JP2024038779A - Aromatic polyetherketone resin, method for producing the resin, composition containing the resin, molded article - Google Patents

Abstract

To provide a PAEK resin which can lower a molding processing temperature without impairing excellent characteristics as a super engineering plastic resin, especially, heat resistance.SOLUTION: An aromatic polyether ketone resin has a flow initiation temperature of 330°C or lower, reduction viscosity of 0.6 (dL/g) or more and a glass transition temperature of 140°C or higher.SELECTED DRAWING: None

Description

The present invention relates to an aromatic polyetherketone resin having a specific flow initiation temperature and reduced viscosity, a method for producing the same, a resin composition containing the same, and a molded article thereof.

Aromatic polyetherketone resin (hereinafter referred to as ``PAEK resin'') is a so-called super engineering plastic (hereinafter referred to as ``super engineering plastic'') that has excellent mechanical properties such as heat resistance, chemical resistance, toughness, and dimensional stability. It is widely used in electrical and electronic related parts, automobile parts, medical parts, textiles, film applications, etc.
For example, aromatic polyetheretherketone resin (hereinafter referred to as "PEEK resin"), which is one of the PAEK resins, has two ether sites and one ketone site in the repeating structure of the resin, and their higher order regularity It is known that it exhibits high thermal stability, mechanical properties, etc. as a partially crystalline resin due to (Patent Document 1). Furthermore, aromatic polyetheretherketoneketone resin (PEEKK resin), which is a PAEK resin with one ketone group added to the repeating structure of PEEK resin, is widely known as a super engineering plastic with similar excellent resin properties. (Patent Document 2, Non-Patent Document 1).

Japanese Unexamined Patent Publication No. 54-90296 Japanese Patent Application Publication No. 2005-133047

Eur. Polym. J. Vol. 33, No. 6, pp. 913-918. 1997

Partially crystalline super engineering plastics represented by the above-mentioned PEEK resin and PEEKK resin exhibit a glass transition temperature of 140°C or higher and are excellent in heat resistance, while their melting point is as high as 340°C or higher. Therefore, in general, it is necessary to raise the molding temperature to 390°C or higher to maintain resin fluidity, which poses an issue of energy load during manufacturing, and it is also difficult to easily manufacture molded objects with complex shapes by injection molding. It's not easy either. Further, when the molecular weight of the resin is kept low in order to improve the fluidity during molding, problems such as a decrease in the mechanical properties of the resulting molded article arise.
Therefore, an object of the present invention is to provide a PAEK resin that can lower the molding temperature without impairing its excellent properties as a super engineering plastic, especially its heat resistance.

In view of the above-mentioned current situation, the present invention aims to lower the molding temperature by imparting a specific structure to the repeating unit of the resin, and by controlling the flow start temperature and reduced viscosity of the resin within a specific range. We have discovered a PAEK resin that can be used and a method for producing the same, and have solved the above problems.
That is, the gist of the present invention is as follows.

[1] An aromatic polyetherketone resin having a flow start temperature of 330°C or lower, a reduced viscosity of 0.6 (dL/g) or higher, and a glass transition temperature of 140°C or higher.
[2] The aromatic polyetherketone resin according to [1], which contains a repeating unit represented by the following general formula (1).

（式（１）において、構造Ａは、下記一般式（２）、式（３）及び式（４）からなる群より選ばれるいずれか１つであり、構造Ｂは、置換していてもよい二価の芳香族炭化水素環である）

(In formula (1), structure A is any one selected from the group consisting of general formula (2), formula (3), and formula (4) below, and structure B may be substituted. divalent aromatic hydrocarbon ring)

[3] The aromatic polyetherketone resin according to [2], wherein the ratio of ketone groups to ether groups contained in the structure of the aromatic polyetherketone resin is 1 or more.
[4] The aromatic polyetherketone resin according to [2] or [3], which is a copolymer containing two or more types of repeating units represented by the general formula (1).
[5] The aromatic polyetherketone according to any one of [2] to [4], which is a mixture of two or more types of aromatic polyetherketone resins containing repeating units represented by the general formula (1). resin.

[6] The structure A according to any one of [2] to [5], wherein the structure A is any one selected from the group consisting of the following general formula (2A), formula (3A), and formula (4A). Aromatic polyetherketone resin.

[7] The aromatic polyetherketone resin according to any one of [2] to [6], wherein the structure B is any one selected from the group consisting of the following general formulas (5) to (10). .

In formula (7), n1 is 0 or 1.

[8] The aromatic polyetherketone resin according to any one of [2] to [7], wherein the structure B is the following general formula (5B), (6B), or (7B).

[9] The aromatic polyetherketone resin according to any one of [1] to [8], which has a flow initiation temperature of 250° C. or higher.
[10] The aromatic polyetherketone resin according to any one of [1] to [9], which has a reduced viscosity of 2.0 (dL/g) or less.
[11] The aromatic polyetherketone resin according to any one of [1] to [10], which has a melting point (Tm) in differential scanning calorimetry of 250°C or more and 325°C or less.

[12] The aromatic polyetherketone resin according to any one of [1] to [11], which has a Td5 of 420° C. or higher as measured by TG/DTA.

[13] A resin composition comprising the aromatic polyetherketone resin according to any one of [1] to [12].
[14] The resin composition according to [13], containing a filler.
[15] A molded article obtained using the aromatic polyetherketone resin according to any one of [1] to [12].
[16] A molded article obtained using the resin composition described in [13] or [14].

[17] In the presence of a base, a dihalogen compound represented by the following general formula (11) and a diol compound represented by the following general formula (12) are heated in a solvent to cause a polycondensation reaction, resulting in the following A method for producing an aromatic polyetherketone resin, which produces an aromatic polyetherketone resin containing a repeating unit represented by general formula (1),
In the polycondensation reaction, a non-sublimating aprotic solvent having a boiling point of 200° C. or higher is allowed to coexist in the method for producing the aromatic polyetherketone resin.

(In formula (1), formula (11) and formula (12), structure A represents any one selected from the group consisting of the following general formula (2), formula (3) and formula (4), Structure B represents an optionally substituted divalent aromatic hydrocarbon ring, and X represents a halogen atom.)

[18] The method for producing an aromatic polyetherketone resin according to [17], wherein the non-sublimable aprotic solvent with a boiling point of 200° C. or higher is triglyme, butyl diglyme, or tetraglyme. .
[19] [17] or [18] comprising a step of suspending and washing the aromatic polyetherketone resin crude product produced in the polycondensation reaction with an aprotic solvent having a dielectric constant of 30 or more at 25°C. ] The method for producing an aromatic polyetherketone resin.
[20] The aprotic solvent having a dielectric constant of 30 or more at 25° C. or higher is any one of N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and sulfolane. The method for producing an aromatic polyetherketone resin according to [19].
[21] The aromatic polyetherketone resin has a flow start temperature of 330°C or lower, a reduced viscosity of 0.6 (dL/g) or higher, and a glass transition temperature of 140°C or higher, [17] The method for producing an aromatic polyetherketone resin according to any one of [20].

The PAEK resin of the present invention has a flow start temperature of 330°C or lower, a reduced viscosity of 0.6 (dL/g) or higher, and a glass transition temperature of 140°C or higher, so it has excellent heat resistance and mechanical properties as a super engineering plastic. Since the molding temperature can be lowered without impairing the physical properties, the resin is less likely to undergo deterioration due to high-temperature heating during processing, and has excellent molding fluidity, so even molded objects with complex shapes can be easily produced.

Hereinafter, the present invention will be described in detail by showing embodiments, examples, etc., but the present invention should not be interpreted as being limited to the embodiments, examples, etc. shown below.
In this specification, unless otherwise specified, "~" is used to include the numerical values written before and after it as a lower limit value and an upper limit value.
Moreover, "independently" used when describing two or more objects together is used to mean that the two or more objects may be the same or different.

[First embodiment]
The first embodiment of the present invention is an aromatic polyetherketone resin having a flow start temperature of 330°C or lower, a reduced viscosity of 0.6 (dL/g) or higher, and a glass transition temperature of 140°C or higher. PAEK resin).

<Aromatic polyetherketone resin>
The PAEK resin of the present invention has a repeating structure consisting of an optionally substituted aromatic ring and a skeleton containing an ether group and a ketone group bonding the aromatic ring. Polyetherketone resin (hereinafter referred to as "PEK resin") containing one ether group and one ketone group in the repeating structure, PEEK resin containing two ether groups and one ketone group, two ether groups and a ketone group. Examples include a PEEKK resin containing two groups, a PEKEKK resin containing two ether groups and three ketone groups, and the like. Among these, PEEK resin and PEEKK resin are preferred from the viewpoint of easy availability of raw materials, efficiency of synthesis reaction, etc., and PEEKK resin is more preferred from the viewpoint of a large number of variations in molecular design and manufacturing cost.

The structures of the various PAEK resins described above are shown below. An example of the manufacturing route for PEEKK resin will also be shown.

(Flow starting temperature)
The flow start temperature in the present invention is the flow start temperature measured with a Koka type flow tester. Specifically, using a Koka type flow tester CFT-500C (manufactured by Shimadzu Corporation), the sample was placed in a cylinder with an inner diameter of 10 mm equipped with a nozzle with a hole diameter of φ1 mm and a length of 2 mm, and was dried with hot air at 130° C. for 3 hours or more. The temperature at which the resin starts to flow from the nozzle outlet when 1.5 g of the resin sample is put in, preheated at 290°C for 5 minutes, and the plunger of the flow tester is lowered at a heating rate of 3°C/min and a load of 40 kg/ ^cm3 . It is. (Compliant with JIS standard: K7210-1 2014)
Note that, as shown in this example, the preheating temperature is preferably changed as appropriate depending on the type of resin.

The flow start temperature of the PAEK resin of the present invention is usually 200°C or higher, preferably 210°C or higher, more preferably 220°C or higher, even more preferably 230°C or higher, particularly preferably 240°C or higher. The temperature is most preferably 250°C or higher. Further, the temperature is usually 330°C or lower, preferably 325°C or lower, more preferably 310°C or lower, and particularly preferably 300°C or lower. A preferred form of the PAEK resin of the present invention has a furan ring, a thiophene ring, and a pyridine ring in its structure, and by introducing these heterocyclic structures into its structure, it is possible to achieve a preferable melting point range.
In this evaluation method, the lower the resin starts to flow at a lower temperature, the lower the heating temperature during molding can be set, so that deterioration due to high temperature heating of the resin during processing is less likely to occur. Furthermore, since it has excellent molding fluidity, it can be easily manufactured even into a molded article having a complicated shape.

(reduced viscosity)
The reduced viscosity (η sp/c) of the present invention refers to the specific viscosity ( ηsp) was measured and divided by the concentration c. It is known that the reduced viscosity is correlated with the molecular weight of the resin, and it is common to relatively compare the molecular weight of PAEK resins based on reduced viscosity values. That is, this shows that the PAEK resin of the present invention having a reduced viscosity of 0.6 (dL/g) or more has a sufficiently high molecular weight to the extent that its properties do not change significantly due to molding.

The reduced viscosity of the PAEK resin of the present invention is usually 0.6 dL/g or more. Further, it is preferably 0.8 dL/g or more, particularly preferably 0.9 dL/g or more. On the other hand, the reduced viscosity of the aromatic polyetherketone resin of the present invention is usually 3.5 dL/g or less, preferably 3.0 dL/g or less, and more preferably 2.5 dL/g or less. It is more preferably 2.0 dL/g or less, particularly preferably 1.9 dL/g or less, particularly preferably 1.8 dL/g or less, particularly preferably 1.7 dL/g or less. Most preferably, it is 1.6 dL/g or less.

In order to obtain the PAEK resin of the present invention as a polymer having a reduced viscosity within a preferable range, it is sufficient to carry out the reaction in the coexistence of a non-sublimating aprotic solvent with a boiling point of 200°C or higher in the polycondensation reaction. This can be achieved by obtaining a molecular weight polymer. In addition, low molecular weight components such as by-produced cyclic oligomers are removed by suspending and cleaning the produced aromatic polyetherketone resin crude product with an aprotic solvent having a dielectric constant of 30 or more at 25°C. This is preferable, and thereby the reduced viscosity described above can be achieved more effectively. By setting the above-mentioned preferable reduced viscosity, it is possible to produce a molded article in which the PAEK resin has an appropriate melt viscosity, has excellent moldability, crystallinity, and excellent heat resistance. In the present invention, the reduced viscosity can be measured by the method described in the Examples described below. As described above, the PAEK resin shown in the first embodiment of the present invention has a flow start temperature of 330 ° C. or lower, In addition, since the reduced viscosity is 0.6 (dL/g) or more, the resin is less likely to undergo deterioration due to high-temperature heating during molding, making it excellent as a super engineering plastic.

(Glass transition temperature (Tg))
Super engineering plastics are required to have high heat resistance, which requires them to have a high glass transition temperature. The glass transition temperature of the PAEK resin of the present invention is usually 140°C or higher, preferably 145°C, since it exhibits high heat resistance. Further, the temperature is usually 170°C or lower, preferably 165°C or lower. A preferred form of the PAEK resin of the present invention has a furan ring, a thiophene ring, and a pyridine ring in its structure, but even if these heterocyclic structures are introduced into the polymer structure, the presently commonly distributed benzene ring A high glass transition temperature comparable to that of PAEK resins can be maintained. Furthermore, the PAEK resin of the present invention has a repeating structure consisting of a skeleton containing ether groups and ketone groups in the resin structure. In order for the PAEK resin of the present invention to have a glass transition temperature in a preferable range, it is preferable that the number of ketone groups in the resin structure is equal to or greater than the number of ether groups because the transition temperature is lowered. Specifically, it is preferable that the ratio of ketone groups to ether groups is set to ``ketone group/ether group = 1 or more.The glass transition temperature can be determined by, for example, differential thermal analysis (DTA) or differential scanning calorimetry (DSC). However, in the present invention, it is measured by differential scanning calorimetry (DSC), which is the method described in the Examples below.

(Melting point (Tm))
The melting point of the PAEK resin of the present invention is usually 200°C or higher, preferably 210°C or higher, more preferably 220°C or higher, still more preferably 230°C or higher, and especially The temperature is preferably 240°C or higher, most preferably 250°C or higher. Further, the temperature is usually 340°C or lower, preferably 325°C or lower, more preferably 310°C or lower, particularly preferably 300°C or lower. A preferred form of the PAEK resin of the present invention has a furan ring, a thiophene ring, and a pyridine ring in its structure, and by introducing these heterocyclic structures into the polymer structure, it is possible to achieve a preferable melting point range. Note that any method can be used to measure the melting point of the PAEK resin, and in the present invention, it is measured by the method described in the Examples below. The melting point can be measured by a thermal analysis method such as a differential thermal analysis method, or simply by a visual method (JIS K6220).

(5% weight loss temperature (Td5))
In the present invention, the 5% weight loss temperature (Td5) is measured by TG/DTA.
There is no upper limit to the 5% weight loss temperature (Td5) of the PAEK resin of the present invention as long as heat resistance and mechanical properties are not impaired. However, since it has particularly excellent heat resistance and can be applied to engineering plastics, the temperature is usually 400°C or higher, preferably 410°C or higher, and more preferably 420°C or higher. In order to obtain the PAEK resin of the present invention as a polymer having Td5 within a preferable range, sufficient molecular weight can be obtained by carrying out the reaction in the coexistence of a non-sublimating aprotic solvent with a boiling point of 200°C or higher in the polycondensation reaction. This can be achieved by obtaining a polymer of In addition, low molecular weight components such as by-produced cyclic oligomers are removed by suspending and cleaning the produced aromatic polyetherketone resin crude product with an aprotic solvent having a dielectric constant of 30 or more at 25°C. This is preferable, and thereby the above-mentioned Td5 can be achieved more effectively. Note that any method can be used to measure Td5 of the aromatic polyetherketone resin, and in the present invention, it can be measured by the method described in the Examples below.

(Structure of PAEK resin)
The aromatic polyetherketone resin of the present invention preferably contains a repeating unit represented by the following general formula (1), and in formula (1), structure B is an optionally substituted divalent aromatic carbonized It is a hydrogen ring, and structure A is any one selected from the group consisting of the following general formula (2), formula (3), and formula (4).

As mentioned above, from the viewpoint of making the PAEK resin of the present invention have a flow start temperature of 330°C or lower, a reduced viscosity of 0.6 (dL/g) or higher, and a glass transition temperature of 140°C or higher, the structure Specific examples of A include the following. Note that * in the figure below represents a binding site.

Structure B is preferably a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 20 carbon atoms. In addition, it may be a structure in which two or more types of aromatic hydrocarbon rings are connected, but when the aromatic hydrocarbon rings are connected directly, or by a substituent, the substituent Preferably, it does not contain an ether group. Moreover, it is more preferable that it is unsubstituted.

Specifically, structure B is preferably any one selected from the group consisting of general formulas (5) to (10) below. Note that * in the figure below represents a binding site.

In formula (7), n1 is 0 or 1.

More specifically, structure B includes structures represented by the following formulas B-1 to B13.

PAEKs, which are currently in general circulation and consist of benzene rings, ether groups, and ketone groups, are all semicrystalline polymers, and have a high melting point and sufficient crystallinity, resulting in excellent heat resistance, mechanical properties, and chemical resistance. This is one of the reasons for performance such as durability and flame retardancy. The reason for its high crystallinity is that the ether and ketone groups in its structure form a regular zigzag structure. The preferred form of PAEK resin of the present invention has a furan ring, a thiophene ring, and a pyridine ring in structure A in structure (1), but in order to have a structure with sufficient crystallinity, the PAEK resin has a zigzag structure as regular as possible. A sufficiently crystalline polymer can be produced by designing the bonding positions of these heterocycles so that they do not collapse. The same applies to ring B. Specifically, ring A includes a furanyl group (A-1) with a ketone group bonded to the 2 and 5 positions, a thienyl group (A-5) with a ketone group bonded to the 2 and 5 positions, and a thienyl group (A-5) with a ketone group bonded to the 2 and 5 positions. A pyridinyl group (A-9) to which a ketone group is bonded is desirable for achieving high crystallinity.

Ring B is preferably B-1, B-5, B-6, B-7, B-8, or B-9. Incidentally, the crystallinity of the PAEK resin of the present invention can be evaluated by the enthalpy of fusion described below. It can be seen that the larger the melting enthalpy observed under the same measurement conditions, the higher the crystallinity.

Next, a specific example of structure (1) will be shown. However, ring A and ring B are not limited to these.

Among the above specific examples, preferred structures are (1)-1, (1)-2, (1)-3, and (1)-4 in terms of the polymer flow start temperature being 330°C or lower and the melting point being easy to mold. , (1)-5, (1)-21, (1)-22, (1)-23, (1)-24, (1)-25, (1)-41, (1)-42, ( 1)-43, (1)-44, (1)-45, and (1)-1, (1)-2, (1)-4, ( 1)-21, (1)-22, (1)-24, (1)-41, (1)-42, and (1)-44 are more preferred.

(Copolymerization/blend)
In the PAEK resin of the present invention, two or more types of PAEK resins having different ring A and ring B can be mixed and used in any ratio. Moreover, the PAEK resin of the present invention and two or more types of commercially available PAEK resins can be mixed and used. It can also be used as a copolymer containing two or more types of repeating units represented by (1). However, when blending with a PAEK resin other than the PAEK resin of the present invention, it has a melting point that is easy to mold with a flow start temperature of 330°C or lower, and stable moldability with a reduced viscosity of 0.6 (dL/g) or higher. In terms of the need for high crystallinity of the polymer, the content of the PAEK resin component of the present invention is preferably 50% by mass, more preferably 70% by mass or more, based on the entire mixed composition. More preferably 90% by mass or more.

<Resin composition>
The PAEK resin of the present invention may be further mixed with resins other than the PAEK resin of the present invention, additives, etc., and used as a composition, depending on the intended use, required performance, etc. As components such as resins other than the PAEK resin of the present invention and additives used in the composition, one type may be used alone or two or more types may be used in combination.
The content of these components is not particularly limited, and is preferably large in that the effects of containing the additives can be easily obtained. On the other hand, it is preferable that the amount of the additive is small because it is easily dispersed, has excellent moldability and mechanical properties, and can reduce the load of the entire process.
Examples of resins other than the PAEK resin of the present invention include polyphenylene sulfide resin, polyetherimide resin, LCP (liquid crystal polymer), polyphenylsulfone resin, polyethersulfone resin, polyphthalamide resin, polysulfone resin, polyimide resin, epoxy resin, etc. can be mentioned.

(filler)
The additives are not particularly limited and can be appropriately selected depending on the purpose, and include, for example, inorganic fillers and organic fillers. There is no particular limitation on the shape of the filler, and examples thereof include fillers such as particulate, plate-like, and fibrous fillers. Among the fibrous fillers, carbon fibers and glass fibers are preferred because they have a wide range of industrial applications.

(Other additives)
There are no particular restrictions on other additives that may be added to the resin composition, and additives such as heat stabilizers, lubricants, antiblocking agents, nucleating agents, colorants, pigments, ultraviolet absorbers, light stabilizers, etc. , a modifier, a crosslinking agent, etc. may be included.

<Molded object>
The PAEK resin of the present invention and the resin composition of the present invention can be molded by melt molding methods such as injection molding or extrusion molding, or by a method in which the resin composition is treated as a solution using an appropriate good solvent, depending on the intended use and required performance. It can be used as a body. Specific examples of the shape and use of the molded article include films, fibers, pipes, rods, rings, gears, bearings, coating materials, and in-vivo implant materials. In addition, as for its form, a molded body may be composed only of the PAEK resin of the present invention or the composition of the present invention, but as long as the properties can be exhibited, it may be combined with other materials in any shape, for example, a laminated body. It can also be used as a body etc.

(Application)
Specific uses of the PAEK resin of the present invention include films, fibers, pipes, rods, rings, gears, bearings, coating materials, in-vivo implant materials, and electronic substrates. In addition, as for the form thereof, a molded article may be composed only of the aromatic polyetherketone resin of the present invention or the composition of the present invention, but it may be combined with other materials in any shape as long as the properties can be exhibited. For example, it can also be used as a laminate.

[Second embodiment]
A second embodiment of the present invention is a method for producing an aromatic polyether ketone resin, comprising heating a dihalogen compound represented by the following general formula (11) and a diol compound represented by the following general formula (12) in a solvent in the presence of a base to cause a polycondensation reaction to produce an aromatic polyether ketone resin containing a repeating unit represented by the following general formula (1), wherein a non-sublimable aprotic solvent having a boiling point of 200° C. or higher is coexistent in the polycondensation reaction.

(In formula (1), formula (11) and formula (12), structure A represents any one selected from the group consisting of the following general formula (2), formula (3) and formula (4), Structure B represents an optionally substituted divalent aromatic hydrocarbon ring, and X represents a halogen atom.)

A preferred form of the PAEK resin of the present invention is a PEEKK structure, but the general method for producing PEEKK resin is a method of polymerizing a dicarboxylic acid chloride and an aromatic compound by a Friedel-Crafts acylation reaction, or a method of polymerizing a dicarboxylic acid chloride with an aromatic compound. There is a method in which a dihalo compound is synthesized by a Friedel-Crafts acylation reaction with an aromatic halide and then polymerized by a nucleophilic substitution reaction with a diol in the presence of a base. However, it is known that the former polymerization produces a plurality of positional isomers, and there is a concern that the resulting resin will have poor thermophysical properties. In addition, in the Friedel-Crafts acylation reaction, aluminum chloride is used as a catalyst in an amount equal to or more than the same mole relative to the substrate, so it is known that a large amount of aluminum hydroxide, which is a residue, is produced as a by-product. If the resin is turned into a resin, its removal requires a large amount of cost and labor, and productivity is significantly reduced. In contrast, by performing appropriate purification at the stage of low molecular weight intermediates immediately after Friedel-Crafts acylation reaction, deterioration of resin physical properties due to incorporation of isomers and catalyst residues can be easily removed. The latter aromatic nucleophilic substitution reaction is preferred as a production method because it can be carried out efficiently.
The method for producing PAEK resin of the second embodiment is based on this latter aromatic nucleophilic substitution reaction.

When producing the PAEK resin of the present invention by an aromatic nucleophilic substitution reaction, a polycondensation reaction is performed using a dihalogen compound derived from a dicarboxylic acid chloride, a diol, and a base by heating and stirring. The synthesis method using aromatic nucleophilic substitution reaction will be described in detail below.
The ratio of each structural unit contained in the PAEK resin can be adjusted to an arbitrary ratio by adjusting the molar ratio of the raw materials.

<Dihalogen compound>
In the PAEK resin of the present invention, the dihalogen compound is synthesized from an aromatic heterocyclic dicarboxylic acid. For example, 2,5-bis(fluorobenzoyl)furan (hereinafter sometimes referred to as "BFBF") is produced from 2,5-furandicarboxylic acid, and 2,5-bis(fluorobenzoyl)furan (hereinafter sometimes referred to as "BFBF") is produced from 2,5-furandicarboxylic acid. -Bis(fluorobenzoyl)thiophene (hereinafter sometimes referred to as "BFBT") is converted from 2,5-pyridinedicarboxylic acid to 2,5-bis(fluorobenzoyl)pyridine (hereinafter referred to as "BFBPy"). ) can be synthesized and used as monomers.

These can be manufactured by known manufacturing methods. For example, BFBF can be produced by converting 2,5-furandicarboxylic acid into 2,5-furandicarboxylic acid dichloride with a suitable chlorinating agent and a Friedel-Crafts acylation reaction with fluorobenzene catalyzed by Lewis acid. . BFBF produced by this method has three positional isomers in which the two fluorine substitution positions on the carbonyl group are the 2,2', 2,4', and 4,4' positions, and usually, The reaction product is obtained as a mixture of these. Although the obtained BFBF can be used as a mixture of positional isomers in the polymerization, from the viewpoint of the heat resistance, mechanical properties, and crystallinity of the resin, it is preferable to use the 4,4'-position one in the polymerization. Any known method can be used to isolate the 4,4'-position component from the positional isomer, but recrystallization and the like are particularly preferred. BFBT and BFBPy can also be synthesized in the same manner.
Note that the dihalogen compound synthesized as described above is preferably a difluoro compound since it has good polymerization reactivity.

The PAEK resin of the present invention contains a dihalogen compound synthesized from one or more other aromatic dicarboxylic acids in addition to a difluoro compound containing a furan ring, a thiophene ring, and a pyridine ring, such as BFBF, BFBT, and BFBPy. They can be used in combination as monomers serving as structural units. Other aromatic dicarboxylic acids are not particularly limited, but aromatic dicarboxylic acids having 4 to 30 carbon atoms are preferred, aromatic dicarboxylic acids having 4 to 25 carbon atoms are more preferred, and aromatic dicarboxylic acids having 4 to 20 carbon atoms are preferred. Acids are more preferred, aromatic dicarboxylic acids having 4 to 18 carbon atoms are particularly preferred, and aromatic dicarboxylic acids having 4 to 15 carbon atoms are most preferred.

Other aromatic dicarboxylic acids include substituted benzene derivatives such as terephthalic acid, isophthalic acid, and phthalic acid; 4,4'-dicarboxydiphenyl ether, 2,2'-dicarboxydiphenyl ether, 2,4' -Diphenyl ether derivatives such as dicarboxydiphenyl ether; benzophenone derivatives such as 4,4'-dicarboxydiphenyl ether, 2,2'-dicarboxybenzophenone, 2,4'-dicarboxybenzophenone; 4,4'-dicarboxybiphenyl, 2 , 2'-dicarboxybiphenyl, 2,4'-dicarboxybiphenyl and other biphenyl derivatives; 1,2-dicarboxynaphthalene, 1,3-dicarboxynaphthalene, 1,4-dicarboxynaphthalene, 1,5-dicarboxynaphthalene Carboxynaphthalene, 1,6-dicarboxynaphthalene, 1,7-dicarboxynaphthalene, 1,8-dicarboxynaphthalene, 2,3-dicarboxynaphthalene, 2,6-dicarboxynaphthalene, 2,7-dicarboxynaphthalene naphthalene derivatives such as and the like, which may further have any functional group other than a carboxy group. Among them, terephthalic acid, isophthalic acid, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxydiphenyl ether, 4,4'- are easy to increase the melting point, glass transition temperature and crystallinity of the resin. Preferred are dicarboxybiphenyl, 2,6-dicarboxynaphthalene, and 2,7-dicarboxynaphthalene. The other aromatic dicarboxylic acids may be used alone or in combination of two or more.

The proportion of structural units derived from the dihalogen compound synthesized from the other aromatic dicarboxylic acids mentioned above is preferably small from the viewpoint of crystallinity of the resin. Specifically, the total of these structural units is 49 mol% or less, preferably 40 mol% or less, more preferably 30 mol% or less, based on all the structural units derived from dihalogen compounds in the repeating unit (1). It is not more than 10% by mole, particularly preferably not more than 10% by mole. Moreover, the lower limit is 0 mol% or more.

<Diol compound>
The raw material forming the structural unit derived from an aromatic diol is not particularly limited, but aromatic diols having 4 to 30 carbon atoms are preferred, aromatic diols having 4 to 25 carbon atoms are more preferred, and aromatic diols having 4 to 20 carbon atoms are preferred. Aromatic diols are more preferred, aromatic diols having 4 to 18 carbon atoms are particularly preferred, and aromatic diols having 4 to 15 carbon atoms are most preferred.

Specifically, substituted benzene derivatives such as hydroquinone (HQ), resorcinol, and catechol; diphenyl ether derivatives such as 4,4'-dihydroxydiphenyl ether, 2,2'-dihydroxydiphenyl ether, and 2,4'-dihydroxydiphenyl ether; 4,4' - Benzophenone derivatives such as dihydroxybenzophenone (DHBP), 2,2'-dihydroxybenzophenone, 2,4'-dihydroxybenzophenone; 4,4'-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 2,4'-dihydroxybiphenyl Biphenyl derivatives such as; 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8 Examples include naphthalene derivatives such as -dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene, and may further have any functional group other than a hydroxyl group. Among these, substituted benzene derivatives, diphenyl ether derivatives, benzophenone derivatives, biphenyl derivatives, naphthalene derivatives, and bisphenol S are preferred. Particularly preferred are hydroquinone, 4,4'-dihydroxydiphenyl ether (DHDPE), 4,4'-dihydroxybenzophenone, 4,4'-dihydroxybiphenyl, 2,6-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene. The raw materials for the aromatic diol unit may be used alone or in combination of two or more.

<Raw material charging molar ratio>
In producing the PAEK resin of the present invention, the molar ratio of the monomers used for polymerization is not particularly limited as long as the PAEK resin of the present invention can be produced. The molar ratio of the diol compound to the dicarboxylic acid derivative (dihalogen compound) (diol compound/dihalogen compound) is usually 0.90 or more, preferably 0.95 or more, from the viewpoint of obtaining a polymer with a high degree of polymerization. Yes, more preferably 0.97 or more, still more preferably 0.99 or more. Further, it is usually 1.10 or less, preferably 1.05 or less, more preferably 1.03 or less, still more preferably 1.01 or less.

<Base>
When producing the PAEK resin of the present invention by aromatic nucleophilic substitution reaction, the polymerization reaction is usually carried out in the presence of a base. As bases, carbonates of alkali metals such as lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate; carbonates of alkaline earth metals such as calcium carbonate, strontium carbonate, and barium carbonate; lithium hydrogen carbonate, hydrogen carbonate Alkali metal bicarbonates such as sodium, potassium bicarbonate, rubidium bicarbonate, cesium bicarbonate; alkaline earth metal bicarbonates such as calcium bicarbonate, strontium bicarbonate, barium bicarbonate; lithium hydroxide, hydroxide Examples include hydroxides of alkali metals such as sodium, potassium hydroxide, rubidium hydroxide, and cesium hydroxide; hydroxides of alkaline earth metals such as calcium hydroxide, strontium hydroxide, and barium hydroxide. Among these, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate are particularly preferred from the viewpoint of ease of handling and reactivity. One type of base may be used alone, or two or more types may be used in combination. From the viewpoint of converting all the hydroxy groups involved in the reaction into alkali metal salts, the molar ratio of alkali metal to hydroxy groups is usually 1.00 equivalent or more, preferably 1.01 equivalent or more, and more preferably 1. It is .02 equivalent or more, more preferably 1.03 equivalent or more, and most preferably 1.05 equivalent or more. In addition, from the viewpoint of resin quality and electrical properties, the amount is usually 2.00 equivalents or less, preferably 1.50 equivalents or less, more preferably 1.30 equivalents or less, and even more preferably 1.20 equivalents. or less, most preferably 1.10 equivalent or less.

<Reaction solvent (high boiling point solvent in polycondensation reaction)>
In aromatic nucleophilic substitution reactions, it is generally said that it is preferable to carry out the reaction in an aprotic polar solvent. Specific examples of aprotic polar solvents include N-methylpyrrolidone, N,N-dimethylformamide, N-methylcaprolactam, N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, and hexamethyl. Compounds containing amide groups such as phosphoramide and tetramethylurea; Compounds containing sulfonyl groups such as dimethylsulfone, sulfolane, diphenylsulfone, dibenzothiophene-5,5'-dioxide, and 4-phenylsulfonylbiphenyl; Sulfinyl groups such as dimethylsulfoxide Containing compounds; nitrile group-containing compounds such as benzonitrile; ether bond-containing compounds such as diphenyl ether; ketone group-containing compounds such as benzophenone and acetophenone; chlorine-containing compounds such as chlorobenzene; In the reaction using -2-pyrrolidone, the reduced viscosity did not increase in any of the PAEK resins obtained in the polymerization reactions using BFBF, BFBT, and BFBPy as dihalogen compounds (Comparative Examples 1 to 4).

The cause of this was that the reaction temperature was insufficient, and in order to improve the reduced viscosity, it was necessary to use compounds with higher boiling points such as 1,3-dimethyl-2-imidazolidinone, hexamethylphosphoramide, sulfolane, and diphenylsulfone. , dibenzothiophene-5,5'-dioxide is preferred. In order to avoid coloration during polymerization, sulfolane and diphenyl sulfone are preferred, and diphenyl sulfone is most preferred because it has a high boiling point, allows polymerization reaction to occur at a higher temperature, and more easily dissolves the produced polymer.

<Aprotic solvent for stabilizing monomer ratio (non-sublimating aprotic solvent with a boiling point of 200°C or higher)>
In order to obtain a PAEK resin with a reduced viscosity of 0.6 (dL/g) or more, it is preferable to use diphenyl sulfone, which has a higher boiling point, as a solvent, but since diphenyl sulfone has sublimation properties, it does not react during the polymerization reaction. There was a risk that sublimated crystals would adhere to the top of the container and the condenser, clogging the system. It was also found that when diphenylsulfone was used alone as a solvent, a PAEK resin with low reduced viscosity was obtained (Comparative Example 7).
The present inventors hypothesized that the cause of this was that hydroquinone sublimated as well as diphenyl sulfone during the reaction, and the monomer ratio shifted, thereby inhibiting molecular weight extension. Furthermore, there was a risk that the sublimated diphenyl sulfone would adhere to the reaction system and clog the system. For this reason, a small amount of a non-sublimable aprotic solvent with a boiling point of 200°C or higher is added separately from the main solvent, and the added solvent becomes refluxed during polymerization, causing diphenylsulfone and monomers to form in the upper part of the reaction vessel. The present inventors have discovered that it is possible to prevent the adhesion of sublimated crystals and to obtain a PAEK resin with sufficient reduced viscosity.

Non-sublimable aprotic solvents with a boiling point of 200°C or higher can be selected from N-methylpyrrolidone, N,N-dimethylformamide, N-methylcaprolactam, N,N-dimethylacetamide, sulfolane, triglyme, butylglyme, tetraglyme, etc., but alkyl ethers such as triglyme, butyldiglyme, and tetraglyme are particularly desirable because they can react at higher temperatures and produce a reflux effect with a small amount of solvent. The inventors have found that the combination of two high-boiling solvents (reaction solvent + aprotic solvent for stabilizing the monomer ratio) in this way allows for a safe polymerization reaction and the desired improvement in reduced viscosity.

Note that if the amount of the main reaction solvent such as diphenyl sulfone is too small, the polymer will not dissolve sufficiently and the time required for the reaction will become longer, or the purified polymer will precipitate and the polymerization reaction will not proceed. The amount is preferably 0.1 L or more, more preferably 0.15 L or more, even more preferably 0.2 L or more, particularly preferably 0.25 L or more, per 1 mole of the total amount. There is no particular upper limit to the amount of solvent, but if the amount of solvent used is large, economic efficiency will deteriorate, and the concentration of functional groups that contribute to the reaction in the reaction system will decrease, resulting in an increase in the time required for the reaction. Therefore, it is preferably 10 L or less, more preferably 5 L or less, even more preferably 3 L or less, particularly preferably 2 L or less, particularly preferably 1.5 L or less, and most preferably 1 L, based on 1 mole of the total amount of monomers. It is as follows.
The amount of non-sublimable aprotic solvent with a boiling point of 200°C or higher for stabilizing the monomer ratio is sufficient to eliminate the adhesion of diphenylsulfone in the reaction vessel by refluxing, so It is preferably 0.01 weight or more and 0.1 weight, more preferably 0.05 weight or more and 0.08 weight or less.

<Polycondensation reaction>
When carrying out the present invention by aromatic nucleophilic substitution reaction, polycondensation is usually carried out at a relatively low temperature and then at a relatively high temperature. The reaction is carried out at a relatively low temperature to prevent sublimation and thermal decomposition of the monomer while producing oligomer-sized polymers, and then the reaction is carried out at a relatively high temperature in the latter stage to increase the molecular weight.
Conditions such as temperature, time, and pressure for polycondensation at a relatively low temperature can be within the range of conventionally known PAEK resin manufacturing methods. The reaction temperature is preferably a high temperature in that it can increase the solubility of the reaction substrate, reaction product, and base, accelerate the reaction rate, and improve the molecular weight, and specifically, 150 ° C. or higher, The temperature is more preferably 170°C or higher, further preferably 180°C or higher, particularly preferably 190°C or higher. On the other hand, from the point of view of suppressing side reactions such as sublimation and thermal decomposition of monomers, it is preferable that the temperature is lower than 250°C, more preferably 230°C or lower, and even more preferably 220°C The temperature is preferably 210°C or lower, particularly preferably 210°C or lower. The reaction atmosphere is preferably an inert gas atmosphere such as nitrogen or argon. The reaction time is preferably long from the viewpoint of sufficiently advancing the polycondensation, and specifically, it is usually 10 minutes or more, preferably 20 minutes or more, and more preferably 30 minutes or more. , more preferably 45 minutes or more, and most preferably 1 hour or more. Further, from the viewpoint of suppressing side reactions such as thermal decomposition, it is preferably short, and specifically, it is usually 5 hours or less, preferably 4 hours or less, more preferably 3 hours or less, and even more preferably is 2 hours and 30 minutes or less, most preferably 2 hours or less. The reaction pressure is preferably low from the viewpoint of promoting discharge of water generated during the polymerization reaction out of the reaction system and suppressing side reactions such as depolymerization, and suppressing volatilization of reaction substrates and intermediates. High pressure is preferable from the viewpoint that a polymer with a high degree of polymerization can be easily obtained by maintaining the molar balance of functional groups in the reaction system. Specifically, normal pressure is preferable.

Conditions such as temperature, time, pressure, etc. in polycondensation at a relatively high temperature can be those of conventionally known PAEK resin manufacturing methods. The reaction temperature is preferably 200°C or higher, more preferably 220°C or higher, and even more preferably 240°C or higher, in that it can increase the solubility of the reaction substrate, reaction product, and base, as well as speed up the reaction rate. , particularly preferably 260°C or higher. On the other hand, from the viewpoint of suppressing side reactions such as thermal decomposition, the reaction temperature is preferably 400°C or lower, more preferably 380°C or lower, even more preferably 350°C or lower, and particularly preferably 320°C or lower. be. The reaction atmosphere is preferably an inert gas atmosphere such as nitrogen or argon. The reaction time is preferably long from the viewpoint of sufficiently advancing the polycondensation to obtain a polymer, and specifically, it is usually 10 minutes or more, preferably 20 minutes or more, and more preferably It is 30 minutes or more, more preferably 45 minutes or more, and most preferably 1 hour or more. Further, from the viewpoint of suppressing side reactions such as thermal decomposition, a shorter time is preferable, and specifically, it is usually 20 hours or less, preferably 15 hours or less, more preferably 10 hours or less, and even more preferably is 5 hours or less, particularly preferably 4 hours or less, particularly preferably 3 hours or less, and most preferably 2 hours or less. The reaction pressure is preferably low from the viewpoint of promoting discharge of water generated during the polymerization reaction out of the reaction system and suppressing side reactions such as depolymerization, and suppressing volatilization of reaction substrates and intermediates. By maintaining the molar balance of the functional groups in the reaction system, it is easier to obtain a polymer with a high degree of polymerization, and the distillation of the solvent out of the reaction system is suppressed, allowing the flow of the reaction solution until the final stage of the reaction. High pressure is preferable because the properties are easily maintained. Specifically, normal pressure is preferable.

<Suspension cleaning process>
Usually, after completing the polycondensation reaction process, the polymerization product is taken out from the reaction vessel in a solid state, pulverized, suspended in an organic solvent, washed, and the solid component is filtered to obtain the desired resin crude product. get. Any polar solvent can be used as the organic solvent used for washing, and examples thereof include aprotic polar solvents such as acetone; alcohols such as methanol, ethanol, and isopropanol; and the like. By washing the recovered solid components with water and recovering the solid components by filtration, by-product inorganic salts can be removed and PAEK resin can be obtained. Furthermore, it is preferable to suspend and wash the PAEK resin crude product with an aprotic solvent having a dielectric constant of 30 or more at 25°C. This has the effect of making it easier to obtain a PAEK resin of high purity and reduced viscosity of 0.6 dL/g or more by removing cyclic or linear oligomers that are byproducts of the polymerization reaction. In addition to the method of washing the polymerized product taken out from the reaction solution in a solid state, the method of suspending and washing with an aprotic solvent with a dielectric constant of 30 or more at 25°C is also available after the polymerization reaction has finished. Also effective are a method in which an aprotic solvent having a dielectric constant of 30 or more at 25° C. is added to the reaction solution for suspension washing, and a method in which the polymerization product is filtered and then washed by sprinkling the product with a solvent. The most effective cleaning method is a combination of suspension cleaning and sprinkle cleaning. Examples of aprotic solvents having a dielectric constant of 30 or more at 25°C include N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile, nitrobenzene, dimethylsulfoxide, sulfolane, etc. be. Among these, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and sulfolane are preferred, and more preferably N,N-dimethylformamide and N- Methyl-2-pyrrolidone, with N-methyl-2-pyrrolidone being most preferred.

The amount of the aprotic solvent with a dielectric constant of 30 or more at 25°C used in suspension cleaning is not particularly limited as long as it has a sufficient cleaning effect, but if it is too small, the oligomer removal effect will be impaired. Therefore, the amount is preferably 1 L or more, more preferably 2 L or more, and even more preferably 5 L or more based on the amount of polymer crude product (1 kg). There is no particular restriction on the upper limit of the amount of solvent, but since increasing the amount of solvent used may worsen economic efficiency and reduce the yield of the polymer, it should be 50 L for the amount of crude polymer product (1 g). It is preferably below, more preferably 20 L or less, still more preferably 10 L or less.
Further, the temperature for suspension washing is not particularly limited and can be selected from room temperature to the boiling point of the solvent used, but heating is more effective for removal.

Hereinafter, the present invention will be explained in more detail based on Examples. Note that the present invention is not limited to the following examples.

<Methods for measuring and evaluating physical properties>
The physical properties of the PAEK resins obtained in the following Examples and Comparative Examples were measured and evaluated by the following methods.
(1) Reduced viscosity (RV) (dL/g)
The reduced viscosity was measured using an Ubbelohde viscometer in the following manner. That is, using concentrated sulfuric acid (>95%) as a solvent, the falling seconds of an aromatic polyetherketone resin sample solution with a concentration of 0.1 g/dL and only the solvent were measured at 25°C, and the following formula (1 ).
RV=ηsp/C (1)
In formula (1), ηsp=η/η0−1, η is the number of seconds for the sample solution to fall, η0 is the number of seconds for the solvent to fall, and C is the concentration of the sample solution (g/dL).

(2) Glass transition temperature (Tg) (℃)
To measure the glass transition temperature, use a differential operation calorimeter "DSC7020" (manufactured by Hitachi High-Tech Science Co., Ltd.) to heat approximately 10 mg of a resin sample at a heating rate of 20°C/min to measure the amount of heat. The temperature is raised to 360°C at a rate of 10°C/min, then cooled from 360°C to 30°C at a rate of 10°C/min, and further heated from 30°C to 360°C at a rate of 10°C/min. At this time, the temperature at the intersection of the tangent at the first inflection point of the DSC curve during the second heating process and the baseline before the inflection point was read and determined as the glass transition point of the PEAK resin.

(3) Melting point (Tm) (℃)
The melting point was measured using a differential scanning calorimeter "DSC7020" (manufactured by Hitachi High-Tech Science Co., Ltd.), after heating approximately 2 mg of the resin sample from 30°C to 360°C at a rate of 10°C/min. ℃ at a rate of 10° C./min, and further heated from 30° C. to 360° C. at a rate of 10° C./min. At this time, the endothermic peak temperature during the second heating process was read and determined as the melting point of the PAEK resin.

(4) Enthalpy of fusion (ΔHm) (J/g)
The enthalpy of fusion was measured using a differential scanning calorimeter "DSC7020" (manufactured by Hitachi High-Tech Science Co., Ltd.), after heating approximately 2 mg of the resin sample from 30°C to 360°C at a rate of 10°C/min. This is carried out by cooling to 30°C at a rate of 10°C/min and further increasing the temperature from 30°C to 360°C at a rate of 10°C/min. At this time, the area of the endothermic peak corresponding to the melting of the sample during the second heating process was defined as the enthalpy of fusion (ΔHm), and was used as an index of crystallinity.

(5) 5% weight loss temperature (Td5)
Approximately 5 mg of the resin sample was heated at a heating rate of 10°C/min using a simultaneous differential thermogravimetric measurement device "TG-DTA EXTER6000" (manufactured by SII), and the pyrolysis temperature was determined from the pyrolysis curve obtained. (5% weight loss temperature, Td5) was measured.

(6) Measurement of flow start temperature using a flow tester The flow start temperature was measured using a Koka type flow tester CTE-500C manufactured by Shimadzu Corporation, in a cylinder with an inner diameter of 10 mm equipped with a nozzle with a hole diameter of φ1 mm and a length of 2 mm. Add 1.5 g of a resin sample that has been previously dried with hot air at 130°C for 3 hours or more, and preheat for 5 minutes ( ^* ) at the preheating temperature shown below. The temperature at which the liquid began to flow from the nozzle outlet was measured.
(*) Preheating time: The waiting time for the sample to reach the test temperature after it is put into the cylinder.

(Preheating temperature)
Example 1 290°C
Example 5 290°C
Example 7 295°C
Comparative example 5 375°C
Comparative example 6 335°C

<Example 1>
In a reaction vessel equipped with a stirring blade, a nitrogen inlet and pressure reduction port, and a heating device, 4.25 parts by mass of bisfluorobenzoylfuran (BFBF), 1.50 parts by mass of hydroquinone (HQ), 1.90 parts by mass of potassium carbonate, 16.3 parts by mass of diphenylsulfone and 0.9 parts by mass of triglyme were charged. While stirring the contents of the reaction vessel, nitrogen gas was introduced into the vessel, and the inside of the system was brought into a nitrogen atmosphere by vacuum displacement. Next, the temperature of the system was raised to 200° C. while stirring, and the reaction was carried out at this temperature for 1 hour. Thereafter, the temperature was raised to 280° C. over 5 minutes, and polycondensation was continued at this temperature for 2 hours. The polymerization product was taken out from the reaction vessel and crushed with a hammer to form a powder, and then washed by solid-liquid extraction with 118 parts by mass of acetone at room temperature for 15 minutes to recover solid components. Washing with acetone was performed once again under the same conditions. Subsequently, washing was performed by solid-liquid extraction with 150 parts by mass of water at 60° C. for 15 minutes, and solid components were recovered. Washing with water was performed again under the same conditions. Thereafter, washing was performed by solid-liquid extraction with 52 parts by mass of N-methyl-2-pyrrolidone at 120° C. for 30 minutes to recover solid components. The solid component collected by filtration was vacuum-dried at 120° C. for 6 hours in a vacuum dryer to obtain the desired aromatic polyetherketone resin. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1. This PAEK resin could be molded into a film having sufficient strength by melt-molding it using a hot press machine at a melting point of +20°C and then cooling it using a cooling press machine. The results are shown in Table 1 as ○. Note that this production method in which diphenylsulfone and triglyme are used together as a solvent in the polycondensation reaction is referred to as "Production Method A."

<Example 2>
In Example 1, the steps from the start of the operation to the operation in which the reaction temperature was raised to 280° C. and the polycondensation was continued for 2 hours were carried out in the same manner. Thereafter, the temperature was lowered to 150°C, and 87 parts by mass of N-methyl-2-pyrrolidone was added at 150°C. After cooling the reaction solution to room temperature, solid components were collected by filtration and washed with 30 parts by mass of N-methyl-2-pyrrolidone. Subsequently, washing was performed by solid-liquid extraction with 150 parts by mass of water at 60° C. for 15 minutes, and solid components were recovered. Washing with water was performed again under the same conditions. Thereafter, washing was performed by solid-liquid extraction with 118 parts by mass of acetone at room temperature for 15 minutes to recover solid components. The target PAEK resin was obtained by vacuum drying the solid component at 120° C. for 6 hours in a vacuum dryer. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1. This PAEK resin was melt-molded using a hot press machine at a melting point of +20°C, and then cooled using a cooling press machine, thereby making it possible to form a film having sufficient strength. The results are shown in Table 1 as ○.

<Example 3>
In Example 1, BFBF was 5.67 parts by mass, potassium carbonate was 2.59 parts by mass, and the molar ratio of each substance used in the polymerization to BFBF was adjusted to be the same as in Example 1. The same reaction as in Example 1 was carried out to obtain the desired PAEK resin. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1. This PAEK resin was melt-molded using a hot press machine at a melting point of +20°C, and then cooled using a cooling press machine, thereby making it possible to form a film having sufficient strength. The results are shown in Table 1 as ○.

<Example 4>
In Example 1, 0.49 parts by mass of dihydroxybenzophenone (DHBP) was used instead of HQ, the molar ratio of each substance used for polymerization was adjusted to be the same as in Example 1, and heating at 280 ° C. The reaction was carried out in the same manner as in Example 1, except that the reaction time was 1 hour, and then the temperature was raised to 300° C. over 5 minutes, and the polycondensation was continued at this temperature for 1 hour, to obtain the desired PAEK resin. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1.

<Example 5>
In Example 1, 3.73 parts by mass of bisfluorobenzoylthiophene (BFBT) was used instead of BFBF, the molar ratio of each substance used for polymerization was adjusted to be the same as in Example 1, and the polymerization was carried out at 280°C. The same reaction as in Example 1 was carried out except that the heating time was changed to 100 minutes to obtain the desired PAEK resin. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1. This PAEK resin was melt-molded using a hot press machine at a melting point of +20°C, and then cooled using a cooling press machine, thereby making it possible to form a film having sufficient strength. The results are shown in Table 1 as ○.

<Example 6>
Example 1 except that 1.22 parts by mass of bisfluorobenzoylthiophene (BFBT) was used instead of BFBF, and the molar ratio of each substance used in the polymerization was adjusted to be the same as in Example 1. The same reaction as in 1 was carried out to obtain the desired PAEK resin. The obtained PAEK resin was also subjected to the above-mentioned evaluations, and the results are shown in Table 1. This PAEK resin was melt-molded using a hot press machine at a melting point of +20°C, and then cooled using a cooling press machine, thereby making it possible to form a film having sufficient strength. The results are shown in Table 1 as ○.

<Example 7>
In Example 1, 3.67 parts by mass of 2,5-(bisfluorobenzoyl)pyridine (BFBPy) was used instead of BFBF, so that the molar ratio of each substance used in the polymerization was the same as in Example 1. The same reaction as in Example 1 was conducted except that the heating time at 280° C. was changed to 100 minutes to obtain the desired PAEK resin. The obtained PAEK resin was also subjected to the above-mentioned evaluations, and the results are shown in Table 1. This PAEK resin was melt-molded using a hot press machine at a melting point of +20°C, and then cooled using a cooling press machine, thereby making it possible to form a film having sufficient strength. The results are shown in Table 1 as ○.

<Example 8>
In Example 1, 0.66 parts by mass of 2,5-(bisfluorobenzoyl)pyridine (BFBPy) was used instead of BFBF, so that the molar ratio of each substance used in the polymerization was the same as in Example 1. The same reaction as in Example 1 was carried out except for the adjustment, and the desired PAEK resin was obtained. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1. This PAEK resin was melt-molded using a hot press machine at a melting point of +20°C, and then cooled using a cooling press machine, thereby making it possible to form a film having sufficient strength. The results are shown in Table 1 as ○.

<Comparative example 1>
0.58 parts by mass of hydroquinone (HQ), 1.53 parts by mass of potassium carbonate, and 10 parts by mass of N-methyl-2-pyrrolidone were placed in a reaction vessel equipped with a stirring blade, a nitrogen inlet/decompression port, a heating device, and a Dean-Stark device. .3 parts by mass and 8.7 parts by mass of toluene were charged. While stirring the contents of the reaction vessel, nitrogen gas was introduced into the vessel, and the inside of the system was brought into a nitrogen atmosphere by vacuum displacement. Next, the temperature of the system was raised to 165° C. while stirring, and the reaction was allowed to proceed for 1 hour at this temperature, and toluene and water were distilled off from the Dean-Stark apparatus. Thereafter, 1.66 parts by mass of BFBF was added, and polycondensation was performed at 150° C. for 30 minutes. Thereafter, the temperature was raised to 200° C. over 15 minutes, and polycondensation was continued at this temperature for 30 minutes. The product was poured into cold methanol, and the resulting precipitate was collected by filtration. The solid component collected by filtration was washed by solid-liquid extraction with water, 2M hydrochloric acid, water, and methanol in this order, and the solid component was recovered. Soxhlet extraction was performed using methanol/toluene (volume ratio 9:1) for 4 hours, and solid components were collected. The target PAEK resin was obtained by vacuum drying this in a vacuum dryer at 120° C. for 6 hours. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1. When this PAEK resin was melt-molded using a hot press machine at a temperature higher than the melting point +20°C, it was found that the film was brittle and unsuitable for molding. The results are shown in Table 1 as ×. This production method using only N-methyl-2-pyrrolidone as a solvent in the polycondensation reaction is referred to as "Production Method B."

<Comparative example 2>
In Comparative Example 1, the same reaction as in Comparative Example 1 was carried out, except that 10.3 parts by mass of N-methyl-2-pyrrolidone was added at the same time as BFBF was added, and the target PAEK resin was obtained. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1. When this PAEK resin was melt-molded using a hot press machine at a temperature higher than the melting point +20°C, it was found that the film was brittle and unsuitable for molding. The results are shown in Table 1 as ×.

<Comparative example 3>
In Comparative Example 1, 1.73 parts by mass of 1,4-(bisfluorobenzoyl)thiophene (BFBT) was used instead of BFBF, so that the molar ratio of each substance used in the polymerization was the same as in Comparative Example 1. The same reaction as in Comparative Example 1 was carried out except for the adjustment, and the desired PAEK resin was obtained. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1. When this PAEK resin was melt-molded using a hot press machine at a temperature higher than the melting point +20°C, it was found that the film was brittle and unsuitable for molding. The results are shown in Table 1 as ×.

<Comparative example 4>
In Comparative Example 1, 1.70 parts by mass of 2,5-(bisfluorobenzoyl)pyridine (BFBPy) was used instead of BFBF, so that the molar ratio of each substance used in the polymerization was the same as in Comparative Example 1. The same reaction as in Comparative Example 1 was carried out except for the adjustment, and the desired PAEK resin was obtained. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1. When this PAEK resin was melt-molded using a hot press machine at a temperature higher than the melting point +20°C, it was found that the film was brittle and unsuitable for molding. The results are shown in Table 1 as ×.

<Comparative example 5>
In Example 1, 3.66 parts by mass of 1,4-(bisfluorobenzoyl)benzene (BFBB) was used instead of BFBF, so that the molar ratio of each substance used in the polymerization was the same as in Example 1. The same reaction as in Example 1 was carried out except for the adjustment, and the desired aromatic polyetherketone resin was obtained. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1.

<Comparative example 6>
As a reference resin, polyether ether ketone (PEEK) (3300G manufactured by Daicel Evonik Co., Ltd.) was subjected to the above evaluations, and the results are shown in Table 1. This PAEK resin was melt-molded using a hot press machine at a melting point of +20°C, and then cooled using a cooling press machine, thereby making it possible to form a film having sufficient strength. The results are shown in Table 1 as ○.

<Comparative example 7>
In Example 1, 1.418 parts by mass of BFBF, 0.50 parts by mass of HQ, 2.72 parts by mass of diphenylsulfone, and 0.635 parts by mass of potassium carbonate were charged. While stirring the contents of the reaction vessel, nitrogen gas was introduced into the vessel, and the inside of the system was brought into a nitrogen atmosphere by vacuum displacement. Next, the temperature of the system was raised to 200°C while stirring, and the reaction system was heated for dehydration at this temperature for 1 hour.Then, the temperature was raised to 280°C over 5 minutes, and polycondensation was carried out at this temperature for 2 hours. continued. A white sublimate was present during the reaction. Next, the polymerization product was taken out from the reaction vessel and crushed with a hammer to form a powder, and then washed by solid-liquid extraction with 40 parts by mass of acetone at room temperature for 15 minutes to recover solid components. Washing with acetone was performed once again under the same conditions. Subsequently, washing was performed by solid-liquid extraction with 50 parts by mass of water at 60° C. for 15 minutes, and solid components were recovered. Washing with water was performed again under the same conditions. Subsequently, in order to remove water in the solid components, washing was performed by liquid extraction with 40 parts by mass of a mixed solvent of acetone/methanol (volume ratio 1:1) for 15 minutes, and the solid components were recovered. Thereafter, the filtered solid component was vacuum-dried at 120° C. for 6 hours in a vacuum dryer to obtain the desired PAEK resin. The above-mentioned evaluations were performed on the obtained PAEK resin, and the results are shown in Table 1. The present production method using only diphenyl sulfone as a solvent in the polycondensation reaction is referred to as "Production Method C."

HQ: Hydroquinone DHBP: 4,4'-dihydroxybenzophenone BFBF: 1,1'-(2,5-furandiyl)bis[1-(4-fluorophenyl)methaneone]
BFBT: 1,1'-(2,5-thienyl)bis[1-(4-fluorophenyl)methaneone]
BFBPy: 1,1'-(2,5-pyridinyl)bis[1-(4-fluorophenyl)methane]
BFBB: 1,1'-(1,4-phenylene)bis[1-(4-fluorophenyl)methaneone]
DFB: 4,4'-difluorobenzophenone

<Consideration>
From the above results, the following can be understood.
In Table 1, since the PAEK resin of the present invention (Examples 1, 5, and 7) has a flow start temperature of around 300°C, it is found that the PAEK resin of the present invention is molded in comparison with the PEEK resin of Comparative Example 5 and the PEEK resin of Comparative Example 6. The heating temperature during processing can be set low. In addition, the PAEK resins (Examples 1 to 8) produced by the PAEK resin production method of the present invention can obtain resins with higher reduced viscosity than Comparative Examples 1 to 4 synthesized by known production methods, and have high heat resistance. Stability can be imparted, and a film with sufficient strength can be obtained by melt molding.

Claims (21)

An aromatic polyetherketone resin having a flow start temperature of 330°C or lower, a reduced viscosity of 0.6 (dL/g) or higher, and a glass transition temperature of 140°C or higher. The aromatic polyetherketone resin according to claim 1, comprising a repeating unit represented by the following general formula (1).

(In formula (1), structure A is any one selected from the group consisting of general formula (2), formula (3), and formula (4) below, and structure B may be substituted. divalent aromatic hydrocarbon ring)

The aromatic polyetherketone resin according to claim 2, wherein the ratio of ketone groups to ether groups contained in the structure of the aromatic polyetherketone resin is 1 or more. The aromatic polyetherketone resin according to claim 2 or 3, which is a copolymer containing two or more types of repeating units represented by the general formula (1). The aromatic polyetherketone resin according to claim 2 or 3, which is a mixture of two or more types of aromatic polyetherketone resins containing repeating units represented by the general formula (1). The aromatic polyetherketone resin according to claim 2 or 3, wherein the structure A is any one selected from the group consisting of the following general formula (2A), formula (3A), and formula (4A).

The aromatic polyetherketone resin according to claim 2 or 3, wherein the structure B is any one selected from the group consisting of the following general formulas (5) to (10).

In formula (7), n1 is 0 or 1. The aromatic polyetherketone resin according to claim 2 or 3, wherein the structure B is the following general formula (5B), (6B), or (7B).

The aromatic polyetherketone resin according to any one of claims 1 to 3, which has a flow initiation temperature of 250°C or higher. The aromatic polyetherketone resin according to any one of claims 1 to 3, having a reduced viscosity of 2.0 (dL/g) or less. The aromatic polyetherketone resin according to any one of claims 1 to 3, which has a melting point (Tm) in differential scanning calorimetry of 250°C or more and 325°C or less. The aromatic polyetherketone resin according to any one of claims 1 to 3, which has a Td5 of 420°C or higher as measured by TG/DTA. A resin composition comprising the aromatic polyetherketone resin according to any one of claims 1 to 3. The resin composition according to claim 13, comprising a filler. A molded article obtained using the aromatic polyetherketone resin according to any one of claims 1 to 3. A molded article obtained using the resin composition according to claim 13. In the presence of a base, a dihalogen compound represented by the following general formula (11) and a diol compound represented by the following general formula (12) are heated in a solvent to cause a polycondensation reaction, resulting in the following general formula ( 1) A method for producing an aromatic polyetherketone resin containing a repeating unit represented by
In the polycondensation reaction, a non-sublimating aprotic solvent having a boiling point of 200° C. or more is allowed to coexist in the method for producing the aromatic polyetherketone resin.

(In formula (1), formula (11) and formula (12), structure A represents any one selected from the group consisting of the following general formula (2), formula (3) and formula (4), Structure B represents an optionally substituted divalent aromatic hydrocarbon ring, and X represents a halogen atom.)

The method for producing an aromatic polyetherketone resin according to claim 17, wherein the non-sublimable aprotic solvent having a boiling point of 200° C. or higher is triglyme, butyl diglyme, or tetraglyme. The aromatic polyether ketone resin crude product according to claim 17, comprising a step of suspending and washing the aromatic polyetherketone resin crude product produced by the condensation polymerization reaction with an aprotic solvent having a dielectric constant of 30 or more at 25°C. Method for producing ether ketone resin. 19. The aprotic solvent having a dielectric constant of 30 or more at 25° C. or higher is any one of N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and sulfolane. A method for producing an aromatic polyetherketone resin as described in . Any one of claims 17 to 20, wherein the aromatic polyetherketone resin has a flow start temperature of 330°C or lower, a reduced viscosity of 0.6 (dL/g) or higher, and a glass transition temperature of 140°C or higher. The method for producing an aromatic polyetherketone resin according to item 1.