JP6963245B2 - Method for Producing Norbornene-Conjugated Diene Copolymer - Google Patents

Description

The present invention relates to a method for producing a norbornene-diene copolymer.

Conventionally, a method for producing a norbornene-diene copolymer by copolymerizing norbornene and diene has been known.
For example, in the example of Patent Document 1, norbornene and diene are copolymerized using a catalyst containing a nickel atom (nickel catalyst).

JP-A-2002-249527

Under these circumstances, when the present inventors copolymerize norbornene and diene using a nickel catalyst with reference to the examples of Patent Document 1, the molecular weight may not easily increase and the physical properties of the polymer may become insufficient. It became clear that there was. It was also clarified that a long time must be spent on polymerization in order to sufficiently increase the molecular weight.

Therefore, in view of the above circumstances, it is an object of the present invention to provide a method for producing a norbornene-diene copolymer capable of efficiently producing a norbornene-diene copolymer having a high molecular weight.

As a result of diligent studies on the above problems, the present inventors have found that the above problems can be solved by using a catalyst containing a metal atom of Group 4 as a catalyst.
That is, the present inventors have found that the above problems can be solved by the following configuration.

(1) A method for producing a norbornene-diene copolymer, in which a monomer containing norbornene and diene is copolymerized using a catalyst containing a metal atom of Group 4.
(2) The method for producing a norbornene-diene copolymer according to (1) above, wherein the metal atom of Group 4 is a titanium atom.
(3) The method for producing a norbornene-diene copolymer according to (1) or (2) above, wherein the monomer further contains an olefin.

As shown below, according to the present invention, it is possible to provide a method for producing a norbornene-diene copolymer capable of efficiently producing a norbornene-diene copolymer having a high molecular weight.

The method for producing the norbornene-diene copolymer of the present invention will be described below.
The numerical range represented by using "~" in the present specification means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.

[Method for producing norbornene-diene copolymer]
In the method for producing a norbornene-diene copolymer of the present invention (hereinafter, also simply referred to as "the production method of the present invention"), a catalyst containing a metal atom of Group 4 is used to coexist a monomer containing norbornene and a diene. Polymerize.
First, the monomer and the catalyst will be described in detail, and then the polymerization method will be described.

〔monomer〕
The monomer used in the production method of the present invention contains norbornene and diene. The monomer may contain yet another monomer.

<Norbornene>
The content of norbornene in the monomer is not particularly limited, but is preferably 1 to 99 mol%, more preferably 10 to 90 mol% in the total monomer.

<Diene>
The diene is not particularly limited, and examples thereof include butadiene (for example, 1,3-butadiene), isoprene, and chloroprene. Of these, 1,3-butadiene and isoprene are preferable. These dienes can be used alone or in combination of two or more.
The content of diene in the monomer is not particularly limited, but is preferably 1 to 99 mol%, more preferably 2 to 90 mol% in all the monomers.

<Other monomers>
The monomer used in the production method of the present invention may contain yet another monomer. Such monomers include, for example, olefins; aromatic vinyl; acrylonitrile, and α, β-unsaturated nitriles such as methacrylonitrile; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and maleic anhydride or acid anhydride. Substances; unsaturated carboxylic acid esters such as methyl methacrylate, ethyl acrylate, and butyl acrylate; 1,5-hexadiene, 1,6-heptadiene, 1,7-octadien, dicyclopentadiene, and 5-ethylidene- Examples include non-conjugated dienes such as 2-norbornen.

(Olefin)
The olefin is not particularly limited, but an olefin having 3 to 18 carbon atoms is preferable. Specific examples of the olefin include propylene, butene-1, penten-1, hexene-1, 4-methyl-pentene-1, 3-methyl-butene-1, heptene-1, octene-1, decene-1 and the like. Can be mentioned. These olefins can be used alone or in combination of two or more.

(Aromatic vinyl)
The above aromatic vinyl is not particularly limited, and is, for example, styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2 , 4-Diisopropyl styrene, 2,4-dimethyl styrene, 4-t-butyl styrene, 5-t-butyl-2-methyl styrene, vinyl naphthalene, dimethyl amino methyl styrene, dimethyl amino ethyl styrene and the like. .. Among these, styrene, α-methylstyrene, and 4-methylstyrene are preferable, and styrene is more preferable. These aromatic vinyls can be used alone or in combination of two or more.

When the monomer contains other monomers, the content of the other monomers in the monomer is not particularly limited, but is preferably 0.1 to 30 mol%, more preferably 1 to 20 mol% in all the monomers. preferable.

〔catalyst〕
The catalyst used in the production method of the present invention is a catalyst containing a Group 4 metal atom (hereinafter, also referred to as "specific catalyst").
The Group 4 metal atom represents a Group 4 metal atom in the periodic table, and examples thereof include a titanium atom, a zirconium atom, and a hafnium atom. Of these, a titanium atom is preferable because the obtained copolymer has a higher molecular weight. That is, the specific catalyst is preferably a catalyst containing a titanium atom (hereinafter, also referred to as "titanium catalyst"). The titanium catalyst is also preferable from the following points (1) to (3).
(1) When the above-mentioned monomer contains another monomer such as an olefin (that is, when a copolymer of ternary or more is produced), the polymerization reaction becomes easier to proceed.
(2) It becomes easier to control the molecular weight of the copolymer by the charging ratio of the monomer and the catalyst.
(3) It becomes easier to control the microstructure of the diene.

<Preferable aspect 1>
Preferable embodiments of the specific catalyst include, for example, a compound represented by the following formula (1).
M (A) _a (B) _b (C) _c (D) _d (1)

In the above formula (1), M represents a Group 4 metal atom. Specific examples of Group 4 metal atoms are as described above.
In the above formula (1), A, B, C and D each independently represent an organic group bonded to M in the formula (1). The organic group may have a substituent. A, B, C and D may be bonded to each other to form a ring.
In the above equation (1), a, b, c and d represent an integer of 0 to 4 and satisfy the relational expression of a + b + c + d = 4. When a, b, c or d is an integer of 2 or more, a plurality of A, B, C or D may be the same or different.

Examples of the organic group include a hydrogen atom, a halogen atom, an alkyl group (for example, a methyl group and a tert-butyl group) (including a cycloalkyl group, a bicycloalkyl group and a tricycloalkyl group), and an alkenyl group (cycloalkenyl group). , Bicycloalkenyl group), alkynyl group, aryl group (eg, phenyl group, naphthyl group, cyclopentadienyl group, indenyl group, fluorenyl group), heterocyclic group (may be called heterocyclic group), cyano Group, hydroxy group, nitro group, carboxy group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (anilino group) Includes), ammonio group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio Group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl or heterocyclic azo group, imide group, phosphino group, phosphinyl group , Phosphinyloxy group, phosphinylamino group, phosphono group, silyl group, hydrazino group, ureido group, boronate group (-B (OH) ₂ ), phosphat group (-OPO (OH) ₂ ), sulfato group (-OSO ₃ H) and the like.
Specific examples of the above-mentioned substituent are the same as those of the above-mentioned organic group.

Specific examples of the compound represented by the above formula (1) include the compounds described in paragraphs [0055] to [0078] of JP-A-2005-162809.

(Preferable Aspect 1A)
Preferable embodiments of the compound represented by the above formula (1) include, for example, a compound represented by the following formula (1A).

Equation (1A)

In the above formula (1A), M represents a Group 4 metal atom. Specific examples of Group 4 metal atoms are as described above.

In the above formula (1A), X ¹ and X ² are alkyl groups, aryl groups, or halogen atoms which may independently have a halogen atom having 1 to 10 carbon atoms, and specifically, Halogen atoms such as fluorine atom, chlorine atom, bromine atom, iodine atom, alkyl group such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, phenyl group, naphthyl Examples thereof include an aryl group such as a group and a halogen-substituted aryl group such as a pentafluorophenyl group. X ¹ and X ² may have a substituent. Specific examples of the substituent are the same as those of the organic group described above.

In the above formula (1A), R ^{1 to} R ¹¹ independently have a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a halogen atom and an aryl group having a substituent having 1 to 10 carbon atoms, and a halogen. A silyl group which may have an atom and a substituent having 1 to 10 carbon atoms is shown. Among them, R ^{1 to} R ³ are preferably alkyl groups or aryl groups having 1 to 10 carbon atoms independently, and may contain a halogen atom. Specifically, R ^{1 to} R ¹¹ are alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group and hexyl group, phenyl group and naphthyl group. Examples thereof include an aryl group such as, a halogen-substituted aryl group such as a pentafluorophenyl group, an unsubstituted silyl group, a trimethylsilyl group, a triethylsilyl group, and a silyl group such as a tripropylsilyl group.
R ² and R ³ , R ⁴ and R ⁵ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ⁸ and R ⁹ or R ⁹ and R ¹⁰ , R ¹⁰ and R ¹¹ , respectively, join each other to form a ring. It may be formed.
R ^{1 to} R ¹¹ may have a substituent. Specific examples of the substituent are the same as those of the organic group described above.

In the production method of the present invention, the amount of the specific catalyst used is not particularly limited, but is preferably 0.00001 to 10 mol%, more preferably 0.0001 to 1 mol% with respect to the monomer. As the specific catalyst, one type may be used alone, or two or more types may be used in combination.

[Co-catalyst]
In the production method of the present invention, a co-catalyst may be used in addition to the above-mentioned specific catalyst.
The co-catalyst is not particularly limited, but is preferably an organoaluminum compound. Examples of the organoaluminum compound include aluminoxane and alkylaluminum compounds.

<Aluminoxane>
The aluminoxane is a product obtained by reacting trialkylaluminum with water. Examples of the aluminoxane include methylaluminoxane, ethylaluminoxane, propylaluminoxane, butylaluminoxane, isobutylaluminoxane, methylethylaluminoxane, methylbutylaluminoxane, and methylisobutylaluminoxane. Of these, modified methylaluminoxane (modified methylaluminoxane) (MMAO) such as methylethylaluminoxane, methylbutylaluminoxane, and methylisobutylaluminoxane is preferable. These aluminoxanes can be used alone or in combination of two or more.
Aluminoxane may be treated with a phenol compound by using a phenol compound such as 2,6-di-tert-butyl-p-cresol together with aluminoxane. The amount of the phenol compound used is not particularly limited, but the molar ratio of the phenol compound to the aluminum atom in the aluminoxane is preferably 0.1 to 10, and more preferably 1 to 5.

<Alkyl aluminum compound>
The alkylaluminum compound is not particularly limited, and specific examples thereof include alkylaluminums such as triethylaluminum, tripropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum. , Triarylaluminum such as triphenylaluminum and tritrylaluminum, halogen-containing alkylaluminum such as dimethylaluminum chloride and diethylaluminum chloride.

In the production method of the present invention, the amount of the co-catalyst used when the co-catalyst is an organoaluminum compound is not particularly limited, but the molar ratio of aluminum atoms in the organoaluminum compound to the catalyst is 20 to 10,000. , More preferably 50 to 2,000, and even more preferably 100 to 1,000.

[Polymerization method]
The method of copolymerizing the above-mentioned monomer using the above-mentioned specific catalyst is not particularly limited, and examples thereof include a method of stirring the monomer, the specific catalyst, and a co-catalyst if necessary in a solvent. The polymerization temperature is not particularly limited, but is preferably -30 to 100 ° C.

[Norbornene-diene copolymer]
The norbornene-diene copolymer of the present invention is a norbornene-diene copolymer produced by the production method of the present invention.
The norbornene-diene copolymer of the present invention is a binary copolymer of norbornene and diene when the above-mentioned monomer contains only norbornene and diene (one type), and the above-mentioned monomer further contains another monomer. When it is contained, and when the above-mentioned monomer contains two or more kinds of diene, it is a ternary or more copolymer.

In the norbornene-diene copolymer of the present invention, the amount of the repeating unit derived from norbornene is not particularly limited, but is preferably 1 to 99 mol%, more preferably 10 to 90 mol% of all the repeating units. ..
In the norbornene-diene copolymer of the present invention, the amount of the repeating unit derived from diene is not particularly limited, but is preferably 1 to 99 mol%, more preferably 2 to 90 mol% of all the repeating units. ..
In the norbornene-diene copolymer of the present invention, the amount of the repeating unit derived from norbornene is not particularly limited, but is preferably 0.1 to 30 mol%, preferably 1 to 20 mol% of all the repeating units. More preferred.

The molecular weight of the norbornene diene copolymer of the present invention is preferably 10,000 or more, more preferably 10,000 to 1,000,000 in terms of number average molecular weight (Mn). The polydispersity (Mw / Mn) is preferably 1-5.
In the present specification, the number average molecular weight (Mn) and the weight average molecular weight (Mw) are standard polystyrene-equivalent values obtained by gel permeation chromatography (GPC) measurement under the following conditions.
・ Solvent: Tetrahydrofuran ・ Detector: RI detector

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[Manufacturing of norbornene-diene copolymer]
<Examples 1 to 8>
Add 2,6-di-tert-butyl-p-cresol (DBC) to a mixed hexane / toluene solution of modified methylaluminoxane (MMAO) (molar ratio of DBC to aluminum atoms in MMAO: 1.2). The mixture was stirred at room temperature for 30 minutes.
The monomers shown in Table 1 below were added to the obtained solution at the ratios shown in the same table. Further, 20 μmol of a catalyst containing titanium atoms (titanium catalyst) (structure below) was added (molar ratio of aluminum atoms in MMAO to titanium atoms in titanium catalyst: 462), and the mixture was stirred at room temperature for 1 hour to copolymerize the monomers. (Polymerization solution: 30 ml).
Then, hydrochloric acid and methanol were added to terminate the polymerization. After distilling off the volatile component, the residue was dissolved in toluene and added dropwise to methanol to separate the methanol-insoluble component. In this way, a norbornene-diene copolymer was produced. The norbornene-diene copolymers obtained in Examples 1 to 5 are binary copolymers of norbornene and diene, and the norbornene-diene copolymers obtained in Examples 6 to 8 are norbornene and diene. It is a ternary copolymer of olefin and olefin.

Titanium catalyst (where t-Bu represents a t-butyl group)

<Comparative Examples 1-2>
Add 2,6-di-tert-butyl-p-cresol (DBC) to a mixed hexane / toluene solution of modified methylaluminoxane (MMAO) (molar ratio of DBC to aluminum atoms in MMAO: 1.2), and further. 6.0 mg of nickel bis (2,4-pentazionate) (nickel catalyst) was added, and the mixture was stirred at room temperature for 30 minutes. The monomers shown in Comparative Examples 1 and 2 in Table 1 below were added to the obtained solution at the ratios shown in the same table, and the mixture was stirred at room temperature for 1 hour to copolymerize the monomers (polymerization solution: 30 ml).
Then, hydrochloric acid and methanol were added to terminate the polymerization. After distilling off the volatile component, the residue was dissolved in toluene and added dropwise to methanol to separate the methanol-insoluble component. In this way, a norbornene-diene copolymer was produced. The norbornene-diene copolymer obtained in Comparative Example 1 is a binary copolymer of norbornene and diene, and the norbornene-diene copolymer obtained in Comparative Example 2 is a combination of norbornene, diene and olefin. It is a ternary copolymer.

〔evaluation〕
<Measurement of molecular weight>
The number average molecular weight (Mn) and the degree of polydispersity (PDI = Mw / Mn) of the obtained norbornene-diene copolymer were measured. Some results are shown in Table 1. The method for measuring the number average molecular weight and the degree of polydispersity is as described above.

In Table 1, the "catalyst" column represents the catalyst used.
In Table 1, the column of "yield" represents the amount [g] of the obtained norbornene-diene copolymer.
In Table 1, the column of "activity" represents "amount of obtained norbornene-diene copolymer [kg]" / "amount of catalyst used [mol]" / "polymerization time [time]".
In Table 1, the column of "polymer" represents the amount [mol%] of the repeating unit derived from each monomer in all the repeating units in the obtained norbornene-diene copolymer. The amount of repeating units derived from each monomer in the norbornene-diene copolymer was determined by ¹ H NMR measurement (nuclear magnetic resonance measurement) (solvent: 1,1,2,2-tetrachloroethane-d ₂ ).

The norbornene-diene copolymer produced by the production methods of Examples 1 to 5 of the present application using a specific catalyst is a norbornene-diene copolymer produced by the production method of Comparative Example 1 using a catalyst other than the specific catalyst. The molecular weight was higher than that of the (binary copolymer). In Comparative Example 1, in order to make the molecular weight of the obtained norbornene-diene copolymer comparable to that of the norbornene-diene copolymer produced by the production methods of Examples 1 to 5 of the present application, the polymerization time was set to 1. It had to be extended from time to about 70 hours.
Similarly, the norbornene-diene copolymer produced by the production methods of Examples 6 to 8 of the present application using a specific catalyst is a norbornene-diene produced by the production method of Comparative Example 2 using a catalyst other than the specific catalyst. The molecular weight was higher than that of the copolymer (ternary copolymer). In Comparative Example 2, in order to make the molecular weight of the obtained norbornene-diene copolymer comparable to that of the norbornene-diene copolymer produced by the production methods of Examples 6 to 8 of the present application, the polymerization time was set to 1. It had to be extended from time to about 70 hours.
From the above results, it was found that the production method of the examples of the present application can efficiently produce a norbornene-diene copolymer having a high molecular weight.

Claims (2)

A method for producing a norbornene-conjugated diene copolymer, in which a monomer containing norbornene and a conjugated diene is copolymerized using an aluminoxane treated with a phenol compound as a co-catalyst together with a catalyst containing a Group 4 metal atom. hand,
A method for producing a norbornene-conjugated diene copolymer, wherein the catalyst containing a Group 4 metal atom is a compound represented by the following formula (1A) .

In formula (1A), M represents a titanium atom.
In formula (1A), X ¹ and X ² are independently alkyl groups having 1 to 10 carbon atoms.
In the formula (1A), R ^{1 to} R ¹¹ independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.
R ² and R ³ , R ⁴ and R ⁵ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ⁸ and R ⁹ , R ⁹ and R ¹⁰ or R ¹⁰ and R ¹¹ , respectively, join each other to form a ring. It may be formed. The monomer further contains, norbornene of claim 1 - method of manufacturing conjugated diene copolymer.