JP2022060008A - Method for producing cycloolefin copolymer - Google Patents

Abstract

To provide a production method that allows a cycloolefin copolymer to be efficiently produced by copolymerizing monomers comprising a norbornene monomer and ethylene while inhibiting the formation of polyethylene-like impurities.SOLUTION: Monomers comprising a norbornene monomer and ethylene are polymerized in the presence of both a metal-containing catalyst having a specific structure and an organic solvent including a halogenated hydrocarbon. The content of the halogenated hydrocarbon in the organic solvent is preferably 0.01-5 vol% inclusive in terms of volume ratio at 20°C.SELECTED DRAWING: None

Description

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

Cyclic olefin homopolymers and cyclic olefin copolymers have low hygroscopicity 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 copolymer composition of cyclic olefin and ethylene, the coweight in which the glass transition temperature (Tg) is adjusted in a wide temperature range. Coagulation can be produced (see, eg, Non-Patent Document 1).

Incoronata, Tritto et al., Coordination Chemistry Reviews, 2006, Vol. 250, p. 212-241

However, depending on the method described in Non-Patent Document 1, there is a problem that a copolymer of cyclic olefin and ethylene cannot be produced in high yield. As a countermeasure against this problem, it is conceivable to carry out polymerization using a highly active catalyst.
However, when polymerization is carried out using a highly active catalyst for the purpose of increasing the production efficiency of the cyclic olefin copolymer, polyethylene-like impurities may be easily 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. Further, when polyethylene-like impurities are generated, in a general production process for producing a cyclic olefin copolymer, a process of filtering and removing insoluble polyethylene-like impurities is required, which increases the production cost.

The present invention has been made in view of the above problems, and the cyclic olefin copolymer is made efficient by copolymerizing a norbornene monomer and a monomer containing ethylene while suppressing the formation of polyethylene-like impurities. It is an object of the present invention to provide a method for producing a cyclic olefin copolymer that can be produced well.

The present inventors have solved the above-mentioned problems by polymerizing a monomer containing norbornene monomer and ethylene in the presence of a metal-containing catalyst having a specific structure and an organic solvent containing a halogenated hydrocarbon. We have found that it can be solved and have completed the present invention. More specifically, the present invention provides the following.

（式（ａ１）中、Ｍは、Ｔｉ、Ｚｒ、又はＨｆであり、Ｘは、ヘテロ原子を含んでいてもよい炭素原子数１～２０の有機置換基、又はハロゲン原子であり、Ｌ^１は下記式（ａ１ａ）又は下記式（ａ１ｂ）：

で表される基であり、
Ｌ^１が式（ａ１ａ）で表される基である場合、Ｌ^２は、式（ａ１ｂ）、下記式（ａ１ｃ）、又は下記式（ａ１ｄ）：

で表される基であり、
Ｌ^１が式（ａ１ｂ）で表される基である場合、Ｌ^２は、式（ａ１ｂ）で表される基であり、
式（ａ１ａ）中、Ｒ^ａ１～Ｒ^ａ５は、それぞれ独立に、同一でも異なっていてもよく、水素原子、ヘテロ原子を含んでいてもよい炭素原子数１～２０の有機置換基、又は無機置換基であり、Ｒ^ａ１～Ｒ^ａ５のうちの５員環上で隣接する２つの基は相互に結合して環を形成してもよく、
式（ａ１ｂ）中、Ｒ^ａ６～Ｒ^ａ８は、それぞれ独立に、同一でも異なっていてもよく、水素原子、ヘテロ原子を含んでいてもよい炭素原子数１～２０の有機置換基、又は無機置換基であり、Ｒ^ａ６～Ｒ^ａ８から選択される２つの基が相互に結合して環を形成してもよく、
式（ａ１ｃ）中、Ｒ^ａ９～Ｒ^ａ１１は、それぞれ独立に、同一でも異なっていてもよく、水素原子、ヘテロ原子を含んでいてもよい炭素原子数１～２０の有機置換基、又は無機置換基であり、ｎ１は０～３の整数であり、
式（ａ１ｄ）中、Ｒ^ａ１２、及びＲ^ａ１３は、それぞれ独立に、同一でも異なっていてもよく、水素原子、ヘテロ原子を含んでいてもよい炭素原子数１～２０の有機置換基、又は無機置換基であり、Ｒ^ａ１２、及びＲ^ａ１３の２つの基は相互に結合して環を形成してもよい。）
で表される含金属化合物である、環状オレフィン共重合体の製造方法。 (1) A method for producing a cyclic olefin copolymer containing a structural unit derived from a norbornene monomer and a structural unit derived from ethylene.
At least, the norbornene monomer and ethylene are charged into the polymerization vessel as monomers, and
It comprises polymerizing the monomer in the polymerization vessel in the presence of a metal-containing catalyst and an organic solvent.
The organic solvent contains halogenated hydrocarbons and
The metal-containing catalyst has the following formula (a1):

(In the formula (a1), M is Ti, Zr, or Hf, X is an organic substituent having 1 to 20 carbon atoms which may contain a hetero atom, or a halogen atom, and L ¹ is. The following formula (a1a) or the following formula (a1b):

It is a group represented by
When L ¹ is a group represented by the formula (a1a), L ² is the formula (a1b), the following formula (a1c), or the following formula (a1d):

It is a group represented by
When L ¹ is a group represented by the formula (a1b), L ² is a group represented by the formula (a1b).
In the formula ( ^a1a ), Ra1 to ^Ra5 may be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. Two groups that are groups and are adjacent on a 5-membered ring among ^Ra1 to ^Ra5 may be bonded to each other to form a ring.
In the formula (a1b), R ^a6 to R ^a8 may be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. It is a group, and two groups selected from ^Ra6 to ^Ra8 may be bonded to each other to form a ring.
In the formula (a1c), ^{Ra9 to Ra11 may} be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. It is an atom, n1 is an integer of 0 to 3, and
In the formula ( ^a1d ), Ra 12 and Ra ¹³ may be independently the same or different from each other, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substance. It is a substituent, and the two groups Ra ¹² and Ra ¹³ may be bonded to each other to form a ring. )
A method for producing a cyclic olefin copolymer, which is a metal-containing compound represented by.

(2) Production of the cyclic olefin copolymer according to (1), wherein the content of the halogenated hydrocarbon in the organic solvent is 0.01% by volume or more and 5% by volume or less as a volume ratio at 20 ° C. Method.

(3) The method for producing a cyclic olefin copolymer according to (1) or (2), wherein the organic solvent is a hydrocarbon solvent and a halogenated hydrocarbon.

(4) The method for producing a cyclic olefin copolymer according to any one of (1) to (3), wherein the halogenated hydrocarbon has a relative permittivity of 6 or more at 25 ° C.

(5) In the formula (a1), whether L ¹ is a group represented by the formula (a1a) and L ² is a group represented by the formula (a1b) or a group represented by the formula (a1d). , Or the method for producing a cyclic olefin copolymer according to any one of (1) to (4), wherein both L ¹ and L ² are groups represented by the formula (a1b).

(6) The method for producing a cyclic olefin copolymer according to any one of (1) to (5), wherein M is Ti in the formula (a1).

(7) The method for producing a cyclic olefin copolymer according to any one of (1) to (6), wherein the monomer is polymerized in the presence of a metal-containing catalyst and an aluminoxane.

(8) A DSC curve obtained by measuring a sample of a cyclic olefin copolymer according to the method described in JIS K7121 under a nitrogen atmosphere under a condition of a heating rate of 20 ° C./min with a differential scanning calorimeter is obtained. The method for producing a cyclic olefin copolymer according to any one of (1) to (7), which does not have a melting point peak derived from a polyethylene-like impurity in the range of 100 ° C to 140 ° C.

According to the present invention, a cyclic olefin copolymer capable of efficiently producing a cyclic olefin copolymer by copolymerizing a norbornene monomer and a monomer containing ethylene while suppressing the generation of polyethylene-like impurities. A manufacturing method can be provided.

<< 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 a norbornene monomer and a structural unit derived from ethylene is produced.
The manufacturing method is
At least, the norbornene monomer and ethylene are charged into the polymerization vessel as monomers, and
It comprises polymerizing the monomer in the polymerization vessel in the presence of a metal-containing catalyst and an organic solvent. The organic solvent contains a halogenated hydrocarbon.
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 in the presence of a metal-containing catalyst and an organic solvent is also referred to as a polymerization step.

The monomer in the polymerization vessel is polymerized in the presence of a metal-containing catalyst having a predetermined structure, which will be described later, and an organic solvent. The organic solvent contains a halogenated hydrocarbon. In the copolymerization of the norbornene monomer and ethylene, by using a metal-containing catalyst having a predetermined structure described later and an organic solvent containing a halogenated hydrocarbon in combination, the cyclic olefin co-weight per unit weight of the catalyst is used. The yield of coalescence can be increased.

Further, in general, when ethylene and a norbornene monomer are copolymerized in the presence of a highly active catalyst, the polymerization of ethylene is likely to proceed and polyethylene-like impurities are likely to be generated.

However, when ethylene and a norbornene monomer are polymerized, if a metal-containing catalyst having a predetermined structure described later and an organic solvent containing a halogenated hydrocarbon are used in combination, the formation of polyethylene-like impurities is suppressed. However, it is easy to produce a cyclic olefin copolymer in a good yield.

<Preparation process>
In the charging step, the 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 constituent units derived from the norbornene monomer and the ratio of the constituent units derived from ethylene in the cyclic olefin copolymer is typically 80% by mass or more with respect to all the constituent units. It is preferably 95% by mass or more, more preferably 95% by mass or more. 98% by mass or more is more preferable.

The norbornene monomer and the monomer 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 C3 to C12 are not particularly limited, and are, 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.

The method of charging ethylene into the polymerization solution is not particularly limited as long as a desired amount of ethylene can be charged in the polymerization container. Typically, ethylene is charged into the polymerization vessel so that the charging pressure of ethylene in the polymerization vessel is 0.5 MPa or more. The ethylene charging pressure is preferably 0.55 MPa or more, more preferably 0.6 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, still more preferably 3 MPa or less.

An organic solvent is charged into the polymerization vessel together with the norbornene monomer and ethylene. The organic solvent is not particularly limited as long as it contains a halogenated hydrocarbon. The halogenated hydrocarbon is a compound in which a part or all of hydrogen atoms contained in the hydrocarbon compound are replaced with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, preferably a fluorine atom, a chlorine atom, and a bromine atom, more preferably a chlorine atom and a bromine atom, and particularly preferably a chlorine atom.
The halogenated hydrocarbon may be charged in the polymerization vessel as a polymerization solvent or a part of the polymerization solvent, or may be charged in the polymerization vessel as a catalyst composition described later.
The halogenated hydrocarbon is preferably liquid at the polymerization temperature under atmospheric pressure, and more preferably liquid at 20 ° C. The halogenated hydrocarbon does not necessarily have to be liquid at a temperature near room temperature of about 20 ° C.
From the viewpoint of enhancing the activity of the catalyst, it is preferable that the halogenated hydrocarbon does not have a polar group such as a hydroxyl group in the molecule.
Further, the halogenated hydrocarbon preferably has a high relative permittivity from the viewpoint of increasing the activity of the catalyst. The relative permittivity of the halogenated hydrocarbon at 25 ° C. is preferably 2 or more, more preferably 6 or more, still more preferably 8 or more.
The mechanism by which the yield of the cyclic olefin copolymer per unit weight of the catalyst can be increased by using a metal-containing catalyst having a predetermined structure in combination with an organic solvent containing a halogenated hydrocarbon is a mechanism of halogenated hydrocarbons. However, it is presumed that this is because the solubility of the cationic catalytically active species is increased and the effective catalytic concentration in the polymerization system is increased.
The halogenated hydrocarbon is selected from the group consisting of dichloromethane, 1,2-dichloroethane, chlorobenzene, p-dichlorobenzene, m-dichlorobenzene, and o-dichlorobenzene because of its ease of handling and availability. At least one of the above is preferred. Among them, at least one selected from the group consisting of dichloromethane, 1,2-dichloroethane, p-dichlorobenzene, m-dichlorobenzene, and o-dichlorobenzene is more preferable.
As mentioned above, the organic solvent contains halogenated hydrocarbons. The organic solvent preferably contains an organic solvent other than the halogenated hydrocarbon in addition to the halogenated hydrocarbon, and more preferably comprises a hydrocarbon solvent and a halogenated hydrocarbon.
Specific examples of preferable solvents other than halogenated hydrocarbons include hydrocarbons such as pentane, hexane, heptane, octane, isooctane, isododecane, mineral oil, cyclohexane, methylcyclohexane, decahydronaphthalene (decalin), benzene, toluene, and xylene. A hydrogen solvent can be mentioned.

The concentration of the norbornene monomer in the polymerization solvent, that is, the solution subjected to the polymerization reaction is preferably, for example, 0.5% by mass or more, and more preferably 10% by mass or more as the lower limit. As for the upper limit, for example, 50% by mass or less is preferable, and 35% by mass or less is more preferable.
Since it is easy to produce a cyclic olefin copolymer in high yield, the ratio of the mass of the halogenated hydrocarbon in the organic solvent to the solution to be subjected to the polymerization reaction is 0.01 volume as the volume ratio at 20 ° C. % Or more and 5% by volume or less are preferable, and 0.05% by volume or more and 3% by volume or less are more preferable.

When a co-catalyst described later is used for the polymerization reaction, it is effective that the amount of halogenated hydrocarbon in the organic solvent is small as described above. In particular, when aluminoxane, which will be described later, is used as the co-catalyst, it is effective that the amount of halogenated hydrocarbon in the organic solvent is small as described above. This is because the co-catalyst may be slightly deteriorated due to the presence of the co-catalyst in a large amount of halogenated hydrocarbons.

Hereinafter, the norbornene monomer will be described.

[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 substituted norbornene is not particularly limited, and examples of the substituent contained in the 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).

（式中、Ｒ^１～Ｒ^１２は、それぞれ同一でも異なっていてもよく、水素原子、ハロゲン原子、及び、炭化水素基からなる群より選ばれるものであり、
Ｒ^９とＲ^１０、Ｒ^１１とＲ^１２は、一体化して２価の炭化水素基を形成してもよく、
Ｒ^９又はＲ^１０と、Ｒ^１１又はＲ^１２とは、互いに環を形成していてもよい。
また、ｎは、０又は正の整数を示し、
ｎが２以上の場合には、Ｒ^５～Ｒ^８は、それぞれの繰り返し単位の中で、それぞれ同一でも異なっていてもよい。
ただし、ｎ＝０の場合、Ｒ^１～Ｒ^４及びＲ^９～Ｒ^１２の少なくとも１個は、水素原子ではない。）

(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, anthryl groups; benzyl groups, phenethyl groups, and other alkyl groups substituted with aryl groups such as aralkyl groups. They can 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 propyridene 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-en, 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 partially hydrogenated additive thereof (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 . 17 and ¹⁰ ] Dodeca-3-ene, 8-ethyltetracyclo [4.4.0.1 ^2,5 . 1 ⁷ , 10] Dodeca-3-en, 8-methylidenetetracyclo [4.4.0.1 ^2,5 . 17 and ¹⁰ ] Dodeca-3-en, 8-ethylidenetetracyclo [4.4.0.1 ^2,5 . 1 ⁷ , 10] Dodeca-3-en, 8-vinyltetracyclo [4,4.0.1, ^2,5 . 17 and ¹⁰ ] Dodeca-3-en, 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-en, 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 referred to as 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 . ^09,13 ] -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 4} . 1 ^{11, 17} ． 0 ^3,8 . 0 ^12,16 ] -5-eikosen, heptacyclo [8.7.0.1 ^2,9 . 0 ^3,8 . 1 ^{4, 7 4} . 0 ^12,17 . ^{113, l6} ] -14-eicosene; polycyclic cyclic olefins such as cyclopentadiene tetramers can be mentioned.

Among them, alkyl-substituted norbornene (eg, bicyclo [2.2.1] hepta-2-ene substituted with one or more alkyl groups), alkylidene-substituted norbornene (eg, 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 in the presence of the following metal-containing catalyst and an organic solvent containing a halogenated hydrocarbon.
The temperature at the time of polymerization is not particularly limited. Since the yield of the cyclic olefin copolymer is good, the temperature at the time of polymerization is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, further preferably 50 ° C. or higher, still more preferably 60 ° C. or higher. 70 ° C. or higher is particularly preferable. The temperature at the time of polymerization may be 80 ° C. or higher.
The upper limit of the temperature at the time of polymerization is not particularly limited, and 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.

（式（ａ１）中、Ｍは、Ｔｉ、Ｚｒ、又はＨｆであり、Ｘは、ヘテロ原子を含んでいてもよい炭素原子数１～２０の有機置換基、又はハロゲン原子であり、Ｌ^１は下記式（ａ１ａ）又は下記式（ａ１ｂ）：

で表される基であり、
Ｌ^１が式（ａ１ａ）で表される基である場合、Ｌ^２は、式（ａ１ｂ）、下記式（ａ１ｃ）、又は下記式（ａ１ｄ）：

で表される基であり、
Ｌ^１が式（ａ１ｂ）で表される基である場合、Ｌ^２は、式（ａ１ｂ）で表される基であり、
式（ａ１ａ）中、Ｒ^ａ１～Ｒ^ａ５は、それぞれ独立に、同一でも異なっていてもよく、水素原子、ヘテロ原子を含んでいてもよい炭素原子数１～２０の有機置換基、又は無機置換基であり、Ｒ^ａ１～Ｒ^ａ５のうちの５員環上で隣接する２つの基は相互に結合して環を形成してもよく、
式（ａ１ｂ）中、Ｒ^ａ６～Ｒ^ａ８は、それぞれ独立に、同一でも異なっていてもよく、水素原子、ヘテロ原子を含んでいてもよい炭素原子数１～２０の有機置換基、又は無機置換基であり、Ｒ^ａ６～Ｒ^ａ８から選択される２つの基が相互に結合して環を形成してもよく、
式（ａ１ｃ）中、Ｒ^ａ９～Ｒ^ａ１１は、それぞれ独立に、同一でも異なっていてもよく、水素原子、ヘテロ原子を含んでいてもよい炭素原子数１～２０の有機置換基、又は無機置換基であり、ｎ１は０～３の整数であり、
式（ａ１ｄ）中、Ｒ^ａ１２、及びＲ^ａ１３は、それぞれ独立に、同一でも異なっていてもよく、水素原子、ヘテロ原子を含んでいてもよい炭素原子数１～２０の有機置換基、又は無機置換基であり、Ｒ^ａ１２、及びＲ^ａ１３の２つの基は相互に結合して環を形成してもよい。） As the metal-containing catalyst, a compound represented by the following formula (a1) is used.

(In the formula (a1), M is Ti, Zr, or Hf, X is an organic substituent having 1 to 20 carbon atoms which may contain a hetero atom, or a halogen atom, and L ¹ is. The following formula (a1a) or the following formula (a1b):

It is a group represented by
When L ¹ is a group represented by the formula (a1a), L ² is the formula (a1b), the following formula (a1c), or the following formula (a1d):

It is a group represented by
When L ¹ is a group represented by the formula (a1b), L ² is a group represented by the formula (a1b).
In the formula ( ^a1a ), Ra1 to ^Ra5 may be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. Two groups that are groups and are adjacent on a 5-membered ring among ^Ra1 to ^Ra5 may be bonded to each other to form a ring.
In the formula (a1b), R ^a6 to R ^a8 may be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. It is a group, and two groups selected from ^Ra6 to ^Ra8 may be bonded to each other to form a ring.
In the formula (a1c), ^{Ra9 to Ra11 may} be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. It is an atom, n1 is an integer of 0 to 3, and
In the formula ( ^a1d ), Ra 12 and Ra ¹³ may be independently the same or different from each other, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substance. It is a substituent, and the two groups Ra ¹² and Ra ¹³ may be bonded to each other to form a ring. )

In the formula (a1), M is Ti, Zr, or Hf, and Ti is particularly preferable from the viewpoint of easy acquisition and production of a metal-containing catalyst, the activity of the catalyst, and the like.

In the formula (a1), X is an organic substituent or a halogen atom having 1 to 20 carbon atoms which may contain a heteroatom.
Regarding the organic substituent having 1 to 20 carbon atoms which may contain a hetero atom, when the organic substituent 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.

The organic substituent is not particularly limited as long as it is a group that does not inhibit the formation reaction of the metal-containing 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, and α-. Naftylcarbonyl group, β-naphthylcarbonyl group, aromatic hydrocarbon group with 6 to 20 carbon atoms, aralkyl group with 7 to 20 carbon atoms, trialkylsilyl group with 3 to 20 carbon atoms, 1 to 1 carbon atom Examples thereof include a mono-substituted amino group substituted with 20 hydrocarbon groups and a di-substituted amino group substituted with a hydrocarbon group having 1 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. A group, a benzoyl group, a phenyl group, a benzyl group, a phenethyl group, and a trialkylsilyl group having 3 to 10 carbon atoms are preferable.

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

As X, a halogen atom is preferable, a chlorine atom and a bromine atom are more preferable, and a chlorine atom is particularly preferable.

In the formula ( ^a1a ), Ra1 to ^Ra5 may be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. It is the basis. Further, two adjacent groups on the 5-membered ring of R ^a1 to R ^a5 may be bonded to each other to form a ring.
Specific examples and preferred examples of the organic substituents having 1 to 20 carbon atoms which may contain a heteroatom as R ^a1 to ^Ra5 are carbon atoms which may contain a heteroatom as X, respectively. It is the same as the specific example and preferable example of the organic substituent of the number 1-20.

The inorganic substituent is not particularly limited as long as it is a group that does not inhibit the formation reaction of the metal-containing compound represented by the above formula (a1).
Specific examples of the inorganic substituent include a halogen atom, a nitro group, an unsubstituted amino group, a cyano group and the like.

In the formula (a1b), R ^a6 to R ^a8 may be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. It is the basis. Further, two groups selected from R ^a6 to R ^a8 may be bonded to each other to form a ring.
Specific examples and preferred examples of the organic substituents having 1 to 20 carbon atoms which may contain a heteroatom as R ^a6 to ^Ra8 are carbon atoms which may contain a heteroatom as X, respectively. It is the same as the specific example and preferable example of the organic substituent of the number 1-20.
In addition, as R ^a6 to R ^a8 , the organic substituent having 1 to 20 carbon atoms which may contain a heteroatom is a group represented by the formula (a1b) and is R ^a6 to R ^a8 . However, a group which is a hydrocarbon group having 1 to 20 carbon atoms independently is also preferable.
As a preferable example when the organic substituent having 1 to 20 carbon atoms which may contain a heteroatom, such as R ^a6 to R ^a8 , is a group represented by the formula (a1b), -N = P. (Me) ₃ , -N = P (Et) ₃ , -N = P (n-Pr) ₃ , -N = P (iso-Pr) ₃ , -N = P (n-Bu) ₃ , -N = Examples thereof include P (iso-Bu) ₃ , -N = P (sec-Bu) ₃ , -N = P (tert-Bu) ₃ , and -N = P (Ph) ₃ . Among these, -N = P (tert-Bu) ₃ and -N = P (iso-Pr) ₃ are preferable, and -N = P (tert-Bu) ₃ is more preferable. Me is a methyl group, Et is an ethyl group, n-Pr is an n-propyl group, iso-Pr is an iso-propyl group, n-Bu is an n-butyl group, and iso. -Bu is an isobutyl group, sec-Bu is a sec-butyl group, tert-Bu is a tert-butyl group, and Ph is a phenyl group.
Further, the specific examples of the inorganic substituents as R ^a6 to R ^a8 are the same as the specific examples of the inorganic substituents as R ^a1 to R ^a5 .

Preferred examples of the group represented by the formula (a1b) are -N = P (Me) ₃ , -N = P (Et) ₃ , -N = P (n-Pr) ₃ , and -N = P (iso). -Pr) ₃ , -N = P (n-Bu) ₃ , -N = P (iso-Bu) ₃ , -N = P (sec-Bu) ₃ , -N = P (tert-Bu) ₃ ,- Examples thereof include N = P (Ph) ₃ , -N = P (-N = P (tert-Bu) ₃ ) Ph ₂ , and -N = P (-N = P (iso-Pr) ₃ ) Ph ₂ . Among them, -N = P (tert-Bu) ₃ and -N = P (iso-Pr) ₃ are preferable, and -N = P (tert-Bu) ₃ is more preferable.

In the formula (a1c), ^{Ra9 to Ra11 may} be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. It is an atom, and n1 is an integer of 0 to 3. n1 is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
The specific examples and preferred examples of the above groups for R ^a9 to Ra 11 in the formula ( ^a1c ) are the same as the specific examples and preferred examples of the above groups for R ^a1 to R ^a5 , respectively.

Preferred examples of the group represented by the formula (a1c) include a phenoxy group, a 2,6-dimethylphenoxy group, and a 2,6-diisopropylphenoxy group.

In the formula ( ^a1d ), Ra 12 and Ra ¹³ may be independently the same or different from each other, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substance. It is a substituent. The two groups R ^a12 and R ^a13 may be coupled to each other to form a ring.
Specific examples and preferred examples of the organic substituents having 1 to 20 carbon atoms which may contain a heteroatom as R ^a12 and ^Raa13 are carbons which may contain a heteroatom as X, respectively. This is the same as the specific example and preferable example of the organic substituent having 1 to 20 atoms.
Further, a mono-substituted amino group substituted with a hydrocarbon group having 1 to 20 carbon atoms and a di-substituted amino group substituted with a hydrocarbon group having 1 to 20 carbon atoms are also preferable as the organic substituent.
With respect to the mono-substituted amino group or di-substituted amino group as Ra 12 and Ra 13 in the formula ( ^a1d ), a ^suitable example of the hydrocarbon group having 1 to 20 carbon atoms bonded to the nitrogen atom is with respect to X. Preferred examples of organic substituents include hydrocarbon groups.
Specific examples of the inorganic substituents as Ra ¹² and Ra ¹³ are the same as the specific examples of the inorganic substituents as Ra ¹ to ^{Ra 5} .

Preferred examples of the group represented by the formula (a1d) include the following groups.

In the formula (a1), L ¹ is a group represented by the formula (a1a) and L ² is a group represented by the formula (a1b) because it is easy to obtain a cyclic olefin copolymer in a good yield. Alternatively, it is preferably a group represented by the formula ( ^a1d ), or ^both L1 and L2 are preferably groups represented by the formula (a1b). When L ¹ and L ² are both groups represented by the formula (a1b), L ¹ and L ² may be the same group or different groups, and are preferably the same group.

Preferred specific examples of the metal-containing compound represented by the above-described formula (a1) include the following metal-containing compounds. In addition, M in the following formula is the same as M in the formula (a1). Further, in the following formula, Me is a methyl group, Et is an ethyl group, n-Pr is an n-propyl group, iso-Pr is an iso-propyl group, and n-Bu is an n-butyl group. Iso-Bu is an isobutyl group, sec-Bu is a sec-butyl group, tert-Bu is a tert-butyl group, Ph is a phenyl group, and Si (Me) ₃ is a trimethylsilyl group. Yes, Si (Me) ₂ tert-butyl is a tert-butyldimethylsilyl group.

The polymerization of the monomer is preferably carried out in the presence of the above-mentioned metal-containing catalyst and co-catalyst. As the co-catalyst, a compound generally used as a co-catalyst in the polymerization of olefins can be used without particular limitation. Preferable examples of the co-catalyst include aluminoxane and ionic compounds. From the viewpoint that the polymerization reaction easily proceeds, the polymerization of the monomer is particularly preferably carried out using at least one of aluminoxane and a borate compound as an ionic compound as an co-catalyst, and aluminoxane is used as a co-catalyst. It is more preferable to be polymerized.

That is, it is preferable to polymerize the monomer in the presence of the metal-containing catalyst and at least one of the aluminoxane and the borate compound, and it is more preferable to polymerize the monomer in the presence of the metal-containing catalyst and the aluminoxane.

The metal-containing 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 metal-containing catalyst.

The catalyst composition is preferably prepared using a solution of a metal-containing catalyst. The solvent contained in the solution of the metal-containing catalyst 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 metal-containing 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 0.0000001 to 20 mol / L. A certain amount of solvent is used.

When the liquid containing the raw material of the catalyst composition is mixed, the number of moles of the transition metal element in the metal-containing catalyst is set to _{Ma, the number of moles of aluminum in the aluminoxane is set to M b1 ,} and the number of moles of the ionic compound is set to M _b2 . The liquid containing the raw material of the catalyst composition is such that the value of (M _b1 + M _b2 ) / _Ma is preferably 1 to 200,000, more preferably 5 to 100,000, and particularly preferably 10 to 80,000. It is preferable to mix.

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 metal-containing 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 in the polymerization vessel, It may be carried out before or during the polymerization.

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

[Aluminoxan]
As the alkynexane, various aluminoxanes conventionally used as co-catalysts and the like 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, an alkylaluminoxane 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.

（式（ｂ１－１）及び式（ｂ１－２）中、Ｒは炭素原子数１～４のアルキル基、ｎは０～４０、好ましくは２～３０の整数を示す。）

(In the formula (b1-1) and the formula (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 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 in particular, a modified methylaluminoxane is preferable. 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, propylaluminoxan, butylaluminoxane, isobutylaluminoxan, methylethylaluminoxan, methylbutylaluminoxane, methylisobutylaluminoxan and the like, and among them, methylaluminoxane and methylisobutylaluminoxan 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 Toso Finechem Co., Ltd.), methylaluminoxane solution (manufactured by Albemarle Corporation), and the like. .. It is more preferable to use an alkylaluminoxane other than solid MAO because it is easy to suppress the formation of polyethylene-like impurities.

[Ionic compound]
The ionic compound is a compound that produces a cationic transition metal compound by reacting with a metal-containing catalyst.
Such ionic compounds include tetrakis (pentafluorophenyl) borate anions, amine cations having active protons such as dimethylphenylammonium cations ((CH ₃ ) ₂ N (C ₆ H ₅ ) H ⁺ ), (C ₆ H). ₅ ) Ionic compounds containing ions such as trisubstituted carbonium cations such as _3C ⁺ , carborane cations, metal carborane cations, and ferrosenium cations with transition metals can be used.

Borate is a good example of an ionic compound. Preferred specific examples of borate are tetrakis (pentafluorophenyl) trityl borate, dimethylphenylammonium tetrakis (pentafluorophenyl) borate, and N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, N-methyldinormaldecyl. 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, the aluminoxane or a plurality of phenols are placed in the polymerization vessel before the metal-containing catalyst or the catalyst composition containing the metal-containing catalyst is added. It is preferable to have at least one selected from an aromatic compound having a sex hydroxyl group and one or more halogen atoms on the 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 condensed 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 tree, 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 the 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 thereof include 6-trimethylbenzene.
Among these, 2,6-di-tert-butyl-p-cresol (BHT), and 2,6- Di-tert-butylphenol is preferred.
Hindered phenol contributes to the increase in 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. Further, the hindered phenol may be used by mixing with alkylaluminum in the 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 a catalyst composition.

When aluminoxane is added into the polymerization vessel before adding the metal-containing catalyst or the catalyst composition containing the metal-containing catalyst, the amount used is 1 to 1,000,000 mol as the number of moles of aluminum in the aluminoxane with respect to 1 mol of the metal-containing catalyst. Is preferable, and 10 to 100,000 mol is more preferable.

It is also preferable that the polymerization is carried out in the presence of a metal-containing catalyst, aluminoxane and hindered phenol, or in the presence of a metal-containing catalyst, an ionic compound and hindered phenol.

It is also preferable that the monomer in the polymerization vessel is polymerized in the presence of the metal-containing catalyst and the alkyl metal compound.
The alkyl metal compound is not particularly limited as long as it is a compound conventionally applied to the polymerization reaction of an olefin such as a cyclic olefin. Suitable alkyl metal compounds include an alkylaluminum compound having at least one alkyl group bonded to an Al atom and an alkylzinc compound having at least one alkyl group bonded to a Zn atom.
When the above metal-containing catalyst and an alkyl metal compound are used in combination, a cyclic olefin copolymer is obtained by copolymerizing a norbornene monomer and a monomer containing ethylene while suppressing the formation of polyethylene-like impurities. It is particularly easy to manufacture efficiently.

The alkyl metal compound may be used alone or in combination of two or more.

As the alkylaluminum compound, those conventionally used for the 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 ⁰¹ ) _z1 AlX _3-z1 (II)
(In the formula (II), R ⁰¹ is an alkyl group having 1 to 15 carbon atoms, X is a halogen atom or a hydrogen atom, and z1 is an integer of 1 to 3).

The number of carbon atoms of the alkyl group as R ⁰¹ is 1 to 15, and 1 to 8 is more preferable, and 2 to 8 is further preferable, from the viewpoint that the desired effect can be easily obtained. Preferred specific examples of the alkyl group include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group and an n-. Examples include octyl groups.

Specific examples of the alkylaluminum compound include trimethylaluminum, triethylaluminum, trin-propylaluminum, triisopropylaluminum, trin-butylaluminum, triisobutylaluminum, trisec-butylaluminum, trin-pentylaluminum, and trin-. Trialkylaluminum such as hexylaluminum, trin-heptylaluminum, trin-octylaluminum; dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, diisobutylaluminum chloride; dimethylaluminum hydride, diethylaluminum hydride, din-propyldimethyl Aluminum hydride, diisopropyldimethylaluminum hydride, din-butylaluminum hydride, diisobutylaluminum hydride, disec-butylaluminum hydride, din-pentyl aluminum hydride, din-hexyl aluminum hydride, din-heptyl aluminum hydride, din- Dialkylaluminum hydrides such as octylaluminum hydride; examples include dialkylaluminum alkoxides such as dimethylaluminum methoxydide.

As the alkyl zinc compound, those conventionally used for the polymerization of olefins and the like can be used without particular limitation. Examples of the alkyl zinc compound include compounds represented by the following general formula (III).
(R ⁰² ) _z2 ZnX _2-z2 (III)
(In the formula (II), R ⁰² is an alkyl group having 1 to 15 carbon atoms, preferably 1 to 8 carbon atoms, X is a halogen atom or a hydrogen atom, and z2 is an integer of 1 to 3).

The number of carbon atoms of the alkyl group as R ⁰² is 1 to 15, and 1 to 8 is more preferable, and 2 to 8 is further preferable, from the viewpoint that a desired effect can be easily obtained. Preferred specific examples of the alkyl group include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group and an n-. Examples include octyl groups.

Specific examples of the alkyl zinc compound include dimethyl zinc, diethyl zinc, din-propyl zinc, diisopropyl zinc, din-butyl zinc, diisobutyl zinc, disec-butyl zinc, din-pentyl zinc, and din-hexyl zinc. , Dialkyl zinc such as di-n-heptyl zinc, di-n-octyl zinc; alkyl zinc halides such as methyl zinc chloride, ethyl zinc chloride, isobutyl zinc chloride; alkyl zinc hydride such as methyl zinc hydride, ethyl zinc hydride, isobutyl zinc hydride and the like. Can be mentioned.

Among the alkyl metal compounds, one or more selected from the group consisting of trialkylaluminum, dialkylaluminum hydride, and dialkylzinc is preferable, and trialkylaluminum and / or dialkylaluminum hydride is more preferable.

The amount of the alkyl metal compound used together with the metal-containing catalyst is preferably 1 to 500,000 mol, more preferably 10 to 50,000 mol, as the number of moles of the alkyl metal compound per 1 mol of the metal-containing catalyst.

The polymerization conditions are not particularly limited as long as the cyclic olefin copolymer having desired physical properties can be obtained, and known conditions can be used.
The amount of the catalyst composition used is derived from the amount of the metal-containing compound used in its preparation. The amount of the catalyst composition used is preferably 0.000000001 to 0.005 mol, preferably 0.00000001 to 0.0005 mol, based on 1 mol of the norbornene monomer, as the mass of the metal-containing compound used for the preparation thereof. More preferred.

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 hours to 120 hours, preferably 0.1 hours to 80 hours, and 0.2 hours to 0.2 hours. 10 hours is 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, a cyclic olefin copolymer can be efficiently produced by copolymerizing a norbornene monomer and a monomer containing ethylene to suppress the formation of polyethylene-like impurities.
The glass transition temperature of the obtained cyclic olefin copolymer is not particularly limited, but from the viewpoint of processability, for example, it is preferably 185 ° C. or lower, more preferably 160 ° C. or lower, further preferably 130 ° C. or lower, still more preferably 120 ° C. or lower. It is preferable, and 100 ° C. or lower is particularly preferable.
Further, a sample of the cyclic olefin copolymer produced by the above method was measured by a differential scanning calorimeter (DSC) under a nitrogen atmosphere and a heating rate of 20 ° C./min according to the method described in JIS K7121. In this case, 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 polyethylene-like impurities in the cyclic olefin copolymer are absent or very few. 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. Ru.

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 copolymer produced by the above method is required to have a high degree of transparency in terms of optical function and aesthetics, and is an optical film or an optical sheet, or a film or sheet for a packaging material. It is particularly preferably used as a material for the above.

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 6, Comparative Example 1 and Comparative Example 2]
In producing the cyclic olefin resin composition, the following C1 and C2 were used as metal-containing catalysts in Examples and Comparative Examples.

In Examples and Comparative Examples, 6.5% by mass (as the content of Al atom) MMAO-3A toluene solution ([(CH ₃ ) _0.7 (iso-C ₄ H ₉ ) _0.3 AlO) as a co-catalyst ] A solution of methylisobutylaluminoxane represented by _n , manufactured by Toso Finechem Co., Ltd., and still containing 6 mol% of trimethylaluminum with respect to total Al) was used.

To a well-dried 150 mL stainless steel autoclave containing a stir bar was added an organic solvent of the type shown in Table 1 and 90 mmol 2-norbornene. Then, 5000 mmol of the above co-catalyst was added to the autoclave.
After heating the autoclave until the polymerization temperature reached 90 ° C., a metal-containing catalyst solution was added so that the amount of the metal-containing catalyst was 0.5 μmol. The metal-containing catalyst solution was prepared using the organic solvents shown in Table 1. Next, after applying an ethylene pressure with a gauge pressure of 0.9 MPa, 30 seconds later was set as the polymerization start point.
The composition of the organic solvent charged in the autoclave and the composition of the organic solvent contained in the catalyst solution are the concentration (volume%) of the halogenated hydrocarbon (dichloromethane or chlorobenzene) in the organic solvent in the solution to be subjected to the polymerization reaction. , 20 ° C.) was adjusted to the concentration shown in Table 1.
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 put into 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.

Further, according to the following method, the glass transition temperature was measured, and the impurity thermal analysis and the turbidity test for confirming the polyethylene-like impurities were performed. Table 1 shows the measurement results of the glass transition temperature and the results of the impurity thermal analysis.

<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 1 indicates that the peak of the melting point derived from the polyethylene-like impurity 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. If turbidity is observed, the cyclic olefin copolymer contains polyethylene-like impurities. If no turbidity is observed, the cyclic olefin copolymer does not contain polyethylene-like impurities. As a result, turbidity was observed only in Comparative Example 1. The result of turbidity in Comparative Example 1 is consistent with the result of impurity thermal analysis.

According to Examples 1 to 6, a polyethylene-like impurity is obtained by polymerizing a norbornene monomer and ethylene in the presence of a metal-containing catalyst having a predetermined structure and an organic solvent containing a halogenated hydrocarbon. It can be seen that a copolymer of norbornene and ethylene can be efficiently obtained while suppressing the formation of ethylene.
Further, from the comparison between Examples 4 and 5 in which only the type of halogenated hydrocarbon was changed, the higher the relative permittivity of the halogenated hydrocarbon at 25 ° C., the higher the yield of the cyclic olefin copolymer per 1 g of the catalyst. It turns out that can be enhanced.
On the other hand, according to Comparative Examples 1 and 2, even if a metal-containing compound having a predetermined structure is used, a copolymer of norbornene and ethylene can be obtained when the polymerization is carried out under the condition that the halogenated hydrocarbon does not exist in the organic solvent. It can be seen that it is difficult to obtain it efficiently, and that ethylene-like impurities may be generated.

[Reference Example 1]
0.45 mL of the toluene solution of MMAO-3A used in the examples and 1 mL of dichloromethane were mixed at room temperature. When the obtained mixed solution was kept at room temperature, it was confirmed that the mixed solution was colored (brown) and a small amount of gas was generated from the mixed solution 60 minutes after the start of holding. It is considered that the decomposition of methylisobutylaluminoxane caused coloring and gas generation.

[Reference Example 2]
0.9 mL of the toluene solution of MMAO-3A used in the examples and 0.2 mL of dichloromethane were mixed at room temperature. When the obtained mixed solution was kept at room temperature, it was confirmed that the mixed solution was colored (brown) and a small amount of gas was generated from the mixed solution when 75 minutes had passed from the start of holding. It is considered that the decomposition of methylisobutylaluminoxane caused coloring and gas generation.

[Reference Example 3]
0.2 mL of the toluene solution of MMAO-3A, 0.44 mL of dichloromethane and 35 mL of toluene used in the examples were mixed at room temperature. When the obtained mixed solution was kept at room temperature, no coloring of the mixed solution or generation of gas from the mixed solution was confirmed even after 10 hours had passed from the start of holding. It is considered that the decomposition of methylisobutylaluminoxane is unlikely to occur in a system in which the halogenated hydrocarbon is diluted.

Claims (8)

A method for producing a cyclic olefin copolymer containing a structural unit derived from a norbornene monomer and a structural unit derived from ethylene.
At least, the norbornene monomer and ethylene are charged into the polymerization vessel as monomers, and
The above-mentioned monomer in the polymerization vessel is polymerized in the presence of a metal-containing catalyst and an organic solvent.
The organic solvent contains a halogenated hydrocarbon and contains
The metal-containing catalyst has the following formula (a1):

(In the formula (a1), M is Ti, Zr, or Hf, X is an organic substituent having 1 to 20 carbon atoms which may contain a hetero atom, or a halogen atom, and L ¹ is. The following formula (a1a) or the following formula (a1b):

It is a group represented by
When L ¹ is a group represented by the above formula (a1a), L ² is the formula (a1b), the following formula (a1c), or the following formula (a1d):

It is a group represented by
When L ¹ is a group represented by the above formula (a1b), L ² is a group represented by the above formula (a1b).
In the formula ( ^a1a ), Ra1 to ^Ra5 may be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. Two groups that are groups and are adjacent on a 5-membered ring among ^Ra1 to ^Ra5 may be bonded to each other to form a ring.
In the formula (a1b), R ^a6 to R ^a8 may be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. It is a group, and two groups selected from ^Ra6 to ^Ra8 may be bonded to each other to form a ring.
In the formula (a1c), ^{Ra9 to Ra11 may} be independently the same or different, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substituent. It is an atom, n1 is an integer of 0 to 3, and
In the formula ( ^a1d ), Ra 12 and Ra ¹³ may be independently the same or different from each other, and may contain a hydrogen atom, a hetero atom, an organic substituent having 1 to 20 carbon atoms, or an inorganic substance. It is a substituent, and the two groups Ra ¹² and Ra ¹³ may be bonded to each other to form a ring. )
A method for producing a cyclic olefin copolymer, which is a metal-containing compound represented by. The method for producing a cyclic olefin copolymer according to claim 1, wherein the content of the halogenated hydrocarbon in the organic solvent is 0.01% by volume or more and 5% by volume or less as a volume ratio at 20 ° C. .. The method for producing a cyclic olefin copolymer according to claim 1 or 2, wherein the organic solvent comprises a hydrocarbon solvent and the halogenated hydrocarbon. The method for producing a cyclic olefin copolymer according to any one of claims 1 to 3, wherein the halogenated hydrocarbon has a relative permittivity of 6 or more at 25 ° C. In the formula (a1), the L ¹ is a group represented by the formula (a1a), and the L ² is a group represented by the formula (a1b) or a group represented by the formula (a1d). The method for producing a cyclic olefin copolymer according to any one of claims 1 to 4, wherein L ¹ and L ² are both groups represented by the formula (a1b). The method for producing a cyclic olefin copolymer according to any one of claims 1 to 5, wherein M is Ti in the formula (a1). The method for producing a cyclic olefin copolymer according to any one of claims 1 to 6, wherein the monomer is polymerized in the presence of the metal-containing catalyst and aluminoxane. 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 any one of claims 1 to 7, which does not have a melting point peak derived from a polyethylene-like impurity in the range of about 140 ° C.