TW202033617A - Method for producing polyimide resin - Google Patents

Abstract

The present invention provides a method for producing a polyimide resin, which is capable of controlling the molecular weight. This method for producing a polyimide resin comprises: a step (I) for obtaining an intermediate (K), said step (I) comprising a step (A) wherein a diamine compound and a carboxylic acid compound having three or more carbonyl groups are reacted with each other; a step (II) wherein the viscosity A of the reaction system is measured after the step (I); and a step (III) wherein the viscosity A is compared with a target viscosity range of the reaction system so as to check whether the viscosity A is within the target viscosity range or not.

Description

Manufacturing method of polyimide resin

The present invention relates to a method for manufacturing polyimide resin used as a material for flexible display devices and the like.

Display devices such as liquid crystal display devices or organic EL display devices are widely used in various applications such as mobile phones and smart watches. As the front panel of such a display device, glass is used, but the glass is very rigid and easy to break, so it is difficult to be used as a front panel material for a flexible display device. As an alternative to glass, there is a polyimide-based resin, and an optical film using this polyimide-based resin has been studied (Patent Document 1). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2017-203984

[The problem to be solved by the invention]

The polyimide resin used in this optical film needs to be controlled to a specific molecular weight in order to ensure specific mechanical properties or optical properties. However, according to the research of the present inventors, the reason is not clear, but it is known that due to some factors, the molecular weight cannot be controlled, and the polyimide-based resin of the target molecular weight or a molecular weight close to it cannot be obtained stably.

Therefore, the object of the present invention is to provide a method for producing a polyimide resin with a controllable molecular weight. [Technical means to solve the problem]

In order to solve the above-mentioned problems, the inventors have conducted intensive research and found that, in the production method of polyimide resin, after the process (I) of obtaining the intermediate (K), the viscosity A of the reaction system is included. The process (II) of the measurement and the process (III) of comparing the viscosity A with the target viscosity range of the reaction system corresponding to the target molecular weight to confirm whether the viscosity A is within the target viscosity range can solve the above-mentioned problems and complete this invention.

[1] A manufacturing method of polyimide resin, which includes: Process (I), which includes the step (A) of reacting a diamine compound with a carboxylic acid compound having more than 3 carbonyl groups to obtain an intermediate (K); Process (II), which measures the viscosity A of the reaction system after process (I); and Process (III), which compares the viscosity A with the target viscosity range of the reaction system to confirm whether the viscosity A is within the target viscosity range. [2] The production method as described in [1], wherein in the process (I), after the step (A), the step (B) of reacting the dicarboxylic acid compound is further included. [3] The manufacturing method as described in [1] or [2], which includes process (IV), when the viscosity A is not in the target viscosity range in the process (III), the viscosity is adjusted to the target range. [4] The manufacturing method described in any one of [1] to [3], which includes the process (IV'), which is when the viscosity A does not reach the target viscosity range in the process (III), and the viscosity is increased. Adjust to the target viscosity range. [5] The manufacturing method as described in any one of [1] to [3], which includes the process (IV''), which is to reduce the viscosity when the viscosity A exceeds the target viscosity range in the process (III) Adjust to the target viscosity range. [6] The manufacturing method as described in [4], wherein a diamine compound is added in the process (IV') to increase the viscosity A. [7] The production method as described in [5], wherein the intermediate (K) is decomposed in the process (IV'') to reduce the viscosity A. [8] The manufacturing method according to any one of [1] to [7], wherein the target viscosity range is a viscosity range of 0.8 to 1.5 times the target viscosity. [Effects of Invention]

According to the production method of the present invention, the molecular weight of the polyimide resin can be controlled, and the polyimide resin of the target molecular weight or a molecular weight close to it can be stably obtained.

The manufacturing method of the present invention includes: process (I), which includes the step (A) of reacting a diamine compound with a carboxylic acid compound having more than 3 carbonyl groups to obtain intermediate (K); process (II), It measures the viscosity A of the reaction system after process (I); and in process (III), it compares the viscosity A with the target viscosity range of the reaction system to confirm whether the viscosity A is within the target viscosity range. In this specification, reaction refers to a phase in which raw materials or intermediates are reacting, and when a solvent is included, it refers to a reaction solution. The polyimide-based resin obtained by the production method of the present invention means polyimide resin, polyimide resin, polyimide resin precursor, or polyimide resin precursor. In addition, the polyimide resin precursor and the polyimide resin precursor may be collectively referred to as the polyimide resin precursor. Polyimide resins are polymers containing repeating structural units containing imine groups, such as those containing repeating structural units derived from diamine compounds, and those derived from repeating structural units derived from tetracarboxylic acid compounds. Resins of repeating structural units of carboxylic acid compounds with 3 or more carbonyl groups. Polyamidoimide resins are polymers containing both repeating structural units containing imine groups and repeating structural units containing amide groups, for example, containing repeating structural units derived from diamine compounds, and for example as derived from The repeating structural unit of a tricarboxylic acid compound is a resin derived from a repeating structural unit of a carboxylic acid compound having 3 or more carbonyl groups, or contains a repeating structural unit derived from a diamine compound, for example, as a resin derived from a tetracarboxylic acid compound A resin derived from a repeating structural unit of a carboxylic acid compound having 3 or more carbonyl groups, such as a repeating structural unit, and a repeating structural unit derived from a dicarboxylic acid compound. The polyimide resin precursor refers to the precursor before the polyimide resin is produced by imidization, and the polyimide resin precursor refers to the precursor before the polyimide resin is produced by imidization Predecessor. In addition, in this specification, the "repeating structural unit" is sometimes referred to as the "structural unit".

＜Process (I)＞ Process (I) is a process for obtaining intermediate (K) including step (A) of reacting a diamine compound with a carboxylic acid compound having more than 3 carbonyl groups.

(Step A) Examples of the diamine compound used in step A include aliphatic diamines such as acyclic or cyclic aliphatic diamines, aromatic diamines, or mixtures of these. Furthermore, the "aromatic diamine" in this embodiment refers to a diamine in which an amine group is directly bonded to an aromatic ring, and a part of its structure may also include an aliphatic group or other substituents. The aromatic ring may be a monocyclic ring or a condensed ring. Examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, and a sulphur ring, but are not limited to these. In addition, the term "aliphatic diamine" refers to a diamine in which an amine group is directly bonded to an aliphatic group, and a part of the structure may include an aromatic ring or other substituents. The diamine compound can be used individually or in combination of 2 or more types.

所表示之化合物(以下，有稱為二胺化合物(1)之情形)。於使用兩種以上之二胺化合物之情形時，可使用二胺化合物(1)之X之種類互不相同之兩種以上的二胺化合物。In one embodiment of the present invention, the diamine compound preferably includes, for example, formula (1) [化1]

The compound shown (hereinafter, it may be referred to as a diamine compound (1)). When two or more kinds of diamine compounds are used, two or more kinds of diamine compounds with different types of X in the diamine compound (1) can be used.

In formula (1), X represents a divalent organic group independently of each other, preferably a divalent organic group with 4 to 40 carbons, and more preferably a divalent organic group with 4 to 40 carbons having a cyclic structure base. Examples of the cyclic structure include alicyclic, aromatic, and heterocyclic structures. In the above-mentioned organic group, the hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. In this case, the carbon number of the hydrocarbon group and the fluorine-substituted hydrocarbon group is preferably 1-8. As X, exemplify: formula (10), formula (11), formula (12), formula (13), formula (14), formula (15), formula (16), formula (17), and formula (18) The group represented by the formula (10) to formula (18) in which the hydrogen atom in the group represented by the formula (10) to formula (18) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and a carbon number of 6 The following chain hydrocarbon groups.

[化2]

In formulas (10) to (18), * represents a bonding bond, and V ¹ , V ² and V ³ independently represent a single bond, -O-, -S-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -, -CO- or -N(Q)-. Here, Q represents a monovalent hydrocarbon group having 1 to 12 carbons which may be substituted with a halogen atom. In one example, V ¹ and V ³ are single bonds, -O- or -S-, and V ² is -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -or- SO ₂ -. The bonding position of V ¹ and V ² to each ring and the bonding position of V ² and V ³ to each ring are respectively for each ring, preferably meta or para, more preferably para. As the monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom, those exemplified above in the formula (3) can be cited.

Among the bases represented by formulas (10) to (18), from the viewpoint that it is easy to improve the elastic modulus, flex resistance and surface hardness of a film containing polyimide resin, the formula The groups represented by (13), formula (14), formula (15), formula (16), and formula (17) are more preferably groups represented by formula (14), formula (15), and formula (16). In addition, V ¹ , V ² and V ³ are independent of each other from the viewpoint of easily improving the elastic modulus, flexibility, flex resistance, and surface hardness of a film containing polyimide resin Single bond, -O- or -S-, more preferably single bond or -O-.

[式(2)中，R¹ ～R⁸ 相互獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基，R¹ ～R⁸ 所包含之氫原子可相互獨立地被取代為鹵素原子， *表示鍵結鍵] 所表示之基。若包含式(1)中之X為式(2)所表示之基之化合物作為二胺化合物，則包含聚醯亞胺系樹脂而成之光學膜容易顯現較高之彈性模數、耐撓曲性及光學特性。In a preferred embodiment of the present invention, X in formula (1) is formula (2): [化3]

[In formula (2), R ¹ to R ⁸ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbons, an alkoxy group having 1 to 6 carbons, or an aryl group having 6 to 12 carbons, and R ¹ to The hydrogen atoms contained in R ⁸ can be substituted with halogen atoms independently of each other, and * represents the group represented by the bond]. If the compound in which X in the formula (1) is the group represented by the formula (2) is included as a diamine compound, the optical film containing the polyimide-based resin is likely to exhibit a higher modulus of elasticity and resistance to deflection Sex and optical properties.

In formula (2), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbons, and a carbon number of 1 to 6 The alkoxy group or the aryl group with 6-12 carbons. Examples of alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, second butyl, tertiary butyl, n-pentyl, and 2-methyl -Butyl, 3-methylbutyl, 2-ethyl-propyl, n-hexyl, etc. Examples of alkoxy groups having 1 to 6 carbon atoms include: methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tertiary butoxy, and pentoxy , Hexyloxy, cyclohexyloxy, etc. Examples of aryl groups having 6 to 12 carbon atoms include phenyl, tolyl, xylyl, naphthyl, biphenyl and the like. R ¹ to R ⁸ are independent of each other, and preferably represent a hydrogen atom or an alkyl group having 1 to 6 carbons, and more preferably represent a hydrogen atom or an alkyl group having 1 to 3 carbons. Here, R ¹ to R ⁸ include The hydrogen atoms can be substituted with halogen atoms independently of each other. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. R ¹ to R ⁸ are independent of each other, and from the viewpoint that it is easy to increase the surface hardness, optical properties, elastic modulus, and flex resistance of a film containing polyimide resin, hydrogen atoms and formaldehyde are more preferred. R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are hydrogen atoms, and R ⁷ and R ⁸ are hydrogen atoms and methyl groups. , Fluoro, chloro or trifluoromethyl, more preferably R ⁷ and R ⁸ are methyl or trifluoromethyl.

表示。若包含式(2)中之X為式(2')所表示之基之化合物作為二胺化合物，則包含聚醯亞胺系樹脂而成之膜容易降低霧度及黃度，容易提高光學特性。又，藉由含有氟元素之骨架，容易提高聚醯亞胺系樹脂對於溶劑之溶解性，將樹脂清漆之黏度抑制為較低。In a preferred embodiment of the present invention, formula (2) is derived from formula (2'): [化4]

Said. If a compound in which X in formula (2) is a group represented by formula (2') is included as a diamine compound, a film containing polyimide-based resin is likely to reduce haze and yellowness and improve optical properties . In addition, the fluorine-containing skeleton makes it easy to increase the solubility of the polyimide-based resin in solvents and suppress the viscosity of the resin varnish to be low.

Specifically, as aliphatic diamines, for example, acyclic aliphatic diamines such as hexamethylene diamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis (Aminomethyl) cyclohexane, noralkanediamine and 4,4'-diamine dicyclohexylmethane and other cycloaliphatic diamines. These can be used alone or in combination of two or more.

Examples of aromatic diamines include p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-xylylenediamine, p-xylylenediamine, 1,5-diaminonaphthalene, 2 ,6-Diaminonaphthalene and other aromatic diamines with one aromatic ring; 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diamine Diphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'- Diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy) ) Benzene, bis[4-(4-aminophenoxy)phenyl] ash, bis[4-(3-aminophenoxy)phenyl] ash, 2,2-bis[4-(4- Aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2'-dimethylbenzidine, 2,2'-bis (Trifluoromethyl)-4,4'-diaminobiphenyl (sometimes referred to as TFMB), 4,4'-bis(4-aminophenoxy)biphenyl, 9,9-bis(4 -Aminophenyl) pyrene, 9,9-bis(4-amino-3-methylphenyl) pyrene, 9,9-bis(4-amino-3-chlorophenyl) pyrene, 9,9 -Aromatic diamines with two or more aromatic rings, such as bis(4-amino-3-fluorophenyl) pyridium. These can be used individually or in combination of 2 or more types.

The aromatic diamine is preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,3' -Diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 1,4-bis(4-aminophenoxy)benzene , Bis[4-(4-aminophenoxy)phenyl] sulphur, bis[4-(3-aminophenoxy)phenyl] sulphur, 2,2-bis[4-(4-amino) Phenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2'-dimethylbenzidine, 2,2'-bis(tris Fluoromethyl)-4,4'-diaminobiphenyl (TFMB), 4,4'-bis(4-aminophenoxy)biphenyl, more preferably 4,4'-diaminodiphenyl Methane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 1,4-bis(4-amino) Phenoxy)benzene, bis[4-(4-aminophenoxy)phenyl] chrysene, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2' -Dimethylbenzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 4,4'-bis(4-aminophenoxy) benzene. These can be used alone or in combination of two or more.

Among the above-mentioned diamine compounds, from the viewpoint of high surface hardness, high transparency, high modulus of elasticity, high flexibility, high flexibility and low coloring properties of a film made of polyimide resin It is preferable to use one or more selected from the group consisting of aromatic diamines having a biphenyl structure. More preferably, use selected from 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)benzidine, 4,4'-bis(4-aminophenoxy)biphenyl and At least one of the group consisting of 4,4'-diaminodiphenyl ether, and more preferably 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB).

Among the diamine compounds used in step A, X in formula (1) is a diamine compound represented by formula (2), for example, X in formula (1) is a group represented by formula (2') The ratio of the diamine compound relative to the total molar amount of the diamine compound used in step A is preferably 30 mol% or more, more preferably 50 mol% or more, and even more preferably 70 mol% or more , Particularly preferably 80 mol% or more, and more preferably 100 mol% or less. If the ratio of the diamine compound in which X in the formula (1) is the group represented by the formula (2) is in the above range, the film containing the polyimide-based resin can improve the resin by containing the fluorine element skeleton Regarding the solvent solubility, the viscosity of the resin varnish is kept low, and the yellowness or haze of the film can be reduced, and the optical properties can be easily improved. Furthermore, the ratio of the diamine compound in which X in the formula (1) is the group represented by the formula (2), etc. can also be calculated based on the addition ratio of the raw materials.

The carboxylic acid compound having 3 or more carbonyl groups used in step A is preferably a tricarboxylic acid compound or a tetracarboxylic acid compound, and more preferably a tetracarboxylic acid compound.

The tetracarboxylic acid compound means tetracarboxylic acid or a tetracarboxylic acid derivative. Examples of tetracarboxylic acid derivatives include tetracarboxylic acid anhydrides and chlorinated acids, and preferably tetracarboxylic acid dianhydrides. Examples of tetracarboxylic acid compounds include aromatic tetracarboxylic acids and their anhydrides, preferably aromatic tetracarboxylic acid compounds such as dianhydrides; aliphatic tetracarboxylic acids and their anhydrides, preferably fatty acids such as dianhydrides Group tetracarboxylic acid compounds and so on. These tetracarboxylic acid compounds can be used alone or in combination of two or more kinds.

所表示之化合物(以下，有稱為四羧酸化合物(3)之情形)。四羧酸化合物可單獨使用或組合兩種以上使用，於使用兩種以上四羧酸化合物之情形時，亦可使用四羧酸化合物(3)之Y之種類互不相同之兩種以上之四羧酸化合物。In one embodiment of the present invention, the tetracarboxylic acid compound is preferably tetracarboxylic dianhydride. The tetracarboxylic dianhydride is preferably, for example, formula (3) [化5]

The compound shown (hereinafter, it may be referred to as a tetracarboxylic acid compound (3)). The tetracarboxylic acid compound can be used alone or in combination of two or more. When two or more tetracarboxylic acid compounds are used, two or more types of Y of the tetracarboxylic acid compound (3) can also be used. Carboxylic acid compound.

In formula (3), Y represents a tetravalent organic group independently of each other, preferably represents a tetravalent organic group with 4 to 40 carbons, and more preferably represents a tetravalent organic group with 4 to 40 carbons having a cyclic structure base. Examples of the cyclic structure include alicyclic, aromatic, and heterocyclic structures. The above-mentioned organic group is an organic group in which the hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. In this case, the carbon number of the hydrocarbon group and the fluorine-substituted hydrocarbon group is preferably 1-8. As Y, exemplify the following formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) ) And the group represented by the formula (29); the hydrogen atom in the group represented by the formula (20) ~ formula (29) is substituted with methyl, fluoro, chloro or trifluoromethyl Group; and tetravalent chain hydrocarbon group with carbon number 6 or less. [化6]

In formulas (20) to (29), * represents a bonding bond, W ¹ represents a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C (CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -Ar-, -SO ₂ -, -CO-, -O-Ar-O-, -Ar-O-Ar-, -Ar-CH ₂ -Ar-, -Ar-C(CH ₃ ) ₂ -Ar- or -Ar-SO ₂ -Ar-. Ar represents an arylene group having 6 to 20 carbon atoms in which a hydrogen atom can be substituted with a fluorine atom, and a specific example includes a phenylene group.

Among the bases represented by formulas (20) to (29), from the viewpoint of easily improving the elastic modulus, flex resistance and surface hardness of the film, formulas (26), (28) or The group represented by formula (29) is more preferably the group represented by formula (26). In addition, W ¹ is preferably a single bond, -O-, -CH ₂ -, -CH in terms of easily improving the elastic modulus, flex resistance, and surface hardness of the optical film, and also easily improving the optical properties. _{The group represented by 2} -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -or -C(CF ₃ ) ₂ -, more preferably a single bond, -O-, -CH _2- , -CH(CH ₃ )-, -C(CH ₃ ) ₂ -or -C(CF ₃ ) ₂ -, and more preferably a single bond, -C(CH ₃ ) ₂ -or -C( CF ₃ ) ₂ -The base indicated.

[式(4)中，R⁹ ～R¹⁶ 相互獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基，R⁹ ～R¹⁶ 所包含之氫原子可相互獨立地被取代為鹵素原子，*表示鍵結鍵] 所表示之基。若包含式(3)中之Y為式(4)所表示之基之化合物作為四羧酸化合物，則容易提高包含聚醯亞胺系樹脂而成之膜之彈性模數、光學特性、耐撓曲性及表面硬度。又，可提高樹脂對於溶劑之溶解性，將樹脂清漆之黏度抑制為較低，使膜之製造變得容易。In a preferred embodiment of the present invention, Y in formula (3) is formula (4) [化7]

[In formula (4), R ⁹ to R ¹⁶ independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, or an aryl group with 6 to 12 carbons, R ⁹ to The hydrogen atoms contained in R ¹⁶ can be independently substituted with halogen atoms, and * represents the group represented by the bond]. If the compound in which Y in the formula (3) is the group represented by the formula (4) is included as a tetracarboxylic acid compound, it is easy to improve the elastic modulus, optical properties, and flexibility of the film containing the polyimide resin Flexibility and surface hardness. In addition, the solubility of the resin in the solvent can be improved, and the viscosity of the resin varnish can be suppressed to be low, making the production of the film easier.

In formula (4), preferably R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, an alkyl group with 1 to 6 carbon atoms, and a carbon number An alkoxy group having 1 to 6 or an aryl group having 6 to 12 carbons. Examples of alkyl groups having 1 to 6 carbons, alkoxy groups having 1 to 6 carbons, or aryl groups having 6 to 12 carbons include the alkyl groups having 1 to 6 carbons in formula (2), and carbon number 1. The alkoxy group of ~6 or the aromatic of carbon number 6-12 are based on the above-exemplified ones. R ⁹ to R ¹⁶ are independent of each other, and preferably represent a hydrogen atom or an alkyl group with 1 to 6 carbon atoms, more preferably represent a hydrogen atom or an alkyl group with 1 to 3 carbon atoms, where R ⁹ to R ¹⁶ include The hydrogen atoms can be substituted with halogen atoms independently of each other. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R ⁹ to R ¹⁶ are independent of each other, and from the viewpoint that it is easy to increase the elastic modulus, optical properties, flex resistance and surface hardness of a film containing polyimide resin, hydrogen atoms and formaldehyde are more preferred. Group, fluoro group, chloro group or trifluoromethyl group, and more preferably R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ are hydrogen atoms and R ¹⁵ and R ¹⁶ are hydrogen atoms, methyl Group, fluoro group, chloro group or trifluoromethyl group, particularly preferably R ¹⁵ and R ¹⁶ are methyl or trifluoromethyl.

表示。若包含式(4)中之Y為式(4')所表示之基之化合物作為四羧酸化合物，則包含聚醯亞胺系樹脂而成之膜容易提高彈性模數、光學特性、耐撓曲性及表面硬度。又，可藉由含有氟元素之骨架，提高樹脂對於溶劑之溶解性，將樹脂清漆之黏度抑制為較低，使膜之製造變得容易。In a preferred embodiment of the present invention, formula (4) is derived from formula (4'): [化8]

Said. If a compound in which Y in the formula (4) is a group represented by the formula (4') is included as a tetracarboxylic acid compound, a film containing a polyimide-based resin can easily improve the modulus of elasticity, optical properties, and flexibility Flexibility and surface hardness. In addition, the fluorine-containing skeleton can improve the solubility of the resin in solvents, and suppress the viscosity of the resin varnish to a low level, making the production of the film easier.

Specific examples of aromatic tetracarboxylic dianhydrides include: non-condensed polycyclic aromatic tetracarboxylic dianhydrides, monocyclic aromatic tetracarboxylic dianhydrides, and condensed polycyclic aromatic tetracarboxylic dianhydrides Acid dianhydride. Examples of non-condensed polycyclic aromatic tetracarboxylic dianhydrides include: 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic acid Dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3' -Biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2, 2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene Yl)diphthalic dianhydride (sometimes described as 6FDA), 1,2-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxybenzene Base) ethane dianhydride, 1,2-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(3 ,4-Dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, 4,4'-(p-phenylenedioxy)diphthalic dianhydride, 4, 4'-(Phenylenedioxy)diphthalic dianhydride. In addition, examples of monocyclic aromatic tetracarboxylic dianhydrides include 1,2,4,5-benzenetetracarboxylic dianhydride, and examples of condensed polycyclic aromatic tetracarboxylic dianhydrides include 2,3,6,7-Naphthalenetetracarboxylic dianhydride.

Among these, preferred examples include 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2', 3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride , 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3- Dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic acid Anhydride (6FDA), 1,2-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,2-bis (3,4-Dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, Bis(2,3-dicarboxyphenyl)methane dianhydride, 4,4'-(p-phenylenedioxy)diphthalic dianhydride and 4,4'-(p-phenylenedioxy)di Phthalic dianhydride, more preferably 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3 ,3'-Biphenyltetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA), bis(3,4-dicarboxyphenyl)methane dianhydride And 4,4'-(p-phenylenedioxy) diphthalic dianhydride. These can be used alone or in combination of two or more.

As the aliphatic tetracarboxylic dianhydride, cyclic or acyclic aliphatic tetracarboxylic dianhydride can be mentioned. Cycloaliphatic tetracarboxylic dianhydride is a tetracarboxylic dianhydride having an alicyclic hydrocarbon structure. Specific examples include: 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1, 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride and other cycloalkane tetracarboxylic dianhydrides, bicyclo[2.2.2]oct-7- En-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyl-3,3',4,4'-tetracarboxylic dianhydride and their positional isomers. These can be used individually or in combination of 2 or more types. Specific examples of acyclic aliphatic tetracarboxylic dianhydride include 1,2,3,4-butane tetracarboxylic dianhydride, 1,2,3,4-pentane tetracarboxylic dianhydride, etc. These can be used alone or in combination of two or more kinds. Moreover, cycloaliphatic tetracarboxylic dianhydride and acyclic aliphatic tetracarboxylic dianhydride can also be used in combination.

Among the above-mentioned tetracarboxylic dianhydrides, from the viewpoints of high surface hardness, high transparency, high flexibility, high elastic modulus, high flexibility resistance and low coloration of the optical film, 4,4 are preferred '-Oxydiphthalic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2 ,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxybenzene Base) propane dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride, and mixtures thereof, more preferably 3,3',4,4'-biphenyltetracarboxylic acid Acid dianhydride and 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride, and mixtures of these, and more preferably 4,4'-(hexafluoroisopropylidene) diortho Phthalic dianhydride (6FDA).

Among the tetracarboxylic acid compounds used in step A, Y in formula (3) is a tetracarboxylic acid compound represented by formula (4), for example, Y in formula (3) is represented by formula (4') The ratio of the tetracarboxylic acid compound of the base to the total molar amount of the tetracarboxylic acid compound used in step A is preferably 30 mol% or more, more preferably 50 mol% or more, and more preferably 70 Mole% or more, more preferably 80 mole% or more, and preferably 100 mole% or less. If the ratio of the tetracarboxylic acid compound in which Y in the formula (3) is the group represented by the formula (4) is within the above range, the film containing the polyimide-based resin is likely to improve the elastic modulus, optical properties, Flexibility and surface hardness. In addition, the fluorine-containing skeleton can improve the solubility of the resin in the solvent, and suppress the viscosity of the resin varnish to a low level, making the production of the film easier. Furthermore, the ratio of the tetracarboxylic acid compound in which Y in the formula (3) is the group represented by the formula (4), etc. can also be calculated based on the addition ratio of the raw materials.

所表示之化合物(以下，有稱為四羧酸化合物(5)之情形)等。四羧酸化合物(5)可單獨使用或組合兩種以上使用，於使用兩種以上四羧酸化合物(5)之情形時，亦可使用四羧酸化合物(5)之Y¹ 之種類互不相同之兩種以上之四羧酸化合物(5)。Furthermore, as the tetracarboxylic acid compound, tetracarboxylic dianhydride is preferred, but tetracarboxylic monoanhydride may also be used. As the tetracarboxylic acid monoanhydride, formula (5) can be cited

The represented compound (hereinafter, sometimes referred to as the tetracarboxylic acid compound (5)), etc. The tetracarboxylic acid compound (5) can be used alone or in combination of two or more. When two or more tetracarboxylic acid compounds (5) are used, the types of Y ¹ of the tetracarboxylic acid compound (5) can also be used. Two or more identical tetracarboxylic acid compounds (5).

In formula (5), Y ¹ is a tetravalent organic group, preferably an organic group in which the hydrogen atom in the organic group can be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. Examples of Y ¹ include: formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) ) Or the group represented by the formula (29); the hydrogen atom in the group represented by the formula (20) ~ formula (29) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group Group; and tetravalent chain hydrocarbon group with carbon number 6 or less. In addition, R ¹⁷ and R ¹⁸ are independently -OH, -OMe, -OEt, -OPr, -OBu or -Cl, preferably -Cl.

The tricarboxylic acid compound means a tricarboxylic acid or a tricarboxylic acid derivative, and examples of the tricarboxylic acid derivative include tricarboxylic acid chlorides, acid anhydrides, and esters.

所表示之化合物(以下，有稱為三羧酸化合物(8)之情形)等。三羧酸化合物可單獨使用或組合兩種以上使用，於使用兩種以上三羧酸化合物之情形時，亦可使用三羧酸化合物(8)之Y² 之種類互不相同之兩種以上之三羧酸化合物(8)。式(8)中，R³⁴ 為-OH、-OMe、-OEt、-OPr、-OBu或-Cl，較佳為-Cl。In one embodiment of the present invention, as the tricarboxylic acid compound, for example, formula (8) [formation 10]

The compound shown (hereinafter, it may be referred to as a tricarboxylic acid compound (8)), etc. The tricarboxylic acid compound can be used alone or in combination of two or more kinds. When two or more tricarboxylic acid compounds are used, two or more kinds of Y ² of the tricarboxylic acid compound (8) different from each other can also be used. Tricarboxylic acid compound (8). In formula (8), R ³⁴ is -OH, -OMe, -OEt, -OPr, -OBu or -Cl, preferably -Cl.

In formula (8), Y ² is a trivalent organic group, preferably an organic group in which the hydrogen atom in the organic group can be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. As Y ² , for example: formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) ) Or a group in which any one of the bonding bonds of the group represented by the formula (29) is substituted with a hydrogen atom, and a trivalent chain hydrocarbon group with 6 or less carbon atoms.

Examples of tricarboxylic acid compounds include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, and derivatives of these (for example, chlorine, acid anhydrides, etc.), and specific examples thereof include: 1,3,5- Benzenetricarboxylic acid and its chloride, 1,2,4-benzenetricarboxylic acid anhydride; 2,3,6-naphthalenetricarboxylic acid-2,3-anhydride; phthalic anhydride and benzoic acid via single bond , -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -or phenylene linking compound. These tricarboxylic acid compounds can be used alone or in combination of two or more kinds.

In one embodiment of the present invention, the amount of the carboxylic acid compound having 3 or more carbonyl groups for the reaction in the process (I) (step (A)) can be determined according to the required polyimide resin The ratio of the structural units is appropriately selected. When the total amount of the diamine compound for reaction in the process (I) (step (A)) is set to 100 mol, it is preferably 1 mol or more, more preferably 5 More than mol, more preferably 10 mol or more, and preferably 150 mol or less, more preferably 100 mol or less, still more preferably 80 mol or less, and particularly preferably 50 mol or less. If the usage amount of the carboxylic acid compound having 3 or more carbonyl groups is within the above range, it is easy to control the molecular weight of the polyimide resin. In addition, it is easy to improve the flexural resistance of the film containing the polyimide-based resin. Furthermore, when the manufacturing method of the present invention includes process (IV'), the amount of the carboxylic acid compound with more than 3 carbonyl groups for reaction in process (I) can be used in process (I) and process (IV') The total amount of diamine compound for reaction in) is the basis.

When the manufacturing method of the present invention includes process (IV'), the amount of diamine compound for reaction in process (I) (step (A)) is used in process (I) and process (IV') When the total amount of the diamine compound for reaction is 100 mol, it is preferably 80 mol or more, more preferably 85 mol or more, still more preferably 90 mol or more, and even more preferably 95 mol or more , Particularly preferably 98 mol or more, and more preferably 99.99 mol or less. If the amount of the diamine compound used for the reaction in the process (I) is within the above range, it is easy to control the molecular weight of the polyimide resin, and it is easier to improve the resistance of the film containing the polyimide resin. Flexibility.

The reaction in the process (I) is preferably carried out in a solvent that is inert to the reaction. The solvent is not particularly limited as long as it does not affect the reaction. Examples include water, methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methyl Alcohol solvents such as oxy-2-propanol, 2-butoxyethanol, and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, γ-pentane Lactone, propylene glycol methyl ether acetate, ethyl lactate and other ester solvents; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, methyl isobutyl ketone and other ketone solvents; Aliphatic hydrocarbon solvents such as pentane, hexane and heptane; alicyclic hydrocarbon solvents such as ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; tetrahydrofuran and dimethoxyethane Ether solvents; solvents containing chlorine such as chloroform and chlorobenzene; amine solvents such as N,N-dimethylacetamide and N,N-dimethylformamide; dimethyl sulfide, dimethyl Sulfur-containing solvents such as sulfite and cyclobutyl; carbonate-based solvents such as ethylene carbonate and propylene carbonate; and combinations of these. Among them, diamine compounds and carboxylic acid compounds having 3 or more carbonyl groups, preferably tetracarboxylic acid compounds, have good solubility and easy control of the molecular weight of the polyimide resin. An amide-based solvent is preferably used.

Regarding the amount of solvent used, it is preferably 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, and more preferably 1 part by mass relative to the total amount of the diamine compound and the carboxylic acid compound having 3 or more carbonyl groups It is 5 to 15 parts by mass. If the content of the solvent is within the above range, it is advantageous from the viewpoint of controlling the viscosity of the reaction system, and it is easy to control the molecular weight of the polyimide resin.

When a solvent is used, it can be performed by dissolving any one of the diamine compound and the carboxylic acid compound having 3 or more carbonyl groups in the solvent, adding the other to the obtained solution, and stirring. The reaction can also be carried out by dissolving a diamine compound and a carboxylic acid compound having 3 or more carbonyl groups in a solvent to obtain a solution, and then mixing and stirring these solutions for the reaction, or by combining the two These are added to the solvent together, and the reaction is performed by stirring and the like.

The reaction temperature of step (A) is not particularly limited, and may be, for example, -5 to 100°C, preferably 0 to 50°C, and more preferably 5 to 30°C. The reaction time can be, for example, 1 minute to 72 hours, preferably 10 minutes to 24 hours, more preferably 30 minutes to 10 hours. In addition, the reaction can be carried out in air or in an inert gas atmosphere such as nitrogen or argon while stirring, or can be carried out under normal pressure, under pressure, or under reduced pressure. In a preferred embodiment, it is performed while stirring under normal pressure and/or the aforementioned inert gas atmosphere.

[式(A)中，G¹ 係與式(3)中之Y相同， X¹ 係與式(1)中之X相同]In the case where the process (I) is composed of step (A), the obtained intermediate (K) has structural units derived from diamine compounds and structural units derived from carboxylic acid compounds with more than 3 carbonyl groups . In a preferred aspect of the present invention, the intermediate (K) includes a repeating structural unit represented by formula (A) obtained by reacting a diamine compound (1) with a tetracarboxylic acid compound (3). [化11]

[In formula (A), G ¹ is the same as Y in formula (3), and X ¹ is the same as X in formula (1)]

When there are two or more diamine compounds (1) and/or tetracarboxylic acid compounds (3), the intermediate (K) has two or more repeating structural units represented by formula (A). In addition, the intermediate (K) having the structural unit derived from the diamine compound and the structural unit derived from the tetracarboxylic acid compound is sometimes referred to as the intermediate (K-1).

In one embodiment of the present invention, the process (I) further includes the step (B) of reacting the dicarboxylic acid compound after the step (A).

所表示之化合物(以下，有稱為二羧酸化合物(6)之情形)。二羧酸化合物可單獨使用或組合兩種以上使用，於使用兩種以上二羧酸化合物之情形時，可使用二羧酸化合物(6)之W之種類互不相同之兩種以上之二羧酸化合物(6)。式(6)中，R¹⁹ 及R²⁰ 相互獨立地為-OH、-OMe、-OEt、-OPr、-OBu或-Cl，較佳為-Cl。(Step B) The dicarboxylic acid compound used in the step (B) means a dicarboxylic acid or a dicarboxylic acid derivative, and examples of the dicarboxylic acid derivative include the chloride or ester of the dicarboxylic acid. In one embodiment of the present invention, the dicarboxylic acid compound is preferably, for example, formula (6) [formation 12]

The compound shown (hereinafter, it may be referred to as a dicarboxylic acid compound (6)). The dicarboxylic acid compound can be used alone or in combination of two or more. When two or more dicarboxylic acid compounds are used, two or more dicarboxylic acid compounds with different W types of the dicarboxylic acid compound (6) can be used. Acid compound (6). In the formula (6), R ¹⁹ and R ²⁰ are independently -OH, -OMe, -OEt, -OPr, -OBu or -Cl, preferably -Cl.

In formula (6), W is a divalent organic group, preferably a divalent organic group with 4 to 40 carbons which can be substituted by a hydrocarbon group with 1 to 8 carbons or a hydrocarbon group with 1 to 8 carbons substituted by fluorine, More preferably, it is a divalent organic group having a cyclic structure and having a carbon number of 4 to 40, which can be substituted with a hydrocarbon group having 1 to 8 carbons or a hydrocarbon group having 1 to 8 carbons substituted by fluorine. Examples of the cyclic structure include alicyclic, aromatic, and heterocyclic structures. As the organic group of W, the formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula ( 28) and a group in which two non-adjacent bonding bonds of the group represented by the formula (29) are substituted with hydrogen atoms and a divalent chain hydrocarbon group with 6 or less carbon atoms. From the viewpoint of easily suppressing the yellowness (lowering the YI value) of the film composed of the polyimide resin, the group represented by the formula (20) to the formula (28) and the one having a thiophene ring skeleton are preferred base.

[式(20')～式(29')中，W¹ 及*係如式(20)～式(29)中所定義] 所表示之2價有機基。再者，式(20)～式(29)及式(20')～式(29')中之環上之氫原子可被取代為碳數1～8之烴基、經氟取代之碳數1～8之烴基、碳數1～6之烷氧基、或經氟取代之碳數1～6之烷氧基。As the organic group of W, it is more preferably formula (20'), formula (21'), formula (22'), formula (23'), formula (24'), formula (25'), formula (26') , Formula (27'), formula (28') and formula (29'): [化13]

[In formula (20') to formula (29'), W ¹ and * are as defined in formula (20) to formula (29)]. Furthermore, the hydrogen atoms on the ring in formulas (20) to (29) and (20') to (29') can be substituted with hydrocarbon groups with 1 to 8 carbons, and 1 with fluorine substituted carbon atoms. ~8 hydrocarbon group, alkoxy group having 1 to 6 carbon atoms, or alkoxy group having 1 to 6 carbon atoms substituted by fluorine.

[式(d1)中，R^c 相互獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基， R^d 表示R^c 或-C(=O)R^e ， R^e 相互獨立地表示-OH、-OMe、-OEt、-OPr、-OBu或-Cl， *表示鍵結鍵] 所表示之化合物(以下，有時稱為化合物(d1))。In the case where the dicarboxylic acid compound includes a compound in which W in formula (6) is represented by any of the above formulas (20') to (29'), especially when W in formula (6) is contained by the following formula In the case of the compound represented by (6a), from the viewpoint that it is easy to improve the film-forming properties of the varnish and the uniformity of the film containing the polyimide resin, it is preferable that the dicarboxylic acid compound contains the formula In addition to the compound represented by formula (6a), W in (6) further includes the following formula (d1): [化14]

[In formula (d1), R ^c independently represents a hydrogen atom, an alkyl group having 1 to 6 carbons, an alkoxy group having 1 to 6 carbons or an aryl group having 6 to 12 carbons, and R ^d represents R ^c or -C(=O)R ^e and R ^e independently represent -OH, -OMe, -OEt, -OPr, -OBu or -Cl, * represents a bonding bond] The compound represented (hereinafter, sometimes referred to as Compound (d1)).

In R ^c , as the alkyl group having 1 to 6 carbons, the alkoxy group having 1 to 6 carbons, and the aryl group having 6 to 12 carbons, respectively, the alkane having 1 to 6 carbons in the formula (2) Exemplified by the group, an alkoxy group having 1 to 6 carbons, or an aryl group having 6 to 12 carbons. As the compound (d1), specifically, a compound in which R ^c and ^Rd are both hydrogen atoms, a compound in which both R ^c are hydrogen atoms and R ^d is -C(=0)R ^e , etc. can be mentioned.

[式(6a)中，R^a 及R^b 相互獨立地表示鹵素原子、碳數1～6之烷基、碳數1～6之烷氧基、或碳數6～12之芳基，R^a 及R^b 所包含之氫原子可相互獨立地被取代為鹵素原子， A及*分別與式(7b)中之A及*相同， m為0～4之整數， t為0～4之整數， u為0～4之整數] 表示之基，更佳為由式(7a)： [化16]

[式(7a)中，R²¹ ～R²⁴ 相互獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基， R²¹ ～R²⁴ 所包含之氫原子可相互獨立地被取代為鹵素原子， m2為1～4之整數， *表示鍵結鍵] 表示之基。若包含式(6)中之W為式(7a)所表示之基之化合物作為二羧酸化合物，則包含聚醯亞胺系樹脂而成之膜容易顯現優異之彈性模數、耐撓曲性及光學特性。再者，有時將式(6)中之W為式(7a)所表示之基之化合物及式(6)中之W為式(6a)所表示之基之化合物分別稱為二羧酸化合物(7a)及二羧酸化合物(6a)。The dicarboxylic acid compound in the present invention may contain a plurality of types of W as W in formula (6), and the plurality of types of W may be the same or different from each other. Especially from the viewpoint of easily improving the optical properties, modulus of elasticity, and flex resistance of a film comprising polyimide resins, W in formula (6) is preferably represented by formula (6a): [化15]

[In the formula (. 6A), R ^a and R ^b each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, the alkoxy group having a carbon number of 1 to 6, carbon atoms, or an aryl group of 6 to 12, R ^a The hydrogen atoms contained in and R ^b can be independently substituted with halogen atoms. A and * are the same as A and * in formula (7b), m is an integer of 0-4, and t is an integer of 0-4, u is an integer from 0 to 4] represents the base, more preferably from the formula (7a): [化16]

[In formula (7a), R ²¹ to R ²⁴ independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, or an aryl group with 6 to 12 carbons, and R ²¹ to The hydrogen atoms contained in R ²⁴ can be substituted with halogen atoms independently of each other, m2 is an integer of 1 to 4, and * represents a bonding bond]. If a compound in which W in the formula (6) is a group represented by the formula (7a) is included as a dicarboxylic acid compound, a film containing a polyimide-based resin is likely to exhibit excellent elastic modulus and flexibility resistance And optical properties. Furthermore, the compound in which W in formula (6) is the group represented by formula (7a) and the compound in which W in formula (6) is the group represented by formula (6a) are sometimes called dicarboxylic acid compounds, respectively (7a) and dicarboxylic acid compound (6a).

In formula (6a), the bonding bond of each benzene ring can be bonded to any position of ortho, meta or para position based on -A-, and preferably can be bonded to meta or para position. R ^a and R ^b independently represent a halogen atom, an alkyl group having 1 to 6 carbons, an alkoxy group having 1 to 6 carbons, or an aryl group having 6 to 12 carbons. In the formula (. 6A) t, and u is preferably 0, but at t and / or u more of the case 1, R ^a and R ^b each independently, preferably represent an alkyl group having 1 to 6 carbon atoms, the more Preferably, it represents an alkyl group having 1 to 3 carbon atoms. In R ^a and R ^b in the formula (6a), as a halogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, and an aryl group with 6 to 12 carbons, respectively, the formula (2) Halogen atom, C1-C6 alkyl group, C1-C6 alkoxy group or C6-C12 aryl group are exemplified.

In formula (6a), t and u are independently an integer of 0-4, preferably an integer of 0-2, more preferably 0 or 1, and even more preferably 0.

In formula (6a), m is an integer in the range of 0-4, and if m is within this range, the film containing the polyimide-based resin has good flexural resistance or elastic modulus. Furthermore, in formula (6a), m is preferably an integer in the range of 0-3, more preferably an integer in the range of 0-2, more preferably 0 or 1, and particularly preferably 0. When m is in this range, the flexural resistance or elastic modulus of the film containing the polyimide-based resin is good, and the availability of raw materials is relatively good. The compound represented by the formula (6a) in which m is 0 is, for example, terephthalic acid or isophthalic acid or derivatives thereof. The compound is preferably a compound in which m is 0 and u is 0 in the formula (6a) . In addition, the dicarboxylic acid compound may also include one or more of the compounds represented by the formula (6a) in the formula (6), which includes the elastic modulus and resistance of the film made of the polyimide resin. From the viewpoint of improvement in flexibility and reduction in yellowness (YI value), two or more compounds having different values of m, preferably two compounds having different values of m may be included.

From the viewpoint of the improvement of the elastic modulus and the flexural resistance and the decrease of the yellowness (YI value) of the film comprising the polyimide resin, it is preferable to include the formula (6a) where m is 0 The compound represented by the formula (6a) more preferably includes a compound represented by the formula (6a) in which m is 1 in addition to the compound.

In formula (7a), R ²¹ , R ²² , R ²³ and R ²⁴ independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, or an aromatic group with 6 to 12 carbons. base. Examples of alkyl groups having 1 to 6 carbons, alkoxy groups having 1 to 6 carbons, or aryl groups having 6 to 12 carbons include the alkyl groups having 1 to 6 carbons in formula (2), and carbon number 1. The alkoxy group of ~6 or the aromatic of carbon number 6-12 are based on the above-exemplified ones. From the viewpoint of easily improving the surface hardness, flexibility, and flex resistance of a film made of polyimide resins, R ²¹ to R ²⁴ are independent of each other, and preferably represent a hydrogen atom or a carbon number of 1 to 6 The alkyl group more preferably represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably represents a hydrogen atom. Here, the hydrogen atoms contained in R ²¹ to R ²⁴ may be independently substituted with halogen atoms.

In formula (7a), from the viewpoint of easily improving the flexural resistance and elastic modulus of the film containing polyimide resin, m2 is preferably an integer of 1 to 3, more preferably 1 or 2 , And more preferably 1. If all of R ²¹ to R ²⁴ are hydrogen atoms, it is advantageous in terms of improving the elastic modulus and flexural resistance of a film containing a polyimide-based resin.

In a preferred embodiment of the present invention, from the viewpoint that a film comprising a polyimide-based resin is likely to exhibit good flexibility resistance, the dicarboxylic acid compound contains two or more aromatic hydrocarbon rings Aromatic dicarboxylic acid compound formed by connecting single bonds or divalent groups other than aromatic groups. As the aromatic hydrocarbon ring, for example, a monocyclic hydrocarbon ring such as a benzene ring; a polycyclic hydrocarbon ring such as a condensed bicyclic hydrocarbon ring such as naphthalene and an aggregate ring hydrocarbon ring such as biphenyl, and a benzene ring is preferable.

[式(7b)中，R²⁵ ～R³² 相互獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基，R²⁵ ～R³² 所包含之氫原子可相互獨立地被取代為鹵素原子， A相互獨立地表示單鍵、-O-、-CH₂ -、-CH₂ -CH₂ -、-CH(CH₃ )-、-C(CH₃ )₂ -、-C(CF₃ )₂ -、-SO₂ -、-S-、-CO-或-N(R³³ )-， R³³ 表示氫原子、可經鹵素原子取代之碳數1～12之1價烴基， m¹ 為1～4之整數， *表示鍵結鍵] 所表示之基之化合物。若包含式(6)中之W為式(7b)所表示之基之化合物作為二羧酸化合物，則包含聚醯亞胺系樹脂而成之膜容易顯現優異之彈性模數、耐撓曲性及光學特性。再者，有時將式(6)中之W為式(7b)所表示之基之化合物稱為二羧酸化合物(7b)。Specifically, an aromatic dicarboxylic acid compound in which two or more aromatic hydrocarbon rings are connected by a single bond or a divalent group other than the aromatic group is an aromatic dicarboxylic acid compound in the formula (6) where W is the formula (7b) ]

[In formula (7b), R ²⁵ to R ³² independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, or an aryl group with 6 to 12 carbons, and R ²⁵ to The hydrogen atoms contained in R ³² can be independently substituted with halogen atoms, and A independently represents a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -, -S-, -CO- or -N(R ³³ )-, R ³³ represents a hydrogen atom, which can be substituted by a halogen atom The monovalent hydrocarbon group with carbon number of 1-12, m ¹ is an integer of 1 to 4, and * represents the compound of the group represented by the bond]. If the compound in which W in the formula (6) is the group represented by the formula (7b) is included as a dicarboxylic acid compound, the film containing the polyimide-based resin is likely to exhibit excellent elastic modulus and flexibility resistance And optical properties. Furthermore, the compound in which W in formula (6) is a group represented by formula (7b) is sometimes referred to as a dicarboxylic acid compound (7b).

In formulas (7b) and (6a), A independently represents a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -, -S-, -CO- or -N(R ³³ )-, it is easy to improve the elastic modulus of the film made of polyimide resin From the viewpoint of number and flex resistance, it is preferable to represent -O- or -S-, and it is more preferable to represent -O-. Examples of alkyl groups having 1 to 6 carbons, alkoxy groups having 1 to 6 carbons, or aryl groups having 6 to 12 carbons include the alkyl groups having 1 to 6 carbons in formula (2), and carbon number 1. The alkoxy group of ~6 or the aromatic of carbon number 6-12 are based on the above-exemplified ones. From the viewpoint of easily improving the surface hardness, flexibility, and flex resistance of a film composed of polyimide-based resins, R ²⁵ to R ³² are independent of each other, and preferably represent a hydrogen atom or a carbon number of 1 to 6 The alkyl group more preferably represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably represents a hydrogen atom. Here, the hydrogen atoms contained in R ²⁵ to R ³² may be independently substituted with halogen atoms. R ³³ represents a hydrogen atom or a monovalent hydrocarbon group with 1 to 12 carbon atoms which may be substituted with a halogen atom. Examples of monovalent hydrocarbon groups having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, second butyl, tertiary butyl, n-pentyl, and 2-methyl -Butyl, 3-methylbutyl, 2-ethyl-propyl, n-hexyl, n-heptyl, n-octyl, tertiary octyl, n-nonyl, n-decyl, etc., which can pass through halogen atoms replace. As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned. When m ¹ is 2 to 4, A may be the same or different.

In formula (7b), m ¹ is an integer of 1 to 4, and if m ^{1 is in} this range, the flexural resistance or elastic modulus of the film containing the polyimide resin is likely to become good. Furthermore, in formula (7b), m ^{1 is} preferably an integer of 1 to 3, more preferably 1 or 2, and still more preferably 1. If m ¹ is within this range, the flexural resistance of the optical film or The elastic modulus tends to become good.

From the viewpoint of improving the elastic modulus and flexural resistance of a film comprising polyimide-based resin, and reducing the yellowness (YI value), the dicarboxylic acid compound in step (B) is preferably In order to use the dicarboxylic acid compound (7a) or (7b), it is more preferable to use the dicarboxylic acid compound (7a) and the dicarboxylic acid compound (7b) in combination.

表示。又，式(7b)係由式(7b')： [化19]

表示。若使用式(6)中之W為式(7a')所表示之基之化合物或為式(7b')所表示之基之化合物、或者該等兩者作為二羧酸化合物，則容易獲得彈性模數及耐撓曲性得到更為提高之膜。In a more preferable embodiment of the present invention, the formula (7a) is derived from the formula (7a'): [化18]

Said. Also, the formula (7b) is derived from the formula (7b'): [化19]

Said. If W in the formula (6) is a compound represented by the formula (7a') or a compound represented by the formula (7b'), or both of them are used as the dicarboxylic acid compound, elasticity is easily obtained A film with improved modulus and flex resistance.

Examples of the dicarboxylic acid compound include aromatic dicarboxylic acid, aliphatic dicarboxylic acid, and similar chlorinated compounds, acid anhydrides, and the like, and they may be used in combination of two or more. More specifically, examples include: terephthalic acid; isophthalic acid; naphthalenedicarboxylic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; those with 8 or less carbon atoms The chain hydrocarbon dicarboxylic acid compound and two benzoic acids are connected by a single bond, -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -or phenylene And the chlorinated compounds. Among these dicarboxylic acid compounds, 4,4'-oxybisbenzoic acid is preferred from the viewpoint that it is easy to increase the elastic modulus and flex resistance of a film made of polyimide resin , Terephthalic acid, or these chlorines, as described above, more preferably 4,4'-oxybis(benzyl chloride) and terephthalic acid chloride, and more preferably 4,4' -Oxybis (benzoic acid chloride) and terephthalic acid chloride are used in combination.

When the process (I) includes step (B), the intermediate (K-1) obtained in step (A) can also be isolated and supplied to step (B), but it is usually continuous without isolation Go to step (B).

In a preferred embodiment of the present invention, the amount of the dicarboxylic acid compound used for the reaction in the process (I) (step (B)) can be appropriately selected according to the ratio of the structural units of the polyimide resin required For example, when the total amount of the diamine compound for reaction in the process (I) (step (A)) is set to 100 mol, it is preferably 5 mol or more, more preferably 20 mol or more, and more preferably It is 30 mol or more, more preferably 40 mol or more, more preferably 50 mol or more, more preferably 60 mol or more, and preferably 95 mol or less, and more preferably 90 mol or less, It is more preferably 85 mol or less, and particularly preferably 80 mol or less. If the amount of the dicarboxylic acid compound used is within the above range, it is easy to control the molecular weight of the polyimide resin. In addition, it is easy to improve the elastic modulus and flexural resistance of an optical film containing a polyimide-based resin. Furthermore, when the manufacturing method of the present invention includes process (IV'), the usage amount of the dicarboxylic acid compound for reaction in process (I) can be the second of the reaction in process (I) and process (IV') The total amount of amine compounds is used as a benchmark.

In a preferred embodiment of the present invention, among the dicarboxylic acid compounds used in the process (I) (step (B)), the ratio of the dicarboxylic acid compound (6a) to that used in the process (I) The total molar amount of the dicarboxylic acid compound is preferably 30 mol% or more, more preferably 50 mol% or more, further preferably 70 mol% or more, particularly preferably 80 mol% or more, and more preferably Less than 100 mol%. If the ratio of the dicarboxylic acid compound (6a) is within the above range, it is advantageous from the viewpoint of controlling the molecular weight of the polyimide-based resin. In addition, a film containing a polyimide-based resin can easily improve the modulus of elasticity, optical properties, flex resistance, and surface hardness. Furthermore, the solubility of the resin in the solvent can be improved by the skeleton containing the fluorine element, and the viscosity of the resin varnish can be suppressed to be low, making the production of the film easier. Furthermore, the ratio of the dicarboxylic acid compound (6a) can also be calculated based on the addition ratio of the raw materials.

In a preferred embodiment of the present invention, among the dicarboxylic acid compounds used in process (I) (step (B)), the total ratio of dicarboxylic acid compounds (7a) and (7b) is relative to that in process (I) The total molar amount of the dicarboxylic acid compound used in) is preferably 30 mol% or more, more preferably 50 mol% or more, further preferably 70 mol% or more, and particularly preferably 80 mol% Above, and preferably 100 mol% or less. If the total ratio of the dicarboxylic acid compounds (7a) and (7b) is within the above range, it is advantageous from the viewpoint of controlling the molecular weight of the polyimide-based resin. In addition, a film containing a polyimide-based resin can easily improve the modulus of elasticity, optical properties, flex resistance, and surface hardness. Furthermore, the solubility of the resin in the solvent can be improved by the skeleton containing the fluorine element, and the viscosity of the resin varnish can be suppressed to be low, making the production of the film easier. Furthermore, the total ratio of the dicarboxylic acid compounds (7a) and (7b) can also be calculated based on the addition ratio of the raw materials.

In a preferred embodiment of the present invention, as the dicarboxylic acid compound, the dicarboxylic acid compound (7a) and (7b) are preferably used in combination. The usage amount of the dicarboxylic acid compound (7b) is preferably 0.01 mol or more, more preferably 0.05 mol or more, and still more preferably 0.1 mol or more relative to 1 mol of the dicarboxylic acid compound (7a). It is preferably 20 mol or less, more preferably 15 mol or less, further preferably 10 mol or less, still more preferably 1 mol or less, particularly preferably 0.5 mol or less, and even more preferably 0.3 mol or less . If the amount of the dicarboxylic acid compound (7b) used is within the above range, it is advantageous from the viewpoint of controlling the molecular weight of the polyimide-based resin, and the film after film formation is likely to have both flexibility resistance and elastic modulus.

In one embodiment of the present invention, in step (B), a solvent may be further added. By adding the solvent in step (B), the rapid increase in viscosity of the reaction system can be suppressed, and the state of uniform stirring can be maintained for a long time. Therefore, the polymerization reaction can proceed sufficiently, the molecular weight of the polyimide-based resin can be easily increased, and it is also advantageous from the viewpoint of controlling the molecular weight. Examples of the solvent to be added include those exemplified in the item of (Step (A)), and these solvents can be used alone or in combination of two or more. From the viewpoint of good solubility and easy increase or control of the molecular weight of the polyimide-based resin, an amide-based solvent can be preferably used. The solvent added in step (B) may be different from the solvent used in step (A), but from the viewpoint of easy increase or control of molecular weight, it is preferably the same. The solvent can be added at one time, or in multiple batches.

The usage amount of the solvent added in step (B) is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and more preferably, relative to 1 part by mass of the dicarboxylic acid compound used in step (B) 10 parts by mass or more, more preferably 20 parts by mass or more, and more preferably 300 parts by mass or less, more preferably 200 parts by mass or less, still more preferably 100 parts by mass or less, particularly preferably 50 parts by mass or less. If the usage amount of the solvent added in step (B) is within the above range, it is easy to increase or control the molecular weight of the polyimide-based resin.

In step (B), the dicarboxylic acid compound can be added all at once or in batches. If added in batches, it is easy to suppress the rapid increase in viscosity of the reaction system, and it is easy to maintain a uniform stirring state for a long time. Therefore, it is easy to make the polymerization reaction proceed, and it is easy to increase the molecular weight of the obtained polyimide-based resin. In addition, it is also advantageous from the viewpoint of controlling the molecular weight of the polyimide resin.

In step (B), the number of batches when adding the dicarboxylic acid compound in batches can be appropriately selected according to the scale of the reaction or the type of raw materials, etc., preferably 2-20 times, more preferably 2-10 times, and more preferably For 2 to 6 times. If the number of batches is in the above range, it is easy to increase the molecular weight of the polyimide resin. In addition, it is also advantageous from the viewpoint of controlling the molecular weight of the polyimide resin.

The dicarboxylic acid compound may be divided into equal amounts and added, or divided into uneven amounts and added. The time of each addition period (hereinafter referred to as the addition interval) may all be the same or different. In addition, when two or more dicarboxylic acid compounds are added, the term "addition in batches" means that the total amount of all dicarboxylic acid compounds is divided and added, and the division method of each dicarboxylic acid compound is not particularly limited. For example, each dicarboxylic acid compound may be separately added at once or in batches, or each dicarboxylic acid compound may be added in batches together, or a combination thereof.

In one embodiment of the present invention, when there are two dicarboxylic acid compounds (hereinafter referred to as the first dicarboxylic acid compound and the second dicarboxylic acid compound), for example, the first dicarboxylic acid compound Add at once and add the second dicarboxylic acid compound at one time; you can also add the first dicarboxylic acid compound and the second dicarboxylic acid compound in batches separately; you can also add the first dicarboxylic acid compound and the second dicarboxylic acid compound The acid compounds are added together in batches; it is also possible to add the remaining part separately or add the remaining part of one after the addition in batches together, or to add the remaining part together or add the remaining part of one after the addition in batches. From the viewpoint of the high molecular weight of the polyimide resin, it is preferable to add the first dicarboxylic acid compound and the second dicarboxylic acid compound together in batches; or after adding in batches together, add the remainder of one section

In the case of further adding a solvent in step (B), the solvent can be added together with the dicarboxylic acid compound or added separately from the dicarboxylic acid, and when the dicarboxylic acid is added in batches, it can also be the same combination.

The reaction temperature of step (B) is not particularly limited, and may be, for example, -5 to 100°C, preferably 0 to 50°C, and more preferably 5 to 30°C. The reaction time can be, for example, 1 minute to 72 hours, preferably 10 minutes to 24 hours, more preferably 30 minutes to 10 hours. In addition, the reaction can be carried out in air or in an inert gas atmosphere such as nitrogen or argon while stirring, or can be carried out under normal pressure, under pressure, or under reduced pressure. In a preferred aspect, it is performed while stirring under normal pressure and/or the aforementioned inert gas atmosphere.

In the step (B), the intermediate (K) is obtained by performing the reaction by stirring for a specific time after adding the dicarboxylic acid compound.

[式(A)及式(B)中，G² 係與式(6)中之W相同， G¹ 係與式(3)中之Y相同， X¹ 及X² 分別與式(1)中之X相同，X¹ 及X² 可相同亦可不同]When the process (I) consists of steps (A) and (B), the intermediate (K) has a structural unit derived from a diamine compound and a structural unit derived from a carboxylic acid compound with more than 3 carbonyl groups , And structural units derived from dicarboxylic acid compounds. In a preferred aspect of the present invention, the intermediate (K) includes a repeating structural unit represented by formula (A) obtained by reacting a diamine compound (1) with a tetracarboxylic acid compound (3), and a diamine compound ( A) A repeating structural unit represented by formula (B) obtained by reacting with a dicarboxylic acid compound (6). [化20]

[In formulas (A) and (B), G ² is the same as W in formula (6), G ¹ is the same as Y in formula (3), and X ¹ and X ² are respectively the same as in formula (1) X is the same, X ¹ and X ² can be the same or different]

When at least one selected from the group consisting of diamine compound (1), tetracarboxylic acid compound (3), and dicarboxylic acid compound (5) is two or more, the intermediate (K) has two or more formulas ( A) the repeating structural unit represented by and/or the repeating structural unit represented by formula (B). Furthermore, the intermediate (K) having a structural unit derived from a diamine compound, a structural unit derived from a tetracarboxylic acid compound, and a dicarboxylic acid compound may be referred to as an intermediate (K-2).

In the case of manufacturing polyimide-based resins, the intermediate (K) can also be isolated and then supplied to the following process (II), but from the viewpoint of manufacturing efficiency, it is directly supplied without isolation. In process (II).

＜Process (II)＞ Process (II) is a process in which the viscosity A of the reaction system is measured after process (I). The method for measuring the viscosity A of the reaction system is not particularly limited. For example, the following method may be used: a very small amount of liquid is taken from the reaction solution, and the viscosity of the liquid is measured with a viscometer; or, for example, installed in a reaction vessel The method of measuring the viscometer in the tube in the reaction system; the method of calculating backward from the stirring power calculated from the motor current value of the stirring wing installed in the reaction system or the torque value obtained from the torque meter. Furthermore, the viscosity A of the reaction system can be measured at a certain temperature. From the viewpoint of suppressing the thermal decomposition of the resin during the measurement and measuring the exact viscosity, it is preferable to measure at a low temperature, and more preferably, for example, 5 It is measured at -20°C, preferably 5-15°C. The viscosity A of the reaction system can be measured, for example, by the method described in the examples.

＜Process (III)＞ Process (III) compares the viscosity A with the target viscosity range of the reaction system to confirm whether the viscosity A is within the target viscosity range.

In the manufacturing method of the present invention, by converting the target molecular weight into the viscosity of the reaction system and adjusting the viscosity of the reaction system to the target viscosity range before and after the converted viscosity, the molecular weight of the polyimide resin can be controlled. In more detail, the target viscosity corresponding to the target molecular weight is determined in advance, and the target viscosity range before and after the target viscosity is set based on the target viscosity. Furthermore, the target viscosity is set based on the same conditions as the actual reaction system, such as the measurement temperature or the concentration of the liquid to be measured. In the process (III), the viscosity A of the reaction system is compared with the target viscosity range of the reaction system. When the viscosity A is not in the target viscosity range, the viscosity is adjusted to the target viscosity range in the process (IV). Thereby, the molecular weight of the polyimide resin can be controlled, and the polyimide resin of the target molecular weight or a molecular weight close to it can be stably obtained.

The method of converting the target molecular weight (hereinafter, sometimes referred to as the target molecular weight) into the viscosity of the reaction system is not particularly limited, and can be exemplified by conventional methods, such as a method of measuring the viscosity of a resin with a desired molecular weight; or manufacturing; The method of the calibration curve showing the correlation between the molecular weight of the resin and the viscosity of the reaction system, etc.

The target viscosity varies depending on the target molecular weight, the type and amount of the raw material, and the type and amount of the solvent of the reaction system (reaction solution). Therefore, it is not particularly limited. In one embodiment of the present invention, it is, for example, 0.1 to 50 Pa·s, preferably 0.5 to 20 Pa·s, more preferably 1.0 to 10 Pa·s. If the target viscosity is in the above range, the reaction system can be sufficiently stirred, and the polymerization reaction is easy to proceed, so it is easy to control the molecular weight.

After determining the target viscosity corresponding to the target molecular weight, the target viscosity range is set based on the target viscosity. The target viscosity range is not particularly limited as long as the viscosity range corresponding to the allowable molecular weight range based on the target molecular weight is appropriately set. For example, relative to the target viscosity, it is preferably 0.8 times or more, more preferably 0.85 times or more, and It is preferably 1.5 times or less, more preferably 1.3 times or less, and still more preferably 1.1 times or less. If the target viscosity range is in the above range, the molecular weight of the polyimide resin can be effectively controlled, and it is easy to obtain the polyimide resin with the target molecular weight or a molecular weight close to it.

The initial viscosity of the reaction system varies depending on the target molecular weight, the type and amount of the raw material, and the type and amount of the solvent of the reaction system (reaction solution). Therefore, it is not particularly limited. In one embodiment of the present invention, for example, When the target viscosity is 1 Pa·s, it is preferably 0.05 Pa·s or more, more preferably 0.1 Pa·s or more, still more preferably 0.2 Pa·s or more, and particularly preferably 0.3 Pa·s or more, and It is preferably 30 Pa·s or less, more preferably 15 Pa·s or less, still more preferably 10 Pa·s or less, and particularly preferably 5 Pa·s or less. If the initial viscosity of the reaction system is in the above range, it is easy to adjust the viscosity of the reaction system to the target viscosity range.

When the viscosity A is the target viscosity range in the process (III), the polyimide resin precursor or the polyimide resin precursor can be refined without being used in the process (IV), or It is applied to the imidization process (V) to obtain polyimide resin or polyimide resin. When the viscosity A is not in the target viscosity range in the process (III), it is used in the process (IV).

＜Process (IV)＞ Process (IV) is a process in which viscosity A is adjusted to be within the target range when viscosity A is not within the target viscosity range in process (III). It is better to increase the viscosity and adjust to the target viscosity range when the viscosity A does not reach the target viscosity range (called process (IV')), and when the viscosity A exceeds the target viscosity range, reduce the viscosity and adjust to the target Viscosity range (called process (IV'')).

＜Process (IV')＞ The process (IV') is a process in which the viscosity of the reaction system is increased and adjusted to the target viscosity range when the viscosity A does not reach the target viscosity range in the process (III). In the process (IV'), the method of increasing the viscosity A of the reaction system is not particularly limited, and a method of increasing the viscosity A by adding a diamine compound to the reaction system is preferred. When a diamine compound is added to the reaction system, the intermediate (K) reacts with the diamine compound to increase the molecular weight of the intermediate (K), and the viscosity A increases. If this method is used, the viscosity of the reaction system can be easily adjusted to the target viscosity range. Examples of the diamine compound include those exemplified above as the diamine compound to be reacted in step (A). The diamine compound can be used individually or in combination of 2 or more types.

Among the diamine compounds for reaction in process (IV'), X in formula (1) is a diamine compound represented by formula (2), for example, X in formula (1) is represented by formula (2') The ratio of the diamine compound of the indicated base relative to the total molar amount of the diamine compound used in the process (IV') is preferably 30 mol% or more, more preferably 50 mol% or more, and more preferably It is 70 mol% or more, more preferably 80 mol% or more, and more preferably 100 mol% or less. If the ratio of the diamine compound in which X in the formula (1) is the group represented by the formula (2) is within the above range, the film containing the polyimide-based resin can improve the resin by the skeleton containing the fluorine element Regarding the solvent solubility, the viscosity of the polyimide resin varnish can be kept low, and the yellowness or haze of the film can be reduced, and the optical properties can be easily improved. Furthermore, the ratio of the diamine compound in which X in the formula (1) is a group represented by the formula (2), etc. can also be calculated based on the addition ratio of the raw materials.

In one embodiment of the present invention, from the viewpoint that it is easy to increase the molecular weight of the intermediate (K), and the flexural resistance of the film containing the polyimide resin is easily improved, the manufacturing process Preferably, at least one of the diamine compound for reaction in (I) and the diamine compound for reaction in process (IV′) is the same compound. If the diamine compound for reaction in process (I) is set as diamine compound (I), and the diamine compound for reaction in process (IV') is set as diamine compound (IV'), then "at least one It is the same compound" when the diamine compound (I) is one type and the diamine compound (IV') is one type, it means that the diamine compounds (I) and (IV') are the same. When the compound (I) is one kind and the diamine compound (IV') is two or more kinds, it means that one or more kinds of the diamine compound (IV') are the same as the diamine compound (I). In addition, when there are two or more types of diamine compounds (I) and one type of diamine compound (IV'), it means that one or more types of diamine compound (I) are the same as diamine compound (IV'), When there are two or more diamine compounds (I) and two or more diamine compounds (IV'), it means that one or more of them are the same as each other. In a better embodiment, it is easier to increase the molecular weight of the intermediate (K), and it is easier to increase the flexibility resistance of the film containing the polyimide resin, in the process (I) The diamine compound to be reacted and the diamine compound to be reacted in the process (IV') are preferably all the same.

It is also possible to adjust the viscosity A to the target viscosity range by adding the diamine compound once or several times in the process (IV'). For example, when the viscosity A does not rise to the target viscosity range with one addition, the viscosity A can also be adjusted to within the target viscosity range by adding again or multiple times.

Furthermore, a solvent may be further added in the process (IV'). In the case of further adding a solvent, it may be added together with the diamine compound, or may be added separately from the diamine compound, and when the diamine compound is added multiple times, it may be a combination of these.

Examples of the solvent for addition include those exemplified in the item (Step (A)), and these solvents can be used alone or in combination of two or more. In the case of adding a solvent, it may be the same as or different from the solvent used in step (A), but from the viewpoint of easily increasing the molecular weight of the polyimide-based resin, it is preferably the same as in step (A) The solvents used are the same. The solvent can be added at one time, or in multiple batches.

The more the amount of the diamine compound for reaction in the process (IV') is increased, the more the molecular weight of the intermediate (K) tends to increase. In one embodiment of the present invention, depending on the difference between the viscosity A and the target viscosity range, the addition amount of the diamine compound is appropriately adjusted to adjust to the target viscosity range. Furthermore, the addition amount of diamine can also be determined by, for example, calculating the degree of viscosity change with respect to the addition amount through experiments in advance.

In one embodiment of the present invention, the amount of diamine compound used for reaction in the process (IV') can be appropriately selected according to the difference between the viscosity A of the reaction system and the target viscosity range, for example, in the process (I) and the process When the total amount of the diamine compound to be reacted in (IV') is 100 mol, it is preferably 0.01 mol or more, and preferably 20 mol or less, more preferably 15 mol or less, and more preferably 10 mol or less, more preferably 5 mol or less, and particularly preferably 2 mol or less. If the amount of the diamine compound used for the reaction in the process (IV') is within the above range, it is easy to increase the molecular weight of the polyimide resin, so it is easy to adjust the molecular weight to the target viscosity range, and it is easy to increase the content of polyimide Flexibility of the film made of imine resin.

In one embodiment of the present invention, regarding the total amount of the diamine compound for reaction in the process (I) and the process (IV'), the carboxyl group with more than 3 carbonyl groups for the reaction in the process (I) When the acid compound is set to 100 mol, it is preferably 10 to 1,000 mol, more preferably 50.0 to 150 mol, still more preferably 80.0 to 120 mol, still more preferably 90.0 to 110 mol, and particularly preferably 95.0-100 mol, more preferably 97.0-99.9 mol, and still more preferably 98.0-99.9 mol. If the total amount of the diamine compound for reaction in the process (I) and process (IV') is in the above range, it is easy to control the molecular weight of the polyimide-based resin, and it is easier to increase the content of the polyimide-based resin. Flexibility of the formed film. Furthermore, the carboxylic acid compound means a carboxylic acid compound including the dicarboxylic acid compound, the tetracarboxylic acid compound, and the tricarboxylic acid compound used in the process (I).

The reaction temperature of the process (IV') is not particularly limited, and may be, for example, -5 to 100°C, preferably 0 to 50°C, more preferably 5 to 30°C. The reaction time can be, for example, 1 minute to 72 hours, preferably 10 minutes to 24 hours, more preferably 30 minutes to 10 hours. In addition, the reaction can be carried out in air or in an inert gas atmosphere such as nitrogen or argon while stirring, and can also be carried out under normal pressure, under increased pressure or reduced pressure. In a preferred embodiment, it is performed while stirring under normal pressure and/or the aforementioned inert gas atmosphere.

In one embodiment of the present invention, after the treatment of increasing the viscosity in the process (IV'), the viscosity A of the reaction system is measured again in the process (II), and then the viscosity A is confirmed in the process (III) Whether it is the target viscosity range, when the viscosity A does not reach the target viscosity range, the process (IV') can be repeated again to adjust the viscosity A to the target viscosity range.

＜Process (IV'')＞ The process (IV") is a process in which the viscosity of the reaction system is reduced to adjust to the target viscosity range when the viscosity A exceeds the target viscosity range. The method of reducing the viscosity A of the reaction system in the process (IV'') is not particularly limited, and a method of decomposing the intermediate (K) to reduce the viscosity A is preferable. If a method of decomposing the intermediate (K) by a decomposition reaction is used, the molecular weight of the intermediate (K) can be reduced, so it is easy to adjust the viscosity of the reaction system to the target viscosity range.

The method for decomposing the intermediate (K) is not particularly limited. For example, a method of heating the reaction system (a method of thermal decomposition), a method of stirring in the presence of an inorganic acid, etc., or the like Combination etc. If these methods are used, the molecular weight of the intermediate (K) can be effectively reduced, and the viscosity of the reaction system can be adjusted to the target viscosity range more easily.

In the method of heating the reaction system, the higher the heating temperature, the more the decomposition reaction proceeds, and the molecular weight of the intermediate (K) is reduced, so the viscosity A of the reaction system tends to decrease. In one embodiment of the present invention, the heating temperature is appropriately adjusted according to the difference between the viscosity A and the target viscosity range, so that the viscosity A can be adjusted to the target viscosity range. In addition, the heating temperature may be determined by, for example, obtaining the degree of the decomposition reaction with respect to the temperature through experiments in advance.

In the method of heating the reaction system, the heating temperature of the reaction system can be appropriately selected depending on the difference between the viscosity A of the reaction system and the target viscosity range, preferably 30°C or higher, more preferably 35°C or higher, and preferably 80 ℃ or less, more preferably 60 ℃ or less. If the heating temperature of the reaction is in the above range, it is easy to adjust the viscosity A of the reaction system to the target viscosity range. The heating time may be appropriately selected depending on the heating temperature and the like, and may be, for example, 1 minute to 72 hours, preferably 10 minutes to 24 hours, and more preferably 30 minutes to 12 hours. Furthermore, when the raw material monomers in the process (I) remain in the reaction system, the viscosity of the reaction system may increase within a certain time after the heating is started, but even in this case, after a certain time, The viscosity also decreases.

In methods such as stirring in the presence of an inorganic acid, the type or amount of the inorganic acid may be appropriately selected depending on the difference between the viscosity A and the target viscosity range. There is a tendency that the greater the amount of inorganic acid, the lower the viscosity of the reaction system. As an inorganic acid, nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, etc. are mentioned, for example, Among these, hydrochloric acid is preferable. If an inorganic acid is present in the reaction system, it is easier to advance the decomposition reaction, so it is easy to adjust the viscosity A to the target viscosity range.

The amount of inorganic acid is preferably 0.1-10 mol, more preferably 0.3-5 mol, and still more preferably 0.5-1 mol relative to 1 mol of amine group in the diamine compound used in the process (I) Mol. If the amount of the inorganic acid is within the above range, the decomposition reaction is easier to proceed, and therefore the viscosity A is easily adjusted to the target viscosity range. Furthermore, when the process (IV') is performed before the process (IV''), the amount of inorganic acid can be based on the total amount of the diamine compound used in the process (I) and the process (IV').

In methods such as stirring in the presence of an inorganic acid, the stirring time is selected from, for example, the same range as the above-mentioned heating time.

The decomposition reaction can be carried out in air or in an inert gas atmosphere (such as nitrogen, argon, etc.) while stirring, and can also be carried out under normal pressure, under pressure or under reduced pressure. In a preferred embodiment, it is performed while stirring under normal pressure and/or an inert gas atmosphere.

In one embodiment of the present invention, after the viscosity reduction treatment is performed in the process (IV''), the viscosity A of the reaction system is measured again in the process (II), and then whether the viscosity A is confirmed in the process (III) It is the target viscosity range. When the target viscosity range is exceeded, the process (IV") can be repeated again to adjust the viscosity A to the target viscosity range. Here, in a preferred embodiment of the present invention, after the intermediate (K) is decomposed in the process (IV'') to reduce the viscosity A, the measurement of the process (II) and the confirmation of the process (III) When the viscosity A becomes the target viscosity range, the next step is to stop the decomposition reaction. In this specification, the process of stopping the decomposition reaction is included in the process (IV''), and the process of stopping the decomposition reaction is denoted as the process (IV''-2).

＜Process (IV''-2)＞ The process (IV''-2) is a process to stop the decomposition reaction that decomposes the intermediate (K). The method of stopping the decomposition reaction is not particularly limited, and examples thereof include a method of adding an alkali to the reaction system, a method of cooling the temperature of the reaction system, or a combination of these.

In one embodiment of the present invention, the decomposition reaction can also be stopped by adding a base to the reaction system. For example, when the decomposition reaction is carried out with an inorganic acid such as hydrochloric acid, the decomposition reaction can be stopped by adding an alkali to neutralize the hydrochloric acid. As the base, an organic base and an inorganic base may be used, or both may be used in combination. From the viewpoint of compatibility with the reaction system, an amine is preferred. Examples of amines include methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, tertiary butylamine, n-octylamine, n-decylamine, aniline, and ethylenediamine. Amine and other primary amines; dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, di-tertiary butylamine, di-n-octylamine, di-n-decylamine, pyrrolidine, hexamethyldisil Azane, diphenylamine and other secondary amines; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, diisopropylethylamine, tri-n-octylamine, tri-n-decylamine, triphenylamine, N,N -Dimethylaniline, N,N,N',N'-tetramethylethylenediamine, N-methylpyrrolidine, 4-dimethylaminopyridine and other tertiary amines, among these, easy From the viewpoint of effectively stopping the decomposition reaction, tertiary amines such as diisopropylethylamine are preferred. Amines can be used alone or in combination of two or more. Moreover, as an inorganic base, an alkali metal base, an alkaline earth metal base, etc. can be used, and an alkali metal base is preferable from a viewpoint of the solubility to a solvent. As the alkali metal base, for example, lithium hydroxide, lithium carbonate, lithium hydrogen carbonate, lithium methoxide, lithium ethoxide, lithium isopropoxide, lithium tert-butoxide, sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, sodium methoxide are preferred. , Sodium ethoxide, sodium isopropoxide, sodium tertiary butoxide, potassium hydroxide, potassium carbonate, potassium bicarbonate, potassium methoxide, potassium ethoxide, potassium isopropoxide, potassium tertiary butoxide, cesium hydroxide, cesium carbonate, Cesium bicarbonate, cesium methoxide, cesium ethoxide, cesium isopropoxide, cesium tert-butoxide, etc., can be used alone or in combination of two or more.

In one embodiment of the present invention, the decomposition reaction can also be stopped by lowering the temperature of the reaction system by cooling or the like. For example, by adjusting the temperature of the reaction system to preferably 20°C or lower, more preferably 15°C or lower, and still more preferably 10°C or lower, the decomposition reaction of the reaction system can be effectively stopped. In addition, the time for lowering the temperature of the reaction system may be, for example, 1 minute to 72 hours, preferably 10 minutes to 24 hours, and more preferably 30 minutes to 12 hours.

The process of stopping the decomposition reaction can be carried out in air or an inert gas atmosphere such as nitrogen, argon, etc., while stirring, or under normal pressure, under pressure or under reduced pressure. In a preferred embodiment, it is performed while stirring under normal pressure and/or the aforementioned inert gas atmosphere.

In the manufacturing method of the present invention, the process (II), the process (III), the process (IV'), and the process (IV") can be combined arbitrarily. For example, through process (II) and process (III), the viscosity A did not reach the target viscosity range, so the process of increasing the viscosity was performed in process (IV'), but after the process (II) and process (III) When it is confirmed that the viscosity A exceeds the target viscosity range, the viscosity reduction treatment is carried out in the process (IV''). In this way, the viscosity A can be adjusted to the target viscosity range (equivalent to the following process sequence 3). The following shows an example of the process sequence when adjusting the viscosity A within the target viscosity range, but it is not limited to these. 1. Process (II) → Process (III) → Process (IV') → Process (II) → Process (III) 2. Process (II) → Process (III) → Process (IV'') → Process (II) → Process (III) 3. Process (II) → Process (III) → Process (IV') → Process (II) → Process (III) → Process (IV'') → Process (II) → Process (III) 4. Process (II) → Process (III) → Process (IV'') → Process (II) → Process (III) → Process (IV') → Process (II) → Process (III) 5. Process (II) → Process (III) → Process (IV') → Process (II) → Process (III) → Process (IV') → Process (II) → Process (III) 6. Process (II) → Process (III) → Process (IV'') → Process (II) → Process (III) → Process (IV'') → Process (II) → Process (III) 7. Process (II) → Process (III) → Process (IV') → Process (IV'') → Process (II) → Process (III) 8. Process (II) → Process (III) → Process (IV'') → Process (IV') → Process (II) → Process (III)

Furthermore, for example, when the process (IV'') in the above-mentioned process sequence 2 is a process for decomposing the intermediate (K) to reduce the viscosity A, it is preferable to perform the process (IV'' for stopping the decomposition reaction) -2), so the process sequence becomes process (II) → process (III) → process (IV'') → process (II) → process (III) → process (IV''-2).

In one embodiment of the present invention, the molecular weight of the intermediate (K) immediately after the process (I) and the viscosity of the reaction system (sometimes referred to as the initial viscosity) can be compared to the diamine compound in the process (I) The ratio of the carboxylic acid compound for the reaction is adjusted and controlled. For example, the molar ratio of the diamine compound to the carboxylic acid compound for reaction in the process (I) is less than 1:1, the molecular weight and initial viscosity of the intermediate (K) immediately after the process (I) become small. Conversely, the closer the molar ratio of the diamine compound is to 1:1, the greater the molecular weight and initial viscosity of the intermediate (K) immediately after the process (I).

In one embodiment of the present invention, compared to reducing the viscosity A of the reaction system, it is easier to handle the increase of the viscosity A of the reaction system, and it is easy to control the viscosity of the reaction system. Therefore, it is better to increase the viscosity A of the reaction system. The process (IV') adjusts the viscosity A to the target viscosity range. For example, the ratio of the diamine compound to the carboxylic acid compound for reaction in the process (I) can be reduced in advance so that the viscosity A of the reaction system does not reach the target viscosity range, and the diamine can be added in the process (IV') Compound, and adjust the viscosity A of the reaction system to the target viscosity range.

In one embodiment of the present invention, when the viscosity A is adjusted to the target viscosity range through the process (I) to the process (III) without performing the process (IV), the intermediate (K) is not used The process of changing the molecular weight, therefore, the intermediate (K) is relative to the polyimide resin precursor. On the other hand, when the manufacturing method of the present invention includes process (IV), the polyimide resin precursor is processed by changing the molecular weight of the intermediate (K), such as the addition reaction or decomposition of diamine Resin obtained by reaction. Furthermore, the polyimide resin precursor is the resin before imidization, that is, the resin adjusted to the end of the target viscosity range, and the intermediate (K) includes the resin on the way to the target viscosity range.

Among the polyimide resin precursors, the polyimide resin precursor has at least a structural unit derived from a diamine compound and a structural unit derived from a carboxylic acid compound having 3 or more carbonyl groups, in a preferred aspect Contains the structural unit represented by formula (A). In addition, the polyamide imine precursor has at least a structural unit derived from a diamine compound, a structural unit derived from a carboxylic acid compound having 3 or more carbonyl groups, and a structural unit derived from a dicarboxylic acid compound. A preferred aspect includes the structural unit represented by formula (A) and the structural unit represented by formula (B). Furthermore, the polyimide resin precursor or polyimide imine precursor can be precipitated by adding a large amount of water or methanol to the reaction solution containing the resin precursor and then filtered and concentrated. , Dry and so on.

In the case of manufacturing polyimide resin or polyimide imide resin, the polyimide resin precursor or polyimide resin precursor can also be separated and used in the following process ( V), but from the viewpoint of manufacturing efficiency, it is preferable to directly supply to the process (V) without isolation.

＜Process (V)＞ Process (V) is a process in which the polyimide resin precursor is imidized in the presence of an imidization catalyst. For example, by supplying the polyimide resin precursor containing the structural unit represented by the formula (A) to the process (V), the structural unit represented by the formula (A) is partially imidized (ring closed), and it can be obtained The polyimide resin containing the structural unit represented by formula (C). Also, for example, by supplying the polyamide imide precursor comprising the structural unit represented by the formula (A) and the structural unit represented by the formula (B) to the process (V), the polyimide imine precursor In the structural unit, the structural unit represented by formula (A) is partially imidized (ring closed), and a polyamide containing the structural unit represented by formula (C) and the structural unit represented by formula (B) can be obtained Amine resin.

[式(B)及式(C)中，G¹ 係與式(3)中之Y相同， G² 係與式(6)中之W相同， X¹ 及X² 分別與式(1)中之X相同，X¹ 及X² 可相同亦可不同][化21]

[In formulas (B) and (C), G ¹ is the same as Y in formula (3), G ² is the same as W in formula (6), and X ¹ and X ² are respectively the same as in formula (1) X is the same, X ¹ and X ² can be the same or different]

Examples of the imidization catalyst include aliphatic amines such as tripropylamine, diisopropylethylamine, dibutylpropylamine, and ethyldibutylamine; N-ethylpiperidine, Alicyclic amines such as N-propylpiperidine, N-butylpyrrolidine, N-butylpiperidine, and N-propylhexahydroazepine (monocyclic); azabicyclo[2.2.1]heptane Alkane, azabicyclo[3.2.1]octane, azabicyclo[2.2.2]octane, and azabicyclo[3.2.2]nonane and other alicyclic amines (polycyclic); and pyridine, 2 -Methylpyridine (2-methylpyridine), 3-methylpyridine (3-methylpyridine), 4-methylpyridine (4-methylpyridine), 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2,4-lutidine, 2,4,6-trimethylpyridine, 3,4-cyclopentenepyridine, 5,6,7,8-tetrahydroisoquinoline, and Aromatic amines such as isoquinoline. These imidation catalysts can be used alone or in combination of two or more.

Regarding the usage amount of the imidization catalyst, it is preferably 0.1 to 10 mol, more preferably 1 to 5 relative to 1 mol of the carboxylic acid compound having 3 or more carbonyl groups used in step (A) Mol.

In the process (V), from the viewpoint of facilitating the promotion of the imidization reaction, it is preferable to use the imidization catalyst together with the acid anhydride. Examples of the acid anhydride include conventional acid anhydrides used in the imidization reaction, and specific examples thereof include aliphatic anhydrides such as acetic anhydride, propionic anhydride, and butyric anhydride, and aromatic anhydrides such as phthalic acid.

In the case of using acid anhydride, the amount of the acid anhydride used is 1 mol relative to the carboxylic acid compound having 3 or more carbonyl groups, preferably 0.5-25 mol, more preferably 1-20 mol, and more preferably 1 ~15 moles.

The reaction temperature of the process (V) is not particularly limited, and may be, for example, -5 to 100°C, preferably 0 to 90°C, and more preferably 5 to 80°C. The reaction time can be, for example, 1 minute to 72 hours, preferably 10 minutes to 24 hours, more preferably 30 minutes to 10 hours. In addition, the reaction can be carried out in air or an inert gas atmosphere such as nitrogen, argon, etc., while stirring, or under normal pressure, under pressure, or under reduced pressure. In a preferred aspect, it is performed while stirring under normal pressure and/or the aforementioned inert gas atmosphere.

The polyimide resin obtained in the process (V) can also be formed by conventional methods, such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography and other separation methods; or a combination of these The separation and purification of the separation method is performed by separation. In a preferred aspect, the polyimide resin can be precipitated and carried out by adding a large amount of water or methanol to the reaction liquid containing the polyimide resin. Concentrate, filter, dry, etc. and separate.

[Polyimide resin] In the manufacturing method of the present invention, the molecular weight of the polyimide resin can be controlled, and a polyimide resin having a target molecular weight or a molecular weight close to it can be obtained. Furthermore, in the production method of the present invention, the target molecular weight is adjusted based on the viscosity of the reaction system, so the operation is simple and easy, and the polyimide-based resin having the target molecular weight or a molecular weight close to it can be produced efficiently. The weight average molecular weight of the polyimide-based resin is appropriately selected depending on the target molecular weight set as the target, and therefore is not particularly limited. In one embodiment of the present invention, it is preferably 150,000 in terms of standard polystyrene. Above, more preferably 200,000 or more, still more preferably 250,000 or more, particularly preferably 300,000 or more, and preferably 1,000,000 or less, more preferably 800,000 or less, still more preferably 700,000 or less, and particularly preferably 500,000 or less. If the weight average molecular weight is more than the above lower limit, it is easy to increase the modulus of elasticity, flex resistance, and surface hardness of the film containing the polyimide resin, and if it is less than the above upper limit, it is easy to suppress polyimide The gelation of amine resin varnish can easily improve the optical properties of the film. In addition, the weight average molecular weight can be determined by, for example, gel permeation chromatography (GPC) measurement and conversion based on standard polystyrene, for example, it can be determined by the method described in the examples.

When polyimide resin is dissolved in N,N-dimethylacetamide at a concentration of 10% by mass, the viscosity at 25°C is preferably 1,000 mPa·s or more, more preferably 5,000 mPa·s or more , More preferably 10,000 mPa·s or more, particularly preferably 20,000 mPa·s or more, and preferably 70,000 mPa·s or less, more preferably 60,000 mPa·s or less, and still more preferably 50,000 mPa·s or less, especially Preferably, it is 40,000 mPa·s or less. If the viscosity of the polyimide-based resin is more than the above lower limit, the interaction between the molecules becomes larger, and it is easy to improve the flex resistance and mechanical strength. If the viscosity is less than the above upper limit, the film forming property becomes good and easy Form a uniform film. Furthermore, the viscosity can be measured with a Brookfield viscometer.

Among the polyimide resins obtained by the manufacturing method of the present invention, the polyimine resin has at least a structural unit derived from a diamine compound and a structural unit derived from a carboxylic acid compound having 3 or more carbonyl groups, In a preferred aspect, it contains the repeating structural unit represented by formula (C). In addition, the polyamide imine resin has at least a structural unit derived from a diamine compound, a structural unit derived from a carboxylic acid compound having 3 or more carbonyl groups, and a structural unit derived from a dicarboxylic acid compound, preferably In the aspect, the repeating structural unit represented by formula (C) and the repeating structural unit represented by formula (B) are included. The polyimide-based resin may also include structural units derived from diamine compounds and structural units derived from tricarboxylic acid compounds. In the above-mentioned preferred aspect, it may further include structural units derived from tricarboxylic acid compounds. By. The polyimide-based resin containing the structural unit derived from the tetracarboxylic acid compound and the structural unit derived from the tricarboxylic acid compound, for example, can be added with the tetracarboxylic acid compound together or separately in step (A). It can be produced by adding a tricarboxylic acid compound together with the dicarboxylic acid compound or separately in step (B).

[式(D)中，G³ 係與式(8)中之Y² 相同， X³ 係與式(1)中之X相同]In one embodiment of the present invention, the polyimide resin having at least the structural unit derived from the diamine compound (1) and the structural unit derived from the tetracarboxylic acid compound (3) includes the formula (C) Repeating structural units. In addition, it has at least a structural unit derived from the diamine compound (1), and at least one selected from the group consisting of a structural unit derived from a tetracarboxylic acid compound (3) and a structural unit derived from a tricarboxylic acid compound (8) One kind of structural unit, and the polyamide imide resin derived from the structural unit of the dicarboxylic acid compound (6) includes the repeating structural unit represented by the formula (B) and the repeating structure selected from the formula (C) At least one structural unit in the group consisting of the unit and the repeating structural unit represented by formula (D). [化22]

[In formula (D), G ³ is the same as Y ² in formula (8), and X ³ is the same as X in formula (1)]

[式(E)中，G⁴ 係與式(5)中之Y¹ 相同， X⁴ 係與式(1)中之X相同， R¹⁸ 係與式(5)中之R¹⁸ 相同]In one embodiment of the present invention, it has at least a structural unit derived from the diamine compound (1), a structural unit selected from the tetracarboxylic acid compound (3), and a structure derived from the tetracarboxylic acid compound (5) At least one structural unit in the group composed of the unit, and the polyamide imine resin derived from the structural unit of the dicarboxylic acid compound (6) includes the repeating structural unit represented by the formula (B), and is selected from free formulas At least one structural unit in the group consisting of the repeating structural unit represented by (C) and the repeating structural unit represented by formula (E). [化23]

[In the formula (E), G ⁴ based same formula Y (5) in the ^1, X ⁴ the same line in the formula (1) in the X, the same as in the formula R ¹⁸ lines (. 5) R ^18]

In the preferred embodiment of the present invention, the film formed by the polyimide resin obtained by the manufacturing method of the present invention has excellent flexibility resistance and optical properties, and therefore can be preferably used as a display The device, especially the front panel of the flexible display device (hereinafter, sometimes referred to as window film). The front panel has the function of protecting the display elements of the flexible display device. Examples of display devices include wearable devices such as televisions, smart phones, mobile phones, car navigation, tablet PCs, portable game consoles, electronic paper, indicators, bulletin boards, hour hands, and smart watches. Examples of flexible displays include: display devices with flexible characteristics, such as TVs, smart phones, mobile phones, smart watches, and the like. [Example]

Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples. The "%" and "parts" in the examples mean mass% and parts by mass unless otherwise stated. First, the measurement method will be described.

＜Determination of weight average molecular weight＞ Gel permeation chromatography (GPC) was used for the measurement. The preparation method and measurement conditions of the measurement sample are as follows. (1) Sample adjustment method Weigh 20 mg of polyimide resin, add 10 mL of DMF leaching solution (10 mmol/L lithium bromide solution) to completely dissolve it. This solution was filtered with a chromatography disc (pore size 0.45 μm) to prepare a sample solution. (2) Measurement conditions Device: HLC-8020GPC String: protection string + TSKgelα-M (300 mm×7.8 mm diameter)×2 pieces +α-2500 (300 mm×7.8 mm diameter)×1 pieces Eluent: DMF (add 10 mmol/L lithium bromide) Flow rate: 1.0 mL/min Detector: RI detector Column temperature: 40℃ Injection volume: 100 μL Molecular weight standard: standard polystyrene

＜Determination of viscosity of reaction solution＞ (1) Measuring sample Sampling is performed from the reaction solution, and the measurement sample is measured under the following conditions. (2) Measurement conditions Device name: LVDV-II+Pro (manufactured by Brookfield) Measuring temperature: 10℃ Spindle: CPE-52 Sample size: 0.6 mL Rotor rotation speed: 0.3 rpm

[Example 1] [Target value] The target value of the weight average molecular weight (hereinafter, sometimes referred to as the target molecular weight) was set to 370,000, and the polyimide-based resin was synthesized. In this case, the target viscosity of the solution containing the intermediate (K) is 3.1 Pa·s, and the target viscosity range is 2.7 to 4.4 Pa·s. [Process I] A fully dried reaction vessel equipped with a stirrer and a thermometer was introduced with nitrogen gas to replace the inside of the vessel with nitrogen. Cool the reaction vessel to 10°C, add 1907.2 parts of dimethylacetamide (DMAc) to the reaction vessel, add 111.38 parts of 2,2'-bis(trifluoromethyl)benzidine (TFMB) and 4, 46.82 parts of 4'-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA), and stirred for 3 hours. Then, 10.37 parts of 4,4'-oxy bis(benzyl chloride) (OBBC) and 38.54 parts of terephthalate chloride (TPC) were added and stirred. To the resulting reaction liquid, 1907.2 parts of DMAc and 4.28 parts of TPC were added, and further stirred at 10°C for 1 hour. [Process II] Sampling the solution and measuring the viscosity, the result was 2.4 Pa·s. [Process III] Compare with the target viscosity range and confirm that it is lower than the target viscosity range. [Process IV'] 0.56 part of TFMB was added and stirred for 2 hours. [Process II] Sampling the solution and measuring the viscosity, the result was 3.9 Pa·s. [Process III] Confirm that the measured viscosity falls within the target viscosity range, and enter the next process. [Process V] 31.80 parts of diisopropylethylamine and 75.32 parts of acetic anhydride were added, and after stirring for 30 minutes while keeping the temperature at 10°C, 22.90 parts of 4-picoline was added, and the reaction vessel was heated to 75°C and stirred for 3 Hours to obtain a reaction solution. The reaction liquid was cooled, and when it dropped to 40°C or lower, 1147.1 parts of methanol was added. Nitrogen gas was passed through a reaction vessel equipped with a stirrer and a thermometer to replace the inside of the vessel with nitrogen. While stirring at 20°C, the above reaction solution was added to the reaction vessel. Then, 4575.1 parts of methanol was dropped, and 2861.7 parts of ion-exchanged water was dropped to precipitate a white solid. The precipitated white solid is captured by centrifugal filtration, and washed with methanol, thereby obtaining a wet cake containing polyimide-based resin. The obtained wet cake was dried at 78°C under reduced pressure, thereby obtaining a powder of a polyimide-based resin. The weight average molecular weight of the obtained polyimide-based resin was 373,000.

[Example 2] [Target value] The target molecular weight, target viscosity, and target viscosity range are the same as in Example 1. [Process I] The amount of TFMB used was set to 111.94 parts, except for this, the same operation as the process I of Example 1 was performed. [Process II] Sampling the solution and measuring the viscosity, the result was 14.2 Pa·s. [Process III] Compare with the target viscosity range and confirm that it is higher than the target viscosity range. [Process IV''] Set the temperature of the solution to 50°C and keep it for 8.5 hours. [Process II] Sampling the solution and measuring the viscosity, the result was 4.4 Pa·s. [Process III] It is confirmed that the measured viscosity falls within the target viscosity range. [Process IV''-2] Add 31.80 parts of diisopropylethylamine and lower the temperature of the solution to 10°C. [Process V] Then, 75.32 parts of acetic anhydride was added, and after stirring for 30 minutes while keeping the temperature at 10°C, 22.90 parts of 4-picoline was added, the reaction vessel was heated to 75°C, and further stirred for 3 hours to obtain a reaction liquid. The reaction liquid was cooled, and when it dropped to 40°C or lower, 1147.1 parts of methanol was added. Nitrogen gas was passed through a reaction vessel equipped with a stirrer and a thermometer to replace the inside of the vessel with nitrogen. While stirring at 20°C, the above reaction solution was added to the reaction vessel. Then, 4575.1 parts of methanol was dropped, and 2861.7 parts of ion-exchanged water was dropped to precipitate a white solid. The precipitated white solid is captured by centrifugal filtration, and washed with methanol, thereby obtaining a wet cake containing polyimide-based resin. The obtained wet cake was dried at 78°C under reduced pressure, thereby obtaining a powder of a polyimide-based resin. The weight average molecular weight of the obtained polyimide-based resin was 375,000.

[Example 3] [Target value] The target molecular weight, target viscosity, and target viscosity range are the same as in Example 1. [Process I] The amount of TFMB used was set to 111.60 parts by mass, except for this, the same operation as the process I of Example 1 was performed. [Process II] Sampling the solution and measuring the viscosity, the result was 4.1 Pa·s. [Process III] After confirming that the measured viscosity falls within the target viscosity range, proceed to the next [Process V]. [Process V] The same operation as in Example 1 was performed. The weight average molecular weight of the obtained polyimide-based resin was 378,000.

[Example 4] [Target value] The target value (target molecular weight) of the weight average molecular weight was set to 470,000, and the polyimide resin was synthesized. In this case, the target viscosity of the solution containing the intermediate (K) is 7.5 Pa·s, and the target viscosity range is 6.1～8.2 Pa·s. [Process I] The amount of TFMB used was set to 110.26 parts, except for this, the same operation as the process I of Example 1 was performed. [Process II] Sampling the solution and measuring the viscosity, the result was 2.6 Pa·s. [Process III] Compare with the target viscosity range and confirm that it is lower than the target viscosity range. [Process IV'] Then 1.679 parts of TFMB was added and stirred for 2 hours. [Process II] Sampling the solution and measuring the viscosity, the result was 7.7 Pa·s. [Process III] After confirming that the measured viscosity falls within the target viscosity range, proceed to the next [Process V]. In [Process V], the same operation as in Example 1 was performed. The weight average molecular weight of the obtained polyimide-based resin was 467,000.

[Example 5] [Target value] The target value of the weight average molecular weight (target molecular weight) was set to 440,000, and the polyimide resin was synthesized. In this case, the target viscosity of the solution containing the intermediate (K) is 5.8 Pa·s, and the target viscosity range is 4.8 to 5.9 Pa·s. [Process I] The amount of TFMB used was set to 111.60 parts, except for this, the same operation as the process I of Example 1 was performed. [Process II] Sampling the solution and measuring the viscosity, the result was 3.0 Pa·s. [Process III] Compare with the target viscosity range and confirm that it is lower than the target viscosity range. [Process IV'] 0.224 parts of TFMB was added and stirred for 2 hours. [Process II] Sampling the solution and measuring the viscosity, the result was 6.0 Pa·s. [Process III] Compare with the target viscosity range and confirm that it is higher than the target viscosity range. [Process IV''] Set the temperature of the solution to 40°C and keep it for 6 hours. [Process II] Sampling the solution and measuring the viscosity, the result was 5.0 Pa·s. [Process III] After confirming that the measured viscosity falls within the target viscosity range, proceed to the next [Process IV''-2] and [Process V]. In [Process IV''-2] and [Process V], the same operations as in Example 2 were performed. The weight average molecular weight of the obtained polyimide-based resin was 436,000.

[Comparative Example 1] [Target value] The target value of the weight average molecular weight (target molecular weight) was set to 370,000, and the polyimide resin was synthesized. [Process I] The amount of TFMB used was set to 111.37 parts. Except for this, the same operation as the process I of Example 1 was performed. [Process II] and [III] are not implemented. In the subsequent [Process V], the same operation as in Example 1 was performed to obtain a polyimide resin. The above operation was repeated 3 times to produce 3 batches of polyimide resin. These weight average molecular weights were measured, and the results were 325,000, 387,000, and 456,000, and the molecular weight was not stable.

Table 1 shows the target molecular weight, target viscosity, target viscosity range, initial viscosity of the reaction solution, adjustment operation (correction operation) of viscosity, viscosity after adjustment (correction), and polyimide in the examples and comparative examples It is the weight average molecular weight of the resin. [Table 1] Target molecular weight Target viscosity (Pa.s) Target viscosity range (Pa•s) Initial viscosity (Pa•s) Correction operation Viscosity after correction (Pa•s) Weight average molecular weight (Mw) Example 1 370,000 3.1 2.7~4.4 2.4 Add diamine 3.9 373,000 Example 2 370,000 3.1 2.7~4.4 14.2 Thermal decomposition 4.4 375,000 Example 3 370,000 3.1 2.7~4.4 4.1 No correction 4.1 378,000 Example 4 470,000 7.5 6.1~8.2 2.6 Add diamine 7.7 467,000 Example 5 440,000 5.8 4.8~5.9 3.0 Add diamine + thermal decomposition 5.0 436,000 Comparative example 1 370,000 - - - - - 325,000 (1st time) 387,000 (2nd time) 456,000 (3rd time)

As shown in Table 1, the polyimide resins of Examples 1 to 5 obtained by setting the target viscosity range and adjusting the viscosity of the reaction system to the target viscosity range have a molecular weight close to the target molecular weight. In contrast, the molecular weight of the polyimide-based resin of Comparative Example 1 obtained without adjusting the viscosity of the reaction system was uneven. Therefore, it can be seen that the production method of the present invention can control the molecular weight of the polyimide resin.

Claims (8)

A manufacturing method of polyimide resin, which comprises: Process (I), which includes the step (A) of reacting a diamine compound with a carboxylic acid compound having more than 3 carbonyl groups to obtain an intermediate (K); Process (II), which measures the viscosity A of the reaction system after process (I); and Process (III), which compares the viscosity A with the target viscosity range of the reaction system to confirm whether the viscosity A is within the target viscosity range. The manufacturing method of claim 1, wherein in the process (I), after the step (A), the step (B) of reacting the dicarboxylic acid compound is further included. For example, the manufacturing method of claim 1 or 2, which includes process (IV), is that when the viscosity A is not in the target viscosity range in the process (III), the viscosity is adjusted to the target range. Such as the manufacturing method of any one of claims 1 to 3, which includes process (IV'), which is to increase the viscosity to adjust to the target viscosity range when the viscosity A does not reach the target viscosity range in the process (III). For example, the manufacturing method of any one of claims 1 to 3 includes a process (IV''), which is to reduce the viscosity to adjust to the target viscosity range when the viscosity A exceeds the target viscosity range in the process (III). The manufacturing method of claim 4, wherein in the process (IV'), a diamine compound is added to the reaction system to increase the viscosity A. Such as the manufacturing method of claim 5, wherein in the process (IV''), the intermediate (K) is decomposed to reduce the viscosity A. The manufacturing method of any one of claims 1 to 7, wherein the target viscosity range is a viscosity range of 0.8 to 1.5 times the target viscosity.