JP2025001688A - Polyether ether ketone compound and method for producing the same - Google Patents

Abstract

To provide a polyether ether ketone compound that offers easy synthesis and excellent processability, produces a resin composition containing the same with excellent dielectric characteristics (low relative dielectric constant and low dielectric loss tangent), and exhibits high heat resistance and low moisture absorption.SOLUTION: The present invention provides a polyether ether ketone compound represented by formula (1). In formula (1), R1 and R2 independently represent a substituted or unsubstituted aromatic group, R' independently represents a hydrogen atom, a C1-6 alkyl group or a halogen atom, A1 and A2 independently represent a single bond or a C1-4 alkylene group, and n represents a number of 1-100.SELECTED DRAWING: None

Description

The present invention relates to a polyether ether ketone compound and a method for producing the same.

In recent years, with the increase in the amount of information and communication, the next-generation communication system known as 5G has come into use, and information and communication in the high-frequency band (the millimeter wave region of 26 GHz to 80 GHz) has become more common. Higher performance is also required in electronic devices, and the insulating materials used are required to have even lower relative dielectric constants and dielectric loss tangents.

As insulating materials, epoxy resin compositions containing epoxy resin, a specific phenol-based hardener, phenoxy resin, rubber particles, polyvinyl acetal resin, etc., as shown in Patent Documents 1 and 2, are known, but it has become clear that these materials are not satisfactory for high-frequency band applications, such as those represented by the keyword 5G. In contrast, Patent Document 3 reports that an epoxy resin composition containing epoxy resin, an active ester compound, and a triazine-containing cresol novolac resin is effective in lowering the dielectric tangent, but even this material needs to have a lower dielectric constant for high-frequency applications.

On the other hand, Patent Document 4 reports that a resin film made of a resin composition containing a bismaleimide resin having a long-chain alkyl group as a non-epoxy material and a curing agent has excellent dielectric properties. However, this is essentially a combination of a bismaleimide resin having a long-chain alkyl group and a hard low-molecular aromatic maleimide, and it is very difficult to achieve the high glass transition temperature (Tg) of 100°C or more required for substrate applications. In addition, bismaleimide resins having long-chain alkyl groups have the problem of a large coefficient of thermal expansion (CTE).

In addition, the use of super engineering plastics that have excellent heat resistance and mechanical strength and exhibit low dielectric properties has also attracted attention, and substrates using liquid crystal polymers (LCPs), polytetrafluoroethylene (PTFE), polyether ether ketone (PEEK), polyetherimide (PEI), and the like have been proposed (Patent Document 5).
However, when using super engineering plastics, there are often problems with processability. For example, PEEK has excellent heat resistance, a continuous use temperature of 260°C, and excellent dielectric properties, but it has a high melting point of 300°C or more and poor solubility in solvents, making it difficult to mold.

Non-Patent Document 1 shows an example of introducing a maleimide group to the end of PEEK with a certain molecular weight to impart thermosetting properties. It has also been reported that a composition using this can be made into a varnish and molded, and has excellent dielectric properties (Patent Document 6).

JP 2007-254709 A JP 2007-254710 A JP 2011-132507 A International Publication No. 2016/114287 Patent No. 5958558 JP 2022-25704 A

J. L. Hedrick et al., “Elastomeric behavior of crosslinked poly (aryl ether ketone) at elevated temperatures”, Polymer, 1992, Vol. 33, p. 5094-5097

However, the production of a polyether ether ketone compound having a maleimide group described in Patent Document 6 involves a process in which difluorobenzophenone is reacted with a diol to synthesize a main chain, and then aminophenol is further reacted to convert the terminal into an amine, followed by maleimide formation. This process requires many steps and takes a long reaction time.
Therefore, an object of the present invention is to provide a polyether ether ketone compound which is easy to synthesize, has excellent processability, excellent dielectric properties (low relative dielectric constant and low dielectric tangent), high heat resistance, and low moisture absorption.

As a result of extensive research to solve the above problems, the inventors discovered that the following polyether ether ketone compound can achieve the above objective, and thus completed the present invention.

（式（１）中、Ｒ¹及びＲ²はそれぞれ独立に置換又は非置換の芳香族基を表し、Ｒ’はそれぞれ独立に水素原子、炭素数１～６のアルキル基又はハロゲン原子を表し、Ａ¹及びＡ²は互いに独立に単結合又は炭素数１～４のアルキレン基を表し、ｎは１～１００の数である。）

＜２＞
式（１）中、Ｒ¹及びＲ²がそれぞれ独立に炭素数６～３０の芳香族構造を有する基である＜１＞記載のポリエーテルエーテルケトン化合物。

＜３＞
式（１）で表されるポリエーテルエーテルケトン化合物の数平均分子量が７００～５００００である＜１＞又は＜２＞に記載のポリエーテルエーテルケトン化合物。

＜４＞
４，４’－ジフルオロベンゾフェノンと、
下記式（２）

（式（２）中、Ｒは置換又は非置換の芳香族基を表す。）
で表される化合物と、
をアルカリ金属炭酸塩存在下で反応させて両末端に水酸基を有するポリエーテルエーテルケトン化合物を得る工程Ａ、及び

工程Ａで得られた両末端に水酸基を有するポリエーテルエーテルケトン化合物と、
下記式（３）

（式（３）中、Ｘは塩素原子、臭素原子又はヨウ素原子を表し、Ｒ’はそれぞれ独立に水素原子、炭素数１～６のアルキル基又はハロゲン原子を表し、Ａは単結合又は炭素数１～４のアルキレン基を表す。）
で表される化合物と、
を塩基存在下で反応させる工程Ｂ、又は、
工程Ａで得られた両末端に水酸基を有するポリエーテルエーテルケトン化合物と、
２，３，４，５，６－ペンタフルオロスチレンと、
をアルカリ金属炭酸塩存在下で反応させる工程Ｂ’
を有する＜１＞～＜３＞のいずれか１項に記載のポリエーテルエーテルケトン化合物の製造方法。

＜５＞
工程Ａにおいて、４，４’－ジフルオロベンゾフェノンと式（２）で表される化合物とを、モル比で、４，４’－ジフルオロベンゾフェノン／式（２）で表される化合物＝１／１．０１～２．０で反応させる＜４＞に記載のポリエーテルエーテルケトン化合物の製造方法。 That is, the present invention provides the following polyether ether ketone compound and a method for producing the same.
＜1＞
A polyether ether ketone compound represented by the following formula (1):

(In formula (1), ^R1 and ^R2 each independently represent a substituted or unsubstituted aromatic group, R' each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a halogen atom, ^A1 and ^A2 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms, and n is a number from 1 to 100.)

＜2＞
In the formula (1), R ¹ and R ² each independently represent a group having an aromatic structure having 6 to 30 carbon atoms.

＜3＞
The polyether ether ketone compound according to <1> or <2>, wherein the polyether ether ketone compound represented by formula (1) has a number average molecular weight of 700 to 50,000.

＜4＞
4,4'-difluorobenzophenone,
The following formula (2)

(In formula (2), R represents a substituted or unsubstituted aromatic group.)
and a compound represented by the formula:
in the presence of an alkali metal carbonate to obtain a polyether ether ketone compound having hydroxyl groups at both ends; and

the polyether ether ketone compound having hydroxyl groups at both ends obtained in step A;
The following formula (3)

(In formula (3), X represents a chlorine atom, a bromine atom, or an iodine atom; R' each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom; and A represents a single bond or an alkylene group having 1 to 4 carbon atoms.)
and a compound represented by the formula:
Step B: reacting in the presence of a base; or
the polyether ether ketone compound having hydroxyl groups at both ends obtained in step A;
2,3,4,5,6-pentafluorostyrene,
in the presence of an alkali metal carbonate.
The method for producing a polyether ether ketone compound according to any one of <1> to <3>,

＜5＞
The method for producing a polyether ether ketone compound according to <4>, wherein in step A, 4,4'-difluorobenzophenone and the compound represented by formula (2) are reacted in a molar ratio of 4,4'-difluorobenzophenone/compound represented by formula (2)=1/1.01 to 2.0.

The polyether ether ketone compound of the present invention can be synthesized relatively easily with a small number of steps and has excellent processability. In addition, a resin composition containing the compound has excellent dielectric properties (low relative dielectric constant, low dielectric tangent), high heat resistance, and a cured product with low moisture absorption. Therefore, the polyether ether ketone compound of the present invention is useful as an insulating material for electronic devices used in high frequency bands.

1 is a ¹ H-NMR spectrum of the polyether ether ketone compound having hydroxyl groups at both ends synthesized in Example 1. 1 is an FT-IR spectrum of a polyether ether ketone compound having hydroxyl groups at both ends synthesized in Example 1. 1 is ^{a 1} H-NMR spectrum of the polyether ether ketone compound having fluorostyryl groups at both ends, synthesized in Example 1. 1 is an FT-IR spectrum of a polyether ether ketone compound having fluorostyryl groups at both ends, synthesized in Example 1.

The present invention will be described in detail below.
Polyether ether ketone compound The polyether ether ketone compound of the present invention is represented by the following formula (1).

In formula (1), ^R1 and ^R2 each independently represent a substituted or unsubstituted aromatic group, R' each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom, ^A1 and ^A2 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms, and n is a number from 1 to 100.

（上記式中＊は式（１）中の酸素原子との結合を意味する。） In formula (1), the substituted or unsubstituted aromatic groups represented by R ¹ and R ² are preferably groups having an aromatic structure with 6 to 30 carbon atoms, and more preferably groups having an aromatic structure with 10 to 25 carbon atoms. R ¹ and R ² may be different or the same. The structures of R ¹ and R ² are exemplified below, but these are representative examples and are not limited to these.

(In the above formula, * means a bond with the oxygen atom in formula (1).)

Among these, the following groups are preferred as the aromatic groups represented by R ¹ and R ² in formula (1).

In formula (1), R' are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
In the starting compounds in the production method described below, it is preferable that all of the R' are hydrogen atoms or all of the R' are fluorine atoms.

In formula (1), ^A1 and ^A2 are a single bond or an alkylene group having 1 to 4 carbon atoms. Examples of the alkylene group having 1 to 4 carbon atoms include a methylene group, an ethylene group, a trimethylene group, and a tetramethylene group, and ^A1 and ^A2 are preferably a single bond or a methylene group.

In formula (1), n is a number from 1 to 100, and preferably a number from 5 to 60. If n exceeds 100, the melting point of the resulting polyether ether ketone compound will be too high or the solvent solubility will be poor, which is not preferable.

The number average molecular weight (Mn) of the polyether ether ketone compound is not particularly limited, but is preferably 700 to 50,000, more preferably 1,500 to 40,000, and even more preferably 3,000 to 35,000. Within this range, the polyether ether ketone compound of the present invention has a good melting point and solvent solubility, and the moldability is improved.

The number average molecular weight (Mn) referred to in this specification is the number average molecular weight measured by GPC under the following conditions using polystyrene as the standard.
[GPC measurement conditions]
Developing solvent: tetrahydrofuran (THF)
Flow rate: 0.35mL/min
Detector: Refractive index detector (RI)
Column: TSK Guard column Super H-L
TSKgel SuperHZ4000 (4.6mm I.D. x 15cm x 1)
TSKgel SuperHZ3000 (4.6mm I.D. x 15cm x 1)
TSKgel SuperHZ2000 (4.6mm I.D. x 15cm x 2)
(Both manufactured by Tosoh Corporation)
Column temperature: 40°C
Sample injection volume: 5 μL (THF solution with a concentration of 0.2% by mass)

Method for Producing Polyether Ether Ketone Compound The method for synthesizing the polyether ether ketone compound of the present invention is not particularly limited, but for example, the compound can be efficiently produced by the method shown below.

（式（２）中、Ｒは、置換又は非置換の芳香族基を表す。）
で表される化合物と、
をアルカリ金属炭酸塩存在下で反応させて両末端に水酸基を有するポリエーテルエーテルケトン化合物を得る工程Ａ、及び
前記工程Ａで得られた両末端に水酸基を有するポリエーテルエーテルケトン化合物と、
下記式（３）

（式（３）中、Ｘは塩素原子、臭素原子又はヨウ素原子を表し、Ｒ’はそれぞれ独立に水素原子、炭素数１～６のアルキル基又はハロゲン原子を表し、Ａは単結合又は炭素数１～４のアルキレン基を表す。）
で表される化合物と、
を塩基存在下で反応させる工程Ｂ、又は、
前記工程Ａで得られた両末端に水酸基を有するポリエーテルエーテルケトン化合物と、
２，３，４，５，６－ペンタフルオロスチレンと、
をアルカリ金属炭酸塩存在下で反応させる工程Ｂ’
を有するポリエーテルエーテルケトン化合物の製造方法である。 4,4'-difluorobenzophenone,
The following formula (2)

(In formula (2), R represents a substituted or unsubstituted aromatic group.)
A compound represented by the formula:
in the presence of an alkali metal carbonate to obtain a polyether ether ketone compound having hydroxyl groups at both ends; and
The following formula (3)

(In formula (3), X represents a chlorine atom, a bromine atom, or an iodine atom; R' each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom; and A represents a single bond or an alkylene group having 1 to 4 carbon atoms.)
A compound represented by the formula:
Step B: reacting in the presence of a base; or
the polyether ether ketone compound having hydroxyl groups at both ends obtained in step A;
2,3,4,5,6-pentafluorostyrene,
in the presence of an alkali metal carbonate.
The present invention relates to a method for producing a polyether ether ketone compound having the formula:

In the above manufacturing method, each step can be broadly divided into synthesis of the polyether ether ketone main chain and its terminal modification. The details are explained below.

In step A, for example, aromatic nucleophilic substitution polymerization of 4,4'-difluorobenzophenone with a specific aromatic diol represented by formula (2) can be used. This reaction generally proceeds in an organic solvent (e.g., a non-polar solvent, a high-boiling aprotic polar solvent, etc.) in the presence of an alkali metal carbonate by heating at 130 to 140°C and then further heating to 170 to 180°C.

In formula (2), R may be the same as the groups exemplified for R ¹ and R ² in formula (1) above. Preferred compounds represented by formula (2) are 1,3-dihydroxybenzene, 2,2-bis(4-hydroxyphenyl)propane, 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, and 1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene.

Examples of alkali metal carbonates include, but are not limited to, lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate.

Examples of organic solvents include toluene, xylene, anisole, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), etc. These may be used alone or in combination of two or more.

The molar ratio of 4,4'-difluorobenzophenone to the specific aromatic diol, 4,4'-difluorobenzophenone/aromatic diol, is preferably 1/1.01 to 2.0, more preferably 1/1.02 to 1.80, and even more preferably 1/1.03 to 1.50.
By mixing 4,4'-difluorobenzophenone and a specific aromatic diol in this ratio, it is possible to synthesize polyether ether ketone having hydroxyl groups at both ends.

After step A, the mixture may be purified by any known method. Examples of the purification method include a method in which water is added to the mixture after step A, the mixture is stirred, and the mixture is allowed to stand to separate the organic solvent from the aqueous solution, and a method in which the mixture after step A is poured into a poor solvent to recover a precipitate and then washed with water. The compound obtained in step A may be taken out as a varnish of the organic solvent used in step A, or it may be taken out as a solid by pouring the mixture into a poor solvent to recover a precipitate.
By the above-mentioned step A, a polyether ether ketone compound having hydroxyl groups at both ends can be obtained.

After step A, the hydroxyl groups at both ends of the polyether ether ketone compound having hydroxyl groups at both ends obtained in step A are modified in step B or B'.

（式（３）中、Ｘは塩素原子、臭素原子又はヨウ素原子を表し、Ｒ’はそれぞれ独立に水素原子、炭素数１～６のアルキル基又はハロゲン原子を表し、Ａは単結合又は炭素数１～４のアルキレン基を表す。）
で表される化合物とを塩基存在下で反応させる。工程Ｂの反応条件としては特に制限されないが、例えば、工程Ａで得られた両末端に水酸基を有するポリエーテルエーテルケトン化合物と式（３）で表される化合物とを塩基の存在下、有機溶媒と水との混合溶媒中で６０℃～１００℃で反応させる方法が挙げられる。 In step B, the polyether ether ketone having hydroxyl groups at both ends obtained in step A is reacted with a compound represented by the following formula (3):

(In formula (3), X represents a chlorine atom, a bromine atom, or an iodine atom; R' each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom; and A represents a single bond or an alkylene group having 1 to 4 carbon atoms.)
The reaction conditions for step B are not particularly limited, but an example thereof includes a method in which the polyether ether ketone compound having hydroxyl groups at both ends obtained in step A is reacted with the compound represented by formula (3) in the presence of a base in a mixed solvent of an organic solvent and water at 60° C. to 100° C.

In formula (3), the alkyl group having 1 to 6 carbon atoms represented by R' includes, like the alkyl group having 1 to 6 carbon atoms represented by R' in formula (1), a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group, and the halogen atom includes, like the halogen atom represented by R' in formula (1), a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R' in formula (3) corresponds to R' in formula (1) which is the product, and is preferably a hydrogen atom.
In formula (3), the alkylene group having 1 to 4 carbon atoms represented by A includes, like A ¹ and A ² in formula (1), a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, etc. A in formula (3) corresponds to A ¹ and A ² in formula (1) which is the product, and is preferably a methylene group.
The positional relationship between the vinyl group and the group represented by "-A-X" in the compound represented by formula (3) is not particularly limited, and examples of the compound represented by formula (3) include p-vinylbenzyl halides, m-vinylbenzyl halides, and mixtures thereof. More specific examples include p-vinylbenzyl chloride, m-vinylbenzyl chloride, a mixture of p-vinylbenzyl chloride and m-vinylbenzyl chloride, p-vinylbenzyl bromide, m-vinylbenzyl bromide, a mixture of p-vinylbenzyl bromide and m-vinylbenzyl bromide, p-vinylbenzyl iodide, m-vinylbenzyl iodide, a mixture of p-vinylbenzyl iodide and m-vinylbenzyl iodide, and the like.
The composition ratio of the mixture of p-vinylbenzyl halide and m-vinylbenzyl halide is not particularly limited, but the molar ratio of p-isomer/m-isomer is preferably 90/10 to 10/90, more preferably 75/25 to 25/75, and even more preferably 60/40 to 40/60.

Bases include, for example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and mixtures thereof.
The alkali metal hydroxide preferably has a hydroxyl group/alkali metal hydroxide ratio of 1/1.1 to 15, more preferably 1/1.5 to 10, and even more preferably 1/2 to 5, in the polyether ether ketone compound having hydroxyl groups at both ends obtained in step A.

In step B, a phase transfer catalyst can be used to improve the reaction rate. Examples of phase transfer catalysts include quaternary ammonium compounds. Specific examples include tetramethylammonium chloride, tetraethylammonium bromide, tetrabutylammonium bromide, benzyltriethylammonium chloride, and benzyltriethylammonium bromide. In terms of promoting the reaction, it is preferable to add 0.1 to 1% by mass of the phase transfer catalyst to the polyether ether ketone compound having hydroxyl groups at both ends obtained in step A.

Organic solvents used in step B include toluene, xylene, anisole, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), etc. These may be used alone or in combination of two or more.

The polyether ether ketone compound represented by the above formula (1) is obtained by step B. The polyether ether ketone compound represented by formula (1) may be used for a desired application as it is in the form of a varnish of the organic solvent used in step B, or after step B, it may be purified and isolated by any known method, for example, by reprecipitation by adding a poor solvent to the mixture after step B, and used for a desired application as a solid powder.

In step B', an aromatic nucleophilic substitution reaction between the polyether ether ketone compound having hydroxyl groups at both ends obtained in step A and 2,3,4,5,6-pentafluorostyrene can be used. The reaction between the hydroxyl group and 2,3,4,5,6-pentafluorostyrene in step B' can be described, for example, in Liquid Crystals, 2021, Vol. 48(5), pp. 672-688, and the reaction proceeds in an organic solvent (e.g., a nonpolar solvent or a high-boiling aprotic polar solvent) in the presence of an alkali metal carbonate at 40 to 50°C.

Examples of organic solvents include toluene, xylene, anisole, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), etc. These may be used alone or in combination of two or more.

Examples of alkali metal carbonates include, but are not limited to, lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, and lithium carbonate.

The molar ratio of the polyether ether ketone compound having hydroxyl groups at both ends to 2,3,4,5,6-pentafluorostyrene is preferably hydroxyl groups of the polyether ether ketone compound/2,3,4,5,6-pentafluorostyrene=1/1.1 to 10, more preferably 1/1.5 to 6, and even more preferably 1/2 to 4.

By step B', a polyether ether ketone compound represented by the above formula (1) is obtained. The polyether ether ketone compound represented by formula (1) may be used for a desired application as a varnish of the organic solvent used in step B', or after step B', it may be purified and isolated by any known method, for example, by reprecipitation by adding a poor solvent to the mixture after step B', and the obtained solid powder may be used for a desired application.

The present invention will be specifically explained below with examples and comparative examples, but the present invention is not limited to the following examples. In the examples and comparative examples, "room temperature" means 25°C.

ｎ≒１５（平均値）

以下に¹Ｈ－ＮＭＲスペクトルのピーク帰属を示す。
¹Ｈ－ＮＭＲ（４００ＭＨｚ、ＣＤＣｌ₃）δ＝１．６８（ｓ、２Ｈ、－ＣＨ₃）、δ１．７３（ｓ、６Ｈ、－ＣＨ₃）、６．７－７．８（ｍ、２１Ｈ、Ａｒ－Ｈ） Example 1 Synthesis of polyether ether ketone compound A-1 52.37 g (0.24 mol) of 4,4'-difluorobenzophenone, 68.49 g (0.30 mol) of 2,2-bis(4-hydroxyphenyl)propane, 74.63 g of potassium carbonate, 300 g of N-methyl-2-pyrrolidone, and 150 g of toluene were added to a 1 L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser, and a thermometer, and the toluene was refluxed at 130 to 140°C for 4 hours. Next, the mixture in the flask was heated to 170 to 180°C, and stirred for 10 hours while distilling off the toluene. After the reaction was completed, the mixture in the flask was cooled to room temperature, and then poured into methanol to recover the precipitate, which was washed several times with pure water and methanol, and then dried in a dryer at 100°C for 12 hours to obtain a white powder with a yield of 93%. The ¹ H-NMR spectrum of the product is shown in FIG. 1, and the FT-IR spectrum is shown in FIG. 2. From these results, it was found that the product was a polyether ether ketone compound (number average molecular weight: 6000) having hydroxyl groups at both ends and represented by the following structure.

n ≒ 15 (average value)

The peak assignments of the ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, CDCl ₃ ) δ = 1.68 (s, 2H, -CH ₃ ), δ 1.73 (s, 6H, -CH ₃ ), 6.7-7.8 (m, 21H, Ar-H)

ｎ≒１５（平均値）

以下に¹Ｈ－ＮＭＲスペクトルのピーク帰属を示す。
¹Ｈ－ＮＭＲ（４００ＭＨｚ、ＣＤＣｌ₃）δ＝１．７１（ｓ、２Ｈ、－ＣＨ₃）、δ１．７３（ｓ、６Ｈ、－ＣＨ₃）δ５．７４（ｄ、０．３Ｈ、－ＣＨ＝ＣＨ）、δ６．１３（ｄ、０．３Ｈ、－ＣＨ＝ＣＨ）、δ６．７１（ｍ、０．３Ｈ、－ＣＨ＝ＣＨ）、δ６．９１－７．８１（ｍ、２５Ｈ、Ａｒ－Ｈ） In a 1L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser and a thermometer, 15.00 g of the polyether ether ketone compound having hydroxyl groups at both ends obtained above, 11.68 g (0.06 mol) of 2,3,4,5,6-pentafluorostyrene, 20.78 g of potassium carbonate and 100 g of N,N-dimethylformamide were added and stirred at 40 to 50 ° C for 12 hours. After the reaction was completed, the mixture in the flask was cooled to room temperature, and then toluene was added to the flask, washed several times with pure water, and poured into methanol. The precipitate was collected and dried at 50 ° C for 12 hours to obtain a product as a white-brown powder with a yield of 93%. The ¹ H-NMR spectrum of the product is shown in FIG. 3 and the FT-IR spectrum is shown in FIG. 4. From these results, it was found that the product was a polyether ether ketone compound (number average molecular weight: 6700) having fluorostyryl groups at both ends represented by the following structure.

n ≒ 15 (average value)

The peak assignments of the ¹ H-NMR spectrum are shown below.
¹ H-NMR (400 MHz, CDCl ₃ ) δ = 1.71 (s, 2H, -CH ₃ ), δ 1.73 (s, 6H, -CH ₃ ) δ5.74 (d, 0.3H, -CH=CH), δ6.13 (d, 0.3H, -CH=CH), δ6.71 (m, 0.3H, -CH=CH), δ6.91-7.81 (m, 25H, Ar-H)

Comparing the spectra in FIG. 2 and FIG. 4, the absorption attributable to the hydroxyl group near 3500 cm ⁻¹ seen in FIG. 2 disappeared, and a new signal attributable to C═C was confirmed near 1700 cm ⁻¹ .

ｎ≒１１（平均値） Example 2 Synthesis of polyether ether ketone compound A-2 52.37 g (0.24 mol) of 4,4'-difluorobenzophenone, 103.94 g (0.30 mol) of 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, 74.63 g of potassium carbonate, 300 g of N-methyl-2-pyrrolidone, and 150 g of toluene were added to a 1 L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser, and a thermometer, and the toluene was refluxed at 130 to 140 ° C. for 4 hours. Next, the mixture in the flask was heated to 170 to 180 ° C., and stirred for 10 hours while distilling off the toluene. After the reaction was completed, the mixture in the flask was cooled to room temperature, and then poured into methanol to recover the precipitate, which was washed several times with pure water and methanol, and then dried in a dryer at 100 ° C. for 12 hours to obtain a white powder with a yield of 95%. From the ¹ H-NMR spectrum of the product, it was found that the product was a polyether ether ketone compound (number average molecular weight: 6000) having hydroxyl groups at both ends and represented by the following structure.

n ≒ 11 (average value)

ｎ≒１１（平均値） In a 1L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser and a thermometer, 15.00 g of the polyether ether ketone compound having hydroxyl groups at both ends obtained above, 11.68 g (0.06 mol) of 2,3,4,5,6-pentafluorostyrene, 20.78 g of potassium carbonate and 100 g of N,N-dimethylformamide were added and stirred at 40 to 50 ° C for 12 hours. After the reaction was completed, the mixture in the flask was cooled to room temperature, and then toluene was added to the flask, washed several times with pure water, and poured into methanol. The precipitate was collected and dried at 50 ° C for 12 hours to obtain a product as a white-brown powder with a yield of 92%. From the results of the ¹ H-NMR spectrum of the product, it was found to be a polyether ether ketone compound (number average molecular weight: 6900) having fluorostyryl groups at both ends represented by the following structure.

n ≒ 11 (average value)

Example 3 Synthesis of polyether ether ketone compound A-3 45.82 g (0.21 mol) of 4,4'-difluorobenzophenone, 77.96 g (0.23 mol) of 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, 107.80 g of potassium carbonate, 450 g of N-methyl-2-pyrrolidone, and 170 g of toluene were added to a 1 L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser, and a thermometer, and the toluene was refluxed for 4 hours at 130 to 140° C. Next, the mixture in the flask was heated to 170 to 180° C., and stirred for 10 hours while distilling off the toluene. After completion of the reaction, the mixture in the flask was cooled to room temperature and then poured into methanol to recover the precipitate. The precipitate was washed several times with pure water and methanol and then dried in a dryer at 100° C. for 12 hours to obtain a polyether ether ketone compound having hydroxyl groups at both ends (white powder, number average molecular weight: 18,000, n≒33 (average value)).

ｎ≒３３（平均値） In a 1L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser and a thermometer, 15.00 g of the polyether ether ketone compound having hydroxyl groups at both ends obtained above, 1.51 g (0.008 mol) of 2,3,4,5,6-pentafluorostyrene, 2.68 g of potassium carbonate and 100 g of N,N-dimethylformamide were added and stirred at 40 to 50 ° C for 12 hours. After the reaction was completed, the mixture in the flask was cooled to room temperature, and then toluene was added to the flask, washed several times with pure water, and poured into methanol. The precipitate was collected and dried at 50 ° C for 12 hours to obtain a product as a pale yellow powder with a yield of 93%. From the ¹ H-NMR spectrum of the product, it was found that the product was a polyether ether ketone compound (number average molecular weight: 19,000) having a fluorostyryl group at the end represented by the following structure.

n ≒ 33 (average value)

Example 4 Synthesis of polyether ether ketone compound A-4 45.82 g (0.21 mol) of 4,4'-difluorobenzophenone, 75.36 g (0.22 mol) of 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, 107.80 g of potassium carbonate, 450 g of N-methyl-2-pyrrolidone, and 170 g of toluene were added to a 1 L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser, and a thermometer, and the toluene was refluxed for 4 hours at 130 to 140° C. Next, the mixture in the flask was heated to 170 to 180° C., and stirred for 10 hours while distilling off the toluene. After completion of the reaction, the mixture in the flask was cooled to room temperature and then poured into methanol to recover the precipitate. The precipitate was washed several times with pure water and methanol and then dried in a dryer at 100° C. for 12 hours to obtain a polyether ether ketone compound having a hydroxyl group at its terminal (white powder, number average molecular weight: 30,000, n≒59 (average value)).

ｎ≒５９（平均値） In a 1L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser and a thermometer, 15.00 g of the polyether ether ketone compound having a hydroxyl group at the end obtained above, 0.77 g (0.004 mol) of 2,3,4,5,6-pentafluorostyrene, 1.37 g of potassium carbonate and 100 g of N,N-dimethylformamide were added and stirred at 40 to 50 ° C for 12 hours. After the reaction was completed, the mixture in the flask was cooled to room temperature, and then toluene was added to the flask, washed several times with pure water, and poured into methanol. The precipitate was collected and dried at 50 ° C for 12 hours to obtain a product as a pale yellow powder with a yield of 92%. From the ¹ H-NMR spectrum of the product, it was found that the product was a polyether ether ketone compound (number average molecular weight: 31000) having a fluorostyryl group at the end represented by the following structure.

n ≒ 59 (average value)

ｎ≒１１（平均値） Example 5 Synthesis of polyether ether ketone compound A-5 15.00 g of the polyether ether ketone compound having a hydroxyl group at the end synthesized in Example 2, 0.006 g (0.02 mmol) of tetra-n-butylammonium bromide, 30 g of toluene, and 1 g of a 50% aqueous sodium hydroxide solution were added to a 1 L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser, and a thermometer, and the mixture was stirred at room temperature for 30 minutes. Next, 1.06 g (0.007 mol) of vinylbenzyl chloride (p-form: m-form = 45-55: 45-55) was dropped into the flask and reacted at 65 ° C. for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, washed with water five times, and then poured into methanol. The precipitate was collected by filtration and dried in a dryer at 70 ° C. for 12 hours, to obtain a product (light yellow powder) in a yield of 92%. From the ¹ H-NMR spectrum of the product, it was found that the product was a polyether ether ketone compound (number average molecular weight: 6,800) having a vinylbenzyl ether group at its terminal, as represented by the following structure.

n ≒ 11 (average value)

Comparative Example 1
(A'-1)
In a 1L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser and a thermometer, 65.46 g (0.30 mol) of 4,4'-difluorobenzophenone, 54.79 g (0.24 mol) of 2,2-bis(4-hydroxyphenyl)propane, 74.63 g of potassium carbonate, 300 g of N-methyl-2-pyrrolidone and 150 g of toluene were added, and the toluene was refluxed at 130 to 140 ° C for 4 hours. Next, the mixture in the flask was heated to 170 to 180 ° C, and stirred for 10 hours while distilling off the toluene. After cooling the mixture in the flask to room temperature, 13.10 g (0.12 mol) of 4-aminophenol, 1.0 g of potassium carbonate, 30 g of N-methyl-2-pyrrolidone and 15 g of toluene were added, and the toluene was refluxed at 130 to 140 ° C for 3 hours. Next, the mixture in the flask was heated to 170 to 180°C and reacted for 4 hours while distilling off toluene. After the reaction was completed, the mixture in the flask was cooled to room temperature and then poured into methanol to recover the precipitate, which was washed several times with pure water and methanol and then dried in a dryer at 100°C for 12 hours to obtain a polyether ether ketone compound having amino groups at both ends (white powder).

ｎ≒１５（平均値） Next, 30 g of the polyether ether ketone compound having an amino group at the end obtained above, 2.17 g (0.02 moles) of maleic anhydride, and 100 g of anisole were added to a 1 L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser, and a thermometer, and the mixture was stirred at room temperature for 1 hour to synthesize an amic acid, and then the temperature was raised to 150° C. and the reaction was carried out for 5 hours. After the reaction was completed, the mixture in the flask was cooled to room temperature, poured into methanol to recover the precipitate, washed several times with methanol, and then dried in a dryer at 100° C. for 12 hours to obtain a product (white powder) with a yield of 93%. From the ¹ H-NMR spectrum of the product, it was found that the product was a polyether ether ketone compound (number average molecular weight: 6600) having maleimide groups at both ends represented by the following structure.

n ≒ 15 (average value)

(A'-2): Liquid bisphenol A type epoxy resin (epoxy equivalent 180, "jER828EL" manufactured by Japan Epoxy Resins Co., Ltd.)

（式中のＣ₃₆Ｈ₇₀はダイマー酸に由来する炭化水素基である。）
ｎ≒５（平均値） (A'-3): Bismaleimide compound represented by the following formula (SLK-3000, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 7200)

(In the formula, C ₃₆ H ₇₀ is a hydrocarbon group derived from a dimer acid.)
n ≒ 5 (average value)

上記表１に示すように、本発明のポリエーテルエーテルケトン化合物は、比較例１で合成したポリエーテルエーテルケトン化合物よりも反応工程が１つ短縮されより簡便に合成することができる。

As shown in Table 1 above, the polyether ether ketone compound of the present invention can be synthesized more simply than the polyether ether ketone compound synthesized in Comparative Example 1 by shortening one reaction step.

<Solubility of polyetheretherketone in solvents>
The solubility of the polyether ether ketone compounds (A-1), (A-2), (A-3), (A-4) and (A-5) as well as PEEK (commercially available PEEK powder, polyether ether ketone, VICTREX151G, melting point 343°C, Tg 147°C) as a comparative compound in various solvents was evaluated, and the evaluation results are shown in Table 2.
The solvent solubility was evaluated by adding each solvent to the compound to be evaluated so that the non-volatile content was 50% by mass.
If the solution is uniformly dissolved (no insoluble matter) and flows, it is considered to be ok.
If it does not dissolve (contains insoluble matter) or does not flow, mark it as "X".
The solvents used were chloroform, THF (tetrahydrofuran), toluene, DMSO (dimethylsulfoxide), and NMP (N-methyl-2-pyrrolidone).

<Preparation of Cured Resin Film>
The polyether ether ketone compounds (A-1), (A-2), (A-3), (A-4) and (A-5) as well as the comparative compounds (A'-1), (A'-2) and (A'-3) were each dissolved in toluene to prepare a toluene varnish having a non-volatile content of 65% by mass.
To a toluene varnish containing (A-1), (A-2), (A-3), (A-4), (A-5), (A'-1) or (A'-3), 0.2 g of dicumyl peroxide (Percumyl D, manufactured by NOF Corp.) was added per 10 g of solid content, and the mixture was thoroughly stirred at room temperature to obtain a varnish-like composition.
To the toluene varnish containing (A'-2), 0.1 g of 2-ethyl-4-methylimidazole (2E4MZ: manufactured by Shikoku Kasei Holdings Co., Ltd.) was added per 10 g of solids to obtain a varnish-like composition in the same manner.
The varnish-like composition of each example was applied to a support film made of a PET film with a thickness of 38 μm using a roller coater, and the solvent was removed by drying at 100° C. for 10 minutes to obtain an uncured resin film. A frame with a diameter of 200 mm and a thickness of 200 μm was prepared, and the uncured resin film was sandwiched between a PET film (E7006, manufactured by Toyobo Co., Ltd.) with a thickness of 50 μm that had been subjected to a release treatment, and molded using a vacuum press machine (manufactured by Nikko Materials Co., Ltd.) under conditions of 160° C. for 5 minutes and 4.5 kgf/cm ² , and post-cured at 180° C. for 3 hours to obtain a cured product (cured resin film).

<Dielectric properties>
Using the cured resin film prepared above, a network analyzer (E5063-2D5 manufactured by Keysight Corporation) was connected to a strip line (manufactured by Keycom Corporation) to measure the relative dielectric constant and dielectric loss tangent of the cured resin film at a frequency of 10 GHz. The relative dielectric constant was designated Dk and the dielectric loss tangent was designated Df, and the results are shown in Table 3.

<Moisture absorption>
The cured resin film prepared above was stored for 24 hours under conditions of 85°C and 85% humidity, and the cured resin film after storage was used to connect a network analyzer (E5063-2D5 manufactured by Keysight) and a strip line (manufactured by Keycom Corporation) to measure the relative dielectric constant and dielectric loss tangent of the cured resin film at a frequency of 10 GHz. The results are shown in Table 3.

<Heat resistance>
The cured resin film prepared above was stored for 1000 hours under the condition of 150° C., and the cured resin film after storage was used to connect a network analyzer (E5063-2D5 manufactured by Keysight) and a strip line (manufactured by Keycom Corporation) to measure the relative dielectric constant and dielectric loss tangent of the cured resin film at a frequency of 10 GHz. The results are shown in Table 3.

<Coefficient of Thermal Expansion (CTE)>
The coefficient of thermal expansion (CTE) of the cured resin film was measured using a TMA-Q400 made by TA Instruments Co., Ltd. The coefficient of thermal expansion was calculated from values in the range of 0 to 40° C. The results are shown in Table 3.

From the above results, it was found that the polyether ether ketone compound of the present invention has excellent dielectric properties (low relative dielectric constant and low dielectric tangent), high heat resistance, and low moisture absorption.
The polyether ether ketone compound having a maleimide group at its end in Comparative Example 1 had excellent dielectric properties, high heat resistance, and low moisture absorption, but had disadvantages in production such as many synthesis steps and long reaction times as shown in Table 1. The compound in Comparative Example 2 had a low CTE but insufficient dielectric properties. The compound in Comparative Example 3 showed excellent dielectric properties but a high CTE value.

Claims (5)

A polyether ether ketone compound represented by the following formula (1):

(In formula (1), ^R1 and ^R2 each independently represent a substituted or unsubstituted aromatic group, R' each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a halogen atom, ^A1 and ^A2 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms, and n is a number from 1 to 100.) 2. The polyether ether ketone compound according to claim 1, wherein in formula (1), R ¹ and R ² each independently represent a group having an aromatic structure having 6 to 30 carbon atoms. The polyether ether ketone compound according to claim 1, wherein the number average molecular weight of the polyether ether ketone compound represented by formula (1) is 700 to 50,000. 4,4'-difluorobenzophenone,
The following formula (2)

(In formula (2), R represents a substituted or unsubstituted aromatic group.)
A compound represented by the formula:
in the presence of an alkali metal carbonate to obtain a polyether ether ketone compound having hydroxyl groups at both ends; and

the polyether ether ketone compound having hydroxyl groups at both ends obtained in step A;
The following formula (3)

(In formula (3), X represents a chlorine atom, a bromine atom, or an iodine atom; R' each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom; and A represents a single bond or an alkylene group having 1 to 4 carbon atoms.)
A compound represented by the formula:
Step B: reacting in the presence of a base; or
the polyether ether ketone compound having hydroxyl groups at both ends obtained in step A;
2,3,4,5,6-pentafluorostyrene,
in the presence of an alkali metal carbonate.
The method for producing the polyether ether ketone compound according to any one of claims 1 to 3, comprising: The method for producing a polyether ether ketone compound according to claim 4, wherein in step A, 4,4'-difluorobenzophenone and a compound represented by formula (2) are reacted in a molar ratio of 4,4'-difluorobenzophenone/compound represented by formula (2) = 1/1.01 to 2.0.