example of such a metallocene catalyst is a metallocene compound represented by the following formula (a1).

In the formula (a1), ^Ra1 to ^Ra3 are hydrocarbon groups having 1 to 20 carbon atoms, which may be the same or different, and may contain heteroatoms, respectively.
R ^a4 is a hydrocarbon group or halogen atom having 1 to 20 carbon atoms which may contain a hetero atom.
R ^a1 and R ^a2 are bonded to a silicon atom by a C—Si bond, an O—Si bond, a Si—Si bond, or an N—Si bond, respectively.
R ^a3 is bonded to a nitrogen atom by a CN bond, an ON bond, a Si—N bond, or an NN bond.
When R ^a4 is a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, R ^a4 is bonded to the metal atom M by a ^CM bond.
R ^a5 to R ^a8 are organic substituents or inorganic substituents having 1 to 20 carbon atoms, which may be the same or different, and may contain a hydrogen atom and a hetero atom, respectively.
Two adjacent groups on the 5-membered ring of R ^a5 to R ^a8 may be bonded to each other to form a ring.
M is a Group IV transition metal of the Periodic Table, and Ti, Zr, or Hf is preferable.

R ^a1 to ^Ra3 are hydrocarbon groups having 1 to 20 carbon atoms, which may be the same or different, and may contain heteroatoms, respectively.
R ^a4 is a hydrocarbon group or halogen atom having 1 to 20 carbon atoms which may contain a hetero atom.

Regarding a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, when the hydrocarbon group contains a hetero atom, the type of the hetero atom is not particularly limited as long as the object of the present invention is not impaired. Specific examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, a selenium atom, a halogen atom and the like.

R ^a1 and R ^a2 are bonded to a silicon atom by a C—Si bond, an O—Si bond, a Si—Si bond, or an N—Si bond, respectively.
Preferable examples of R ^a1 and R ^a2 bonded to a silicon atom by an O—Si bond include groups represented by −OR ^a9 and —OC (= O) —R ^a9 .
Preferable examples of R ^a1 and R ^a2 bonded to a silicon atom by a Si—Si bond are −SiR ^a9 ₃ , −Si (OR ^a9 ) R ^a92 ₂ , −Si (OR ^a9 ) ₂ R ^a9 , and −Si. The group represented by (OR ^a9 ) ₃ can be mentioned.
Suitable examples of ^{R a1} and ^{R a2} bonded to the silicon atom by N-Si bonds, -NHR ^a9, and include groups represented by ^{-NR a9} _2.
Here, all of the above Ra ^9s are hydrocarbon groups.

R ^a3 is bonded to a nitrogen atom by a CN bond, an ON bond, a Si—N bond, or an NN bond.
Preferable examples of R ^a3 bonded to a nitrogen atom by an ^ON bond include groups represented by -OR ^a9 and -OC (= O) -R ^a9 .
Preferable examples of R ^a3 that binds to a nitrogen atom by a Si—N bond are -SiR ^a9 ₃ , -Si (OR ^a9 ) R ^a9 ₂ , -Si (OR ^a9 ) ₂ R ^a9 , and -Si (OR ^a9). ) The group represented by ₃ is mentioned.
Preferable examples of ^{R a3} bound to the nitrogen atom by N-N bonds, -NHR ^a9, and include groups represented by ^{-NR a9} _2.
Here, all of the above Ra ^9s are hydrocarbon groups.

Hydrocarbon group as R ^a9 ^is described below for R a1 ^{~ R a4,} it is the same as the hydrocarbon groups that do not contain heteroatoms.

Since the preparation and availability of the compound used as a ligand is easy, preferably the R ^a1 and R ^a2 are the same group.

When R ^a4 is a halogen atom, examples of the halogen atom include a chlorine atom, a fluorine atom, a bromine atom, and an iodine atom, and a chlorine atom and a bromine atom are preferable.

As R ^a1 to R ^a3 , hydrocarbon groups containing no heteroatom are preferable because they are excellent in chemical stability. When R ^a4 is a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarbon group containing no hetero atom is preferable as in R ^a1 to R ^a3 .
Examples of such hydrocarbon groups include linear or branched alkyl groups, linear or branched unsaturated aliphatic hydrocarbon groups which may have double bonds and / or triple bonds, and cycloalkyl. Groups, cycloalkylalkyl groups, aromatic hydrocarbon groups, and aralkyl groups are preferred.

Specific examples of the linear or branched alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group and n-. Pentyl group, isopentyl group, tert-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group. , N-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecil group, and n-icosyl group.

Preferred examples of the linear or branched unsaturated aliphatic hydrocarbon group which may have a double bond and / or a triple bond include specific examples of the linear or branched alkyl group. Examples of the group include a group in which one or more single bonds are replaced with double bonds and / or triple bonds.
More preferably, vinyl group, allyl group, 1-propenyl group, 3-butenyl group, 2-butenyl group, 1-butenyl group, ethenyl group, and propargyl group can be mentioned.

Specific examples of the cycloalkyl group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cycloundecyl group, cyclododecyl group, cyclotridecyl group, Examples thereof include a cyclotetradecyl group, a cyclopentadecyl group, a cyclohexadecyl group, a cycloheptadecyl group, a cyclooctadecyl group, a cyclononadecil group, and a cycloicosyl group.

Specific examples of the cycloalkylalkyl group include cyclopropylmethyl group, cyclobutylmethyl group, cyclopentylmethyl group, cyclohexylmethyl group, cycloheptylmethyl group, cyclooctylmethyl group, cyclononylmethyl group, cyclodecylmethyl group and cycloun. Decylmethyl group, cyclododecylmethyl group, cyclotridecylmethyl group, cyclotetradecylmethyl group, cyclopentadecylmethyl group, cyclohexadecylmethyl group, cycloheptadecylmethyl group, cyclooctadecylmethyl group, cyclononadecilmethyl group, 2-Cyclopropylethyl group, 2-cyclobutylethyl group, 2-cyclopentylethyl group, 2-cyclohexylethyl group, 2-cycloheptylethyl group, 2-cyclooctylethyl group, 2-cyclononylethyl group, 2-cyclo Decylethyl group, 2-cycloundecylethyl group, 2-cyclododecylethyl group, 2-cyclotridecylethyl group, 2-cyclotetradecylethyl group, 2-cyclopentadecylethyl group, 2-cyclohexadecylethyl group , 2-Cycloheptadecylethyl group, 2-cyclooctaethyldecyl group, 3-cyclopropylpropyl group, 3-cyclobutylpropyl group, 3-cyclopentylpropyl group, 3-cyclohexylpropyl group, 3-cycloheptylpropyl group, 3-Cyclooctylpropyl group, 3-cyclononylpropyl group, 3-cyclodecylpropyl group, 3-cycloundecylpropyl group, 3-cyclododecylpropyl group, 3-cyclotridecylpropyl group, 3-cyclotetradecylpropyl group Group, 3-cyclopentadecylpropyl group, 3-cyclohexadecylpropyl group, 3-cycloheptadecylpropyl group, 4-cyclopropylbutyl group, 4-cyclobutylbutyl group, 4-cyclopentylbutyl group, 4-cyclohexylbutyl Group, 4-cycloheptylbutyl group, 4-cyclooctylbutyl group, 4-cyclononylbutyl group, 4-cyclodecylbutyl group, 4-cyclododecylbutyl group, 4-cyclotridecylbutyl group, 4-cyclotetradecyl Examples thereof include a butyl group, a 4-cyclopentadecylbutyl group, and a 4-cyclohexadecylbutyl group.

Specific examples of the aromatic hydrocarbon group include phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2,3-dimethylphenyl group, 2,4-dimethylphenyl group and 2,5-dimethyl. Phenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,3,4-trimethylphenyl group, 2,3,5-trimethylphenyl group, 2,3 , 6-trimethylphenyl group, 2,4,5-trimethylphenyl group, 2,4,6-trimethylphenyl group, 3,4,5-trimethylphenyl group, o-ethylphenyl group, m-ethylphenyl group, p -Ethylphenyl group, o-isopropylphenyl group, m-isopropylphenyl group, p-isopropylphenyl group, o-tert-butylphenyl group, 2,3-diisopropylphenyl group, 2,4-diisopropylphenyl group, 2,5 -Diisopropylphenyl group, 2,6-diisopropylphenyl group, 3,4-diisopropylphenyl group, 3,5-diisopropylphenyl group, 2,6-di-tert-butylphenyl group, 2,6-di-tert-butyl -4-Methylphenyl group, α-naphthyl group, β-naphthyl group, biphenyl-4-yl group, biphenyl-3-yl group, biphenyl-2-yl group, anthracene-1-yl group, anthracene-2-yl Group, anthracene-9-yl group, phenylentren-1-yl group, phenylentren-2-yl group, phenylentren-3-yl group, phenylentren-4-yl group, phenylentren-9-yl group, pyrene-1-yl group , Pyrene-2-yl group, Pyrene-3-yl group, and Pyrene-4-yl group.

Specific examples of the aralkyl group include benzyl group, phenethyl group, 1-phenylethyl group, 3-phenylpropyl group, 2-phenylpropyl group, 1-phenylpropyl group, 2-phenyl-1-methylethyl group and 1-. Phenyl-1-methylethyl group (cumyl group), 4-phenylbutyl group, 3-phenylbutyl group, 2-phenylbutyl group, 1-phenylbutyl group, 3-phenyl-2-methylpropyl group, 3-phenyl- 1-Methylpropyl group, 2-phenyl-1-methylpropyl group, 2-methyl-1-phenylpropyl group, 2-phenyl-1,1-dimethylethyl group, 2-phenyl-2,2-dimethylethyl group, Examples thereof include α-naphthylmethyl group, β-naphthylmethyl group, 2-α-naphthylethyl group, 2-β-naphthylethyl group, 1-α-naphthylethyl group, and 1-β-naphthylethyl group.

R ^a1, and as the ^{R a2,} preferably an alkyl group and aromatic hydrocarbon group having 6 to 20 carbon atoms having 1 to 20 carbon atoms, an alkyl group and 6 to 10 carbon atoms having 1 to 10 carbon atoms The aromatic hydrocarbon group of is more preferable, an alkyl group having 1 to 6 carbon atoms and a phenyl group are further preferable, and an alkyl group having 1 to 4 carbon atoms is particularly preferable.

R ^a3 includes an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. preferable.

R ^a4 includes an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, and an aromatic hydrocarbon group having 6 to 20 carbon atoms. An aralkyl group having 7 to 20 carbon atoms or a halogen atom is preferable.

In the formula (a1), R ^a5 to R ^a8 may be independently the same or different, and may contain a hydrogen atom and a hetero atom. Organic substituents having 1 to 20 carbon atoms or inorganic substituents. It is the basis.

The organic substituent is not particularly limited as long as it is an organic group conventionally known to be capable of substituting on an aromatic ring and does not inhibit the formation reaction of the metallocene compound represented by the above formula (a1). .. For example, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aliphatic acyl group having 2 to 20 carbon atoms, a benzoyl group, α- Examples thereof include a naphthylcarbonyl group, a β-naphthylcarbonyl group, an aromatic hydrocarbon group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms.

Among these organic substituents, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, and an aliphatic acyl having 2 to 6 carbon atoms. Groups, benzoyl groups, phenyl groups, benzyl groups, and phenethyl groups are preferred.

Among the organic substituents, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, methoxy group, ethoxy group and n-propyloxy group. , Isobutyloxy group, n-butyloxy group, isobutyloxy group, sec-butyloxy group, tert-butyloxy group, acetyl group, propionyl group, butanoyl group, and phenyl group are more preferable.

The inorganic substituent is not particularly limited as long as it is an inorganic group conventionally known to be capable of substituting on an aromatic ring and does not inhibit the formation reaction of the metallocene compound represented by the above formula (a1). ..
Specific examples of the inorganic group include a halogen atom, a nitro group, a cyano group and the like.

Preferable examples of the ligand containing a cyclopentadiene ring in the formula (a1) include a cyclopentadienyl group, a methylcyclopentadienyl group, a dimethylcyclopentadienyl group, a trimethylcyclopentadienyl group, and a tetra. Methylcyclopentadienyl group, 4-tert-butylcyclopentadienyl group, 4-adamantylcyclopentadienyl group, monomethylindenyl group, dimethylindenyl group, trimethylindenyl group, tetramethylindenyl group, 4, 5,6,7-Tetrahydroindenyl group, fluorenyl group, 5,10-dihydroindeno [1,2-b] indol-10-yl group, N-methyl-5,10-dihydroindeno [1,2 -B] Indol-10-yl group, N-phenyl-5,10-dihydroindeno [1,2-b] indol-10-yl group, 5,6-dihydroindeno [2,1-b] indol -6-yl group, N-methyl-5,6-dihydroindeno [2,1-b] indol-6-yl group, and N-phenyl-5,6-dihydroindeno [2,1-b] Indol-6-yl group is mentioned.

As the ligand containing the cyclopentadiene ring, a ligand having a fluorene skeleton is also preferable. The ligand having a fluorene skeleton will be described later in the formula (a2).

Among the metallocene compounds represented by the formula (a1), the metallocene compound having the following structure is preferable because it is easy to prepare and obtain and has high activity.

Among the metallocene compounds represented by the formula (a1), a metallocene compound containing a ligand having a fluorene skeleton represented by the following formula (a2) is also preferable.

In the formula (a2), ^Ra1 to ^Ra4 and M are the same as those in the formula (a1).
R ^a10 and R ^a11 are organic substituents or inorganic substituents having 1 to 20 carbon atoms, which may be the same or different, and may contain a hydrogen atom and a hetero atom, respectively, and p and q is an independently integer of 0 to 4.
When there are a plurality of R ^a10 and R ^a11 respectively, the plurality of R ^a10 and R ^a11 may be different groups.
If two groups of the plurality of R ^a10, or two groups of the plurality of R ^a11 are bonded to adjacent positions on the aromatic ring, to form a ring the two groups are bonded to each other May be good.
M is a Group IV transition metal of the Periodic Table, and Ti, Zr, or Hf is preferable.

Wherein (a2), R ^a10 and R ^a11 are each independently, may be the same or different, a hydrogen atom, an organic substituent contain a heteroatom have carbon atoms which may 1 to 20, or inorganic substituent It is a group, and p and q are independently integers of 0 to 4.
When there are a plurality of R ^a10 and R ^a11 respectively, the plurality of R ^a10 and R ^a11 may be different groups.

The organic substituent is not particularly limited as long as it is an organic group conventionally known to be capable of substituting on an aromatic ring and does not inhibit the formation reaction of the metallocene compound represented by the above formula (a2). .. For example, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aliphatic acyl group having 2 to 20 carbon atoms, a benzoyl group, α- Examples thereof include a naphthylcarbonyl group, a β-naphthylcarbonyl group, an aromatic hydrocarbon group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms.

The inorganic substituent is not particularly limited as long as it is an inorganic group conventionally known to be capable of substituting on an aromatic ring and does not inhibit the formation reaction of the metallocene compound represented by the above formula (a2). ..
Specific examples of the inorganic group include a halogen atom, a nitro group, a cyano group and the like.

If two groups of the plurality of R ^a10, or two groups of the plurality of R ^a11 are bonded to adjacent positions on the aromatic ring, to form a ring the two groups are bonded to each other May be good. Such a ring is a fused ring that condenses with the aromatic ring contained in the fluorene skeleton in the formula (a2). The fused ring may be an aromatic ring or an aliphatic ring, and an aliphatic ring is preferable. The fused ring may have a hetero atom such as an oxygen atom, a nitrogen atom, and a sulfur atom in the ring.

Specific examples of the fluorene skeleton with a fused ring formed by two R ^a10 and / or two R ^a11 include the skeleton of the following formula.

A preferred example of the metallocene compound represented by the formula (a2) described above is a metallocene compound having the following structure.

Among the metallocene compounds represented by the formula (a2) described above, the following metallocene compounds are preferable because they have high catalytic activity and are easily available and synthesized.

The metallocene catalyst is preferably mixed with aluminoxane and / or an ionic compound to form a catalyst composition.
Here, the ionic compound is a compound that produces a cationic transition metal compound by reacting with a metallocene catalyst.

The catalyst composition is preferably prepared using a solution of a metallocene catalyst. The solvent contained in the metallocene catalyst solution is not particularly limited. Preferred solvents include hydrocarbon solvents such as pentane, hexane, heptane, octane, isooctane, isododecane, mineral oil, cyclohexane, methylcyclohexane, decahydronaphthalene (decalin), mineral oil, benzene, toluene, and xylene, and chloroform, Examples thereof include halogenated hydrocarbon solvents such as methylene chloride, dichloromethane, dichloroethane, and chlorobenzene.

The amount of the solvent used is not particularly limited as long as the catalyst composition having the desired performance can be produced. Typically, the concentrations of the metallocene catalyst, aluminoxane, and the ionic compound are preferably 0.00000001 to 100 mol / L, more preferably 0.00000005 to 50 mol / L, and particularly preferably 0.000000001 to 20 mol / L. A quantity of solvent is used.

When mixing the liquid containing the raw material of the catalyst composition, the number of moles of transition metal elements in the metallocene catalysts and M _a, the number of moles of aluminum in the aluminoxane and M _b1, to the number of moles of ionic compound M _b2 in _case, the value of _{(M b1 + M b2) /} M a is preferably 1 to 200000 and more preferably 100 to 100,000, as particularly preferably at from 1000 to 80000, the liquid is mixed containing raw materials of the catalyst composition It is preferable to be done.

The temperature at which the liquid containing the raw material of the catalyst composition is mixed is not particularly limited, but is preferably -100 to 100 ° C, more preferably -50 to 50 ° C.

The mixing of the metallocene catalyst solution for preparing the catalyst composition with the aluminoxane and / or the ionic compound may be carried out in a device separate from the polymerization vessel before the polymerization, and the polymerization is carried out in the polymerization vessel. It may be done before or during polymerization.

Hereinafter, the materials used for the preparation of the catalyst composition and the preparation conditions of the catalyst composition will be described.

[Aluminoxane]
As the alminoxane, various aluminoxanes conventionally used as cocatalysts in the polymerization of various olefins can be used without particular limitation. Typically, the aluminoxane is an organic aluminoxane.
In the production of the catalyst composition, one type of aluminoxane may be used alone, or two or more types may be used in combination.

As the aluminoxane, alkyl aluminoxane is preferably used. Examples of the alkylaluminoxane include compounds represented by the following formulas (b1-1) or (b1-2). The alkylaluminoxane represented by the following formula (b1-1) or (b1-2) is a product obtained by reacting trialkylaluminum with water.

(In the formulas (b1-1) and (b1-2), R represents an alkyl group having 1 to 4 carbon atoms, n represents an integer of 0 to 40, preferably 2 to 30.)

Examples of the alkylaluminoxane include methylaluminoxane and modified methylaluminoxane in which a part of the methyl group of the methylaluminoxane is replaced with another alkyl group. As the modified methylaluminoxane, for example, as the substituted alkyl group, a modified methylaluminoxane having an alkyl group having 2 to 4 carbon atoms such as an ethyl group, a propyl group, an isopropyl group, a butyl group and an isobutyl group is preferable, and particularly A modified methylaluminoxane in which a part of the methyl group is replaced with an isobutyl group is more preferable. Specific examples of the alkylaluminoxane include methylaluminoxane, ethylaluminoxane, propylaluminoxane, butylaluminoxane, isobutylaluminoxane, methylethylaluminoxane, methylbutylaluminoxane, methylisobutylaluminoxan and the like, and among them, methylaluminoxane and methylisobutylaluminoxane are preferable.

Alkyl aluminoxane can be prepared by a known method. Further, as the alkylaluminoxane, a commercially available product may be used. Examples of commercially available alkylaluminoxane products include MMAO-3A, TMAO-200 series, TMAO-340 series, solid MAO (all manufactured by Tosoh Finechem Co., Ltd.), methylaminenoxane solution (manufactured by Albemarle Corporation), and the like. ..

[Ionic compound]
The ionic compound is a compound that produces a cationic transition metal compound by reacting with a metallocene catalyst.
Examples of such an ionic compound include an anion of tetrakis (pentafluorophenyl) borate, an amine cation having an active proton such as dimethylphenylammonium cation ((CH ₃ ) ₂ N (C ₆ H ₅ ) H ⁺ ), and (C ₆ H). ₅₎ ₃ C ⁺ trisubstituted carbonium cation such as, carborane cation, can be used an ionic compound containing ions such as ferrocenium cation having metal carborane cation, a transition metal.

A suitable example of an ionic compound is borate. Preferred specific examples of borate are tetrakis (pentafluorophenyl) trityl borate, dimethylphenylammonium tetrakis (pentafluorophenyl) borate, and N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, N-methyldinormal decyl. Examples thereof include N-methyldialkylammonium tetrakis (pentafluorophenyl) borate such as ammonium tetrakis (pentafluorophenyl) borate.

Further, from the viewpoint that it is easy to produce a cyclic olefin copolymer in a good yield, an aluminoxane, an alkylaluminum compound, or one or more thereof is added into the polymerization vessel before adding a metallocene catalyst or a catalyst composition containing a metallocene catalyst. It is preferable to have one or more selected from aromatic compounds having a phenolic hydroxyl group and one or more halogen atoms on an aromatic ring, and hindered phenol.
In the above aromatic compound having a phenolic hydroxyl group and a halogen atom, the phenolic hydroxyl group and the halogen atom are bonded on the same aromatic ring which may be a monocyclic ring or a fused ring.
Hindered phenols are phenols having a bulky substituent at at least one of the two adjacent positions of the phenolic hydroxyl group. Examples of the bulky substituent include an alkyl group other than the methyl group such as an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, and an alkoxy group. , Aryloxy group, substituted amino group, alkylthio group, arylthio group and the like.
Specific examples of hindered phenol include, for example, 2,6-di-tert-butyl-p-cresol (BHT), 2,6-di-tert-butylphenol, 2-tert-butylphenol, 2-tert-butyl-. p-cresol, 3,3', 5,5'-tetra-tert-butyl-4,4'-dihydroxybiphenyl, 3,3', 5,5'-tetra-tert-butyl-2,2'-dihydroxy Biphenyl, 4,4'-butylidenebis (3-methyl-6-tert-butylphenol), 2,2'-methylenebis (6-tert-butyl-4-methylphenol), 4,4', 4 "-(1-) Methylpropanol-3-iriden) tris (6-tert-butyl-m-cresol), and 1,3,5-tris (3,5-di-tert-butyl-4-hydroxyphenylmethyl) 2,4 Examples include 6-trimethylbenzene.
Among these, 2,6-di-tert-butyl-p-cresol (BHT) and 2,6--due to the fact that the molecular weight is small and the desired effect due to the use of hindered phenol can be easily obtained by using a small amount. Di-tert-butylphenol is preferred.
Hindered phenol contributes to an increase in the yield of the cyclic olefin copolymer by reacting with the alkylaluminum compound in the polymerization system. For this reason, hindered phenol is preferably used with alkylaluminum. Moreover, hindered phenol may be used by mixing with alkylaluminum in a polymerization machine. A mixture obtained by mixing alkylaluminum and hindered phenol before polymerization may be introduced into the polymerization machine.

Alminoxane is as described in the method for producing the catalyst composition.
As the alkylaluminum compound, those conventionally used for polymerization of olefins and the like can be used without particular limitation. Examples of the alkylaluminum compound include compounds represented by the following general formula (II).
(R ¹⁰ ) _z AlX _3-z (II)
(In formula (II), R ¹⁰ is an alkyl group having 1 to 15, preferably 1 to 8 carbon atoms, X is a halogen atom or a hydrogen atom, and z is an integer of 1 to 3.)

Examples of the alkyl group having 1 to 15 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-octyl group and the like.

Specific examples of the alkylaluminum compound include trialkylaluminum such as trimethylaluminum, triethylaluminum, triisopropylaluminum, trin-butylaluminum, triisobutylaluminum, trisec-butylaluminum and trin-octylaluminum; dimethylaluminum chloride, Examples thereof include dialkylaluminum halides such as diisobutylaluminum chloride; dialkylaluminum hydrides such as diisobutylaluminum hydride; and dialkylaluminum alkoxides such as dimethylaluminummethoxyde.

The alkylaluminum compound acts as a chain transfer agent and promotes chain polymerization catalyzed by the catalyst composition described above. As the chain transfer agent, hydrogen is preferably used in addition to the alkylaluminum compound.

When aluminoxane is added into the polymerization vessel before adding the metallocene catalyst or the catalyst composition containing the metallocene catalyst, the amount used is preferably 10 to 1,000,000 mol as the number of moles of aluminum in the aluminoxane with respect to 1 mol of the transition metal compound. , 100-100,000 mol is more preferred.
When the alkylaluminum compound is added into the polymerization vessel before adding the metallocene catalyst or the catalyst composition containing the metallocene catalyst, the amount used is preferably 5 to 500,000 mol as the number of moles of aluminum per 1 mol of the transition metal compound. More preferably, 50,000 to 50,000 mol.

The polymerization is preferably carried out in the presence of a metallocene catalyst, aluminoxane and hindered phenol, or in the presence of a metallocene catalyst, an ionic compound and alkylaluminum. When the polymerization is carried out in the presence of a metallocene catalyst, an ionic compound and alkylaluminum, it is also preferable to further add hindered phenol to the polymerization system.

The polymerization conditions are not particularly limited as long as the polymerization temperature is 50 ° C. or higher and a cyclic olefin copolymer having a glass transition temperature of 130 ° C. or lower can be obtained, and known conditions can be used.
The amount of catalyst used is derived from the amount of transition metal compound used in its preparation. The amount of the catalyst composition used is preferably 0.000000001 to 0.005 mol, preferably 0.00000001 mol to 0.0005 mol, based on 1 mol of the norbornene monomer, as the mass of the transition metal compound used in the preparation thereof. Is more preferable.

The polymerization temperature is 50 ° C. or higher. The polymerization temperature is more preferably 60 ° C. or higher, and particularly preferably 70 ° C. or higher, because the yield of the cyclic olefin copolymer is good.
The upper limit of the temperature at the time of polymerization is not particularly limited. The upper limit of the temperature at the time of polymerization may be, for example, 200 ° C. or lower, 140 ° C. or lower, or 120 ° C. or lower.
The polymerization time is not particularly limited, and the polymerization is carried out until a desired yield is reached or the molecular weight of the polymer is increased to a desired degree.
The polymerization time varies depending on the temperature, the composition of the catalyst, and the composition of the monomer, but is typically 0.01 to 120 hours, preferably 0.1 to 80 hours, and 0.2 to 10 hours. More preferred.

It is preferable that at least a part, preferably all of the catalyst composition is continuously added to the polymerization vessel.
By continuously adding the catalyst composition, the cyclic olefin copolymer can be continuously produced, and the production cost of the cyclic olefin copolymer can be reduced.

According to the method described above, even if the norbornene monomer and the monomer containing ethylene are polymerized at a high temperature at which polyethylene-like impurities are likely to be generated, the glass transition temperature (Tg) is suppressed while suppressing the formation of polyethylene-like impurities. ) Is low and the cyclic olefin copolymer is excellent in processability.
The glass transition temperature of the cyclic olefin copolymer is 130 ° C. or lower, preferably 120 ° C. or lower, and particularly preferably 100 ° C. or lower.
Further, when the cyclic olefin copolymer produced by the above method is measured by a differential operating calorimeter (DSC) under a nitrogen atmosphere and a heating rate of 20 ° C./min according to the method described in JIS K7121. It is preferable that the obtained DSC curve does not have a peak of melting point (melting enthalpy) derived from polyethylene-like impurities. This means that the polyethylene-like impurities in the cyclic olefin copolymer are absent or extremely low. When the cyclic olefin copolymer contains polyethylene-like impurities, the peak of the melting point derived from the polyethylene-like impurities on the DSC curve is generally detected in the range of 100 ° C. to 140 ° C.

The cyclic olefin copolymer produced by the above method has a low content of polyethylene-like impurities and is excellent in transparency. Therefore, the cyclic olefin-based copolymer produced by the above method is required to have a high degree of transparency in terms of optical function and aesthetics, such as an optical film or an optical sheet, a film for a packaging material, or a packaging material. It is particularly preferably used as a material for sheets.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

[Examples 1 to 15 and Comparative Examples 1 to 4]
In producing the cyclic olefin resin composition, the following C1 or C2 was used as the metallocene catalyst in Examples and Comparative Example 1.

(C1)

(C2)

In Comparative Examples 2 to 4, the following C3 was used as the metallocene catalyst.
(C3)

The following cocatalysts were used in Examples and Comparative Examples.
CC1: 6.5% by mass (as Al atom content) MMAO-3A toluene solution ([
(CH ₃ ) _0.7 (iso-C ₄ H ₉ ) _0.3 AlO] A solution of methylisobutylaluminoxane represented by _n , manufactured by Tosoh Finechem Co., Ltd., and 6 mol% trimethylaluminum based on total Al. Contains)
CC2: 9.0% by mass (as Al atom content) TMAO-211 toluene solution (solution of methylaluminoxane, manufactured by Toso Finechem Co., Ltd., still containing 26 mol% of trimethylaluminum with respect to total Al)
CC3: 2,6-di-tert-butyl-p-cresol (manufactured by Tokyo Chemical Industry Co., Ltd.)
CC4: Tetrakis (pentafluorophenyl) trityl borate (manufactured by Tokyo Chemical Industry Co., Ltd.)
CC5: N-Methyldialkylammonium tetrakis (pentafluorophenyl) borate (alkyl: C14 to C18 (average: C17.5) (manufactured by Tosoh Finechem Co., Ltd.)
CC6: Triisobutylaluminum (manufactured by Tosoh Finechem Co., Ltd.)

The polymerization solvent shown in Table 2 and 90 mmol of 2-norbornene were added to a well-dried 150 mL stainless steel autoclave containing a stir bar. The cocatalysts listed in Table 1 were then added as described below.
In Examples 1 to 6, Examples 10 to 12 and Comparative Examples 1 to 4, CC1 or CC2 was added.
In Examples 3 and 11, CC1 was added, and then CC3 was further added.
CC6 was added in Examples 7 to 9 and Examples 13 to 15, and CC3 was further added in Examples 9 and 15. In Examples 7 to 9 and 13 to 15, CC4 or CC5 was added after the catalyst solution was added, as described later. The catalyst solution was prepared using the same solvent as the polymerization solvent shown in Table 2.
After adding the co-catalyst as described above, the autoclave was heated to the polymerization temperature shown in Table 2, and then the catalyst solution was added so that the amount of the catalyst was the amount shown in Table 1. Next, after applying an ethylene pressure with a gauge pressure of 0.7 MPa, 30 seconds later was set as the polymerization initiation point. However, in the example in which CC4 or CC5 was used in combination, the catalyst solution was added so that the amount of the catalyst was as shown in Table 1, and then the solution of CC4 or CC5 prepared by using the polymerization solvent shown in Table 2 was added. After the addition, an ethylene pressure with a gauge pressure of 0.7 MPa was applied. In Comparative Example 1, the ethylene pressure was 0.2 MPa.
The total volume of the monomer solution immediately before applying ethylene pressure was 80 mL.
After 15 minutes from the start of the polymerization, the ethylene supply was stopped, the pressure was carefully returned to normal pressure, and then isopropyl alcohol was added to the reaction solution to stop the reaction. Then, the polymerization solution was added to a mixed solvent of 300 mL of acetone, 200 mL of methanol or isopropyl alcohol, and 5 mL of hydrochloric acid to precipitate the copolymer. The copolymer was recovered by suction filtration, washed with acetone and methanol, and vacuum dried at 110 ° C. for 12 hours to obtain a copolymer of norbornene and ethylene.
Table 1 shows the copolymer yield (kg) per 1 g of the catalyst, which is calculated from the amount of the catalyst used and the amount of the copolymer obtained.

In addition, the glass transition temperature was measured, the polyethylene-like impurities were thermally analyzed, and the turbidity test was performed according to the following method. The results of these measurements or tests are shown in Table 2.

<Glass transition temperature (Tg)>
The Tg of the cyclic olefin copolymer was measured by the DSC method (method described in JIS K7121).
DSC device: Differential scanning calorimetry (DSC-Q1000 manufactured by TA Instrument)
Measurement atmosphere: Nitrogen temperature rise condition: 20 ° C / min

<Impurity thermal analysis>
In the DSC curve obtained by measuring the glass transition temperature, the calorific value (mJ / mg) was calculated from the peak area of the melting point derived from the polyethylene-like impurities observed in the range of 100 ° C. to 140 ° C. The larger the calculated calorific value, the higher the content of polyethylene-like impurities.
In addition, ND in Table 2 indicates that a peak derived from polyethylene-like impurities is not detected on the DSC curve.

<Muddy test>
After dissolving 0.1 g of the obtained cyclic olefin copolymer in 10 g of toluene, the presence or absence of turbidity in the solution was observed. When turbidity was observed, it was judged as x, and when turbidity was not observed, it was judged as ◯.

According to Tables 1 and 2, a monomer containing a norbornene monomer and polyethylene is polymerized at a temperature of 50 ° C. or higher in the presence of a metallocene catalyst, and the glass transition temperature is 130 ° C. or lower. When producing a polymer, the pressure of polyethylene charged into the polymerization vessel is set to 0.3 MPa or more, and the ligand containing the cyclopentadiene ring and the nitrogen atom are the transition metal (Ti) of Group IV of the periodic table and silicon. By using a metallocene catalyst having a structure bonded to an atom, the glass transition temperature (Tg) can be increased while suppressing the formation of polyethylene-like impurities even when polymerized at a high temperature at which polyethylene-like impurities are likely to be generated. It can be seen that a cyclic olefin copolymer having low workability and excellent workability can be efficiently produced. It is practically preferable because a cyclic olefin copolymer yield of 0.5 kg or more can be obtained per 1 g of catalyst.
On the other hand, in Comparative Examples 2 to 4 using a metallocene compound having no structure in which a nitrogen atom is bonded to a transition metal of Group IV of the periodic table and a silicon atom, the formation of polyethylene-like impurities could not be suppressed. It was.
Further, even when the same catalyst as in Example was used, in Comparative Example 1 in which the pressure for charging ethylene into the polymerization vessel was less than 0.3 MPa, the yield of the cyclic olefin copolymer per 1 g catalyst was as large as 0.5 kg. Below that, it was not possible to efficiently produce a cyclic olefin copolymer.

Claims

A method for producing a cyclic olefin copolymer containing a structural unit derived from norbornene monomer and a structural unit derived from ethylene and having a glass transition temperature of 130 ° C. or lower.
At least, the norbornene monomer and ethylene are charged into the polymerization vessel as monomers, and
Including the polymerization of the monomer in the polymerization vessel in the presence of a metallocene catalyst at a temperature of 50 ° C. or higher.
The pressure for charging ethylene into the polymerization vessel is 0.3 MPa or more.
A production method, wherein the metallocene catalyst has a ligand containing a cyclopentadiene ring and a structure in which a nitrogen atom is bonded to a transition metal of Group IV of the periodic table and a silicon atom.
The DSC curve obtained by measuring the cyclic olefin copolymer sample with a differential scanning calorimeter under a nitrogen atmosphere and a heating rate of 20 ° C./min according to the method described in JIS K7121 is 100 ° C. The method for producing a cyclic olefin copolymer according to claim 1, which does not have a melting point peak derived from a polyethylene-like impurity in the range of about 140 ° C.
The metallocene catalyst has the following formula (a1):

(In the formula (a1), R a1 to R a3 are hydrocarbon groups having 1 to 20 carbon atoms which may be the same or different, and may contain a heteroatom, respectively, and R a4 is , A hydrocarbon group or a halogen atom having 1 to 20 carbon atoms which may contain a heteroatom, and Ra1 and Ra2 are C—Si bond, O—Si bond, Si—Si bond, or N, respectively. -Si bond to a silicon atom, R a3 to a CN bond, an ON bond, a Si-N bond, or an NN bond to a nitrogen atom, even if R a4 contains a heteroatom In the case of a good hydrocarbon group having 1 to 20 carbon atoms, Ra 4 is bonded to the metal atom M by a CM bond, and Ra 5 to Ra 8 may be independently the same or different, and hydrogen. It is an organic substituent or an inorganic substituent having 1 to 20 carbon atoms which may contain an atom or a heteroatom, and two adjacent groups on the 5-membered ring of R a5 to R a8 are bonded to each other. M may be Ti, Zr, or Hf.)
The method for producing a cyclic olefin copolymer according to claim 1 or 2, which is a metallocene compound represented by.
The metallocene compound represented by the formula (a1) is the following formula (a2):

(In the formula (a2), R a1 to R a4 and M are the same as those in the formula (a1), and R a1 to R a3 may be the same or different, respectively, and contain a heteroatom. It is a good hydrocarbon group having 1 to 20 carbon atoms, R a4 is a hydrocarbon group or halogen atom having 1 to 20 carbon atoms which may contain a hetero atom, and Ra 1 and R a 2 are It is bonded to a silicon atom by a C—Si bond, an O—Si bond, a Si—Si bond, or an N—Si bond, respectively, and Ra3 is a CN bond, an ON bond, a Si—N bond, or an NN. binding by binding to the nitrogen atom, when R a4 is a hydrocarbon group contain an ~ good 1 -C be 20 hetero atom, R a4 is bound to the metal atom M by C-M bonds, R a10 and R a11 are each independently, may be the same or different, a hydrogen atom, an organic substituent contain a heteroatom having 1 carbon atoms which may atom 20, or an inorganic substituent, p and q are are each independently an integer of 0 to 4, when R a10 and R a11 are more respectively, the plurality of R a10 and R a11 may be a different group, two groups of the plurality of R a10 or if the two groups of the plurality of R a11 are bonded to adjacent positions on the aromatic ring, may be the two groups are bonded to each other to form a ring, M is, Ti, Zr, Or Hf.)
The method for producing a cyclic olefin copolymer according to claim 3, which is a metallocene compound represented by.
The method for producing a cyclic olefin copolymer according to any one of claims 1 to 4, wherein the Group IV transition metal of the periodic table is Ti.
The invention according to any one of claims 1 to 5, wherein the polymerization is carried out in the presence of the metallocene catalyst, aluminoxane and hindered phenol, or in the presence of the metallocene catalyst, an ionic compound and alkylaluminum. Method for producing a cyclic olefin copolymer of.