JP3178667B2 - Transition metal complex and method for producing poly-1,4-phenylene ether using the transition metal complex as a catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a transition metal complex and a method for producing poly-1,4-phenylene ether using the transition metal complex as a catalyst.

[0002]

2. Description of the Related Art Oxygen oxidative polymerization using a transition metal complex catalyst of 2,6-dimethylphenol (see, for example,
Poly- (2,6-dimethylphenylene ether) (hereinafter referred to as P) obtained by the method described in Japanese Patent Application Laid-Open No. 6091/1991 and Japanese Patent Application Laid-Open No. 59-131627.
(Sometimes abbreviated as PE) is known to be a useful resin. However, this PPE has a disadvantage that it is difficult to melt-mold the PPE alone because the methyl group substituted by the aromatic ring is susceptible to oxidative deterioration, and is generally used as a polymer alloy with polystyrene, and is used in general-purpose engineering plastics. It is positioned.

On the other hand, poly-1,4-phenylene ether (hereinafter sometimes abbreviated as PAO) is disclosed in Europ. P
olym. J. , 4,275 (1968). Melting point is 298 ° C. (glass transition temperature is 83
° C), which is higher than the melting point of polyphenylene sulfide (285 ° C), which is generally called super engineering plastic, and has the second highest melting point (334 ° C) of polyetheretherketone, making it useful as an ultra-high heat-resistant resin. Sex is extremely large.

A method for producing PAO is disclosed in Europ.
Polym. J. , 4,275 (1968). To p-
It is described that the sodium salt of bromophenol is polymerized in the presence of a copper catalyst, but the reaction temperature must be as high as 200 ° C., and there is a problem that a salt equivalent to the reaction amount is generated. JP-A-59-56426 discloses that
A method for producing PAO by electrolytic oxidation polymerization of phenol is described, but mass production was difficult because the amount of polymer produced per unit time is governed by the surface area of the electrode. Japanese Patent Publication No. 44-28918 proposes a method of irradiating 4-phenoxyphenol with light of a specific wavelength in the presence of a photosensitizer. However, phenol is by-produced as polymerization proceeds. In addition, there is a problem that mass production is difficult due to the method by light irradiation and the like. further,
JP-B-44-28917 proposes a method of heating 4-phenoxyphenol to a temperature at which phenol is distilled. However, it requires a high temperature and has a problem that phenol is by-produced.

As a method of solving these problems, an oxidative polymerization method using a transition metal complex catalyst is cited because the reaction temperature is relatively low and the by-product to be eliminated is water. A transition metal complex catalyzed oxygen oxidative polymerization method using inexpensive oxygen as the oxidizing agent is particularly useful. As an example of the oxygen oxidative polymerization method using a phenol transition metal complex catalyst, JP-B-36-18892, an industrial chemical magazine,
Vol. 72, No. 10, 106 (1969), Japanese Patent Publication No. 48-1
No. 7395, but these methods have a problem that an ortho-position branch or a CC bond structure is generated.

Here, the ortho-position branching means that the benzene ring in the phenol polymer has a 1,2,4-trisubstituted benzene structure, which disrupts the originally desired chain of the 1,4-disubstituted benzene structure. Structure. In addition, the CC bond structure indicates that polymerization of phenol does not occur in the reaction between an oxygen atom and a benzene ring but occurs in a reaction between benzene rings, resulting in a biphenyl structure. When the ortho-branching and the CC bond structure increase, the melting point decreases, and eventually PAO becomes an amorphous resin having no melting point, and loses its usefulness as an ultra-high heat-resistant resin due to its high melting point.

In Japanese Patent Publication No. 36-18692 and Industrial Chemistry Magazine, Vol. 72, No. 10, 106 (1969), in the oxygen oxidative polymerization of a tertiary amine and a cuprous salt as a catalyst, the phenol at the ortho position is used. It has been proposed to use tertiary amines with bulky substituents (such as 2,6-dimethylpyridine etc.) to hinder the reaction. However, the polymer obtained by this method also has a C-C
In addition to containing a bonding structure, the PAO is not sufficiently suppressed, and it is an amorphous resin with no melting point observed.
Could not be called.

On the other hand, Tetrahedron, 23, 2
253 (1967). Discloses an example in which 4-phenoxyphenol is subjected to oxygen oxidative polymerization using a cuprous salt and an N, N, N ′, N′-tetraethylethylenediamine catalyst, but the polymer obtained by this method also has an ortho-position branch. Many, no melting points were observed.

[0009]

As described above, in the current oxygen oxidation polymerization method using a transition metal complex catalyst, a large number of ortho-position branches and CC bond structures are formed, and no useful polymer has been obtained. . Therefore, the current problem is to produce PAO that can exhibit a melting point. That is, an object of the present invention is to provide a novel transition metal complex, and perform C-C by oxygen oxidative polymerization using the transition metal complex catalyst.
An object of the present invention is to provide a method for producing a poly-1,4-phenylene ether having a controlled structure and a melting point in which a bonding structure is not formed and the ortho-position branching is small.

[0010]

Under these circumstances, the present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found a completely new transition metal complex, In the presence of, an oxidative polymerization method using a specific raw material was found, and the present invention was completed.

That is, the present invention provides a transition metal complex represented by the following general formula (I).

Embedded image (Wherein, M represents a complex central metal atom composed of a transition metal atom, R ¹ and R ² represent a hydrogen atom, X is a counter anion, n is the number of X, and In addition, the present invention provides a method for polymerizing a raw material represented by the following general formula (II) in the presence of oxygen using a transition metal complex represented by the above general formula (I) as a catalyst. It is intended to provide a method for producing -1,4-phenylene ether.

Embedded image (Where m represents the number average unit number, and 1 <m)

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the above general formula (I), M is a complex central metal atom capable of coordinating to three nitrogen atoms, and is composed of a transition metal atom. The transition metal atoms in this case include transition metal atoms belonging to Groups 4 to 11 of the Periodic Table of the Elements (IUPAC Inorganic Compound Nomenclature Revised Edition, 1989). Such transition metal atoms include Ti, Zr, Hf, and the like as Group 4 elements, V, Nb, Ta, and the like as Group 5 elements, Cr, as Group 6 elements.
Mo, W, etc., as those of Group 7, Mn, Tc, Re
And the like, Fe, Ru, Os, and the like as Group 8 members, Co, Rh, Ir, and the like as Group 9 members, and Ni, Pd, Pt, and the like as Group 10 members. As a member of the group, Cu, Ag, Au, and the like can be given. This transition metal atom includes, in addition to the metal atom itself, M = O and M = S
A metal atom to which another atom such as (M: transition metal atom) is bonded is also included. Preferred transition metal atoms used in the present invention are Cu, Ag, Ni, Pd, Co, Rh, Fe, R
u, Mn, Tc, Cr, Mo, V, Nb, Ti, Zr, etc., and more preferably Cu, Ni, Co, Fe, M
n, Cr, V, Ti, etc., and more preferably Cu.

The valence of the transition metal atom can be appropriately selected from those normally existing in the natural world, and for example, in the case of copper, monovalent or divalent copper can be used.

In the general formula (I), X is a counter anion, n is the number of X, and is determined by the valence of M. Such a counter anion is not particularly limited, but a conjugate base of Bronsted acid is usually used, and specific examples thereof include fluoride ion, chloride ion,
Bromide, iodide, sulfate, nitrate, carbonate, perchlorate, tetrafluoroborate, hexafluorophosphate, methanesulfonate, trifluoromethanesulfonate, toluenesulfonate, acetate , Trifluoroacetate ion, propionate ion, benzoate ion, hydroxide ion, oxide ion, methoxide ion, ethoxide ion and the like.

The transition metal complex of the present invention may be coordinated with a counter anion or a solvent.

The transition metal complex represented by the general formula (I) is obtained by using a phenolic compound represented by the general formula (II) as a raw material and polymerizing the same in the presence of oxygen to obtain poly-1,4-.
It is advantageously used as a catalyst when producing phenylene ether. By using the transition metal complex of the present invention as a catalyst, a polymer having no CC bond structure and having few ortho-position branches can be obtained. The raw material used in the present invention is a phenolic compound represented by the general formula (II). In the general formula (II), it is important that the number average unit number m is larger than 1. When the number average unit number m is 1, that is, when phenol is used as a raw material, even if it is proposed in Japanese Patent Publication No. 36-18692 and Industrial Chemistry Magazine, Vol. 72, No. 10, 106 (1969). Even if a catalyst that hinders the reaction of phenol at the ortho position is used, the resulting polymer contains a CC bond structure, has many ortho position branches, and has no observable melting point. It becomes impossible to produce phenylene ether. Therefore, even in the case of the present invention, this phenol is not preferably used as a reaction raw material. The number average unit number m is 1.01 ≦
Preferably, m ≦ 6, and more preferably, 1.05 ≦ m ≦ 2.

Specific examples of the phenolic compound when the number average unit number m is larger than 1 include 4-phenoxyphenol, 4- (4-phenoxyphenoxy) phenol and 4- {4- (4-phenoxyphenoxy). A phenolic compound having an integer of 2 or more 1,4-phenylene ether structural units such as phenoxydiphenol;
And a mixture of at least two or more selected from these compounds and phenol. Commercially available 4-phenoxyphenol can be obtained, and other compounds can be obtained by known methods. For example, Tetrahe
dron, 23, 2253 (1967). In the present invention, it is particularly preferable to use 4-phenoxyphenol as the phenolic starting material.

Next, the production of poly-1,4-phenylene ether using the transition metal complex of the present invention as a catalyst will be described in detail. As the transition metal complex used as a catalyst,
Although those synthesized in advance can be used, those formed in a reaction system may be used. Further, this transition metal complex can be used alone or in combination. The amount of the complex used is generally 0.01 to 50 as the amount of the transition metal compound based on the phenolic starting material.
Mol% is preferable, and 0.02 to 10 mol% is more preferable. In the method for polymerizing a raw material phenolic compound of the present invention, the polymerization is carried out in the presence of oxygen. As the oxygen in this case, in addition to pure oxygen, air or a mixture of oxygen and an inert gas can be used. Although the amount of oxygen present in the reaction system is not particularly limited, it is 0.5 mol or more, preferably 1 mol or more, more preferably 2 mol or more, per 1 mol of the starting phenolic compound. This oxygen may be present in the polymerization atmosphere in the polymerization reaction system.

Although the polymerization reaction of the present invention can be carried out in the absence of a reaction solvent, it is generally preferable to use a solvent. The solvent is not particularly limited as long as it is inert to the phenolic starting material and liquid at the reaction temperature. Preferred examples of the solvent include aromatic hydrocarbons such as benzene, toluene and xylene; linear and cyclic aliphatic hydrocarbons such as heptane and cyclohexane; halogenated hydrocarbons such as chlorobenzene, dichlorobenzene and dichloromethane; acetonitrile , Nitriles such as benzonitrile; methanol, ethanol, n-
Alcohols such as propyl alcohol and iso-propyl alcohol; ethers such as dioxane, tetrahydrofuran and ethylene glycol dimethyl ether;
Amides such as N-dimethylformamide and N-methylpyrrolidone; nitro compounds such as nitromethane and nitrobenzene; and water. These are used alone or as a mixture. When a solvent is used, the amount of the solvent used is preferably such that the concentration of the phenolic starting material is 0.5%.
５０50% by weight, more preferably 1-30% by weight.

When the transition metal complex has, as its counter ion, a conjugate base of an acid stronger than phenol, a base which does not inactivate the transition metal complex catalyst coexists with the counter ion in an amount equal to or more than that of the counter ion during polymerization. Is preferred. Examples of such bases include hydroxides, oxides, alkoxides of alkali metals or alkaline earth metals such as sodium hydroxide, potassium hydroxide, calcium oxide, sodium methoxide, sodium ethoxide; methylamine; Amines such as ethylamine, propylamine, butylamine, dibutylamine and triethylamine; pyridine, 2-methylpyridine, 2,6
Pyridines such as -dimethylpyridine and 2,6-diphenylpyridine. Usually, amines and pyridines are often used.

The reaction temperature for carrying out the present invention is not particularly limited as long as the reaction medium is kept in a liquid state. If no solvent is used, a temperature above the melting point of the phenolic starting material is required. A preferred temperature range is 0 ° C to 180 ° C, more preferably 0 ° C to 150 ° C.

[0022]

The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited by these examples.

(A) Transition metal complex Example 1 (i) 1,4,7-tricyclohexyl-1,4,7-
Synthesis of triazacyclononane / 1 perchlorate Sodium hydroxide 1.07 in 100 ml eggplant flask
g (0.027 mol) was dissolved in ethyl alcohol (20 ml), and triazacyclononane trihydrochloride (2.04 g) was dissolved.
(0.0085 mol), and the mixture was stirred at room temperature for 1 hour and 30 minutes. The resulting white precipitate was removed by filtration, and the filtrate was concentrated to dryness using an evaporator. This was put in a 50 ml two-necked flask equipped with a reflux condenser, 20 ml of xylene was added, and 5.67 g of cyclohexyl bromide (0.03 g) was added.
5mol) and potassium hydroxide 2.05g (0.036m
ol), and the mixture was stirred at 120 ° C. for 24 hours under an argon gas atmosphere. Once the temperature was returned to room temperature, 5.70 g (0.035 mol) of cyclohexyl bromide and 2.09 g (0.037 mol) of potassium hydroxide were added, and the mixture was again stirred at 120 ° C. for 48 hours under an argon gas atmosphere. After completion of the reaction, salts were removed by filtration, and the filtrate was concentrated to dryness by an evaporator. 20 ml of methanol was added thereto, and 1.27 g (0.0090 mol) of sodium perchlorate monohydrate was added. After stirring, the insoluble portion was removed by filtration. When distilled water was added dropwise to the filtrate while stirring, white crystals precipitated. This was collected by filtration and dried at 50 ° C. under vacuum. (Yield 1.27 g, 30% yield) ¹ H-NMR (acetone -d6, ppm): 1.06~
1.26 (m, 3H), 1.26 to 1.60 (m, 12
H) 1.60-1.76 (m, 3H), 1.80-
1.98 (m, 12H), 2.78 to 2.96 (m, 9
H) 3.08-3.22 (m, 6H) IR (KBr method, cm ^-1 ): 3424, 2930, 28
57, 2857, 2631, 1486, 1457, 13
85, 1371, 1324, 1299, 1278, 12
15, 1164, 1094, 955, 898, 844,
750, 622, 564, 514 Elemental analysis / measured values: C (60.4%), N (8.6
%), H (9.8%) / calculated: C (60.5%), N
(8.8%), H (9.7%)

(Ii) 1,4,7-tricyclohexyl-
Synthesis of 1,4,7-triazacyclononane-copper complex 0.3 g of 1,4,7-tricyclohexyl-1,4,7-triazacyclononane-1 perchlorate and excess potassium hydroxide After stirring in toluene and desalting by filtration, the solvent was distilled off in vacuo. After 10 ml of methanol and 10 ml of methylene chloride were added thereto to homogenize, 10 ml of a methanol solution containing 0.13 g of cupric chloride dihydrate was added, and the mixture was stirred at room temperature for 1 hour. After completion of the reaction, the solvent was distilled off in vacuo,
It was dissolved in a minimum amount of a methylene chloride / methanol mixed solvent and filtered and desalted. Further, the solvent was distilled off in vacuo and recrystallized from methanol / diethyl ether. (Yield 0.
The complex was identified by elemental analysis, and the calculated value was C (56. Yield: 34%).
51%), H (8.89%), N (8.24%), Cl
(13.90%), measured value: C (56.22%)
%), H (8.93%), N (8.21%), Cl (1
4.58%). In addition, the structure of the complex was determined by single crystal X-ray structure analysis and determined to be the following structure.
Hereinafter, this complex may be abbreviated as Cu (cHex3tacn).

Embedded image

(B) Method for producing poly-1,4-phenylene ether

Example 2 (i) Analysis Conversion of phenolic starting material (Conv.): Reaction mixture 15 containing diphenyl ether as internal standard
mg was sampled, acidified by adding a small amount of concentrated hydrochloric acid, and 2 g of methanol was added to obtain a measurement sample. This sample was subjected to high performance liquid chromatography (pump: SC8020 system manufactured by Tosoh Corporation, detector: U80 manufactured by Tosoh Corporation)
V-8020, detection wavelength: 278 nm, column: YMC
ODS-AM, developing solvent: methanol / water = 50:
Starting from 50, the value was changed to 100/0 after 50 minutes, and then kept until 60 minutes), and diphenyl ether was quantified as an internal standard.

Infrared absorption spectrum analysis and peak area determination of polymer: infrared spectrophotometer P manufactured by PerkinElmer
The measurement was performed using ARAGON1000 (KBr method), and the peak area was quantified.

The amount of the CC bond structure of the polymer (CC / C-
O): In the infrared absorption spectrum, the C—C bond structure peak area was set to an area of 996 to 1004 cm ⁻¹ ,
The bond structure peak area was defined as a value obtained by subtracting the CC bond structure peak area from the area of 996 to 1018 cm ^-1 . As a standard of the amount of CC bond of the polymer, a value obtained by the following formula: peak area of CC bond structure peak / peak area of CO bond structure (C
-C / CO) was used. In addition, when a CC bond structure peak is not observed, N.P. D. It was written.

Ortho-position branching amount (o / p) of polymer: In the infrared absorption spectrum, the ortho-position branch peak area was 9%.
The area was 60 to 986 cm ^-1 . As a standard of the amount of ortho-position branching of the polymer, a value (o / p) obtained by dividing the ortho-position branch peak area / the para-position-linked C—O bond structure peak area.
Was used.

Number average molecular weight (Mn) and weight average molecular weight (Mw) of the polymer: The polymer was analyzed by gel permeation chromatography, and the weight average molecular weight (Mw) and number average molecular weight (Mn) were measured in terms of standard polystyrene. . In the examples, pump: SC8020 system manufactured by Tosoh Corporation, detector: RI-8020 manufactured by Tosoh Corporation, column: two TSK-GELα-M manufactured by Tosoh Corporation, developing solvent: 0.4
N, N-dimethylformamide containing wt% LiCl was used. In the comparative example, the pump is 600E manufactured by Waters.
System, detector: Waters UV / VIS-4
84, detection wavelength: 254 nm, column: Ultrastyragel Linear = 2 tubes +
1000A = 1 tube + 100A = 1 tube, developing solvent: chloroform.

Melting point of polymer: Thermal analysis under nitrogen atmosphere (Example: DSC22 manufactured by Seiko Instruments Inc., Comparative Example: DSC-50 manufactured by Shimadzu Corp.) First, from room temperature to 300 ° C. at 10 ° C./min. The temperature was raised (1st scan), then the temperature was lowered from 300 ° C. to room temperature at -10 ° C./min, and again from 10 ° C./min to 350 ° C.
nd scan). In the second scan, 100
With respect to an endothermic peak at 10 ° C. or higher at 10 ° C. or higher, the highest peak temperature was defined as the melting point.

(Ii) Oxidative polymerization of 4-phenoxyphenol A rubber balloon filled with oxygen was attached to a 25 ml two-neck round bottom flask equipped with a magnetic stirrer, and the inside of the flask was replaced with oxygen. In addition, Cu (cHex3tacn) 0.03
0 mmol, and 4-phenoxyphenol (4-P
(hOPhOH) 0.6 mmol and 2,6- as a base
A solution prepared by dissolving 0.30 mmol of diphenylpyridine (Ph2Py) in 1.2 g of toluene (PhMe) was added. While stirring the contents, the flask was kept warm in a 40 ° C water bath. After the reaction was completed, a few drops of concentrated hydrochloric acid were added to make the mixture acidic, and then 20 ml of methanol was added, and the precipitated polymer was collected by filtration. Wash 3 times with 10 ml of methanol, 1
After drying under reduced pressure at 00 ° C. for 5 hours, a white polymer was obtained.
The analysis results of this polymer are shown in Table 1, and the infrared absorption spectrum is shown in FIG.

Comparative Examples 1-3 Phenolic starting materials, catalysts, solvents, bases, reaction temperatures,
A polymer was obtained in the same manner as in Example 2, except that the reaction time was changed as shown in Table 1. Table 1 shows the results. Note that P
hOH is phenol, CuCl is cuprous chloride, Me ₂ P
y is 2,6-dimethylpyridine, tead is N, N,
N ', N'-tetraethylethylenediamine, PhNO
₂ represents nitrobenzene.

Regarding the melting point of the polymer, the polymer of Example 2 had a melting point at 186 ° C., but the melting points of the polymers of Comparative Examples 1 to 3 were not observed. Also, the coloring of the polymer,
The one obtained in this example was almost white, but the one obtained in this comparative example was brownish.

[0035]

[Table 1]

[0036]

As described above, a completely novel transition metal compound can be provided by the present invention. Further, by using the above transition metal complex as a catalyst and oxygen oxidative polymerization using a specific phenolic starting material, C-C
Poly-1,4-phenylene ether having no bonding structure, little ortho-position branching, melting point and less coloring can be produced economically in high yield, and the industrial value of the present invention is extremely large. is there.

[Brief description of the drawings]

FIG. 1 shows an infrared absorption spectrum of a polymer of Example 2.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kiyoshi Fujisawa 1-19-1 Nishitsurumama, Yamato-shi, Kanagawa 304 Koi Court Minami-Rinkan 304 (72) Inventor Yoshihiko Morooka 2-41-21 Fujigaoka, Aoba-ku, Yokohama-shi, Kanagawa-ken Tokyo Institute of Technology 404 (72) Inventor Shiro Kobayashi 1-1-1 Higashi, Tsukuba, Ibaraki Pref. JP-A-9-324040 (JP, A) JP-A-9-324404 (JP, A) JP-A-9-291145 (JP, A) JP-A-59-59723 (JP, A) A) JP-A-9-20762 (JP, A) Crg. Chem. , (1998) 63 (9) p. 2873-2877 (58) Fields investigated (Int. Cl. ⁷ , DB name) C07D 255/02 C08G 55/44 REGISTRY CAPLUS (STN)

Claims (3)

(57) [Claims] 1. A transition metal complex represented by the following general formula (I). Embedded image (Wherein, M represents a complex central metal atom composed of a transition metal atom, R ¹ and R ² represent a hydrogen atom, X is a counter anion, n is the number of X, and It is determined) 2. Poly-1,4 characterized by polymerizing a phenolic compound represented by the following general formula (II) in the presence of oxygen using the transition metal complex of claim 1 as a catalyst.
-A process for producing phenylene ether. Embedded image (Where m represents the number average unit number, and 1 <m) 3. The number average unit number m is 1.01 ≦ m ≦
3. Poly-1,4 according to claim 2, wherein
-A process for producing phenylene ether.