Method for storing catalyst compositions

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

[Technical Field]

[0001] The present invention relates to a method for preparing a catalyst composition containing a phosphineimide catalyst and a method for storing the catalyst composition. [Background technology]

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

[0003] However, the method described in Non-Patent Document 1 has the problem that copolymers of cyclic olefins and ethylene cannot be produced 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 resulting copolymer, and copolymers with excessively high molecular weight are often obtained. In addition, polymerization using a highly active catalyst can easily generate polyethylene-like impurities. Therefore, in order to solve such problems, the applicant has proposed carrying out copolymerization using a specific phosphine imide catalyst (see Patent Document 1).

[0004] On the other hand, as a technology related to the production of organometallic complex solutions as polymerization catalysts for olefin polymers, a method for producing organometallic complex solutions has been proposed that includes a contact step in which an organometallic complex is brought into contact with an alkylaluminum compound and a predetermined low-polarity solvent (see Patent Document 2). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2022 / 004529 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2018-165309 [Non-Patent Document]

[0006] [Non-Patent Document 1] Incoronata, Tritto et al., Coordination Chemistry Reviews, 2006, Vol. 250, pp. 212-241 [Summary of the Invention] [Problems to be Solved by the Invention]

[0007] Phosphine imide catalysts dissolve in aromatic hydrocarbon solvents such as toluene and xylene. However, these aromatic hydrocarbon solvents have a small boiling point difference from norbornene, which is a monomer of cyclic olefin copolymers. Therefore, after polymerization, it is difficult to separate unreacted monomers by distillation or the like. In addition, since aromatic hydrocarbons generally have strong toxicity, it is preferable to avoid using them as much as possible. Therefore, an aliphatic hydrocarbon solvent is desired as the solvent for phosphine imide catalysts. However, phosphine imide catalysts are hardly soluble in aliphatic solvents such as hexane and decalin. Therefore, until now, aliphatic hydrocarbon solvents could not be used for the preparation and storage of phosphine imide catalyst compositions. In addition, Patent Document 2 describes that an organometallic complex can be dissolved in a low-polarity solvent by adding an alkylaluminum compound to the low-polarity solvent. However, a compound corresponding to a phosphine imide catalyst is not described as an organometallic complex. Further, the phosphine imide catalyst has a P=N double bond in the phosphine imide group, and it is presumed that the P=N double bond easily reacts with an alkylaluminum compound. Therefore, when dissolving the phosphine imide catalyst in an aliphatic hydrocarbon solvent, it is difficult to consider adding an alkylaluminum compound and storing and using the obtained catalyst solution during the period until the production of an olefin polymer or an olefin copolymer is completed.

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

Means for Solving the Problems

[0009] As a result of intensive studies to solve the above 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 completed the present invention.

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

[0011] (2) A method for preparing the catalyst composition according to (1), wherein the alkylaluminum compound (C1) is added such that the ratio of the number of moles of aluminum atoms to the number of moles of metal atoms in the phosphineimide catalyst (B) is 1 to 1000.

[0012] (3) A method for preparing the catalyst composition according to (1) or (2), wherein, when the alkylaluminum compound (C1) and the organoboron compound (C2) are added, the alkylaluminum compound (C1) and the organoboron compound (C2) are brought into contact before the phosphineimide catalyst (B) and the organoboron compound (C2) come into contact.

[0013] (4) A method for preparing a catalyst composition according to any one of (1) to (3), wherein, in addition to at least one of the organic solvents (A1) and (A2), an organic solvent (A3) comprising a compound containing an aromatic group in its molecular structure is used such 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 phosphineimide catalyst (B) is defined by the following formula (a1): [ka] (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 heteroatoms, or a halogen atom, L 1is a group represented by the following formula (a1a), and L 2 is a group represented by the following formula (a1b), [Chemical formula] In formula (a1a), R a1 ~R a5 are each independently, may be the same or different, and are a hydrogen atom, an organic substituent having 1 to 20 carbon atoms which may contain a hetero atom, or an inorganic substituent. Among R a1 ~R a5 two adjacent groups on the 5-membered ring may be bonded to each other to form a ring. In formula (a1b), R a6 ~R a8 are each independently, may be the same or different, and are all tertiary alkyl groups having 4 to 20 carbon atoms which may contain a hetero atom.) A method for preparing the catalyst composition according to any one of (1) to (4) above, which is a compound represented by

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

[0016] [Chemical formula] [In general formula (1), M represents a Group 4 transition metal of the periodic table, X represents an organic substituent having 1 to 20 carbon atoms which may contain a hetero atom or a halogen atom, R a6 ~R a8 are each independently, may be the same or different, and all represent tertiary alkyl groups having 4 to 20 carbon atoms which may contain a hetero atom. 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. n represents an integer of 1 to 5.]

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

[0018] (8) A method for preparing the catalyst composition according to any one of (1) to (7), wherein the phosphineimide catalyst (B) is a catalyst for polymerization of 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 only of carbon and hydrogen atoms and not containing an aromatic group in its molecular structure, and an organic solvent (A2) consisting only of carbon, hydrogen, and halogen atoms and not containing an aromatic group in its molecular structure, and dissolving a phosphineimide catalyst (B) in which a tertiary alkyl group is bonded to the phosphorus atom of a phosphineimide group, and storing the resulting catalyst composition.

[0020] (10) A method for storing the catalyst composition according to (9), wherein the phosphineimide catalyst (B) is a catalyst for polymerization of a cyclic olefin copolymer. [Effects of the Invention]

[0021] According to the present invention, a method for preparing a catalyst composition containing a phosphineimide catalyst is provided, which involves using an aliphatic hydrocarbon solvent as the solvent, and a method for storing the catalyst composition in which the phosphineimide catalyst is dissolved in the aliphatic hydrocarbon solvent. [Modes for carrying out the invention]

[0022] <Method for preparing catalyst compositions> The method for preparing the catalyst composition of this embodiment involves dissolving a phosphineimide catalyst (B), in which a tertiary alkyl group is bonded to the phosphorus atom of a phosphineimide group, in at least one of an organic solvent (A1) consisting of a compound comprising only carbon and hydrogen atoms and not containing an aromatic group in its molecular structure, and an organic solvent (A2) consisting of a compound comprising only carbon, hydrogen, and halogen atoms and not containing an aromatic group in its molecular structure, by adding an alkylaluminum compound (C1), or an alkylaluminum compound (C1) and an organoboron compound (C2).

[0023] In short, the method for preparing the catalyst composition of this embodiment is to prepare the catalyst composition by dissolving a phosphineimide catalyst in an aliphatic hydrocarbon solvent. Here, the organic solvent (A1) consisting of a compound comprising only carbon and hydrogen atoms and not containing aromatic groups in its molecular structure, and the organic solvent (A2) consisting of a compound comprising only carbon, hydrogen, and halogen atoms and not containing aromatic groups in its molecular structure, are aliphatic hydrocarbon solvents. As described above, phosphineimide catalysts are poorly soluble in aliphatic hydrocarbon solvents, but in this embodiment, dissolution of the phosphineimide catalyst in the aliphatic hydrocarbon solvent is achieved by adding an alkylaluminum compound (C1), or an alkylaluminum compound (C1) and an organoboron compound (C2). Furthermore, in this embodiment, by using an aliphatic hydrocarbon solvent, the problems that arise when using an aromatic hydrocarbon solvent, as described above, can be resolved. That is, because the boiling point difference between norbornene and the aliphatic hydrocarbon solvent is large, separation after polymerization is easy. In addition, aliphatic hydrocarbon solvents are less toxic than aromatic hydrocarbon solvents. Furthermore, the stability of the catalyst composition can be improved by optimizing the structure of the phosphineimide catalyst, thereby suppressing the deactivation of the phosphineimide catalyst and obtaining a catalyst solution that can be stored stably. Furthermore, in the catalyst composition obtained in this embodiment, the phosphineimide catalyst (B) can be used as a polymerization catalyst for cyclic olefin copolymers. Therefore, this catalyst composition is useful for the polymerization of cyclic olefin copolymers. More specifically, this catalyst composition is preferably used when copolymerizing norbornene and ethylene to obtain a cyclic olefin copolymer. Furthermore, not all phosphineimide catalysts dissolve in aliphatic hydrocarbon solvents by adding alkylaluminum compounds (C1), etc. In other words, the phosphineimide catalyst targeted in this embodiment is a phosphineimide catalyst in which a tertiary alkyl group is bonded to the phosphorus atom of the phosphineimide group, and other phosphineimide catalysts are not targeted. The following describes in detail each component used in the method for preparing the catalyst composition of this embodiment.

[0024] [Organic solvent (A1)] Organic solvent (A1) is an organic solvent consisting of compounds that consist only of carbon and hydrogen atoms and do not contain aromatic groups in their molecular structure. Examples of organic solvent (A1) include aliphatic hydrocarbon solvents having 5 to 18 carbon atoms. Furthermore, the compounds constituting organic solvent (A1) may have unsaturated bonds and may contain rings other than aromatic rings. Examples include hexane, cyclohexane, methylcyclohexane, isooctane, isododecane, and decalin, with isododecane and decalin being preferred. Furthermore, organic solvent (A1) may be used alone or in combination of two or more types.

[0025] [Organic solvent (A2)] Organic solvent (A2) is an organic solvent consisting of compounds comprising only carbon atoms, hydrogen atoms, and halogen atoms, and which do not contain aromatic groups in their molecular structure. Examples of organic solvent (A2) include compounds exemplified in organic solvent (A1) above in which the hydrogen atoms are replaced with halogen atoms. Chlorine is preferred as the halogen atom. The substitution position of the halogen atom is arbitrary. Examples of organic solvent (A2) include dichloromethane and 1,1,2,2-tetrachloroethane. Among these, dichloromethane is preferred. Furthermore, organic solvent (A2) may be used alone or in combination of two or more types.

[0026] Furthermore, from the viewpoint of having a large boiling point difference with norbornene, which is the monomer of the cyclic olefin copolymer, organic solvent (A1) is preferred over organic solvent (A2). Furthermore, organic solvents (A1) and (A2) may be used individually or in combination. When organic solvents (A1) and (A2) are used in combination, it is preferable that the amount of organic solvent (A2) be 50% by mass or less of the total amount of organic solvents (A1) and (A2).

[0027] [Organic solvent (A3)] Organic solvent (A3) is an organic solvent consisting of a compound containing an aromatic group in its molecular structure. As described above, the main objective of this embodiment is to use an aliphatic hydrocarbon solvent as the solvent, but an organic solvent consisting of a compound containing an aromatic group may also be included in small amounts. That is, organic solvent (A3) is any solvent and is used in addition to at least one of organic solvents (A1) and (A2). Furthermore, the mass ratio of organic solvent (A3) to at least one of organic solvents (A1) and (A2) is set to 0.1 / 99.9 to 10.0 / 90.0. Here, when organic solvent (A1) or organic solvent (A2) is used alone, the above mass ratio is the mass ratio of organic solvent (A3) to organic solvent (A1), or the mass ratio of organic solvent (A3) to organic solvent (A2). Furthermore, when organic solvent (A1) and organic solvent (A2) are used in combination, the above mass ratio is the mass ratio of organic solvent (A3) to the sum of organic solvents (A1) and (A2).

[0028] Examples of organic solvents (A3) include toluene, xylene, and tetralin, with toluene being preferred among them.

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

[0030] The phosphineimide catalyst (B) used in the manufacturing method of this embodiment is preferably a compound represented by the following formula (a1).

[0031] [ka]

[0032] In formula (a1), M is a transition metal of Group 4 of the periodic table, and Ti is particularly preferred due to its ease of availability and manufacture, as well as its catalytic activity. X is an organic substituent having 1 to 20 carbon atoms, which may contain heteroatoms, or a halogen atom. L 1 L is a group represented by the following formula (a1a), 2 This is a group represented by the following formula (a1b).

[0033] [ka]

[0034] In formula (a1a), R a1 ~R a5 These are, independently, organic substituents having 1 to 20 carbon atoms, which may be the same or different, and may contain hydrogen atoms or heteroatoms, or inorganic substituents. a1 ~R a5 Two adjacent groups on one of the five-membered rings may bond to each other to form a ring. In formula (a1b), R a6 ~R a8 These are tertiary alkyl groups having 4 to 20 carbon atoms, which may be identical or different, and may each contain a heteroatom.

[0035] In formula (a1), M represents a transition metal of Group 4 of the periodic table, specifically Ti, Zr, or Hf. Ti is preferred as M. In formula (a1), X is an organic substituent having 1 to 20 carbon atoms, which may contain a heteroatom, or a halogen atom. For organic substituents having 1 to 20 carbon atoms, which may contain heteroatoms, the type of heteroatom is not particularly limited as long as it does not hinder 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 formation reaction of the compound represented by formula (a1) above. Examples include alkyl groups having 1 to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, cycloalkyl groups having 3 to 20 carbon atoms, aliphatic acyl groups having 2 to 20 carbon atoms, benzoyl groups, α-naphthylcarbonyl groups, β-naphthylcarbonyl groups, aromatic hydrocarbon groups having 6 to 20 carbon atoms, aralkyl groups having 7 to 20 carbon atoms, trialkylsilyl groups having 3 to 20 carbon atoms, triarylsilyl groups having 3 to 20 carbon atoms, monosubstituted amino groups substituted with hydrocarbon groups having 1 to 20 carbon atoms, and disubstituted amino groups substituted with hydrocarbon groups 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, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, methoxy group, ethoxy group, n-propyloxy group, isopropyloxy group, n-butyloxy group, isobutyloxy group, sec-butyloxy group, tert-butyloxy group, acetyl group, propionyl group, butanoyl group, phenyl group, trimethylsilyl group, triethylsilyl group, tert-butyldimethylsilyl group, triphenylsilyl group, and trispentafluorophenylsilyl group are more preferred.

[0039] X is preferably a halogen atom, more preferably a chlorine atom, and more preferably a bromine atom, with chlorine atoms being particularly preferred.

[0040] In formula (a1a), R a1 ~R a5Each of these is an organic substituent having 1 to 20 carbon atoms, which may be the same or different, and may contain hydrogen atoms or heteroatoms, or an inorganic substituent. a1 ~R a5 Two adjacent groups on one of the five-membered rings may bond to each other to form a ring. R a1 ~R a5 Specific and preferred examples of organic substituents having 1 to 20 carbon atoms, which may contain heteroatoms, are the same as the specific and preferred examples of organic substituents having 1 to 20 carbon atoms, which may contain heteroatoms, for X. Among them, R a1 ~R a5 As an organic substituent having 1 to 20 carbon atoms, which may contain heteroatoms, -(CH2) n The substituent represented by R is preferred from the viewpoint of high catalytic activity and suppression of polyethylene-like impurities. Furthermore, R a1 ~R a5 Only one of the following is -(CH2) n The substituent is represented by R, and it is particularly preferable that the other four atoms are hydrogen atoms. Note that -(CH2) n In R, R represents one or more selected from a hydrogen atom, alkyl group, cycloalkyl group, alkyl halide, aryl group, aryl halide, alkylsilyl group, and arylsilyl group, and n represents an integer from 1 to 5.

[0041] Examples of alkyl groups for R include alkyl groups having 1 to 5 carbon atoms, with alkyl groups having 1 to 4 carbon atoms being preferred. Specific examples of alkyl groups for R include methyl group, ethyl group, isopropyl group, n-butyl group, and tert-butyl group, with tert-butyl group being preferred among them. Examples of cycloalkyl groups for 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 cycloalkyl groups for R include cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl group, with cyclohexyl group being preferred among them. The alkyl halide for R is an alkyl group having at least one halogen element as a substituent, and includes alkyl groups having 1 to 7 carbon atoms, preferably alkyl groups having 1 to 5 carbon atoms, and more preferably alkyl halide groups having 1 to 3 carbon atoms. Furthermore, fluorine and chlorine are preferred halogen elements in the alkyl halide for R. Specific examples of alkyl halide for R include monofluoromethyl group, difluoromethyl group, trifluoromethyl group, 2,2,2-trifluoroethyl group, pentafluoroethyl group, heptafluoropropyl group, and trichloromethyl group, with trifluoromethyl group being particularly preferred. Examples of aryl groups for R include aryl groups having 6 to 20 carbon atoms, with aryl groups having 6 to 10 carbon atoms being preferred, and aryl groups having 7 to 8 carbon atoms being more preferred. Specific examples of aryl groups as R include phenyl, tolyl, xylyl, mesityl, naphthyl, aralkyl, and biphenyl groups, with the phenyl group being preferred among them. Examples of aryl halides as R include aryl groups having at least one halogen element as a substituent, with aryl groups having 6 to 20 carbon atoms, preferably aryl groups having 6 to 10 carbon atoms, and more preferably aryl groups having 7 to 8 carbon atoms. Furthermore, fluorine and chlorine are preferred halogen elements in the aryl halide as R. Specific examples of aryl halides as R include 4-fluorophenyl group, 2,4-difluorophenyl group, 2,4,6-trifluorophenyl group, 2,3,6-trifluorophenyl group, perfluorophenyl group (-C6F5), perfluorobiphenyl group, and perchlorophenyl group (-C6Cl5), with perfluorophenyl group (-C6F5) being particularly preferred. Examples of alkylsilyl groups for R include trialkylsilyl groups such as trimethylsilyl group and triethylsilyl group, with trimethylsilyl group being preferred. Examples of arylsilyl groups for R include triarylsilyl groups such as triphenylsilyl group and trispentafluorophenylsilyl group, with triphenylsilyl group being preferred. Among these R groups, hydrogen atoms, alkyl groups with a large number of carbon atoms (3 to 12 carbon atoms), or fluorine atoms are preferred. For example, hydrogen atoms, tert-butyl groups, phenyl groups, perfluorophenyl groups (-C6F5), and trimethylsilyl groups are particularly preferred.

[0042] -(CH2) n In R, n represents an integer between 1 and 5, preferably between 1 and 3.

[0043] The inorganic substituent is not particularly limited as long as it is a group that does not inhibit the formation reaction of the compound represented by formula (a1) above. Specific examples of inorganic substituents include halogen atoms, nitro groups, unsubstituted amino groups, and cyano groups.

[0044] In formula (a1b), R a6 ~R a8 These are tertiary alkyl groups having 4 to 20 carbon atoms, which may be identical or different, and may each contain a heteroatom. R a6 ~R a8 The tertiary alkyl group having 4 to 20 carbon atoms, which may contain heteroatoms, may be an acyclic tertiary alkyl group or a cyclic tertiary alkyl group. Examples of acyclic tertiary alkyl groups include the tert-butyl group, and examples of cyclic tertiary alkyl groups include the adamantyl group. R a6 ~R a8 All of these are tertiary alkyl groups having 4 to 20 carbon atoms, but they may all be different tertiary alkyl groups, preferably two of the three are the same tertiary alkyl group, and more preferably all are the same tertiary alkyl group.

[0045] A preferred example of a base represented by formula (a1b) is、 -N=P(tert-Bu)3 but Listed 。

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

[0047] [ka]

[0048] In the manufacturing method of this embodiment, the phosphineimide catalyst (B) used is preferably a compound represented by the general formula (1) below, among the compounds represented by the formula (a1) above.

[0049] [ka] [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 heteroatoms, or a halogen atom, R a6 ~R a8 Each of these independently represents a tertiary alkyl group having 4 to 20 carbon atoms, which may be the same or different, and may each contain a heteroatom; R represents one or more selected from a hydrogen atom, alkyl group, cycloalkyl group, alkyl halide, aryl group, aryl halide, alkylsilyl group, and arylsilyl group; and n represents an integer from 1 to 5.

[0050] The compound represented by general formula (1) is, in the compound represented by formula (a1), L 1 The group is represented by the above formula (a1a), and L 2 This corresponds to a compound in which the group is represented by formula (a1b). And, among the groups represented by formula (a1a), R a1 ~R a5Only one of the following is -(CH2) n R is a substituent, and the other four are hydrogen atoms. In general formula (1), M, X, R a6 ~R a8 , and -(CH2) n In R, R and n are the same as those in the compound represented by formula (a1) above, and the preferred embodiments and examples are also the same. Therefore, their explanations are omitted.

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

[0052] [ka]

[0053] [ka]

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

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

[0056] Specific examples of alkylaluminum compounds (C1) include trialkylaluminum 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. Furthermore, alkylaluminum compounds (C1) may be used individually or in combination of two or more.

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

[0058] [Organoboron compounds (C2)] In this embodiment, the organoboron compound (C2) is present together with the alkylaluminum compound (C1), and the organoboron compound (C2) is not added alone. The organoboron compound is a compound that generates a cationic transition metal compound through reaction with a catalyst having a phosphineimide group. Preferred specific examples of organoboron compounds 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 phosphineimide catalyst (B) in the organic solvent (A1) or organic solvent (A2), an alkylaluminum compound (C1), or an alkylaluminum compound (C1) and an organoboron compound (C2) are added. From the viewpoint of stability, it is preferable to add the alkylaluminum compound (C1) alone rather than adding the alkylaluminum compound (C1) and the organoboron compound (C2). Furthermore, the order in which each component is added to the organic solvent (A1) or organic solvent (A2) is not relevant. However, when adding the alkylaluminum compound (C1) and the organoboron compound (C2), that is, when using both the alkylaluminum compound (C1) and the organoboron compound (C2), it is preferable to bring the alkylaluminum compound (C1) and the organoboron compound (C2) into contact before the phosphineimide catalyst (B) comes into contact with the organoboron compound (C2). The organoboron compound (C2) contains water, and if this water comes into contact with the phosphineimide catalyst (B), the catalyst may be deactivated. Therefore, the organoboron compound (C2) is brought into contact with the alkylaluminum compound (C1) before it comes into contact with the phosphineimide catalyst (B). This prevents the deactivation of the catalyst because the aluminum in the alkylaluminum compound captures the water. In other words, the alkylaluminum compound also functions as a dehydrating agent. On the other hand, even when only an alkylaluminum compound (C1) is added without an organoboron compound (C2), it is preferable to first mix the alkylaluminum compound (C1) with the solvent and then add the catalyst in order to remove any trace amounts of water present, as described above. In this case as well, the alkylaluminum compound functions as a dehydrating agent. Furthermore, it is preferable to add and mix each component at a temperature of -10 to 40°C.

[0060] <Storage method for catalyst compositions> 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 comprising only carbon and hydrogen atoms and not containing an aromatic group in its molecular structure, and an organic solvent (A2) consisting of a compound comprising only carbon, hydrogen, and halogen atoms and not containing an aromatic group in its molecular structure, and then dissolving a phosphineimide catalyst (B), in which a tertiary alkyl group is bonded to the phosphorus atom of a phosphineimide group, and storing the resulting catalyst composition. In the method for storing the catalyst composition of this embodiment, each component is the same as the components in the method for preparing the catalyst composition of this embodiment described above, the preparation method is the same, and furthermore, the preferred embodiment is also the same. That is, in the storage method of this embodiment, the catalyst composition obtained by the method for preparing the catalyst composition of this embodiment described above is stored in its original state. This allows for suppression of deactivation of the phosphineimide catalyst and enables stable storage.

[0061] As mentioned above, the phosphineimide catalyst (B) is poorly soluble in aliphatic hydrocarbon solvents, but it can be dissolved by adding alkylaluminum compounds (C1), etc. Therefore, even when using aliphatic hydrocarbon solvents, the phosphineimide catalyst can be stored stably while suppressing deactivation. Specifically, the phosphineimide catalyst (B) can be stored in a container such as a tank with an organic solvent (A1) or organic solvent (A2), an alkylaluminum compound (C1), or an alkylaluminum compound (C1) and an organoboron compound (C2). Since these components can be stored in a single tank, the number of tanks can be reduced, which can lead to process simplification.

[0062] In this embodiment, the storage temperature of the catalyst composition is preferably -10 to 40°C. Lower temperatures are preferable to suppress the reactions between components in the catalyst composition.

[0063] Furthermore, when storing the catalyst composition, it is preferable to protect it from light by using a light-shielding container or tank.

[0064] In the storage method for the catalyst composition of this embodiment, the phosphineimide catalyst (B) can be used as a polymerization catalyst for cyclic olefin copolymers. Therefore, the catalyst composition according to this embodiment is useful for the polymerization of cyclic olefin copolymers. More specifically, as described above, the catalyst composition is preferably used when copolymerizing norbornene and ethylene to obtain a cyclic olefin copolymer. Furthermore, in the storage method of this embodiment, the deactivation of the phosphineimide catalyst (B) is suppressed and it is stored stably, so even after storage, it can be used directly for the polymerization of cyclic olefin copolymers. [Examples]

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

[0066] [Example 1] Under the mixing temperatures shown in Table 1, an alkylaluminum compound (C1) was dissolved in decahydronaphthalene (decalin) as an organic solvent (A1), and then a phosphineimide catalyst (B) (example compound 1 described above) was mixed in to prepare a catalyst composition. After preparation, the obtained 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 Co., Ltd.) 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 phosphineimide catalyst is expressed as "Al / metal" and is shown in Table 1.

[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 phosphineimide catalyst (B) (Al / metal) was 50, and the composition was then stored.

[0068] [Example 3] Under the mixing temperatures shown in Table 1, the same alkylaluminum compound (C1) as in Example 1 was dissolved in decalin as the organic solvent (A1). To this solution, N-methyldialkylammonium tetrakis(pentafluorophenyl)borate (alkyl: C14-C18 (average: C17.5) (manufactured by Tosoh Finechem Co., Ltd.) was added as the organoboron compound (C2). Finally, the catalyst composition was prepared by mixing in the phosphineimide catalyst (B) (example compound 1 described above). The 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 phosphineimide catalyst (B) (Al / metal) was 250, and the composition was then stored.

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

[0071] [Example 6] A catalyst composition was prepared in the same manner as in Example 4, except that toluene was used as organic solvent (A3) in addition to organic solvent (A1), i.e., organic solvent (A1) and organic solvent (A3) were used in combination, and then stored. At this time, the mass ratio of organic solvent (A3) to 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 phosphineimide catalyst (B) (Al / metal) was 500, and the composition was then 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 phosphineimide catalyst (B) (Al / metal) was 900, and the composition was then 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 phosphineimide catalyst (B) (Al / metal) was 1200, and the composition was then 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. The composition was 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 an 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 an 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 replaced with example compound 3 described above. The composition was 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 phosphineimide catalyst (B) was replaced with example compound 3 described above, and 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 phosphineimide catalyst (B) (Al / metal) was 250. The 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 phosphineimide catalyst (B) was replaced with example compound 3 above, and the alkylaluminum compound (C1) was not used. The 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 phosphineimide catalyst (B) was replaced with example compound 4 described above. The composition was 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 replaced with example compound 4 described above. The composition was then stored at a storage temperature of 2°C for 20 days.

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

[0085] [Comparative Example 5] A catalyst composition was prepared in the same manner as in Example 14, except that the phosphineimide catalyst (B) was replaced with comparative compound 1 described below, and then stored.

[0086] [ka]

[0087] [Comparative Example 6] A catalyst composition was prepared in the same manner as in Example 12, except that the phosphineimide catalyst (B) was replaced with 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 an alkylaluminum compound (C1) was not used, and then stored.

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

[0090] [evaluation] The catalyst compositions obtained in each example and comparative example were evaluated as follows.

[0091] Solubility of phosphineimide catalysts The catalyst compositions obtained in each example and comparative example were visually evaluated to determine whether the phosphineimide catalyst was dissolved. A was used to indicate sufficient dissolution, B to indicate trace amounts of insoluble matter but no practical problems, and C to indicate large amounts 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, a copolymer of norbornene and ethylene was obtained using the catalyst composition as follows. Then, the catalyst composition was stored for 20 days at the storage temperature shown in Table 1, and thereafter, a copolymer of norbornene and ethylene was obtained using the stored catalyst composition as follows.

[0093] Decalin and 2-norbornene (75 mmol) were added to a well-dried 150 mL stainless steel autoclave containing a stirring bar. Next, triisobutylaluminum (manufactured by Tosoh Finechem Co., Ltd.) was added, and the autoclave was heated to 90°C. Catalyst compositions of the catalyst species listed in Table 1, prepared using decalin, were added in a catalyst amount of 0.5 μmol. A total of 500 μmol of triisobutylaluminum and 1.5 μmol of N-methyldialkylammonium tetrakis(pentafluorophenyl) borate (alkyl: C14-C18 (average: C17.5) (manufactured by Tosoh Finechem Co., Ltd.) were added to the autoclave before polymerization initiation. Then, an ethylene pressure of 0.9 MPa was applied, and the polymerization initiation point was set at 30 seconds. Furthermore, the total volume of the monomer solution immediately before applying ethylene pressure was 80 mL. Fifteen minutes after the start of polymerization, the ethylene supply was stopped, and the pressure was carefully returned to atmospheric pressure. Then, isopropyl alcohol was added to the reaction solution to stop the reaction. Subsequently, the polymerization solution was added to a mixed solvent of 300 mL of acetone, 200 mL of methanol or isopropyl alcohol, and 5 mL of hydrochloric acid to precipitate the copolymer. The copolymer was recovered by suction filtration, washed with acetone and methanol, and 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. The amount of copolymer obtained using a catalyst composition stored for 20 days after preparation was evaluated as follows: A if the amount of copolymer obtained using the catalyst composition immediately after preparation was more than 90% of the amount of copolymer obtained using the prepared catalyst composition; B if the amount of copolymer obtained was more than 50% but 90% or less; C if the amount of copolymer obtained was more than 1% but 50% or less; and D if the amount of copolymer obtained was 1% or less. The evaluation results are shown in Table 1.

[0095] [Table 1]

[0096] As shown in Table 1, in Examples 1 to 16, the phosphineimide catalyst dissolved sufficiently and its stability after 20 days was also good. Comparisons of Examples 1-11 with Comparative Examples 1-2, Examples 12-13 with Comparative Example 3, and Examples 14-15 with Comparative Example 4, all using the same phosphineimide catalyst, show that the phosphineimide catalyst is insoluble in decalin without the use of an alkylaluminum compound. Furthermore, Examples 5 and 6 show that the catalyst is effective even when halogenated solvents or aromatic solvents are used in part. Furthermore, a comparison of Example 12 and Example 13 showed that Example 13, in which the Al / metal ratio was set to 250, which falls within the most preferred numerical range, yielded better evaluation results in terms of phosphineimide catalyst solubility than Example 12 (Al / metal: 50). Furthermore, Example 16 differed from Example 4 only in the organic solvent (A1), and obtained 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. Furthermore, Comparative Examples 5-7 were phosphineimide catalysts in which an ethyl group, rather than a tertiary alkyl group, was bonded to the phosphorus atom of the phosphineimide group, and they were insoluble in decalin even when alkylaluminum compounds were 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 only of carbon and hydrogen atoms, having 5 to 18 carbon atoms and not containing aromatic groups in its molecular structure, and an organic solvent (A2) consisting only of carbon, hydrogen, and halogen atoms and not containing aromatic groups in its molecular structure, to a phosphineimide catalyst (B) in which a tertiary alkyl group is bonded to the phosphorus atom of a phosphineimide group, and storing the resulting catalyst composition.

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

3. The method for storing the catalyst composition according to Claim 1, wherein the phosphineimide catalyst (B) contains metal atoms, and the alkylaluminum compound (C1) is added such that the ratio of the number of moles of aluminum atoms to the number of moles of metal atoms in the phosphineimide catalyst (B) is between 1 and 1000.

4. A method for storing a catalyst composition according to claim 1, wherein, when the alkylaluminum compound (C1) and the organoboron compound (C2) are added, the alkylaluminum compound (C1) and the organoboron compound (C2) are brought into contact before the phosphineimide catalyst (B) and the organoboron compound (C2) come into contact.

5. A method for storing a catalyst composition according to claim 1, wherein, in addition to at least one of the organic solvents (A1) and (A2), an organic solvent (A3) comprising a compound containing an aromatic group in its molecular structure is used such 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.

6. The phosphineimide catalyst (B) is defined 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 heteroatoms, or a halogen atom, L １ L is a group represented by the following formula (a1a), ２ This is a group represented by the following formula (a1b), 【Chemistry 2】 In formula (a1a), R ａ１ ~R ａ５ Each of these is an organic substituent having 1 to 20 carbon atoms, which may be the same or different, and may contain a hydrogen atom or a heteroatom, or an inorganic substituent, R ａ１ ~R ａ５ Two adjacent groups on one of the five-membered rings may bond to each other to form a ring. In formula (a1b), R ａ６ ~R ａ８ These are each independent, identical, or different, and are all tertiary alkyl groups having 4 to 20 carbon atoms. A method for storing the catalyst composition according to any one of claims 1 to 5, wherein the compound is represented by [the compound].

7. A method for storing a catalyst composition according to any one of claims 1 to 5, wherein the phosphineimide catalyst (B) is a compound represented by the following general formula (1). 【Transformation 3】 In general formula (1), M represents a Group 4 transition metal 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 to R ａ８ each independently represents a tertiary alkyl group having 4 to 20 carbon atoms 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. A method for storing the catalyst composition according to claim 7, wherein R in the general formula (1) contains a fluorine atom.

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