Storage method of catalyst composition

Abstract

This method for preparing a catalyst composition includes adding either an alkyl ammonium compound (C1) or both an alkyl ammonium compound (C1) and an organic boron compound (C2) when a phosphine imide catalyst (B), in which a tertiary alkyl group is bonded to the phosphorus atom of a phosphine imide group, is dissolved in at least one of an organic solvent (A1) composed of a compound that is made of only carbon atoms and hydrogen atoms and that contains no aromatic groups in the molecular structure, and an organic solvent (A2) composed of a compound that is made of only carbon atoms, hydrogen atoms, and halogen atoms and that contains no aromatic groups in the molecular structure.

Description

Method for preparing catalyst composition and method for storing catalyst composition

[0001] The present invention relates to a method for preparing a catalyst composition containing a phosphine imide catalyst and a method for storing the catalyst composition.

[0002] Cyclic olefin homopolymers and cyclic olefin copolymers have low moisture absorption and high transparency and are used in a variety of applications, including optical materials such as optical disk substrates, optical films, and optical fibers. A representative cyclic olefin copolymer is a copolymer of cyclic olefin and ethylene, which is widely used as a transparent resin. The glass transition temperature (Tg) of a copolymer of cyclic olefin and ethylene can be varied depending on the copolymerization composition of the cyclic olefin and ethylene, allowing the production of copolymers with glass transition temperatures adjusted over a wide temperature range (see, for example, Non-Patent Document 1).

[0003] However, the method described in Non-Patent Document 1 has the problem that it is not possible to produce a copolymer of a cyclic olefin and ethylene in high yield. One possible solution to this problem is to carry out polymerization using a highly active catalyst. However, when polymerization is carried out using a highly active catalyst, it is difficult to control the molecular weight of the copolymer produced, and copolymers with excessively high molecular weights are often obtained. Furthermore, polymerization using a highly active catalyst may be prone to the production of polyethylene-like impurities. Therefore, in order to solve this problem, the present applicant has proposed carrying out copolymerization using a specific phosphine imide catalyst (see Patent Document 1).

[0004] On the other hand, as a technique related to a method for producing an organometallic complex solution as a polymerization catalyst for olefin polymers, a method for producing an organometallic complex solution has been proposed, which includes a contacting step of bringing an organometallic complex, an alkylaluminum compound, and a predetermined low-polarity solvent into contact with each other (see Patent Document 2).

[0005] International Publication No. 2022 / 004529 Japanese Patent Application Laid-Open No. 2018-165309

[0006] Incoronatta, Tritto et al., Coordination Chemistry Reviews, 2006, Vol. 250, pp. 212-241

[0007] Phosphine imide catalysts are soluble in aromatic hydrocarbon solvents such as toluene and xylene. However, these aromatic hydrocarbon solvents have a small boiling point difference with norbornene, the monomer of cyclic olefin copolymers. Therefore, separation from unreacted monomers by distillation or other methods after polymerization is difficult. Furthermore, aromatic hydrocarbons are generally highly toxic, so their use is preferably avoided. Therefore, aliphatic hydrocarbon solvents are desirable as solvents for phosphine imide catalysts. However, phosphine imide catalysts are poorly soluble in aliphatic solvents such as hexane and decalin. Therefore, aliphatic hydrocarbon solvents have not been able to be used for the preparation or storage of phosphine imide catalyst compositions. Patent Document 2 also describes the dissolution of organometallic complexes in low-polarity solvents by adding alkylaluminum compounds to specific low-polarity solvents. However, no compounds equivalent to phosphine imide catalysts are described as organometallic complexes. Furthermore, phosphine imide catalysts have a P=N double bond in the phosphine imide group, which is presumably reactive with alkylaluminum compounds. Therefore, it is difficult to imagine adding an alkylaluminum compound when dissolving a phosphine imide catalyst in an aliphatic hydrocarbon solvent, and storing and using the resulting catalyst solution until the production of an olefin polymer or olefin copolymer is completed.

[0008] The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a method for preparing a catalyst composition containing a phosphine imide catalyst, in which an aliphatic hydrocarbon solvent is used as the solvent, and a method for storing a catalyst composition in which a phosphine imide catalyst is dissolved in an aliphatic hydrocarbon solvent.

[0009] As a result of intensive investigations to solve the above-mentioned problems, the present inventors have found that a phosphine imide catalyst can be dissolved in an aliphatic hydrocarbon solvent by adding an alkylaluminum or an alkylaluminum and an organoboron compound to the aliphatic hydrocarbon solvent, and have thus completed the present invention.

[0010] One aspect of the present invention that solves the above-mentioned problems is as follows: (1) A method for preparing a catalyst composition, comprising adding an alkylaluminum compound (C1), or an alkylaluminum compound (C1) and an organoboron compound (C2), when dissolving a phosphine imide catalyst (B) having a tertiary alkyl group bonded to the phosphorus atom of the phosphine imide group in at least one of an organic solvent (A1) consisting of a compound consisting only of carbon and hydrogen atoms and not containing an aromatic group in its molecular structure, and an organic solvent (A2) consisting of a compound consisting only of carbon, hydrogen, and halogen atoms and not containing an aromatic group in its molecular structure.

[0011] (2) The method for preparing a catalyst composition according to (1) above, wherein the alkylaluminum compound (C1) is added so that the ratio of the number of moles of aluminum atoms to the number of moles of metal atoms in the phosphine imide catalyst (B) is 1 to 1,000.

[0012] (3) The method for preparing a catalyst composition according to (1) or (2) above, wherein, in the case where the alkylaluminum compound (C1) and the organoboron compound (C2) are added, the alkylaluminum compound (C1) is contacted with the organoboron compound (C2) before the phosphine imide catalyst (B) is contacted with the organoboron compound (C2).

[0013] (4) The method for preparing a catalyst composition according to any one of (1) to (3), wherein an organic solvent (A3) comprising a compound containing an aromatic group in its molecular structure is used in addition to at least one of the organic solvents (A1) and (A2) so that the mass ratio of the organic solvent (A3) to at least one of the organic solvents (A1) and (A2) is 0.1 / 99.9 to 10.0 / 90.0.

[0014] (5) The phosphine imide catalyst (B) is represented by the following formula (a1): (In formula (a1), M is a transition metal of Group 4 of the periodic table, X is an organic substituent having 1 to 20 carbon atoms which may contain a heteroatom, or a halogen atom, and L １ is a group represented by the following formula (a1a), and L ２ is a group represented by the following formula (a1b): In formula (a1a), R ａ１ ~R ａ５ are each independently the same or different and are an organic or inorganic substituent having 1 to 20 carbon atoms, which may contain a hydrogen atom or a heteroatom; R ａ１ ~R ａ５ In formula (a1b), two adjacent groups on the five-membered ring may be bonded to each other to form a ring, ａ６ ~R ａ８ and each independently may be the same or different and is a tertiary alkyl group having 4 to 20 carbon atoms, which may contain a heteroatom.

[0015] (6) The method for preparing a catalyst composition according to (5) above, wherein the compound represented by formula (a1) is a compound represented by the following general formula (1):

[0016] [In the general formula (1), M represents a transition metal of Group 4 of the periodic table, X represents an organic substituent having 1 to 20 carbon atoms which may contain a heteroatom or a halogen atom, and R ａ６ ~R ａ８ are each independently the same or different and each independently represent a tertiary alkyl group having 4 to 20 carbon atoms which may contain a heteroatom; R represents one or more selected from a hydrogen atom, an alkyl group, a cycloalkyl group, a halogenated alkyl group, an aryl group, a halogenated aryl group, an alkylsilyl group, and an arylsilyl group; and n represents an integer of 1 to 5.

[0017] (7) The method for preparing a catalyst composition according to (6) above, wherein R in the general formula (1) contains a fluorine atom.

[0018] (8) The method for preparing a catalyst composition according to any one of (1) to (7), wherein the phosphine imide catalyst (B) is a catalyst for polymerizing a cyclic olefin copolymer.

[0019] (9) A method for storing a catalyst composition, comprising adding an alkylaluminum compound (C1), or an alkylaluminum compound (C1) and an organoboron compound (C2), to at least one of an organic solvent (A1) consisting of a compound consisting only of carbon atoms and hydrogen atoms and not containing an aromatic group in its molecular structure, and an organic solvent (A2) consisting of a compound consisting only of carbon atoms, hydrogen atoms, and halogen atoms and not containing an aromatic group in its molecular structure, and dissolving a phosphine imide catalyst (B) in which a tertiary alkyl group is bonded to the phosphorus atom of the phosphine imide group, and storing the resulting catalyst composition.

[0020] (10) The method for storing a catalyst composition according to (9) above, wherein the phosphine imide catalyst (B) is a catalyst for polymerization of a cyclic olefin copolymer.

[0021] According to the present invention, there can be provided a method for preparing a catalyst composition containing a phosphine imide catalyst, the method using an aliphatic hydrocarbon solvent as the solvent, and a method for storing a catalyst composition in which a phosphine imide catalyst is dissolved in an aliphatic hydrocarbon solvent.

[0022] <Method for preparing catalyst composition> In the method for preparing the catalyst composition of this embodiment, when dissolving a phosphine imide catalyst (B) in which a tertiary alkyl group is bonded to the phosphorus atom of the phosphine imide group in at least one of an organic solvent (A1) consisting of a compound consisting only of carbon atoms and hydrogen atoms and not containing an aromatic group in its molecular structure, and an organic solvent (A2) consisting of a compound consisting only of carbon atoms, hydrogen atoms and halogen atoms and not containing an aromatic group in its molecular structure, an alkyl aluminum compound (C1), or an alkyl aluminum compound (C1) and an organoboron compound (C2) are added.

[0023] The method for preparing a catalyst composition according to this embodiment is, in brief, a method for preparing a catalyst composition by dissolving a phosphine imide catalyst in an aliphatic hydrocarbon solvent. Here, the organic solvent (A1) consisting of a compound consisting only of carbon and hydrogen atoms and containing no aromatic groups in its molecular structure, and the organic solvent (A2) consisting of a compound consisting only of carbon, hydrogen, and halogen atoms and containing no aromatic groups in its molecular structure, are aliphatic hydrocarbon solvents. As described above, phosphine imide catalysts are poorly soluble in aliphatic hydrocarbon solvents. However, in this embodiment, the addition of an alkyl aluminum compound (C1) or an alkyl aluminum compound (C1) and an organoboron compound (C2) enables the phosphine imide catalyst to dissolve in the aliphatic hydrocarbon solvent. Furthermore, the use of an aliphatic hydrocarbon solvent in this embodiment can solve the problems associated with the use of aromatic hydrocarbon solvents, as described above. Specifically, the large difference in boiling points between norbornene and the aliphatic hydrocarbon solvent facilitates separation after polymerization. Furthermore, aliphatic hydrocarbon solvents are less toxic than aromatic hydrocarbon solvents. Furthermore, by optimizing the structure of the phosphine imide catalyst, the stability of the catalyst composition can be improved by suppressing deactivation of the phosphine imide catalyst, thereby enabling the production of a catalyst solution that can be stored stably. In the catalyst composition obtained in this embodiment, the phosphine imide catalyst (B) can be used as a catalyst for polymerizing cyclic olefin copolymers. Therefore, this catalyst composition is useful for polymerizing cyclic olefin copolymers. More specifically, this catalyst composition is preferably used when copolymerizing norbornene and ethylene to obtain a cyclic olefin copolymer. Furthermore, adding an alkylaluminum compound (C1) or the like does not necessarily mean that all of the phosphine imide catalyst dissolves in an aliphatic hydrocarbon solvent. That is, the phosphine imide catalyst of interest in this embodiment is a phosphine imide catalyst in which a tertiary alkyl group is bonded to the phosphorus atom of the phosphine imide group, and other phosphine imide catalysts are not of interest. Below, each component used in the method for preparing the catalyst composition of this embodiment is described in detail.

[0024] [Organic Solvent (A1)] The organic solvent (A1) is an organic solvent consisting of a compound consisting only of carbon and hydrogen atoms and not containing any aromatic groups in its molecular structure. Examples of the organic solvent (A1) include aliphatic hydrocarbon solvents having 5 to 18 carbon atoms. The compound constituting the organic solvent (A1) may have an unsaturated bond or may contain a ring other than an aromatic ring. Examples include hexane, cyclohexane, methylcyclohexane, isooctane, isododecane, and decalin, with isododecane and decalin being preferred. The organic solvent (A1) may be used alone or in combination of two or more.

[0025] [Organic Solvent (A2)] The organic solvent (A2) is an organic solvent consisting of a compound consisting only of carbon atoms, hydrogen atoms, and halogen atoms, and not containing an aromatic group in its molecular structure. Examples of the organic solvent (A2) include compounds exemplified as the organic solvent (A1) above in which the hydrogen atoms have been substituted with halogen atoms. Chlorine is preferred as the halogen atom. The halogen atom may be substituted at any position. Examples of the organic solvent (A2) include dichloromethane and 1,1,2,2-tetrachloroethane. Of these, dichloromethane is preferred. The organic solvent (A2) may be used alone or in combination of two or more types.

[0026] Between the organic solvent (A1) and the organic solvent (A2), the organic solvent (A1) is preferred from the viewpoint of a large difference in boiling point with norbornene, which is a monomer of the cyclic olefin copolymer. The organic solvent (A1) and the organic solvent (A2) may be used alone or in combination. When the organic solvent (A1) and the organic solvent (A2) are used in combination, the organic solvent (A2) is preferably 50% by mass or less of the total amount of the organic solvent (A1) and the organic solvent (A2).

[0027] [Organic Solvent (A3)] The organic solvent (A3) is an organic solvent consisting of a compound containing an aromatic group in its molecular structure. As described above, although the primary objective of this embodiment is to use an aliphatic hydrocarbon solvent as the solvent, a small amount of an organic solvent consisting of a compound containing an aromatic group may also be included. That is, the organic solvent (A3) is any solvent and is used in addition to at least one of the organic solvents (A1) and (A2). The organic solvent (A3) is used so that the mass ratio of the organic solvent (A3) to at least one of the organic solvents (A1) and (A2) is 0.1 / 99.9 to 10.0 / 90.0. When the organic solvent (A1) or the organic solvent (A2) is used alone, the above mass ratio refers to the mass ratio of the organic solvent (A3) to the organic solvent (A1), or the mass ratio of the organic solvent (A3) to the organic solvent (A2). When the organic solvent (A1) and the organic solvent (A2) are used in combination, the above mass ratio refers to the mass ratio of the organic solvent (A3) to the total of the organic solvents (A1) and (A2).

[0028] Examples of the organic solvent (A3) include toluene, xylene, and tetralin, and among these, toluene is preferred.

[0029] [Phosphine imide catalyst (B)] The phosphine imide catalyst (B) is a catalyst having a phosphine imide group, and in this embodiment, a phosphine imide catalyst in which a tertiary alkyl group is bonded to the phosphorus atom of the phosphine imide group is targeted. That is, in this embodiment, such a phosphine imide catalyst can be dissolved in a predetermined aliphatic hydrocarbon solvent.

[0030] The phosphine imide catalyst (B) used in the production method of this embodiment is preferably a compound represented by the following formula (a1):

[0031]

[0032] In formula (a1), M is a transition metal of Group 4 of the periodic table, and Ti is particularly preferred in terms of catalyst availability and ease of production, catalytic activity, etc. X is an organic substituent having 1 to 20 carbon atoms which may contain a heteroatom, or a halogen atom. １is a group represented by the following formula (a1a), and L ２ is a group represented by the following formula (a1b):

[0033]

[0034] In formula (a1a), R ａ１ ~R ａ５ R may be the same or different and independently represent a hydrogen atom, an organic substituent having 1 to 20 carbon atoms which may contain a heteroatom, or an inorganic substituent. ａ１ ~R ａ５ In formula (a1b), two adjacent groups on the five-membered ring may be bonded to each other to form a ring. ａ６ ~R ａ８ are each independently the same or different and each is a tertiary alkyl group having 4 to 20 carbon atoms which may contain a heteroatom.

[0035] In formula (a1), M represents a transition metal of Group 4 of the periodic table, specifically Ti, Zr, or Hf. M is preferably Ti. In formula (a1), X represents an organic substituent having 1 to 20 carbon atoms that may contain a heteroatom, or a halogen atom. Regarding the organic substituent having 1 to 20 carbon atoms that may contain a heteroatom, when the organic substituent contains a heteroatom, the type of heteroatom is not particularly limited as long as it does not impair the effects of the preparation method of this embodiment. Specific examples of heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, selenium atoms, and halogen atoms.

[0036] The organic substituent is not particularly limited as long as it does not inhibit the reaction for producing the compound represented by formula (a1) above. Examples include 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, an α-naphthylcarbonyl group, a β-naphthylcarbonyl group, an aromatic hydrocarbon group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, a triarylsilyl group having 3 to 20 carbon atoms, 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.

[0037] Among these organic substituents, alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, cycloalkyl groups having 3 to 8 carbon atoms, aliphatic acyl groups having 2 to 6 carbon atoms, benzoyl groups, phenyl groups, benzyl groups, phenethyl groups, trialkylsilyl groups having 3 to 10 carbon atoms, and triarylsilyl groups having 3 to 10 carbon atoms are preferred.

[0038] 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, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a sec-butyloxy group, a tert-butyloxy group, an acetyl group, a propionyl group, a butanoyl group, a phenyl group, a trimethylsilyl group, a triethylsilyl group, a tert-butyldimethylsilyl group, a triphenylsilyl group, and a trispentafluorophenylsilyl group are more preferred.

[0039] X is preferably a halogen atom, more preferably a chlorine atom or a bromine atom, and particularly preferably a chlorine atom.

[0040] In formula (a1a), R ａ１ ~R ａ５ are each independently the same or different and are an organic or inorganic substituent having 1 to 20 carbon atoms which may contain a hydrogen atom or a heteroatom. ａ１ ~Rａ５ Two adjacent groups on the five-membered ring may be bonded to each other to form a ring. ａ１ ~R ａ５ Specific examples and preferred examples of the organic substituent having 1 to 20 carbon atoms which may contain a heteroatom as R are the same as the specific examples and preferred examples of the organic substituent having 1 to 20 carbon atoms which may contain a heteroatom as X. ａ１ ~R ａ５ As the organic substituent having 1 to 20 carbon atoms which may contain a hetero atom, -(CH ２ ) ｎ The substituent represented by R is preferred from the viewpoint of high catalytic activity and suppression of polyethylene-like impurities. ａ１ ~R ａ５ Only one of the following is -(CH ２ ) ｎ It is particularly preferred that the substituents represented by R are hydrogen atoms. ２ ) ｎ In R, R represents one or more groups selected from a hydrogen atom, an alkyl group, a cycloalkyl group, a halogenated alkyl group, an aryl group, a halogenated aryl group, an alkylsilyl group, and an arylsilyl group, and n represents an integer of 1 to 5.

[0041] Examples of the alkyl group represented by R include alkyl groups having 1 to 5 carbon atoms, with alkyl groups having 1 to 4 carbon atoms being preferred. Specific examples of the alkyl group represented by R include methyl, ethyl, isopropyl, n-butyl, and tert-butyl groups, with tert-butyl being preferred. Examples of the cycloalkyl group represented by R include cycloalkyl groups having 3 to 20 carbon atoms, with cycloalkyl groups having 3 to 10 carbon atoms being preferred, and cycloalkyl groups having 5 to 8 carbon atoms being more preferred. Specific examples of the cycloalkyl group represented by R include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups, with cyclohexyl being preferred. Examples of the halogenated alkyl group represented by R include alkyl groups having at least one halogen atom as a substituent, with alkyl groups having 1 to 7 carbon atoms being preferred, with alkyl groups having 1 to 5 carbon atoms being preferred, and halogenated alkyl groups having 1 to 3 carbon atoms being more preferred. Furthermore, the halogen element in the halogenated alkyl group represented by R is preferably fluorine or chlorine. Specific examples of the halogenated alkyl group represented by R include a monofluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a trichloromethyl group, among which a trifluoromethyl group is preferred. Specific examples of the aryl group represented by R include an aryl group having 6 to 20 carbon atoms, preferably an aryl group having 6 to 10 carbon atoms, and more preferably an aryl group having 7 to 8 carbon atoms. Specific examples of the aryl group represented by R include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a naphthyl group, an aralkyl group, and a biphenyl group, among which a phenyl group is preferred. Specific examples of the halogenated aryl group represented by R include an aryl group having at least one halogen atom as a substituent in the aryl group represented by R, and include an aryl group having 6 to 20 carbon atoms, preferably an aryl group having 6 to 10 carbon atoms, and more preferably an aryl group having 7 to 8 carbon atoms. Furthermore, the halogen element in the halogenated aryl group represented by R is preferably fluorine or chlorine.Specific examples of the halogenated aryl group represented by R include a 4-fluorophenyl group, a 2,4-difluorophenyl group, a 2,4,6-trifluorophenyl group, a 2,3,6-trifluorophenyl group, and a perfluorophenyl group (-C. ６ F ５ ), perfluorobiphenyl group, perchlorophenyl group (-C ６ Cl ５ ), among which perfluorophenyl groups (-C ６ F ５ ) is preferred. Examples of the alkylsilyl group represented by R include trialkylsilyl groups such as trimethylsilyl and triethylsilyl, and among these, trimethylsilyl is preferred. Examples of the arylsilyl group represented by R include triarylsilyl groups such as triphenylsilyl and trispentafluorophenylsilyl, and among these, triphenylsilyl is preferred. Among these R groups, a hydrogen atom, an alkyl group having a large number of carbon atoms (number of carbon atoms: 3 to 12), or an alkyl group containing a fluorine atom is preferred. For example, a hydrogen atom, a tert-butyl group, a phenyl group, a perfluorophenyl group (-C ６ F ５ ), and a trimethylsilyl group are particularly preferred.

[0042] - (CH ２ ) ｎ In R, n represents an integer of 1 to 5, preferably 1 to 3.

[0043] The inorganic substituent is not particularly limited as long as it does not inhibit the reaction for producing the compound represented by formula (a1). Specific examples of the inorganic substituent include a halogen atom, a nitro group, an unsubstituted amino group, and a cyano group.

[0044] In formula (a1b), R ａ６ ~R ａ８ R may be the same or different and each independently represents a tertiary alkyl group having 4 to 20 carbon atoms which may contain a heteroatom. ａ６ ~R ａ８The tertiary alkyl group having 4 to 20 carbon atoms and optionally containing a heteroatom as R may be either a non-cyclic tertiary alkyl group or a cyclic tertiary alkyl group. Examples of the non-cyclic tertiary alkyl group include a tert-butyl group, and examples of the cyclic tertiary alkyl group include an adamantyl group. ａ６ ~R ａ８ are all tertiary alkyl groups having 4 to 20 carbon atoms, but may all be different tertiary alkyl groups, and it is preferable that any two of the three are the same tertiary alkyl group, and it is more preferable that all are the same tertiary alkyl group.

[0045] Preferred examples of the group represented by formula (a1b) include -N=P(n-Bu) ３ , -N=P(iso-Bu) ３ , -N=P(sec-Bu) ３ , -N=P(tert-Bu) ３ , and -N=P (-N=P(tert-Bu) ３ ) Ph ２ Among them, -N=P(tert-Bu) ３ is preferred.

[0046] Preferable specific examples of the compound represented by formula (a1) described above include the following compounds. In the following formula, M is the same as M in formula (a1). In addition, in the following formula, Si(Me) ３ is a trimethylsilyl group, and Si(Me) ２ tert-Butyl is a tert-butyldimethylsilyl group.

[0047]

[0048] The phosphine imide catalyst (B) used in the production method of this embodiment is preferably a compound represented by the following general formula (1) among the compounds represented by the above formula (a1).

[0049] [In the general formula (1), M represents a transition metal of Group 4 of the periodic table, X represents an organic substituent having 1 to 20 carbon atoms which may contain a heteroatom or a halogen atom, and R ａ６ ~Rａ８ are each independently the same or different and each independently represent a tertiary alkyl group having 4 to 20 carbon atoms which may contain a heteroatom; R represents one or more selected from a hydrogen atom, an alkyl group, a cycloalkyl group, a halogenated alkyl group, an aryl group, a halogenated aryl group, an alkylsilyl group, and an arylsilyl group; and n represents an integer of 1 to 5.

[0050] The compound represented by the general formula (1) is a compound represented by the formula (a1), wherein L １ is a group represented by the formula (a1a), and L ２ is a group represented by the formula (a1b). ａ１ ~R ａ５ Only one of the following is -(CH ２ ) ｎ In general formula (1), M, X, and R are substituents represented by R, and the other four are hydrogen atoms. ａ６ ~R ａ８ , and -(CH ２ ) ｎ R and n in R have the same meanings as those in the compound represented by formula (a1), and preferred embodiments and examples are also the same, so the explanation thereof will be omitted.

[0051] Preferable specific examples of the compound represented by formula (1) include the following compounds.

[0052]

[0053]

[0054] [Alkyl aluminum compound (C1)] As the alkyl aluminum compound (C1), any compound conventionally used for the polymerization of olefins can be used. Examples of the alkyl aluminum compound include compounds represented by the following general formula (2): (R ｂ ) ｍ AlX ３－ｍ General formula (2) In general formula (2), R ｂis an alkyl group having 1 to 8, preferably 1 to 4, carbon atoms; X is a halogen atom or a hydrogen atom; and m is an integer of 1 to 3.

[0055] Examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and an n-octyl group.

[0056] Specific examples of the alkylaluminum compound (C1) include trialkylaluminums such as trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-sec-butylaluminum, and tri-n-octylaluminum; dialkylaluminum halides such as dimethylaluminum chloride and diisobutylaluminum chloride; dialkylaluminum hydrides such as diisobutylaluminum hydride; and dialkylaluminum alkoxides such as dimethylaluminum methoxide. Among these, trimethylaluminum, triethylaluminum, and triisobutylaluminum are preferred. The alkylaluminum compound (C1) may be used alone or in combination of two or more.

[0057] The alkylaluminum compound (C1) is preferably present so that the ratio of the number of moles of aluminum atoms to the number of moles of metal atoms in the phosphine imide catalyst (B) is 1 to 1000. When the ratio is 1 to 1000, the phosphine imide catalyst (B) can be stably dissolved in the organic solvent (A1) or (A2). The ratio is more preferably 1 to 800, even more preferably 1 to 700, particularly preferably 100 to 600, and most preferably 200 to 500.

[0058] [Organoboron Compound (C2)] In this embodiment, the organoboron compound (C2) is present together with the alkylaluminum compound (C1), and is not added alone. The organoboron compound is a compound that produces a cationic transition metal compound by reacting with a catalyst having a phosphine imide group. Preferred specific examples of the organoboron compound include tetrakis(pentafluorophenyl)tritylborate, dimethylphenylammonium tetrakis(pentafluorophenyl)borate, and N-methyldialkylammonium tetrakis(pentafluorophenyl)borate such as N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate and N-methyldinormaldecylammonium tetrakis(pentafluorophenyl)borate.

[0059] In this embodiment, as described above, when dissolving the phosphine imide catalyst (B) in the organic solvent (A1) or (A2), an alkyl aluminum compound (C1), or an alkyl aluminum compound (C1) and an organoboron compound (C2) is added. From the viewpoint of stability, adding the alkyl aluminum compound (C1) alone is preferable to adding the alkyl aluminum compound (C1) and the organoboron compound (C2). The order of adding the components to the organic solvent (A1) or (A2) does not matter. However, when adding the alkyl aluminum compound (C1) and the organoboron compound (C2), i.e., when using the alkyl aluminum compound (C1) and the organoboron compound (C2) in combination, it is preferable to contact the alkyl aluminum compound (C1) with the organoboron compound (C2) before contacting the phosphine imide catalyst (B) with the organoboron compound (C2). The organoboron compound (C2) contains moisture, and if this moisture comes into contact with the phosphine imide catalyst (B), the catalyst may be deactivated. Therefore, the organoboron compound (C2) is contacted with the alkylaluminum compound (C1) before contacting the organoboron compound (C2) with the phosphine imide catalyst (B). This allows the aluminum in the alkylaluminum compound to capture moisture, thereby preventing catalyst deactivation. That is, the alkylaluminum compound also functions as a dehydrating agent. On the other hand, when adding only the alkylaluminum compound (C1) without adding the organoboron compound (C2), it is preferable to first mix the alkylaluminum compound (C1) with a solvent and then add the catalyst, as described above, in order to remove any traces of moisture. In this case, the alkylaluminum compound also functions as a dehydrating agent. The addition and mixing of the components is preferably carried out at a temperature of −10 to 40° C.

[0060] <Method for Storing Catalyst Composition> The method for storing the catalyst composition of this embodiment involves adding an alkylaluminum compound (C1) or an alkylaluminum compound (C1) and an organoboron compound (C2) to at least one of an organic solvent (A1) consisting of a compound consisting only of carbon and hydrogen atoms and not containing an aromatic group in its molecular structure, and an organic solvent (A2) consisting of a compound consisting only of carbon, hydrogen, and halogen atoms and not containing an aromatic group in its molecular structure, and dissolving a phosphine imide catalyst (B) in which a tertiary alkyl group is bonded to the phosphorus atom of the phosphine imide group, thereby storing the catalyst composition. In this method for storing the catalyst composition of this embodiment, the components are the same as those in the preparation method of the catalyst composition of this embodiment described above, the preparation method is also the same, and even the preferred aspects are the same. That is, in this storage method of this embodiment, the catalyst composition obtained by the preparation method of the catalyst composition of this embodiment described above is stored as is. This prevents deactivation of the phosphine imide catalyst and allows for stable storage.

[0061] As described above, the phosphine imide catalyst (B) is poorly soluble in aliphatic hydrocarbon solvents, but can be dissolved by adding an alkylaluminum compound (C1) or the like. Therefore, even when an aliphatic hydrocarbon solvent is used as the solvent, the phosphine imide catalyst can be stably stored while preventing deactivation. Specifically, the organic solvent (A1) or organic solvent (A2), the alkylaluminum compound (C1), or the alkylaluminum compound (C1) and the organoboron compound (C2), and the phosphine imide catalyst (B) can be stored in a container such as a tank. Because these components can be stored in a single tank, the number of tanks can be reduced, which can lead to simplification of the process.

[0062] In this embodiment, the storage temperature of the catalyst composition is preferably −10 to 40° C. The lower the temperature, the better in order to suppress reactions between the components in the catalyst composition.

[0063] During storage of the catalyst composition, it is preferable to shield the catalyst composition from light, for example, by using a light-shielding container or tank.

[0064] In the storage method for a catalyst composition of this embodiment, the phosphine imide catalyst (B) can be used as a catalyst for polymerization of a cyclic olefin copolymer. Therefore, the catalyst composition of this embodiment is useful for polymerization of a cyclic olefin copolymer. More specifically, as described above, the catalyst composition is suitably used when norbornene and ethylene are copolymerized to obtain a cyclic olefin copolymer. Furthermore, in the storage method of this embodiment, deactivation of the phosphine imide catalyst (B) is suppressed and the catalyst is stored stably, so that the catalyst can be used directly for polymerization of a cyclic olefin copolymer even after storage.

[0065] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to the following examples.

[0066] Example 1 A catalyst composition was prepared by dissolving an alkylaluminum compound (C1) in decahydronaphthalene (decalin) as an organic solvent (A1) and further mixing with a phosphine imide catalyst (B) (exemplified compound 1 described above) at the mixing temperature shown in Table 1. After preparation, the resulting catalyst composition was placed in a tank and stored for 20 days at the storage temperature shown in Table 1. Triisobutylaluminum (manufactured by Tosoh Finechem Corporation) was used as the alkylaluminum compound. The ratio of the number of moles of aluminum atoms in the alkylaluminum compound to the number of moles of metal atoms in the phosphine imide catalyst is shown in Table 1 as "Al / Metal".

[0067] Example 2 A catalyst composition was prepared in the same manner as in Example 1, except that the amount of each component added was adjusted so that the ratio of the number of moles of aluminum atoms in the alkylaluminum compound (C1) to the number of moles of metal atoms in the phosphine imide catalyst (B) (Al / metal) was 50, and then the catalyst composition was stored.

[0068] Example 3 The same alkylaluminum compound (C1) as in Example 1 was dissolved in decalin as the organic solvent (A1) at the mixing temperature shown in Table 1. To the solution was added N-methyldialkylammonium tetrakis(pentafluorophenyl)borate (alkyl: C14 to C18 (average: C17.5) (manufactured by Tosoh Finechem Corporation) as the organoboron compound (C2). Finally, the phosphine imide catalyst (B) (exemplified compound 1 described above) was mixed to prepare a catalyst composition. The resulting mixture was then stored in the same manner as in Example 1.

[0069] Example 4 A catalyst composition was prepared in the same manner as in Example 1, except that the amount of each component added was adjusted so that the ratio of the number of moles of aluminum atoms in the alkylaluminum compound (C1) to the number of moles of metal atoms in the phosphine imide catalyst (B) (Al / metal) was 250, and then the catalyst composition was stored.

[0070] [Example 5] A catalyst composition was prepared and then stored in the same manner as in Example 4, except that dichloromethane was used as the organic solvent (A2) in addition to the organic solvent (A1), i.e., the organic solvent (A1) and the organic solvent (A2) were used in combination. At this time, the mass ratio of the organic solvent (A2) to the organic solvent (A1) ((A2) / (A1)) was 5 / 95.

[0071] [Example 6] A catalyst composition was prepared and then stored in the same manner as in Example 4, except that toluene was used as the organic solvent (A3) in addition to the organic solvent (A1), i.e., the organic solvent (A1) and the organic solvent (A3) were used in combination. At this time, the mass ratio of the organic solvent (A3) to the organic solvent (A1) ((A3) / (A1)) was 5 / 95.

[0072] Example 7 A catalyst composition was prepared in the same manner as in Example 4, and then stored at a storage temperature of 2°C for 20 days.

[0073] Example 8 A catalyst composition was prepared in the same manner as in Example 1, except that the amount of each component added was adjusted so that the ratio of the number of moles of aluminum atoms in the alkylaluminum compound (C1) to the number of moles of metal atoms in the phosphine imide catalyst (B) (Al / metal) was 500, and then the catalyst composition was stored.

[0074] Example 9 A catalyst composition was prepared in the same manner as in Example 1, except that the amount of each component added was adjusted so that the ratio of the number of moles of aluminum atoms in the alkylaluminum compound (C1) to the number of moles of metal atoms in the phosphine imide catalyst (B) (Al / metal) was 900, and then the catalyst composition was stored.

[0075] Example 10 A catalyst composition was prepared in the same manner as in Example 1, except that the amount of each component added was adjusted so that the ratio of the number of moles of aluminum atoms in the alkylaluminum compound (C1) to the number of moles of metal atoms in the phosphine imide catalyst (B) (Al / metal) was 1,200, and then the catalyst composition was stored.

[0076] Example 11 A catalyst composition was prepared in the same manner as in Example 1 except that the mixing temperature was set to 2°C, and then stored at a storage temperature of 2°C for 20 days.

[0077] Comparative Example 1 A catalyst composition was prepared in the same manner as in Example 1, except that the alkylaluminum compound (C1) was not used, and then stored.

[0078] Comparative Example 2 A catalyst composition was prepared in the same manner as in Example 5, except that the alkylaluminum compound (C1) was not used, and then stored.

[0079] Example 12 A catalyst composition was prepared in the same manner as in Example 3, except that the phosphine imide catalyst (B) was changed to the above-mentioned exemplary compound 3, and then stored at a storage temperature of 2°C for 20 days.

[0080] Example 13 A catalyst composition was prepared in the same manner as in Example 3, except that the phosphine imide catalyst (B) was changed to Exemplified Compound 3 above, and the amounts of the components added were adjusted so that the ratio of the number of moles of aluminum atoms in the alkyl aluminum compound (C1) to the number of moles of metal atoms in the phosphine imide catalyst (B) (Al / metal) was 250. The catalyst composition was then stored at a storage temperature of 2°C for 20 days.

[0081] Comparative Example 3 A catalyst composition was prepared in the same manner as in Example 1, except that the phosphine imide catalyst (B) was changed to the above-mentioned exemplary compound 3 and that the alkyl aluminum compound (C1) was not used. The catalyst composition was then stored at a storage temperature of 2°C for 20 days.

[0082] Example 14 A catalyst composition was prepared in the same manner as in Example 1, except that the phosphine imide catalyst (B) was changed to the above-mentioned exemplary compound 4, and then stored at a storage temperature of 2°C for 20 days.

[0083] Example 15 A catalyst composition was prepared in the same manner as in Example 3, except that the phosphine imide catalyst (B) was changed to the above-mentioned exemplary compound 4, and then stored at a storage temperature of 2°C for 20 days.

[0084] Comparative Example 4 A catalyst composition was prepared and then stored in the same manner as in Example 14, except that the alkylaluminum compound (C1) was not used.

[0085] Comparative Example 5 A catalyst composition was prepared in the same manner as in Example 14, except that the phosphine imide catalyst (B) was changed to the following comparative compound 1, and then stored.

[0086]

[0087] Comparative Example 6 A catalyst composition was prepared in the same manner as in Example 12, except that the phosphine imide catalyst (B) was changed to the above-mentioned comparative compound 1, and then stored.

[0088] Comparative Example 7 A catalyst composition was prepared in the same manner as in Comparative Example 5, except that the alkylaluminum compound (C1) was not used, and then stored.

[0089] Example 16 A catalyst composition was prepared and then stored in the same manner as in Example 4, except that the organic solvent (A1) was changed from decalin to cyclohexane.

[0090] [Evaluation] The catalyst compositions obtained in the examples and comparative examples were evaluated as follows.

[0091] <<Solubility of Phosphine Imide Catalyst>> The catalyst compositions obtained in each Example and Comparative Example were visually evaluated for the dissolution of the phosphine imide catalyst. A was given for complete dissolution, B for a small amount of insoluble matter that was observed but not problematic for practical use, and C for a large amount of insoluble matter. The evaluation results are shown in Table 1.

[0092] <<Stability after 20 days>> In each example and comparative example, immediately after preparing the catalyst composition, the catalyst composition was used to obtain a copolymer of norbornene and ethylene as follows. The catalyst composition was then stored for 20 days at the storage temperature shown in Table 1, and then a copolymer of norbornene and ethylene was obtained using the stored catalyst composition as follows.

[0093] Decalin and 2-norbornene (75 mmol) were placed in a thoroughly dried 150 mL stainless steel autoclave containing a stirrer. Triisobutylaluminum (manufactured by Tosoh Finechem Co., Ltd.) was then added, and the autoclave was heated to 90°C. A catalyst composition of the catalyst species listed in Table 1, prepared using decalin, was added so that the catalyst amount was 0.5 μmol. Before the start of polymerization, a total of 500 μmol of triisobutylaluminum and 1.5 μmol of N-methyldialkylammonium tetrakis(pentafluorophenyl)borate (alkyl: C14 to C18 (average: C17.5) (manufactured by Tosoh Finechem Corporation) were added to the autoclave. Next, ethylene pressure of 0.9 MPa was applied, and the polymerization initiation point was determined to be 30 seconds later. The total amount of the monomer solution immediately before the application of ethylene pressure was 80 mL. 15 minutes after the start of polymerization, the ethylene supply was stopped, and the pressure was carefully returned to normal pressure. The reaction was then terminated by adding isopropyl alcohol to the reaction solution. The polymerization solution was then introduced 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 then vacuum-dried at 110°C for 12 hours to obtain a copolymer of norbornene and ethylene.

[0094] In each example and comparative example, the amount of cyclic olefin copolymer produced was evaluated. When the amount of copolymer obtained using the catalyst composition stored for 20 days after preparation was more than 90% of the amount of copolymer obtained when the catalyst composition was used immediately after preparation, the evaluation was A; when the amount of copolymer obtained was more than 50% but not more than 90%, the evaluation was B; when the amount of copolymer obtained was more than 1% but not more than 50%, the evaluation was C; and when the amount of copolymer obtained was 1% or less, the evaluation was D. The evaluation results are shown in Table 1.

[0095]

[0096] As can be seen from Table 1, in Examples 1 to 16, the phosphine imide catalyst was sufficiently dissolved and showed good stability after 20 days. Comparisons of Examples 1 to 11 with Comparative Examples 1 and 2, Examples 12 and 13 with Comparative Example 3, and Examples 14 and 15 with Comparative Example 4, all of which used the same phosphine imide catalyst, reveal that the phosphine imide catalyst is insoluble in decalin unless an alkyl aluminum compound is used. Furthermore, Examples 5 and 6 reveal that partial use of a halogenated solvent or an aromatic solvent is effective. Furthermore, a comparison of Example 12 with Example 13, in which the Al / metal ratio was set to 250, which is within the most preferred range, yielded better evaluation results in terms of phosphine imide catalyst solubility than Example 12 (Al / metal: 50). Furthermore, Example 16 differs from Example 4 only in the organic solvent (A1), and yielded evaluation results equivalent to those of Example 4. From these results, it can be inferred that equivalent effects can be obtained if the organic solvent (A1) falls within the specified range. In Comparative Examples 5 to 7, the phosphine imide catalysts used had an ethyl group, not a tertiary alkyl group, bonded to the phosphorus atom of the phosphine imide group, and were insoluble in decalin even when an alkyl aluminum compound was used.

Claims

1. A method for storing a catalyst composition, comprising adding an alkylaluminum compound (C1), or an alkylaluminum compound (C1) and an organoboron compound (C2), to at least one of an organic solvent (A1) consisting of a compound which consists only of carbon and hydrogen atoms and does not contain an aromatic group in its molecular structure, and an organic solvent (A2) consisting of a compound which consists only of carbon, hydrogen and halogen atoms and does not contain an aromatic group in its molecular structure, and storing the catalyst composition obtained by dissolving a phosphine imide catalyst (B) in which a tertiary alkyl group is bonded to the phosphorus atom of the phosphine imide group.

2. The method for storing a catalyst composition described in claim 1, wherein the phosphine imide catalyst (B) is a catalyst for polymerization of a cyclic olefin copolymer.

3. A method for storing a catalyst composition described in claim 1, wherein the alkyl aluminum compound (C1) is added so that the ratio of the number of moles of aluminum atoms to the number of moles of metal atoms in the phosphine imide catalyst (B) is 1 to 1,000.

4. A method for storing a catalyst composition as described in claim 1, wherein, in the case of adding the alkylaluminum compound (C1) and the organoboron compound (C2), the alkylaluminum compound (C1) is contacted with the organoboron compound (C2) before the phosphine imide catalyst (B) is contacted with the organoboron compound (C2).

5. The method for storing a catalyst composition according to claim 1, further comprising the step of: adding, to at least one of said organic solvents (A1) and (A2), an organic solvent (A3) consisting of a compound containing an aromatic group in its molecular structure, such that the mass ratio of said organic solvent (A3) to at least one of said organic solvents (A1) and (A2) is 0.1 / 99.9 to 10.0 / 90.

0.

6. The phosphine imide catalyst (B) is represented by the following formula (a1): 【Chemistry 1】 In formula (a1), M is a transition metal of Group 4 of the periodic table, X is an organic substituent having 1 to 20 carbon atoms which may contain a heteroatom, or a halogen atom, L 1 is a group represented by formula (a1a) below, and L 2 is a group represented by formula (a1b) below: 【Chemistry 2】 In formula (a1a), R a1 to R a5 may be the same or different and each independently represent a hydrogen atom, an organic substituent having 1 to 20 carbon atoms which may contain a heteroatom, or an inorganic substituent, and two adjacent groups among R a1 to R a5 on a 5-membered ring may be bonded to each other to form a ring; In formula (a1b), R a6 to R a8 may be the same or different, and each independently represents a tertiary alkyl group having 4 to 20 carbon atoms which may contain a heteroatom. The method for storing a catalyst composition according to any one of claims 1 to 5, wherein the catalyst composition is a compound represented by the formula:

7. A method for storing a catalyst composition described in any one of claims 1 to 5, wherein the phosphine imide catalyst (B) is a compound represented by the following general formula (1): 【Chemistry 3】 [In general formula (1), M represents a transition metal of Group 4 of the periodic table, X represents an organic substituent having 1 to 20 carbon atoms which may contain a heteroatom or a halogen atom, R a6 to R a8 each independently represent a tertiary alkyl group having 4 to 20 carbon atoms which may contain a heteroatom, which may be the same or different, R represents one or more selected from an alkyl group, a cycloalkyl group, a halogenated alkyl group, an aryl group, a halogenated aryl group, an alkylsilyl group, and an arylsilyl group, and n represents an integer of 1 to 5.] 8. The method for storing a catalyst composition according to claim 7, wherein R in the general formula (1) contains a fluorine atom.

Images