JP5277594B2 - Aromatic polyamide and aromatic polyamide film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aromatic polyamide soluble in an aprotic polar solvent, containing neither chlorine atom nor bromine atom in its polymer structure, and giving a film of high Young's modulus when subjected to film formation. <P>SOLUTION: The aromatic polyamide is such as to comprise respective specific rigid-straight components A and B and flexible component C and meet the relationships (1) to (3): 5&le;a&lt;80... (1); 0&lt;b&lt;80... (2); and 0&lt;c&lt;95... (3) (wherein, (a), b and c are the molar fractions of the components A, B and C, respectively). <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an aromatic polyamide and an aromatic polyamide film.

  Aromatic polyamide is a useful polymer as an industrial material because of its high heat resistance and mechanical strength. In particular, aromatic polyamides composed of para-oriented aromatic nuclei as typified by polyparaphenylene terephthalamide (hereinafter sometimes referred to as PPTA) are molded products having excellent strength and elastic modulus in addition to the above properties due to their rigidity. The utility value is high. However, para-oriented aromatic polyamides such as PPTA have low solubility in solvents and are only limited in very limited solvents such as sulfuric acid, so there are significant process restrictions, and the solution also gives optical anisotropy. When obtaining fibers, there is no major problem, but in order to obtain a two-dimensional or higher shaped article such as a film, it is necessary to use a special molding method described in Patent Document 1, and an improvement is required.

On the other hand, introduction of a structural unit having a bridge such as oxygen or a methylene group is known in Patent Document 2 as a means for improving the solubility, but in general, such a structural unit is originally introduced in a para-oriented aromatic polyamide. The mechanical properties such as Young's modulus and strength are impaired. As another means, Patent Document 3 proposes an aromatic polyamide in which a chlorine atom is introduced into an aromatic nucleus, but the introduction of chlorine has a concern that the burden on the environment increases. An aromatic polyamide obtained using 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl as a raw material is disclosed in Patent Document 4, but Patent Document 4 is intended for high light transmittance and is colored. There is no description regarding paraphenylenediamine and 4,4′-diaminodiphenyl ether which contribute greatly, and using these as copolymerization components, an aromatic polyamide which is inexpensive and compatible with rigidity and solubility is obtained. There is no description or suggestion about.
JP-A 62-39634 JP-A-52-98795 JP-A-54-106564 Republished patent WO2004 / 039863

  The present invention has been achieved as a result of studying the solution of the problems in the prior art described above as an issue. That is, the object of the present invention is an aromatic polyamide that is soluble in an aprotic polar solvent with or without a solubilizing agent, does not contain chlorine and bromine atoms in the polymer structure, and has a high Young's modulus when formed into a film There is in getting.

In order to achieve the above object, the present invention includes a structural unit represented by the chemical formulas (I), (II) and (III), and the molar fraction of the structural unit represented by the chemical formulas (I) to (III). When a, b, c are set in this order, and a + b + c = 100, they are aromatic polyamides satisfying the following formulas ( 3 ) to ( 6 ).

10 ≦ a < 70 ( 4 )
10 ≦ b < 70 ( 5 )
0 <c <95 (3)
50 ≦ a + b ≦ 99 (6)

R ¹ : hydrogen, fluorine, methyl group or nitro group

  According to the present invention, it is possible to provide an aromatic polyamide and an aromatic polyamide film which do not contain chlorine or bromine and have excellent solubility and high Young's modulus.

  The aromatic polyamide in the present invention includes the structural units represented by the chemical formulas (I), (II) and (III), and the molar fractions of the structural units represented by the chemical formulas (I) to (III) are sequentially a. , B, c, and a + b + c = 100, it is an aromatic polyamide satisfying the following formulas (1) to (3).

5 ≦ a <80 (1)
0 <b <80 (2)
0 <c <95 (3)

R ¹ : hydrogen, fluorine, methyl group or nitro group

In the chemical formulas (I) to (III), the chemical formula (II) represents Kevlar (registered trademark) or rigid polyparaphenylene terephthalamide (PPTA) known as Aramica (registered trademark) when R ¹ is hydrogen. However, the chemical formula (II) alone does not dissolve in an organic solvent or an organic solvent containing lithium bromide as a solubilizing agent, and a special film forming method using concentrated sulfuric acid. In addition to being required, there is a problem that the film surface becomes rough.

As a result of intensive studies, the inventor has copolymerized the structural unit represented by the chemical formula (I) at a specific mole fraction without greatly reducing the Young's modulus of PPTA, and also has a molecular structure of chlorine or bromine atoms. And was successfully soluble in an organic solvent containing lithium bromide as a dissolution aid. In addition, since the lithium bromide used here is removed in the film forming process, the aromatic polyamide film of the present invention does not contain chlorine and bromine. In the chemical formula (II), R ¹ is any ^one of hydrogen, fluorine, methyl group or nitro group. In the case of fluorine, methyl group or nitro group, the solubility of the polymer obtained is improved compared to the case where R ¹ is hydrogen, but there is a problem that the reactivity of the polymerization reaction is reduced. In the case of a methyl group, it is commercially available as a dihydrochloric acid adduct, which may make it difficult to handle. For this reason, R ¹ should be selected according to its use. However, fluorine is preferably selected for improving solubility, and fluorine is particularly preferable for reducing moisture absorption. On the other hand, hydrogen is preferred for the purpose of increasing the polymerization rate and improving productivity.

The aromatic polyamide of the present invention is preferably soluble in 5% by mass in an N-methyl-2-pyrrolidone solution containing 5% by mass of lithium bromide. In order to improve the solubility, it is preferable to increase the molar fraction of the structural unit represented by the chemical formula (III) containing an ether bond which is a bending component, but the introduction of the structural unit represented by the chemical formula (III) is young. With a decline in rate. For this reason, it is important to copolymerize the structural unit represented by the chemical formula (I). In the case of a homopolymer, the amide group between adjacent molecules is hydrogen-bonded to increase the molecular weight in a pseudo manner, and the solubility is lowered. On the other hand, by copolymerizing chemical formulas (I) to (III) having different structural unit lengths, the hydrogen bond of the amide group is inhibited and the solubility is improved. Furthermore, since the structural unit represented by the chemical formula (I) has a bulky —CF ₃ group, the effect of inhibiting the hydrogen bond of the amide group is great. For example, when R ¹ in chemical formula (II) is hydrogen and a = 50, b = 40, and c = 10, 5% by mass can be dissolved in an N-methyl-2-pyrrolidone solution containing 5% by mass of lithium bromide. And the aromatic polyamide film obtained from this polymer has a large Young's modulus of 6.9 GPa.

  Here, “it can be dissolved in 5% by mass in an N-methyl-2-pyrrolidone solution containing 5% by mass of lithium bromide” (hereinafter, “the solubility is sometimes referred to as“ ◯ ””) is lithium bromide. This means that 5% by mass of a polymer is dissolved in 5% by mass of N-methyl-2-pyrrolidone, and the solution remains fluid after being left at 25 ° C. for 2 weeks. In addition, when the solubility is “◯” at less than 5% by mass of lithium bromide, “◯” is also indicated at 5% by mass of lithium bromide. Further, when the polymer is dissolved exceeding 5% by mass and the solubility is “◯”, the solubility is “◯” even at 5% by mass.

  “Maintaining fluidity” means a state in which 50 ml or more flows out within one hour when 100 ml of a polymer solution is placed in a 100 ml beaker at 25 ° C. and tilted 90 °.

  Chemical formula (I) and chemical formula (III) contribute to the improvement of solubility. In particular, since the chemical formula (III) has an ether bond which is a bending component, it greatly contributes to improvement in solubility, but at the same time, the bending component causes a decrease in Young's modulus. For this reason, the structural unit represented by the chemical formula (I) that contributes to the improvement in solubility by the degree of freedom of the biphenyl moiety and the trifluoromethyl group, while having a rigid rod-like structure having no bending component such as ether, has a specific molarity. Copolymerization at a fraction is important in order to achieve both improvement of Young's modulus and imparting solubility.

  The specific mole fraction of the structural unit represented by the chemical formula (I) is expressed as follows: the mole fractions of the structural units represented by the chemical formulas (I) to (III) are respectively a, b, c, and when a + b + c = 100, Is important to be 5 or more and less than 80. When it is less than 5, there is a problem that b is increased so that it does not dissolve or c is increased so that the Young's modulus is decreased. In addition, when a is 80 or more, a large amount of 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, which is expensive, is used, resulting in a problem that the resulting aromatic polyamide is expensive.

  a is preferably 10 or more and less than 70, more preferably 20 or more and less than 60, and most preferably 30 or more and 50 or less. When a is 30 or more and 50 or less, it is possible to obtain a film having a large Young's modulus while maintaining solubility in an organic solvent containing lithium bromide.

  b is preferably more than 0 and less than 80. When b is 0, the Young's modulus may be small. Moreover, when b is 80 or more, sufficient solubility may not be obtained. b is more preferably 10 or more and less than 70, further preferably 20 or more and less than 70, and more preferably 30 or more and 65 or less. Most preferably, it is 40 or more and 60 or less.

In order to obtain an aramid film having a large Young's modulus, a + b is preferably 50 or more and 99 or less. When a + b is less than 50, Young's modulus may be small. If a + b exceeds 99, the solubility may be insufficient. a + b is more preferably from 60 to 99, and even more preferably from 70 to 95. Most preferably, it is 70 or more and 90 or less. For example, when R ¹ in the chemical formula (II) is hydrogen, a = 50, b = 40, and c = 10, a + b = 90, the solubility is ○, and the aromatic polyamide film obtained from this polymer is It has a large Young's modulus of 6.9 GPa.

  c has a flexible ether bond and contributes to improvement in solubility and elongation of the polymer. On the other hand, if there is much c, Young's modulus will fall. c is preferably greater than 0 and less than 95. When c is 0, the solubility may be insufficient. If it is 95 or more, Young's modulus may be low. c is preferably 1 or more and 50 or less, more preferably 5 or more and 40 or less, and most preferably 10 or more and 30 or less.

The intrinsic viscosity of the aromatic polyamide of the present invention is preferably 2.0 (dl / g) or more. If the intrinsic viscosity is lowered, the solubility is improved, but the resulting film is brittle and has a low elongation. Since the aromatic polyamide of the present invention has a specific molecular structure at a specific molar fraction, even if the intrinsic viscosity is 2.0 or more, the solubility is good and a film with high elongation can be obtained. The intrinsic viscosity is more preferably 2.5 or more, further preferably 3.0 or more, and most preferably 3.5 or more.

A copolymer containing 50% by mass or more of the aromatic polyamide of the present invention described above is also preferable. Other polymer components include, for example, aromatic polyamides, polyimides, polybenzoxazoles, polycarbonates, cyclic polyolefins, polystyrenes, etc. This copolymer has the characteristics of the aromatic polyamide of the present invention and other polymer components, both polymers. For example, it can be suitably used for applications such as circuit boards, cover lay films for circuit materials, and magnetic recording media.

In the case of a copolymer with an aromatic polyamide, as a raw material diamine of the aromatic polyamide to be copolymerized,
9,9-bis (4-amino-3-fluorophenyl) fluorene 9,9-bis (4-aminophenyl) fluorene,
9,9-bis (4-amino-3-methylphenyl) fluorene,
4,4′-diaminodiphenyl sulfone,
3,3′-diaminodiphenyl sulfone,
3,4'-diaminodiphenyl ether,
Bis [4- (4-aminophenoxy) phenyl] sulfone,
Bis [4- (3-aminophenoxy) phenyl] sulfone,
1,4 bis- (4 aminophenoxy) benzene 1,3 bis- (4 aminophenoxy) benzene 2,2-bis [4- (4-aminophenoxy) phenyl] propane,
2,2-bis (4-aminophenyl) hexafluoropropane 1,3-phenylenediamine 4,4′-diaminobenzanilide,
4,4′-bis (4-aminophenoxy) biphenyl 2-trifluoromethyl-1,4-diaminobenzene,
Examples include 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl ether m-tolidine o-tolidine. In particular, 4,4′-diaminobenzanilide and 1,3 bis- (4 aminophenoxy) benzene are preferred for the purpose of improving solubility and mechanical properties. The carboxylic acid dichloride residue is preferably 1,4-phenylene, 1,3-phenylene, 4,4′-biphenyl, 3,3′-biphenyl, 3,4′-biphenyl, naphthalene, or terphenyl. More preferred are 1,4-phenylene and 4,4′-biphenyl.

  In the polymer having the same structure, the intrinsic viscosity has a correlation with the molecular weight, and when the intrinsic viscosity is large, the molecular weight is also large. Low molecular weight polymers may be brittle or have low elongation at break. For this reason, it is required to increase the molecular weight, that is, the intrinsic viscosity.

  As a method of increasing the intrinsic viscosity, for example, in a low temperature polymerization method using diamine and carboxylic acid dichloride as raw materials, the purity of the raw material is improved, and the ratio of diamine and carboxylic acid dichloride is brought close to 100: 100 (mol%). Stirring is sufficiently performed at a low temperature so that the reaction does not occur.

  Although the example which manufactures a film as a manufacturing method and a molded object of the aromatic polyamide composition of this invention is demonstrated below, this invention is not limited to this.

  Various methods can be used for obtaining the aromatic polyamide. For example, a low temperature solution polymerization method, an interfacial polymerization method, a melt polymerization method, a solid phase polymerization method, and the like can be used. When it is obtained from a low temperature solution polymerization method, that is, from acid dichloride and diamine, it is synthesized in an aprotic organic polar solvent. When acid dichloride and diamine are used as monomers in the polymer solution, hydrogen chloride is by-produced. To neutralize this, inorganic neutralizers such as calcium hydroxide, calcium carbonate, lithium carbonate, and ethylene Organic neutralizers such as oxide, propylene oxide, ammonia, triethylamine, triethanolamine, diethanolamine are used. The reaction between isocyanate and carboxylic acid is carried out in an aprotic organic polar solvent in the presence of a catalyst.

  When performing polymerization using two or more kinds of diamines, diamines are added one by one, 10 to 99 mol% of acid dichloride is added to the diamine and reacted, and then another diamine is added, Further, a stepwise reaction method in which acid dichloride is added and reacted, a method in which all diamines are mixed and added, and then acid dichloride is added and reacted can be used. Similarly, when two or more kinds of acid dichlorides are used, a stepwise method, a method of simultaneously adding them, and the like can be used. In any case, the molar ratio of the total diamine to the total acid dichloride is preferably 95 to 105: 105 to 95, and if it is outside this value, it is difficult to obtain a polymer solution suitable for molding.

  Examples of the aprotic polar solvent used in the production of the aromatic polyamide of the present invention include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, and formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide. Solvents, acetamide solvents such as N, N-dimethylacetamide, N, N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol, o-, m- or Phenolic solvents such as p-cresol, xylenol, halogenated phenol, and catechol, or hexamethylphosphoramide, γ-butyrolactone, and the like can be used. These are preferably used alone or as a mixture, but more preferably xylene, toluene The use of aromatic hydrocarbons such as are possible. Furthermore, for the purpose of accelerating the dissolution of the polymer, 50% by mass or less of an alkali metal or alkaline earth metal salt can be added to the solvent. Examples of the dissolution aid include lithium bromide and lithium chloride.

The aromatic polyamide of the present invention may contain 10% by mass or less of an inorganic or organic additive for the purpose of surface formation and processability improvement. Examples of additives for surface formation include inorganic particles such as SiO ₂ , TiO ₂ , Al ₂ O ₃ , CaSO ₄ , BaSO ₄ , CaCO ₃ , carbon black, carbon nanotubes, fullerene, zeolite, and other metal fine powders. Etc. Preferred organic particles include, for example, particles made of an organic polymer such as crosslinked polyvinylbenzene, crosslinked acrylic, crosslinked polystyrene, polyester particles, polyimide particles, polyamide particles, and fluororesin particles, or the above organic polymer on the surface. Inorganic particles that have been subjected to treatment such as coating may be mentioned.

  Next, film formation will be described.

  Since the aromatic polyamide of the present invention is soluble in an organic solvent, a special film forming method using concentrated sulfuric acid like PPTA is not necessarily required. The film-forming stock solution prepared as described above is formed into a film by a so-called solution casting method. The solution casting method includes a dry-wet method, a dry method, a wet method, etc., and any method may be used, but here, the dry-wet method will be described as an example.

  In the case of forming a film by a dry-wet method, the stock solution is extruded from a die onto a support such as a drum or an endless belt to form a thin film, and then dried until the thin film layer has self-holding property. Drying conditions can be performed in the range of room temperature to 220 ° C. and within 60 minutes, for example. If the surface of the drum and endless belt used in this drying step is as smooth as possible, a film having a smooth surface can be obtained. The film after the dry process is peeled off from the support and introduced into the wet process, desalted, desolvated, etc., and further stretched, dried and heat treated to form a film.

  Stretching is in the range of 0.8 to 8 (drawing ratio is defined by dividing the film area after stretching by the area of the film before stretching. 1 or less means relaxation) as the stretching ratio. It is preferable that it is in 1.3, More preferably, it is 1.3-8. The heat treatment is preferably carried out at a temperature of 200 ° C. to 500 ° C., preferably 250 ° C. to 400 ° C. for several seconds to several minutes. Furthermore, it is effective to gradually cool the film after stretching or heat treatment, and it is effective to cool at a rate of 50 ° C./second or less.

  The aromatic polyamide film of the present invention preferably has a tensile elastic modulus (Young's modulus) in at least one direction of 6 GPa or more. By having a high Young's modulus, it is possible to counter high tension and tension fluctuation during winding, and the winding shape becomes better. The Young's modulus in at least one direction of the aromatic polyamide film of the present invention is more preferably 8 GPa or more. Moreover, it is preferable that the Young's modulus of all the directions is 5.5 GPa or more.

  The aromatic polyamide film of the present invention is molded such that the elongation at break in at least one direction is 10% or more, more preferably 20% or more, and still more preferably 40% or more in the measurement based on JIS-K7127-1989. This is preferable because breakage during processing is reduced. The upper limit of the elongation at break is not particularly limited, but is practically about 250%. Examples of the method for increasing the elongation include methods such as increasing the structural unit represented by the chemical formula (III), increasing the molecular weight, increasing the intrinsic viscosity, and reducing foreign matter in the polymer.

  The polyamide film of the present invention has a moisture absorption rate at 25 ° C./75 RH% of 4% by mass or less, more preferably 3.6% by mass or less, and still more preferably 3.5% by mass or less. This is preferable because a change in characteristics due to a change in humidity is reduced. The moisture absorption here is measured by the method described below. First, about 0.5g of a film was collected, heated for 30 minutes at 120 ° C for dehumidification, then cooled to 25 ° C under a nitrogen stream, and the weight after the temperature reduction was accurately weighed to the nearest 0.1 mg. (We assume the weight at this time is W0). Subsequently, it is left to stand in an atmosphere of 75 RH% at 25 ° C. for 48 hours, the weight after that is measured, and this is defined as W1, and the moisture absorption rate is obtained using the following equation.

Moisture absorption (%) = ((W1-W0) / W1) × 100
In addition, although the one where a moisture absorption is lower is preferable, realistically, a minimum is about 0.03%. Examples of a method for reducing the moisture absorption rate include increasing the number of structural units represented by the chemical formula (I) and changing R ¹ to fluorine in the chemical formula (II). For example, when R ¹ in the chemical formula (II) is hydrogen and a = 50, b = 40, and c = 10, the solubility is good, and the aromatic polyamide film obtained from this polymer is sufficiently 3.2%. Has a low water absorption rate.

  The aromatic polyamide and copolymer thereof of the present invention are suitably used for films, membranes, laminates, molded articles, fibers and the like.

  The film obtained from the aromatic polyamide of the present invention may be a single layer film or a laminated film. In addition, the aromatic polyamide film of the present invention is preferably used for various applications such as flexible printed circuit boards, semiconductor mounting boards, multilayer laminated circuit boards, capacitors, printer ribbons, acoustic diaphragms, solar cells, and magnetic film base films. It is done.

  In addition, a laminate including at least one layer containing the above-described aromatic polyamide or copolymer of the present invention is also preferable. In this case, examples of the layer other than the layer containing aromatic polyamide or copolymer include metal foils such as copper foil and stainless steel foil, glass, and silicon.

  For example, a copper-clad laminate in which copper foil is laminated on the aromatic polyamide film of the present invention via an adhesive, or copper foil is formed by sputtering or plating without using an adhesive, is further etched, etc. A circuit is formed by the method, and a flexible printed circuit board is provided. The flexible printed board using the aromatic polyamide of the present invention is a thin film and high rigidity compared to the commonly used flexible printed board based on polyimide, and contributes to the reduction in size and weight of electronic devices.

  Moreover, the aromatic polyamide film of the present invention is also suitably used as a coverlay film that is pasted for the purpose of component protection after mounting the component on a flexible printed board. Furthermore, in an organic EL display using a stainless steel foil, the aromatic polyamide of the present invention is laminated with a stainless steel foil to give an insulating and flattened laminate.

  The structure of the aromatic polyamide is determined by the raw material diamine and carboxylic acid dichloride. When the raw material is unknown, structural analysis is performed from the aromatic polyamide composition. As this method, mass analysis, analysis by nuclear magnetic resonance method, spectroscopic analysis, or the like can be used.

  The present invention will be described more specifically with reference to the following examples.

  The measurement method of physical properties and the evaluation method of effects in the present invention were performed according to the following methods.

(1) Young's modulus, tensile strength, elongation at break The measurement was performed at a temperature of 23 ° C. and a relative humidity of 65% using Robot Tensilon RTA (Orientec). The test piece was a sample having a width of 10 mm and a length of 50 mm in the MD direction or the TD direction, where the film forming direction or the moving direction of the bar coater was the MD direction, and the direction orthogonal thereto was the TD direction. The tensile speed is 300 mm / min. However, the point where the load passed 1 N after the start of the test was taken as the origin of elongation.

(2) Moisture absorption About 0.5g of the film was sampled and heated for 3 hours at 120 ° C for dehumidification, then the temperature was lowered to 25 ° C under a nitrogen stream, and the weight after the temperature reduction was measured in 0.1 mg units. (Weighing at this time is designated as W0). Subsequently, it was left to stand in an atmosphere of 75 RH% at 25 ° C. for 48 hours, and then the weight was measured. This was defined as W1, and the moisture absorption rate was determined using the following equation.

Moisture absorption rate (%) = ((W1-W0) / W0) × 100
(3) Intrinsic viscosity Using an Ubbelohde viscometer, 0.5 g of sample was dissolved in 100 ml of N-methyl-2-pyrrolidone (NMP) containing 5% by mass of lithium bromide, and the temperature was 30 ° C. Calculated.

Intrinsic viscosity = ln (t / t0) /0.5 (dl / g)
t0: Flowing time of NMP containing 5% by mass of lithium bromide (seconds)
t: Flowing time of the solution in which the sample is dissolved (seconds)
(4) Solubility: 5% by mass of a polymer dissolved in 5% by mass of lithium bromide in N-methyl-2-pyrrolidone, and the one that retains fluidity after being allowed to stand at 25 ° C. for 2 weeks is evaluated as “Solid”. did.

  “Maintaining fluidity” means a state in which 50 ml or more flows out within one hour when 100 ml of a polymer solution is placed in a 100 ml beaker at 25 ° C. and tilted 90 °.

(5) Containing bromine and chlorine The presence or absence was judged from the molecular structure.

Example 1
In a 200 ml three-necked flask equipped with a stirrer, 2.80 g of 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl (“TFMB” manufactured by Wakayama Seika Co., Ltd.), 1,4-phenylenediamine (Tokyo Kasei) Industrial Co., Ltd.) 2.16 g, 4,4′-diaminodiphenyl ether (Wakayama Seika Co., Ltd. “DPE”) 3.00 g, N-methyl-2-pyrrolidone 124 ml were placed in a nitrogen atmosphere at 50 ° C. for 30 minutes. Stir. While cooling to 0 ° C. and stirring, 10.15 g of terephthalic acid dichloride was added in 5 portions over 30 minutes. Since the polymer was precipitated, 20 ml of N-methyl-2-pyrrolidone and 5 g of lithium bromide were further added to dissolve the polymer. After stirring for 1 hour, hydrogen chloride generated by the reaction was neutralized with lithium carbonate to obtain a polymer solution. Moreover, this polymer solution maintained fluidity after being left for 2 weeks.

  A part of the obtained polymer solution was taken on a glass plate, and a uniform film was formed using a bar coater. This was heated at 120 ° C. for 7 minutes to obtain a self-holding film. The obtained film was peeled off from the glass plate, fixed to a metal frame, washed with running water for 10 minutes, and further heat treated at 280 ° C. for 1 minute to obtain an aromatic polyamide film. The physical properties of the obtained film were measured and are shown in Table 1.

(Example 2)
In a 200 ml three-necked flask equipped with a stirrer, 8.01 g of 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl (“TFMB” manufactured by Wakayama Seika Co., Ltd.), 1,4-phenylenediamine (Tokyo Kasei) 1.16 g of 4,4′-diaminodiphenyl ether (“DPE” manufactured by Wakayama Seika Co., Ltd.) and 143 ml of N-methyl-2-pyrrolidone are placed in a nitrogen atmosphere at 50 ° C. for 30 minutes. Stir. While cooling to 0 ° C. and stirring, 10.15 g of terephthalic acid dichloride was added in 5 portions over 30 minutes. Since the polymer was precipitated, 130 ml of N-methyl-2-pyrrolidone and 5 g of lithium bromide were further added, and the polymer was dissolved. After stirring for 1 hour, hydrogen chloride generated by the reaction was neutralized with lithium carbonate to obtain a polymer solution. Moreover, this polymer solution maintained fluidity after being left for 2 weeks.

  A part of the obtained polymer solution was taken on a glass plate, and a uniform film was formed using a bar coater. This was heated at 120 ° C. for 7 minutes to obtain a self-holding film. The obtained film was peeled off from the glass plate, fixed to a metal frame, washed with running water for 10 minutes, and further heat treated at 280 ° C. for 1 minute to obtain an aromatic polyamide film. The physical properties of the obtained film were measured and are shown in Table 1.

(Example 3)
In a 200 ml three-necked flask equipped with a stirrer, 2.80 g of 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl (“TFMB” manufactured by Wakayama Seika Co., Ltd.), 1,4-phenylenediamine (Tokyo Kasei) 2.70 g, 4,4′-diaminodiphenyl ether (“DPE” manufactured by Wakayama Seika Co., Ltd.) and 161 ml of N-methyl-2-pyrrolidone are placed in a nitrogen atmosphere at 50 ° C. for 30 minutes. Stir. While cooling to 0 ° C. and stirring, 10.15 g of terephthalic acid dichloride was added in 5 portions over 30 minutes. Since the polymer was precipitated, 30 ml of N-methyl-2-pyrrolidone and 5 g of lithium bromide were further added, and the polymer was dissolved. After stirring for 1 hour, hydrogen chloride generated by the reaction was neutralized with lithium carbonate to obtain a polymer solution. Moreover, this polymer solution maintained fluidity after being left for 2 weeks.

A part of the obtained polymer solution was taken on a glass plate, and a uniform film was formed using a bar coater. This was heated at 120 ° C. for 7 minutes to obtain a self-holding film. The obtained film was peeled off from the glass plate, fixed to a metal frame, washed with running water for 10 minutes, and further heat treated at 280 ° C. for 1 minute to obtain an aromatic polyamide film .

Example 4
2.88 g of 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl (“TFMB” manufactured by Wakayama Seika Co., Ltd.), 2-methyl-1,4-phenylene in a 200 ml three-necked flask equipped with a stirrer Diamine, 2HCl adduct (Tokyo Chemical Industry Co., Ltd.) 3.51 g, 4,4′-diaminodiphenyl ether (Wakayama Seika Co., Ltd. “DPE”). 060 g and N-methyl-2-pyrrolidone (114 ml) were added, cooled to 0 ° C. in a nitrogen atmosphere, and 6.09 g of terephthalic acid dichloride was added in 5 portions over 30 minutes with stirring. After stirring for 1 hour, hydrogen chloride generated by the reaction was neutralized with lithium carbonate to obtain a polymer solution. Moreover, this polymer solution maintained fluidity after being left for 2 weeks.

A part of the obtained polymer solution was taken on a glass plate, and a uniform film was formed using a bar coater. This was heated at 120 ° C. for 7 minutes to obtain a self-holding film. The obtained film was peeled off from the glass plate, fixed to a metal frame, washed with running water for 10 minutes, and further heat treated at 280 ° C. for 1 minute to obtain an aromatic polyamide film .

(Comparative Example 1)
In a 200 ml three-necked flask equipped with a stirrer, 1.62 g of 1,4-phenylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.), 3.00 g of 4,4′-diaminodiphenyl ether (“DPE” manufactured by Wakayama Seika Co., Ltd.), N-methyl-2-pyrrolidone (90 ml) and lithium bromide (4.3 g) were added, and the mixture was stirred at 50 ° C. for 30 minutes in a nitrogen atmosphere. While cooling to 0 ° C. and stirring, 6.09 g of terephthalic acid dichloride was added in 5 portions over 30 minutes. After further stirring for 1 hour, hydrogen chloride generated by the reaction was neutralized with lithium carbonate to obtain a polymer solution. However, this polymer solution lost fluidity by 10 hours and became a gel-like solid.

(Comparative Example 2)
In a 200 ml three-necked flask equipped with a stirrer, 6.40 g of 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl (“TFMB” manufactured by Wakayama Seika Co., Ltd.), 116 ml of N-methyl-2-pyrrolidone, 4.5 g of lithium bromide was added, cooled to 0 ° C. in a nitrogen atmosphere, and 4.06 g of terephthalic acid dichloride was added in 5 portions over 30 minutes with stirring. After further stirring for 1 hour, hydrogen chloride generated by the reaction was neutralized with lithium carbonate to obtain a polymer solution. Moreover, this polymer solution maintained fluidity after being left for 2 weeks.

  A part of the obtained polymer solution was taken on a glass plate, and a uniform film was formed using a bar coater. This was put in water while being spread on a glass plate, washed with running water for 10 minutes, and further heat treated at 280 ° C. for 1 minute to obtain an aromatic polyamide film.

(Comparative Example 3)
In a 200 ml three-necked flask equipped with a stirrer, 5.41 g of 1,4-phenylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.), 212 ml of N-methyl-2-pyrrolidone and 5 g of lithium bromide were placed at 50 ° C. in a nitrogen atmosphere. Stir for 30 minutes. While cooling to 0 ° C. and stirring, 10.15 g of terephthalic acid dichloride was added in 5 portions over 30 minutes. Polymer was precipitated during the addition of terephthalic acid dichloride. An additional 100 ml of N-methyl-2-pyrrolidone was added but did not dissolve.

Claims (9)

Including the structural units represented by the chemical formulas (I), (II) and (III), the molar fractions of the structural units represented by the chemical formulas (I) to (III) are respectively a, b and c, and a + b + c = An aromatic polyamide satisfying the following formulas ( 3 ) to ( 6 ) when 100 is assumed.
10 ≦ a < 70 ( 4 )
10 ≦ b < 70 ( 5 )
0 <c <95 (3)
50 ≦ a + b ≦ 99 (6)

R ¹ : hydrogen, fluorine, methyl group or nitro group

The aromatic polyamide according to claim 1, which is soluble in 5% by mass in an N-methyl-2-pyrrolidone solution containing 5% by mass of lithium bromide. The aromatic polyamide according to claim 1 or 2 , having an intrinsic viscosity of 2.0 (dl / g) or more. The aromatic polyamide film containing the aromatic polyamide in any one of Claims 1-3 . The aromatic polyamide film according to claim 4 , wherein the tensile elastic modulus in at least one direction is 6 GPa or more. The aromatic polyamide film according to claim 4 or 5 , having an elongation at break of 10% or more. The aromatic polyamide film according to any one of claims 4 to 6 , having a moisture absorption rate of 4% by mass or less. A laminate comprising at least one layer comprising the aromatic polyamide according to any one of claims 1 to 3 . A copolymer comprising 50% by mass or more of the aromatic polyamide according to any one of claims 1 to 3 .