Bis(aminophenol) compounds, polyhydroxyamide compounds derived therefrom and their solutions, and polybenzoxazole films and methods for producing the same.

Abstract

The present invention provides a novel bis(aminophenol) compound, from which a polyhydroxyamide compound derived exhibits high solubility in organic solvents, and from which a polybenzoxazole film obtained using the polyhydroxyamide compound exhibits high heat resistance and excellent thermal dimensional stability; a polyhydroxyamide compound derived therefrom and a solution thereof; and a polybenzoxazole film and a method for producing the same. [Solution] A bis(aminophenol) compound represented by the following general formula (1), a polyhydroxyamide compound derived therefrom and a solution thereof, and a polybenzoxazole film and a method for producing the same. TIFF2026043156000031.tif21161 In the above formula, R 1 ~R 4 each independently represents a hydrogen atom or a methyl group.

Description

[Technical Field]

[0001] The present invention relates to a bis(aminophenol) compound, a polyhydroxyamide compound derived therefrom and a solution thereof, a polybenzoxazole film, and a method for producing the same. [Background technology]

[0002] Polyimides and polybenzoxazoles, which combine excellent electrical and mechanical properties with heat resistance, are used as insulating materials for electronic devices, such as heat-resistant insulating substrates for flexible printed wiring boards and insulating films for semiconductors. Polyimides are generally derived from bifunctional monomers, tetracarboxylic dianhydrides and diamine compounds, and various physical properties can be achieved by changing the type and combination of each monomer. Therefore, they have been used in a variety of applications in the electronics field.

[0003] On the other hand, like polyimides, polybenzoxazoles can be derived from bifunctional monomers, bis(aminophenol) compounds and dicarboxylic acid compounds or their activated derivatives. However, there are fewer commercially available monomers than polyimides, and polyhydroxyamide compounds, which are precursors of polybenzoxazoles, have low solubility in organic solvents, which limits the combinations of monomers that can be used in polymerization. For example, poly(p-phenylenebenzobisoxazole), which exhibits excellent physical properties, is insoluble in organic solvents due to its rigid chemical structure. Therefore, the only polymerization method for poly(p-phenylenebenzobisoxazole) is to polymerize diaminoresorcinol hydrochloride monomer and terephthalic acid monomer in a strong acid (polyphosphate), as described in Non-Patent Document 1, and then process (fiberize) the polymerization solution by liquid crystal spinning or the like, making film production by solution coating (casting) extremely difficult. This limitation also applied to polybenzoxazoles having other rigid chemical structures, such as bicyclic biphenyl or tricyclic p-terphenyl structures, in addition to the monocyclic structure derived from diaminoresorcinol hydrochloride monomer described in Non-Patent Document 2, and to polybenzoxazoles obtained by polymerizing 3,3'-diamino-4,4'-dihydroxybiphenyl hydrochloride monomer with aromatic or aliphatic dicarboxylic acid monomers, as described in Non-Patent Document 3.

[0004] To address the aforementioned solubility in organic solvents, attempts have been made to incorporate bulky substituents and / or bent structures into the polymer main chain to inhibit aggregation between polymer chains. For example, Non-Patent Literature 4 describes that polyhydroxyamide compounds obtained by polymerizing 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane with dicarboxylic acid chlorides such as 4,4'-oxydibenzoyl chloride (also known as 4,4'-oxybisbenzoic acid chloride) were soluble in many different organic solvents, including NMP (N-methyl-2-pyrrolidone), DMF (N,N-dimethylformamide), γ-butyrolactone, acetone, and tetrahydrofuran. Non-Patent Literature 4 also describes that a polyhydroxyamide film can be easily obtained by casting a solution of the above polyhydroxyamide compound onto a substrate and drying it, and further, that a polybenzoxazole film can be produced by heating and dehydrating the polyhydroxyamide film. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] SENI GAKKAISHI (Textiles and Industry), 2010, Vol. 66, pp. 176-180 [Non-patent document 2] James F. Wolfe and F.E. Arnold, Macromolecules, 1981, Vol. 14, pp. 909-915 [Non-patent document 3] Y. Imai, et. al., Macromolecular Chemistry and Physics, 1965, Vol. 83, pp. 167-178 [Non-patent document 4] Y. Oishi, et. al., J. Photopolym. Sci. Technol., 2006, Volume 19, p.669-672 Summary of the Invention [Problem to be solved by the invention]

[0006] However, as the inventors investigated further, they found that the polybenzoxazole film described in Non-Patent Document 4 above has insufficient thermal dimensional stability (hereinafter referred to as "thermal dimensional stability") due to the presence of bulky substituents and bent structures derived from 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane in the polymer main chain, which were introduced to improve solubility in organic solvents. This makes it difficult to apply to fields requiring low thermal expansion.

[0007] The present invention has been made in view of the above problems, and aims to provide a novel bis(aminophenol) compound in which a polyhydroxyamide compound derived from this compound exhibits high solubility in organic solvents, and a polybenzoxazole film obtained using this polyhydroxyamide compound exhibits high heat resistance and excellent thermal dimensional stability. Another object of the present invention is to provide a polyhydroxyamide compound that exhibits high solubility in organic solvents and from which polybenzoxazole films obtained using the compound exhibit high heat resistance and excellent thermal dimensional stability, and a solution thereof. Another object of the present invention is to provide a polybenzoxazole film that exhibits high heat resistance and excellent thermal dimensional stability and can be easily produced from a polyhydroxyamide compound precursor, and a method for producing the same. [Means for solving the problem]

[0008] In view of the above problems, the present inventors have conducted extensive research and have found that by using as a monomer a bis(aminophenol) compound represented by the following general formula (1), in which two aminophenols are introduced via imide bonds to a cyclobutane ring, a polyhydroxyamide compound exhibiting solubility in organic solvents can be obtained, and further that a solution of the polyhydroxyamide compound dissolved in an organic solvent can be cast onto a substrate, followed by drying to obtain a film on the substrate, and that the film can be heated on the substrate to dehydrate and ring-close the polyhydroxyamide compound, resulting in a polybenzoxazole film exhibiting high heat resistance and excellent thermal dimensional stability. The present invention was completed based on this finding and further investigation.

[0009] In other words, the above problems were solved by the following means. <1> A bis(aminophenol) compound represented by the following general formula (1). [ka] In the above formula, R 1 ~R 4 each independently represents a hydrogen atom or a methyl group. <2> Represented by the following general formula (2): <1> The bis(aminophenol) compounds described above. [ka] <3> A polyhydroxyamide compound containing a constituent unit represented by the following general formula (3). [ka] In the above formula, R 1 ~R 4 Each of these independently represents either a hydrogen atom or a methyl group. 1 This indicates a divalent aliphatic group or a divalent aromatic group, or a group formed by combining two or more of these groups. 1 When is a group formed by combining two or more of these groups, the two groups to be combined may be bonded via -O- or >SO2. <4> The structural unit represented by the general formula (3) includes a structural unit represented by the following general formula (4): <3> The polyhydroxyamide compounds described above. [ka] Y 1 represents Y in the above general formula (3). 1 is synonymous with. <5> <3> or <4> A polyhydroxyamide solution obtained by dissolving the polyhydroxyamide compound described in [reference] in an organic solvent. <6> <5> and heating the film on the substrate to dehydrate and ring-close the polyhydroxyamide compound, thereby converting the film into a polybenzoxazole film. <7> A polybenzoxazole film containing a constituent unit represented by the following general formula (5). [ka] In the above formula, R 1 ~R 4 Each of these independently represents either a hydrogen atom or a methyl group.1 This indicates a divalent aliphatic group or a divalent aromatic group, or a group formed by combining two or more of these groups. 1 When is a group formed by combining two or more of these groups, the two groups to be combined may be bonded via -O- or >SO2. <8> The structural unit represented by the general formula (5) includes a structural unit represented by the following general formula (6): <7> The polybenzoxazole film according to claim 1. [ka] Y 1 Y in the above general formula (5) is 1 is synonymous with.

[0010] In the present invention, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. [Effects of the Invention]

[0011] The bis(aminophenol) compound of the present invention allows the polyhydroxyamide compound derived from this compound to exhibit solubility in organic solvents (solution processability), and the polybenzoxazole film obtained using this polyhydroxyamide compound can possess both high heat resistance and excellent thermal dimensional stability. Furthermore, the polyhydroxyamide compound of the present invention exhibits solubility in organic solvents (solution processability), and a polybenzoxazole film obtained using a solution obtained by dissolving the polyhydroxyamide compound of the present invention in an organic solvent can exhibit high heat resistance and excellent thermal dimensional stability. The polybenzoxazole film of the present invention exhibits high heat resistance and excellent thermal dimensional stability, and can be produced by a simple process using a polyhydroxyamide compound as a precursor. [Brief explanation of the drawings]

[0012] [Figure 1]FIG. 1 shows the 1H-NMR spectrum of the dinitro compound of Example 1. [Figure 2] FIG. 1 is a diagram showing the 1H-NMR spectrum of the bis(aminophenol) compound of Example 1. [Figure 3] FIG. 1 shows infrared absorption spectra of the polyhydroxyamide film and the polybenzoxazole film of Example 2. [Figure 4] FIG. 1 shows infrared absorption spectra of the polyhydroxyamide film and the polybenzoxazole film of Example 3. [Figure 5] 1 shows infrared absorption spectra of a polyhydroxyamide film and a polybenzoxazole film in Comparative Example 1. [Figure 6] 1 shows infrared absorption spectra of a polyhydroxyamide film and a polybenzoxazole film of Comparative Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0013] [Bis(aminophenol) compounds] The bis(aminophenol) compound of the present invention is represented by the following general formula (1).

[0014] [ka]

[0015] In the above formula, R 1 ~R 4 each independently represents a hydrogen atom or a methyl group.

[0016] The bonding position of the aminophenol with the imide bond is preferably the para position relative to the hydroxy group or amino group, more preferably the para position relative to the hydroxy group.

[0017] The bis(aminophenol) compound represented by the above general formula (1) is preferably represented by the following general formula (2): The bis(aminophenol) compound represented by the general formula (2) is a bis(aminophenol) compound represented by the above general formula (1) in which R 1 ~R 4 corresponds to a compound in which all atoms are hydrogen atoms.

[0018] [ka]

[0019] The bonding position of the aminophenol with the imide bond is preferably the para position relative to the hydroxy group or amino group, more preferably the para position relative to the hydroxy group.

[0020] The bis(aminophenol) compound of the present invention can be suitably used as a raw material (monomer) for polybenzoxazole and polyhydroxyamide compounds, which are precursors of polybenzoxazole. In the bis(aminophenol) compound represented by the general formula (1), the cyclobutane ring and the two imide rings fused to the cyclobutane ring are not coplanar. This is thought to suppress aggregation of the polymer main chain of the polyhydroxyamide compound derived from the bis(aminophenol) compound of the present invention, resulting in high solubility in organic solvents. In particular, when the binding position of the imide bond of the aminophenol in the bis(aminophenol) compound represented by the general formula (1) is para-positioned to the hydroxy group, the main chain of the polyhydroxyamide compound is significantly bent, further enhancing solubility in organic solvents. The resulting polyhydroxyamide solution is then cast onto a substrate and dried to obtain a polyhydroxyamide film, which is subsequently heated on the substrate to dehydrate and ring-close the film. The resulting polybenzoxazole film has improved heat resistance due to the presence of polar imide groups in the polybenzoxazole main chain.

[0021] <Method for producing bis(aminophenol compound)> The bis(aminophenol) compound represented by the general formula (1) can be obtained, for example, by the following reaction scheme: That is, a dinitro intermediate is obtained by a known imidization reaction using a hydroxynitroaniline compound represented by the general formula (7) and a tetracarboxylic dianhydride represented by the general formula (8), and then the obtained dinitro intermediate is reduced by a conventional reduction reaction, thereby producing the bis(aminophenol) compound represented by the general formula (1). The above imidization reaction and reduction reaction are not limited to known reactions, and commonly used imidization reaction and reduction reaction may be used.

[0022] [ka]

[0023] In the above reaction scheme, R 1 ~R 4 is R in the above general formula (1) 1 ~R 4 This is synonymous with [the above]. Furthermore, GBL represents γ-butyrolactone, and DMAc represents N,N-dimethylacetamide. However, the solvent is not limited to these. Suitable examples of the hydroxynitroaniline compound represented by the general formula (7) include, but are not limited to, 4-hydroxy-3-nitroaniline and 3-hydroxy-4-nitroaniline, whose chemical structures are shown below.

[0024] [ka]

[0025] [Polyhydroxyamide compounds] The polyhydroxyamide compounds of the present invention include a constituent unit represented by the following general formula (3). The polyhydroxyamide compounds of the present invention can be obtained by reacting (polymerizing) a bis(aminophenol) compound represented by the above-mentioned general formula (1) with a dicarboxylic acid compound or its active derivative by known methods, and exhibit high solubility in organic solvents.

[0026] [ka]

[0027] In the above formula, R 1 ~R 4 is R in the above general formula (1) 1 ~R 4 It is synonymous with Y. 1 This indicates a divalent aliphatic group or a divalent aromatic group, or a group formed by combining two or more of these groups. 1 When is a group formed by combining two or more of these groups, the two groups to be combined may be bonded via -O- or >SO2.

[0028] The bonding position of the benzene ring with the imide bond is preferably the para position relative to the hydroxy group or -NHC(=O)-, more preferably the para position relative to the hydroxy group. Y 1 This indicates a divalent aliphatic group or a divalent aromatic group, or a group formed by combining two or more of these groups. 1 When is a group formed by combining two or more of these groups, the two groups to be combined may be bonded via -O- or >SO2. Y 1 The divalent aliphatic group that can be taken as may be either an aliphatic hydrocarbon group or an aliphatic hetero group, may be either saturated or unsaturated, and may be either linear or cyclic. Y 1 The number of carbon atoms in the divalent aliphatic group which can be taken as is preferably 1 to 12, more preferably 1 to 10. In addition, some or all of the hydrogen atoms may be substituted with fluorine atoms. Y 1Examples of the divalent aliphatic group that can be taken as aryl include a methylene group, a propylene group, a butylene group, an octylene group, a 1-propene-2,3-diyl group, a 1,4-cyclohexylene group, a 1,4-bicyclo[2.2.2]octylene group, and a decahydro-1,4-naphthalene-diyl group. Y 1 The divalent aromatic group which can be taken as may be either an aromatic hydrocarbon group or an aromatic heterocyclic group, and is preferably an aromatic hydrocarbon group. Y 1 The number of carbon atoms in the divalent aromatic group that can be taken is preferably 6 to 12, more preferably 6 to 10, and even more preferably 6. Y 1 The number of carbon atoms in the divalent aromatic heterocyclic group which can be taken as the group is preferably 2 to 12, more preferably 2 to 10, and heteroatoms constituting the heterocyclic ring include a nitrogen atom, an oxygen atom, and a sulfur atom. Y 1 Examples of the divalent aromatic group that can be taken as aryl include a 1,3-phenylene group, a 1,4-phenylene group, a 1,4-naphthalene-diyl group, a 2,6-naphthalene-diyl group, a 2,5-furanylene group, a 2,5-thiophenylene group, and a 2,6-pyridinylene group. Y 1 Examples of groups that are a combination of two or more groups selected from the above divalent aliphatic groups and the above divalent aromatic groups include divalent aromatic group-divalent aromatic group, divalent aromatic group-O-divalent aromatic group, divalent aromatic group-S(=O)2-divalent aromatic group, divalent aromatic group-divalent aliphatic group-divalent aromatic group, and divalent aliphatic group-O-divalent aliphatic group, and specific examples include the groups shown below. In the following, * indicates a bond.

[0029] [ka]

[0030] In the polybenzoxazole film derived from the polyhydroxyamide compound of the present invention, from the viewpoint of exhibiting the excellent effect of further improving heat resistance, it is preferable that the constituent unit represented by the above general formula (3) includes the constituent unit represented by the following general formula (4), and it is more preferable that the constituent unit represented by the above general formula (3) is the constituent unit represented by the following general formula (4). That is, the polyhydroxyamide compound of the present invention is preferably a polyhydroxyamide compound that includes the constituent unit represented by the following general formula (4).

[0031] [ka]

[0032] Y 1 represents Y in the above general formula (3). 1 is synonymous with.

[0033] The structural unit represented by general formula (4) is a structural unit represented by general formula (3) above, wherein R 1 ~R 4 This corresponds to a constituent unit in which a hydrogen atom is present. The constituent unit represented by general formula (4) can be obtained by reacting the bis(aminophenol) compound represented by general formula (2) with a dicarboxylic acid compound or its derivative by known methods. The description of the imide bond position in the general formula (3) above applies to the imide bond position in the general formula (4).

[0034] In the polyhydroxyamide compound of the present invention, the content of the constituent unit represented by general formula (3) is preferably 10 to 100% by mass, more preferably 20 to 100% by mass, and even more preferably 30 to 100% by mass, when the total amount of all constituent units of the polyhydroxyamide compound is 100% by mass. In the polyhydroxyamide compound, constituent units other than the constituent unit represented by general formula (3) include constituent units that include structures derived from copolymer components described later. The content of the structural unit represented by general formula (4) in the polyhydroxyamide compound of the present invention can be applied by replacing the description of the content of the structural unit represented by general formula (3) in the polyhydroxyamide compound of the present invention above with the content of the structural unit represented by general formula (4).

[0035] <Method of producing polyhydroxyamide compound> The polyhydroxyamide compound of the present invention can be obtained by reacting a bis(aminophenol) compound represented by the above general formula (1) or (2) with a dicarboxylic acid compound or an activated derivative thereof by a known method. The bis(aminophenol) compounds represented by the above general formula (1) or (2) may be used singly or in combination of two or more kinds.

[0036] (Dicarboxylic acid compounds or their active derivatives) A dicarboxylic acid compound (HOOC-Y) that can be used in polymerizing a polyhydroxyamide compound containing a structural unit represented by the general formula (3) or (4) above is 1 -COOH, and Y 1 represents Y in the above general formulas (3) and (4). 1 The term "(a)" is not particularly limited. Examples of dicarboxylic acid compounds having an aromatic carboxylic acid structure include terephthalic acid, isophthalic acid, 2,5-dimethylterephthalic acid, methoxyterephthalic acid, phenoxyterephthalic acid, 2,5-dichloroterephthalic acid, bromoterephthalic acid, 2,5-dibromoterephthalic acid, fluoroterephthalic acid, tetrafluoroterephthalic acid, 2,5-franzicarboxylic acid, 2,5-thiophenedicarboxylic acid, 2,6-pyridinedicarboxylic acid, 2,2-bis(4-carboxyphenyl)hexafluoropropane, 4,4'-oxybisbenzoic acid, 4,4'-sulfonyldibenzoic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and biphenyl-4,4'-dicarboxylic acid. Examples of the aliphatic dicarboxylic acid compound include trans-1,4-cyclohexanedicarboxylic acid, cis-1,4-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid (a mixture of trans- and cis-cyclohexanedicarboxylic acids), bicyclo[2.2.2]octane-1,4-dicarboxylic acid, decahydro-1,4-naphthalenedicarboxylic acid, malonic acid, itaconic acid, glutaric acid, 1,4-butanedicarboxylic acid, 1,8-octanedicarboxylic acid, and diglycolic acid. These dicarboxylic acid compounds may be used alone or in combination of two or more. When polymerizing a polyhydroxyamide compound containing a constitutional unit represented by the above general formula (3) or (4), the dicarboxylic acid compound (HOOC-Y 1 A derivative in which the carboxy group in —COOH) is activated (also referred to as an “activated derivative” in the present invention) may also be used. Examples of active derivatives of the above dicarboxylic acid compound include acid chlorides (ClOC-Y 1 - Represented as COCl, Y 1 represents Y in the above general formula (3). 1 (which has the same meaning as above). ) and esters (active esters) of hydroxybenzotriazole (HOBt) and the like are included, but are not limited to these.

[0037] (Copolymerization component) When polymerizing the polyhydroxyamide compound of the present invention, in addition to the polyhydroxyamide compound and dicarboxylic acid compound or an active derivative thereof for deriving the structural unit represented by the above-mentioned general formula (3) or (4), the following tetracarboxylic acid dianhydride, known bis(aminophenol) compounds, diamine compounds, etc. can be used in combination as copolymerization components, within the scope of not impairing the solubility in organic solvents, polymerization reactivity, and the properties of the polybenzoxazole film obtained from the polyhydroxyamide compound (high heat resistance and excellent thermal dimensional stability). The tetracarboxylic dianhydride usable as a copolymerization component is not particularly limited, and examples thereof include pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic 2,3:6,7-dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, diphenyl-2,3,3'4'-tetracarboxylic dianhydride, bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)1,4-phenylene, 4,4'-(ethyne-1,2-diyl)diphthalic anhydride, 4,4'-oxydiphthalic anhydride, 3,4'-oxydiphthalic anhydride, 4,4'-(hexafluoroisobenzofuran-5-carboxylic acid), ... Isopropylidene)diphthalic anhydride, 4,4'-sulfonyldiphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, N,N'-[(perfluoropropane-2,2-diyl)bis(6-hydroxy-3,1-phenylene)]bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxamide), 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, bis(1,3-dihydro-1,3-dioxoisobenzofuran-5-carboxylic acid)ethane-1,2-diyl, bicyclo[2.2.2) Octo-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 1,2,3,4-butanetetracarboxylic acid 1,2:3,4-dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, octahydrobiphenylene-4a,8b:4b,8a-tetracarboxylic acid dianhydride, 3-(carboxymethyl)-1,2,4-cyclopentanetricarboxylic acid 1,4:2,3-dianhydride, 4-(2,5-dioxotetrahydroxy Examples include drofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, dicyclohexyl-3,4,3',4'-tetracarboxylic acid dianhydride, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid dianhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, and 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride. These tetracarboxylic dianhydrides may be used individually or in combination of two or more types. The bis(aminophenol) compounds that can be used as copolymer components are not particularly limited, but examples include 4,6-diaminoresorcinol dihydrochloride, 3,3'-diamino-4,4'-dihydroxybiphenyl, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, bis(3-amino-4-hydroxyphenyl)sulfone, and 9,9-bis(3-amino-4-hydroxyphenyl)fluorene. These bis(aminophenol) compounds may be used alone or in combination of two or more. The diamine compound that can be used as a copolymerization component is not particularly limited, and examples thereof include 1,4-phenylenediamine, 1,3-phenylenediamine, 5-trifluoromethyl-1,3-phenylenediamine, 2,5-diaminotoluene, 2,5-dimethyl-1,4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, 2,3,5,6-tetrafluoro-1,4-phenylenediamine, 2-(trifluoromethyl)-1,4-phenylenediamine, o-tolidine, m-tolidine, and 3,3',5,5'-tetramethylbenzidine. Benzidine, 2,2'-bis(trifluoromethyl)benzidine, 3,3'-dimethoxybenzidine, 4,4'-diaminooctafluorobiphenyl, bis(4-aminophenyl) terephthalate, 4,4''-diamino-p-terphenyl, 1,5-diaminonaphthalene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, bis(4-amino-2-trifluoromethylphenyl) ether, 3,3'-oxydianiline, 4,4'-diaminodiphenylmethane, bis(4-aminophenyl) sulfide, 9,9-bis(4-aminophenyl) phenyl)fluorene, 3,3'-diaminodiphenyl sulfone, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-amino-2-trifluoromethylphenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl] Nyl]sulfone, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 4,4'-diaminobenzophenone, 4,4'-methylenebis(2-ethyl-6-methylaniline), 4,4'-methylenebis(2,6-diethylaniline), 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-(1,4-phenylenediisopropylidene)bisaniline, p-xylylenediamine, m-xylylenediamine, 4-aminobenzylamine, 3-aminobenzylamine, trans-1,4-cyclohexanediamine, cis-1,Examples of suitable amines include 4-cyclohexanediamine, 1,3-cyclohexanediamine, isophoronediamine, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), hexamethylenediamine, 1,4-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, bis(aminomethyl)norbornane, 3,3'-diamino-N-methyldipropylamine, 1,4-bis(3-aminopropoxy)butane, 1,4-diaminobutane, 1,5-diaminopentane, 1,7-diaminoheptane, 1,10-diaminodecane, 1,12-diaminododecane, and 1,3-bis(3-aminopropyl)tetramethyldisiloxane. These diamine compounds may be used alone or in combination of two or more.

[0038] (organic solvent) The organic solvent used in the polymerization of the polyhydroxyamide compound is not particularly limited as long as it is a solvent that dissolves the raw material monomers and the resulting polyhydroxyamide compound. Specific examples of the solvent include, but are not limited to, aprotic amide solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide; ester solvents such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, α-methyl-γ-butyrolactone, butyl acetate, ethyl acetate, and isobutyl acetate; ethylene carbonate; and propylene carbonate. glycol-based solvents such as diethylene glycol dimethyl ether, triethylene glycol, and triethylene glycol dimethyl ether; phenol-based solvents such as phenol, m-cresol, p-cresol, o-cresol, 3-chlorophenol, and 4-chlorophenol; ketone-based solvents such as cyclopentanone, cyclohexanone, acetone, methyl ethyl ketone, diisobutyl ketone, and methyl isobutyl ketone; and ether-based solvents such as tetrahydrofuran, 1,4-dioxane, dimethoxyethane, diethoxyethane, and dibutyl ether. Other solvents that can be used include acetophenone, sulfolane, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, butanol, ethanol, xylene, toluene, and petroleum naphtha-based solvents. These solvents may be used individually or in mixtures of two or more. In order to enhance the solubility of the polyhydroxyamide compound in an organic solvent, a salt may be added to the organic solvent as a dissolution promoter. The dissolution promoter is not particularly limited, but specifically, inorganic salts such as lithium chloride, lithium bromide, and ammonium chloride, or organic salts such as lithium acetate and ammonium acetate can be used. The method for polymerizing the polyhydroxyamide compound of the present invention is not particularly limited, and known methods such as the "acid chloride method" or the "active esterification method" can be appropriately applied. Specifically, the compound can be synthesized by the following method.

[0039] <Polymerization of polyhydroxyamide compounds by the acid chloride method> In a sealed container, the bis(aminophenol) compound is dissolved in a dehydrated organic solvent (polymerization solvent). To this solution, a silylating agent, such as chlorotrimethylsilane, is added to trimethylsilylate the amino and hydroxyl groups in the bis(aminophenol) compound. Subsequently, a dicarboxylic acid derivative, i.e., dicarbonyl chloride (acid chloride), in substantially equimolar amounts with the silylated bis(aminophenol) compound is gradually added, and the mixture is stirred using a mechanical stirrer or the like at a temperature range of -10 to 50°C, preferably 0 to 40°C, for 0.5 to 72 hours, preferably 1 to 48 hours. At this time, the monomer concentration is usually in the range of 1 to 50% by mass, preferably 5 to 40% by mass. If the polymerization solution thickens during polymerization and stirring becomes difficult, it can be diluted as appropriate using the same polymerization solvent. If the polymerization solution becomes non-uniform, a polymerization solvent containing a dissolution accelerator such as lithium chloride in an amount of 0.1 to 5% by mass may be used as appropriate. A base such as pyridine or triethylamine can also be added to further accelerate the polymerization reaction. While not particularly limited, silylation agents for silylation of bis(aminophenol) compounds include, specifically, acetamide-based agents such as N,O-bis(tert-butyldimethylsilyl)acetamide and N,O-bis(trimethylsilyl)trifluoroacetamide. Chlorosilane-based agents include chlorotrimethylsilane (also known as trimethylsilyl chloride), propyldimethylchlorosilane, tert-butyldimethylchlorosilane, and tributylchlorosilane. Silylation of bis(aminophenol) compounds allows for a more selective reaction between the amino group in the bis(aminophenol) compound and the dicarboxylic acid derivative, thereby obtaining the desired polyhydroxyamide compound.

[0040] <Polymerization of polyhydroxyamide compounds by active esterification method> In a separable flask, under a stream of dry nitrogen, dissolve the bis(aminophenol) compound in a dehydrated organic solvent (polymerization solvent). Gradually add a substantially equimolar amount of the dicarboxylic acid derivative, i.e., the active ester, to the bis(aminophenol) compound, and stir using a mechanical stirrer or the like at a temperature range of -10 to 200°C, preferably 0 to 150°C, for 0.5 to 72 hours, preferably 1 to 24 hours. At this time, the monomer concentration is usually in the range of 1 to 50% by mass, preferably 5 to 40% by mass. If the polymerization solution thickens during polymerization and stirring becomes difficult, it may be diluted as appropriate using the same polymerization solvent. If the polymerization solution becomes non-uniform, a polymerization solvent containing a dissolution accelerator such as lithium chloride in an amount of 0.1 to 5% by mass may be used as appropriate. The solution obtained after polyhydroxyamide polymerization by the "acid chloride method" or the "activated esterification method" contains impurities such as desorbed components, catalysts, and dissolution accelerators generated during polymerization. Therefore, these can be removed and the solution purified. Purification can be carried out using known methods. For example, the simplest method involves adding a polymerization solution adjusted to an appropriate concentration to a large amount of poor solvent while stirring to precipitate the polyhydroxyamide compound, then recovering the polyhydroxyamide compound powder, washing it, and drying it. The poor solvent used is preferably an alcohol-based solvent such as methanol, ethanol, or isopropanol, or water, which precipitates the polyhydroxyamide compound, dissolves and removes impurities, and dries easily. A mixture of these may also be used. By repeating this washing operation until impurities are removed, a high-purity polyhydroxyamide compound powder can be obtained. Alternatively, the recovered polyhydroxyamide compound powder can be dissolved in an organic solvent and then dropped dropwise into a large amount of poor solvent to precipitate the polyhydroxyamide compound. By repeating this operation until impurities are removed, a high-purity polyhydroxyamide compound powder can be obtained. The above description of poor solvents can be applied to this process. If the concentration of the polyhydroxyamide solution when dropped into the poor solvent to precipitate is too high, the precipitated polyhydroxyamide compound will form agglomerates, and impurities may remain in the coarse particles. Furthermore, it will take a long time to redissolve the resulting polyhydroxyamide compound powder in an organic solvent, which is undesirable. On the other hand, if the concentration of the polyhydroxyamide solution is too low, the particle size of the polyhydroxyamide compound powder will be too small, making recovery difficult. Furthermore, a large amount of poor solvent will be required, which is undesirable because it increases the environmental burden and production costs due to waste solvent treatment. Therefore, the concentration of the polyhydroxyamide solution when dropped into the poor solvent is 20% by mass or less, more preferably 10% by mass or less. The amount of poor solvent used in this process is preferably at least equal to the amount of the polyhydroxyamide solution, and is preferably 1.5 to 5 times the amount. Finally, the purified polyhydroxyamide compound powder is recovered, and the residual solvent is removed by vacuum drying, hot air drying, etc. The drying temperature and time are not limited as long as the polyhydroxyamide compound is not altered and the residual solvent is not decomposed. For example, drying at a temperature in the range of 30 to 200°C for 48 hours or less is preferred. The intrinsic viscosity of the polyhydroxyamide compound of the present invention is preferably in the range of 0.1 to 15.0 dL / g, and more preferably in the range of 0.3 to 5.0 dL / g. The above-mentioned intrinsic viscosity is a value measured by the method described in the examples below.

[0041] [Polyhydroxyamide solution] The polyhydroxyamide solution of the present invention is obtained by dissolving the polyhydroxyamide compound of the present invention in an organic solvent. The polyhydroxyamide compound of the present invention is soluble in various organic solvents due to the chemical structure of the constituent unit represented by the above-mentioned general formula (3) or (4), and therefore the organic solvent contained in the polyhydroxyamide solution of the present invention can be appropriately selected depending on the intended use and / or processing conditions. Specifically, although not particularly limited, the organic solvent used as the polymerization solvent is preferred, and the description of the organic solvent used in the polymerization of the polyhydroxyamide compound described above can be applied. The concentration of the polyhydroxyamide compound of the present invention in the polyhydroxyamide solution of the present invention depends on the intrinsic viscosity of the polyhydroxyamide compound and the method for producing the polybenzoxazole film, but is usually preferably 0.1% by mass or more, more preferably 1 to 30% by mass. The polyhydroxyamide compound of the present invention can be dissolved in an organic solvent, for example, by adding the powder of the polyhydroxyamide compound of the present invention to the organic solvent while stirring it, and dissolving it in air or a dry inert gas at a temperature ranging from room temperature (20°C) to the boiling point of the organic solvent for 0.1 to 72 hours to obtain a homogeneous polyhydroxyamide solution. Alternatively, the solution can be filtered after dissolution to remove insoluble matter. If necessary, additives such as a photosensitizer, a sensitizer, an adhesion promoter, a silane coupling agent, a crosslinking agent, an end-capping agent, an antioxidant, an ultraviolet absorber, an antifoaming agent, a leveling agent, a surfactant, an inorganic filler, an organic filler, a dye, a pigment, and a mold release agent may be added to the polyhydroxyamide solution of the present invention.

[0042] [Polybenzoxazole film] The polybenzoxazole film of the present invention contains a structural unit represented by the following general formula (5): That is, it is a polybenzoxazole film containing a structural unit represented by the following general formula (5). The polybenzoxazole film of the present invention can be obtained by a method including the steps of: applying a polyhydroxyamide solution, prepared by dissolving a polyhydroxyamide compound containing a structural unit represented by the above-mentioned general formula (3) in an organic solvent, onto a substrate, and drying the solution to obtain a film on the substrate; and heating the film on the substrate to dehydrate and ring-close the polyhydroxyamide compound, thereby converting the film into a polybenzoxazole film, and the film has high heat resistance and excellent thermal dimensional stability.

[0043] [ka]

[0044] In the above formula, R1 ~R 4 is R in the above general formula (3) 1 ~R 4 It is synonymous with Y. 1 represents Y in the above general formula (3). 1 This is synonymous with a divalent aliphatic group or a divalent aromatic group, or a group formed by combining two or more of these groups. 1 When is a group formed by combining two or more of these groups, the two groups to be combined may be bonded via -O- or >SO2. The bonding position of the benzoxazole ring with the imide bond is preferably the para position relative to the oxygen atom or nitrogen atom in the benzoxazole ring, more preferably the para position relative to the oxygen atom in the benzoxazole ring. In the polybenzoxazole film of the present invention, from the viewpoint of exhibiting the excellent effect of further improving thermal dimensional stability and heat resistance, it is preferable that the constituent unit represented by the above general formula (5) includes the constituent unit represented by the following general formula (6), and it is more preferable that the constituent unit represented by the above general formula (5) is represented by the following general formula (6). That is, the polybenzoxazole film of the present invention is preferably a polybenzoxazole film containing the constituent unit represented by the following general formula (6).

[0045] [ka]

[0046] Y 1 Y in the above general formula (5) is 1 is synonymous with.

[0047] The bond position of the imide bond in general formula (6) is determined by the same description as that for the bond position of the imide bond in general formula (5) above.

[0048] In the polybenzoxazole constituting the polybenzoxazole film of the present invention, the content of the constituent unit represented by general formula (5) is preferably 10 to 100% by mass, more preferably 20 to 100% by mass, and even more preferably 30 to 100% by mass, when the total amount of all constituent units of the polybenzoxazole is taken as 100% by mass. In addition to the constituent unit represented by general formula (5), other constituent units in the polybenzoxazole include those obtained by dehydration and cyclization of constituent units other than the constituent unit represented by general formula (3) in the aforementioned polyhydroxyamide compound. The content of the constituent unit represented by general formula (6) in the polybenzoxazole constituting the polybenzoxazole film of the present invention can be applied by replacing the description of the content of the constituent unit represented by general formula (5) in the polybenzoxazole with the content of the constituent unit represented by general formula (6). The polybenzoxazole film of the present invention may contain additives that may be present in the polyhydroxyamide solution of the present invention described above. If the additives present in the polyhydroxyamide solution of the present invention described above are used in the manufacturing process of the polybenzoxazole film of the present invention and their structure is altered, then the film contains the additives after the reaction.

[0049] The glass transition temperature (Tg) of the polybenzoxazole film of the present invention is preferably 260°C or higher, and more preferably 280°C or higher, because, for example, from the viewpoint of being able to withstand lead-free solder mounting temperatures, a Tg of 260°C or higher is required. Furthermore, a higher Tg is preferable because it provides better heat resistance, and there is no particular upper limit, but a practical upper limit is, for example, 380°C or lower. The average coefficient of linear thermal expansion (average CTE) of the polybenzoxazole film of the present invention, for example, for use as a semiconductor buffer coating agent, is preferably less than the average CTE of current materials, about 60 ppm (parts per million) / K, specifically 45.0 ppm / K or less. The lower the average CTE, the better. There is no particular lower limit, but a practical lower limit is, for example, -10 ppm / K or more. The smaller the difference in average CTE between the substrate (silicon wafer; about 3 ppm / K) and the buffer coating agent, the more easily the interfacial strain between the substrate and the buffer coating agent is eliminated. The 5% mass loss temperature (T d 5 ) is preferably 400°C or higher. The higher the 5% mass loss temperature under nitrogen, the better the heat resistance, so there is no particular upper limit, but a practical upper limit is, for example, 550°C or lower. The glass transition temperature (Tg), the average coefficient of linear thermal expansion (average CTE), and the 5% mass loss temperature under nitrogen (T d 5 ) is a value when the polybenzoxazole film of the present invention does not contain an inorganic filler, an organic filler, etc., and the polybenzoxazole is not crosslinked with a crosslinking agent, etc. When the polybenzoxazole film of the present invention contains the above-mentioned inorganic filler, organic filler, etc., when the polybenzoxazole constituting the polybenzoxazole film of the present invention is crosslinked with the above-mentioned crosslinking agent, etc., or when Y 1 Depending on the structure, the glass transition temperature (Tg) and the 5% mass loss temperature under nitrogen (T d 5 ) may be even higher than the above upper limit, and the average coefficient of linear thermal expansion (average CTE) may be even lower than the above lower limit. The thickness of the polybenzoxazole film of the present invention can be adjusted appropriately depending on the intended use within the range that can be produced, and can be, for example, 1 to 50 μm. The glass transition temperature (Tg), average coefficient of linear thermal expansion (average CTE), and 5% mass loss temperature under nitrogen (T d5 ) and film thickness are values ​​measured by the method described in the Examples below.

[0050] <Method of manufacturing polybenzoxazole film> The polybenzoxazole film of the present invention can be manufactured by a method comprising the steps of: applying the polyhydroxyamide solution of the present invention onto a substrate, drying it to obtain a film on the substrate; and heating the film on the substrate to dehydrate and cyclize the polyhydroxyamide compound, thereby converting the film into a polybenzoxazole film. The polyhydroxyamide solution of the present invention is applied to a substrate by a known method, for example, by casting onto a support substrate such as a glass substrate using a doctor blade. After this, a polybenzoxazole film can be produced by drying and heating using a hot air dryer, infrared drying oven, vacuum dryer, inert oven, etc., usually in the range of 40 to 500°C, preferably in the range of 50 to 450°C. Specifically, the polyhydroxyamide solution cast onto the support substrate is heated at 40 to 150°C to partially dry the organic solvent, and then heated at 150 to 450°C to dehydrate and cyclize the polyhydroxyamide compound, thereby obtaining a high-quality polybenzoxazole film. When peeling the polybenzoxazole film from the support substrate, a known method can be used. For example, the film can be obtained by immersing it in hot water to peel it from the support substrate, and then drying it using a vacuum dryer, etc. Furthermore, when the polyhydroxyamide compound is dehydrated and cyclized on the support substrate, strain (stress) may remain in the polybenzoxazole film after cyclization. In this case, the polybenzoxazole film peeled from the support substrate can be heated to remove the residual strain. It is also possible to produce a laminate of an inorganic substrate and a polybenzoxazole film by applying the composition directly to a silicon wafer, copper, aluminum substrate, or the like, instead of onto a supporting substrate, followed by drying and heating. The polybenzoxazole film manufactured as described above has high heat resistance and excellent thermal dimensional stability, making it suitable for use as an insulating material for electronic devices such as a heat-resistant insulating substrate for flexible wiring boards and an insulating film for semiconductors (e.g., a protective coating material for the surface of a semiconductor element, or an interlayer insulating film for semiconductors). [Example]

[0051] The present invention will be described in more detail below based on examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate, as long as they do not depart from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the examples shown below. The physical property values ​​in the following examples are values ​​measured by the following evaluation method. Also, room temperature means "approximately 20°C".

[0052] <Evaluation method> 1. Infrared absorption spectrum The infrared absorption spectra of synthetic compounds such as bis(aminophenol) compounds were measured using the KBr method with a Fourier transform infrared spectrophotometer FT / IR-4X (trade name, manufactured by JASCO Corporation). In addition, the infrared absorption spectra of polyhydroxyamide films and polybenzoxazole films were measured by preparing thin film samples (approximately 5 μm thick). 2. 1 H-NMR spectrum Using a Fourier transform nuclear magnetic resonance instrument (JNM-ECP400, trade name, manufactured by JEOL), synthetic compounds such as bis(aminophenol) compounds or polyhydroxyamide compounds are analyzed in deuterated dimethyl sulfoxide (DMSO-d6). 1 H-NMR spectrum was measured. 3. Melting Point The melting points of compounds such as bis(aminophenol) compounds were measured using a thermogravimetric analyzer TG-DTA2000 (product name, manufactured by Netsch Corporation) in a nitrogen atmosphere at a heating rate of 5°C / min. 4.Intrinsic viscosity The reduced viscosity of a 0.5% by mass polyhydroxyamide solution was measured at 30°C using an Ostwald viscometer. N-methyl-2-pyrrolidone (NMP) was used as the solvent. This value was considered to be the intrinsic viscosity. 5. Solubility in N-methyl-2-pyrrolidone (NMP) at room temperature A 20 mL screw bottle was fitted with a rotor, and a small amount of fibrous polyhydroxyamide was added to 1 mL of room temperature dehydrated N-methyl-2-pyrrolidone, followed by stirring and dissolution using a high-power magnetic stirrer (AMG-H, manufactured by Asahi Rika Seisakusho Co., Ltd.). When a homogeneous solution was obtained without turbidity or gelation, additional small amounts of fibrous polyhydroxyamide were added. This procedure was repeated until the point at which the fluidity of the polyhydroxyamide solution disappeared (i.e., the point at which at least one of turbidity and gelation occurred) was recorded as the solubility in N-methyl-2-pyrrolidone at room temperature. Light transmittance at 6.365 nm: T i The light transmittance of the polyhydroxyamide film at 365 nm was determined using an ultraviolet-visible spectrophotometer V-530 (trade name, manufactured by JASCO Corporation). 7. Glass transition temperature: T g The glass transition temperature of the polybenzoxazole film was measured using a thermomechanical analyzer TMA8310 (trade name, manufactured by Rigaku Corporation) by first heating a polybenzoxazole film sample (size: width 5 mm, length 15 mm) to 150°C at 5°C / min (first heating) under a load of film thickness (μm) x 0.5 g, then cooling to 20°C and further heating at 5°C / min (second heating). The TMA (mechanical thermal analysis) curve during the second heating was then measured using the tangent method (the tangent of the glass state and the T g This was determined from the intersection points of the subsequent tangent lines. 8. 5% mass loss temperature under nitrogen: T d 5 Using a thermogravimetric analyzer TG-DTA2000 (trade name, manufactured by Netsch) or a differential thermobalance TG8120 (trade name, manufactured by Rigaku), the temperature at which the mass of the polybenzoxazole film decreased by 5% from the initial mass was measured in a temperature rise process from 20°C at a rate of 10°C / min in nitrogen gas. A higher value indicates higher thermal stability. 9. Average linear thermal expansion coefficient: Average CTE The average coefficient of linear thermal expansion (CTE) of polybenzoxazole film was measured using a thermomechanical analyzer TMA8310 (manufactured by Rigaku Corporation) by heating a polybenzoxazole film sample (size: 5 mm wide, 15 mm long) at 5°C / min (first heating) under a load of film thickness (μm) × 0.5 g, then cooling to 20°C and heating at 5°C / min (second heating). The average coefficient of linear thermal expansion (CTE) was calculated from the TMA curve obtained during the second heating. The average coefficient of linear thermal expansion (CTE) was calculated as the average value between 100 and 200°C (i.e., the slope of the secant line passing through 100°C and 200°C on the TMA curve). 10. Film Thickness The film thickness of the polyhydroxyamide film and polybenzoxazole film was determined by measuring the thickness at four points on the film using a digital micrometer MDC-25MX (product name, manufactured by Mitutoyo Corporation) and calculating the average value.

[0053] In the following, in Example 1, a bis(aminophenol) compound of the present invention was synthesized, and in Examples 2 and 3, a polyhydroxyamide compound of the present invention was synthesized using the bis(aminophenol) compound obtained in Example 1, and then a solution of each polyhydroxyamide compound was prepared to produce a polybenzoxazole film of the present invention. Furthermore, in Comparative Examples 1 and 2, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane was used as a bis(aminophenol) compound that does not have the structure represented by general formula (1) to synthesize a comparative polyhydroxyamide compound that does not contain the constituent unit represented by general formula (3). Then, a solution thereof was prepared, and a comparative polybenzoxazole film that does not contain the constituent unit represented by general formula (5) was fabricated. In Comparative Example 3, a comparative polyhydroxyamide compound not containing the structural unit represented by general formula (3) was synthesized using 4,4'-diamino-3,3'-dihydroxybiphenyl as a bis(aminophenol) compound not having a structure represented by general formula (1).

[0054] [Synthesis of bis(aminophenol) compounds represented by general formula (1)] Example 1 (1) Synthesis of dinitro compounds (imidation reaction)

[0055] [ka]

[0056] In a 300 mL three-necked flask, 1.8492 g (12.0 mmol) of 4-hydroxy-3-nitroaniline, dried in a vacuum oven at 60°C for 12 hours, and 46.5 mL of anhydrous γ-butyrolactone (GBL) were added and dissolved at room temperature. To this solution, 1.1794 g (6.00 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride, dried in a vacuum oven at 150°C for 12 hours, was added and stirred at room temperature for 24 hours, resulting in a suspension. This suspension was stirred under a nitrogen atmosphere at 150°C for 5 hours. After cooling to room temperature, the resulting precipitate was collected by filtration, washed with methanol, and dried in a vacuum oven at 80°C for 12 hours to obtain the target product, a yellow powdery dinitro compound represented by the above formula. The yield was 60%. In the infrared absorption spectrum of the obtained product, 3295 cm⁻¹ was observed. -1 Aromatic OH group expansion and contraction, 3105cm -1 Aromatic CH stretches, 2989cm-1 Aliphatic CH stretching, 1772 and 1711 cm -1 Imide group C=O stretching, 1540cm -1 The nitro group stretching was confirmed. 1 The H-NMR spectrum is shown in Figure 1. In Figure 1, signals were confirmed at (DMSO-d6, δ, ppm): 11.4 (s, 2H), 8.10 (d, J = 2.5 Hz, 2H), 7.61 (dd, J = 2.6 Hz, 8.9 Hz, 2H), 7.28 (d, J = 8.9 Hz, 2H), and 3.69 (s, 4H). These analytical results confirmed that the product was a dinitro form.

[0057] (2) Reduction of dinitro compounds

[0058] [ka]

[0059] A 200 mL three-neck flask was charged with 1.775 g of the dinitro compound synthesized in (1) above, 74 mL of N,N-dimethylacetamide (DMAc), and 0.1685 g of palladium / carbon (Pd 10%) (approximately 55% water-wet). The mixture was stirred at 90°C for 3.5 hours while bubbling with hydrogen. The mixture was then allowed to cool to room temperature, the palladium / carbon was filtered off, and the filtrate was recovered. The recovered filtrate was added to 700 mL of methanol to precipitate the target product, which was then filtered and recovered. After washing with methanol, the product was dried in a vacuum dryer at 80°C for 12 hours, yielding the light brown target product represented by the formula above. The yield was 73%. In the infrared absorption spectrum of the obtained product, peaks at 3465 and 3368 cm -1 Amino group NH stretching, 3105cm -1 Aromatic CH stretching, 2990cm -1 Aliphatic CH stretching, 1780 and 1699 cm -1 The absorption of the imide group C=O stretching was confirmed. 1The 1H-NMR spectrum is shown in Figure 2. In Figure 2, signals were observed at (DMSO-d6,δ,ppm):9.38(s,2H), 6.70(d,J=8.2Hz,2H), 6.55(d,J=2.4Hz,2H), 6.38(dd,J=2.4,8.3Hz,2H), 4.75(s,4H), and 3.55(s,4H). Based on these analytical results, the obtained product was confirmed to be the target bis(aminophenol) compound. Furthermore, the melting point was confirmed to be 379°C by measurement using a thermogravimetric analyzer TG-DTA2000 (manufactured by Netsch).

[0060] [Polymerization of polyhydroxyamide compound containing constitutional unit represented by general formula (3), preparation of solution thereof, and preparation of polybenzoxazole film containing constitutional unit represented by general formula (5)] Example 2 <Polyhydroxyamide Compound Polymerization Example 1: Bis(aminophenol) Compound of Example 1 / 4,4'-Oxybisbenzoic Acid Chloride>

[0061] [ka]

[0062] In a 100 mL round-bottom flask, 0.6103 g (1.49 mmol) of the bis(aminophenol) compound synthesized in Example 1, dried in a vacuum dryer at 60°C for 12 hours, and 8.3 mL of anhydrous N-methyl-2-pyrrolidone were added. The flask was immediately sealed with a septum cap and stirred at 120°C for 10 minutes to dissolve the compounds, then allowed to cool to room temperature. To this solution, 6.0 mmol of anhydrous pyridine and 6.0 mmol of trimethylsilyl chloride were added using a syringe and stirred at room temperature for 1 hour to silylate the bis(aminophenol) compound. Subsequently, 0.4411 g (1.49 mmol) of 4,4'-oxybisbenzoic acid chloride powder was added all at once to the solution and stirred at room temperature for 24 hours. Then, this homogeneous solution was added to 500 mL of pH 5 hydrochloric acid aqueous solution to deprotect the silyl groups and precipitate a fibrous polyhydroxyamide compound. The obtained polyhydroxyamide compound was recovered by filtration and washed with deionized water. Washing was carried out by adding an aqueous silver nitrate solution to the washing solution until the removal of chloride ions was confirmed. Then, it was dried in a vacuum dryer at 120°C for 12 hours to obtain the target product, a polyhydroxyamide compound containing the constituent units represented by the above formula. This fibrous polyhydroxyamide compound was dissolved in DMSO-d6. 1 ¹H-NMR measurements revealed no signal for the trimethylsilyl group (around δ0 ppm), suggesting that desilylation was complete. The intrinsic viscosity of the obtained polyhydroxyamide compound was 0.89 dL / g.

[0063] <Preparation of polyhydroxyamide solution, production of polyhydroxyamide film, and production of polybenzoxazole film> The fibrous polyhydroxyamide compound and dehydrated N-methyl-2-pyrrolidone were added to a 20 mL screw bottle and stirred for 24 hours to prepare a 17.5% by mass homogeneous solution. This solution was cast onto a glass substrate and dried at 100°C for 1 hour in a forced convection oven under atmospheric pressure to obtain a polyhydroxyamide film. The polyhydroxyamide film formed on the glass substrate was heated in a vacuum at 250°C for 1 hour, followed by 350°C for 1 hour to heat the polyhydroxyamide compound and dehydrate it to form a polybenzoxazole film. The resulting polybenzoxazole film was immersed in warm water, peeled from the glass substrate, and then thoroughly dried in a vacuum oven.

[0064] Example 3 <Polyhydroxyamide compound polymerization example 2: Bis(aminophenol) compound / 2-methoxyterephthalate chloride from Example 1>

[0065] [ka]

[0066] A 100 mL recovery flask was charged with 0.8167 g (2.00 mmol) of the bis(aminophenol) compound synthesized in Example 1, which had been dried in a vacuum oven at 60°C for 12 hours, and 12.1 mL of dehydrated N-methyl-2-pyrrolidone. The flask was immediately sealed with a septum cap and stirred at 130°C for 10 minutes to dissolve the solution, then allowed to cool to room temperature. To this solution, 8.0 mmol of dehydrated pyridine and 8.0 mmol of trimethylsilyl chloride were added using a syringe and stirred at room temperature for 1 hour to silylate the bis(aminophenol) compound. One-third of the powder of 0.4661 g (2.00 mmol) of 2-methoxyterephthalic acid chloride was then added to the solution every 5 minutes, followed by 0.45 mL of dehydrated N-methyl-2-pyrrolidone, and the mixture was stirred at room temperature for 24 hours. This homogeneous solution was then added to 800 mL of a pH 5 hydrochloric acid solution to deprotect the silyl groups and precipitate a fibrous polyhydroxyamide compound. The resulting polyhydroxyamide compound was collected by filtration and washed with deionized water. The washing was continued by adding an aqueous silver nitrate solution to the wash until the removal of chloride ions was confirmed. The resulting mixture was then dried in a vacuum dryer at 120°C for 12 hours to obtain the target polyhydroxyamide compound containing the structural unit represented by the above formula. This fibrous polyhydroxyamide compound was dissolved in DMSO-d6 and 1 ¹H-NMR measurements revealed no signal for the trimethylsilyl group (around δ0 ppm), suggesting that desilylation was complete. The intrinsic viscosity of the obtained polyhydroxyamide compound was 1.37 dL / g.

[0067] <Preparation of polyhydroxyamide solution, production of polyhydroxyamide film, and production of polybenzoxazole film> The fibrous polyhydroxyamide compound and dehydrated N-methyl-2-pyrrolidone were added to a 20 mL screw bottle and stirred for 24 hours to prepare a 9.13% by mass homogeneous solution. This solution was cast onto a glass substrate and dried at 100°C for 1 hour in a forced convection oven under atmospheric pressure to obtain a polyhydroxyamide film. The polyhydroxyamide film formed on the glass substrate was heated in a vacuum at 250°C for 1 hour, followed by 380°C for 1 hour to heat the polyhydroxyamide compound and dehydrate it to form a polybenzoxazole film. The resulting polybenzoxazole film was immersed in warm water, peeled from the glass substrate, and then thoroughly dried in a vacuum oven.

[0068] [Synthesis of Polyhydroxyamide Compound and Polybenzoxazole Films for Comparison] (Comparative Example 1) <Polyhydroxyamide polymerization>

[0069] [ka]

[0070] A 100 mL recovery flask was charged with 1.4650 g (4.00 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (previously dried in a vacuum oven at 60°C for 12 hours) and 8.0 mL of dehydrated N-methyl-2-pyrrolidone. The flask was immediately sealed with a septum cap and dissolved at room temperature. To this solution, 16.0 mmol of dehydrated pyridine and 16.0 mmol of trimethylsilyl chloride were added via syringe and stirred. An additional 2.2 mL of dehydrated N-methyl-2-pyrrolidone was added midway through the reaction and stirred at room temperature for 1 hour to silylate the bis(aminophenol) compound, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane. 1.1804 g (4.00 mmol) of 4,4'-oxybisbenzoyl chloride was then added to the solution, followed by 4.5 mL of dehydrated N-methyl-2-pyrrolidone, and the mixture was stirred at room temperature for 24 hours. This homogeneous solution was then added to 1000 mL of a pH 5 hydrochloric acid solution to deprotect the silyl groups and precipitate a fibrous polyhydroxyamide compound. The resulting polyhydroxyamide compound was collected by filtration and washed with deionized water. The washing was continued by adding an aqueous silver nitrate solution to the wash until the removal of chloride ions was confirmed. The resulting mixture was then dried in a vacuum dryer at 120°C for 12 hours to obtain the target polyhydroxyamide compound containing the structural unit represented by the above formula. This fibrous polyhydroxyamide compound was dissolved in DMSO-d6 and 1 H-NMR analysis revealed no signal for the trimethylsilyl group (near δ0 ppm), suggesting that desilylation was complete. The intrinsic viscosity of the resulting polyhydroxyamide compound was 0.98 dL / g.

[0071] <Preparation of polyhydroxyamide solution, production of polyhydroxyamide film, and production of polybenzoxazole film> The fibrous polyhydroxyamide compound and dehydrated γ-butyrolactone were added to a 20 mL screw bottle and stirred for 24 hours to prepare an 18.0% by weight solution. This solution was then filtered through a glass filter to obtain a polyhydroxyamide solution. This solution was cast onto a glass substrate and dried at 100°C for 1 hour in a forced convection oven under atmospheric pressure to obtain a polyhydroxyamide film. The polyhydroxyamide film formed on the glass substrate was heated in a vacuum at 250°C for 1 hour, followed by 380°C for 1 hour to heat the polyhydroxyamide compound and dehydrate it into a polybenzoxazole film. The resulting polybenzoxazole film was then immersed in warm water, peeled from the glass substrate, and thoroughly dried in a vacuum oven.

[0072] (Comparative Example 2) <Polyhydroxyamide polymerization>

[0073] [ka]

[0074] 1.4650 g (4.00 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, dried in a vacuum dryer at 60°C for 12 hours, and 8.0 mL of anhydrous N-methyl-2-pyrrolidone were added to a 100 mL round-bottom flask. The flask was immediately sealed with a septum cap and allowed to dissolve at room temperature. To this solution, 16.0 mmol of anhydrous pyridine and 16.0 mmol of trimethylsilyl chloride were added using a syringe and stirred. An additional 1.3 mL of anhydrous N-methyl-2-pyrrolidone was added midway through the process and stirred at room temperature for 1 hour to silylate the mixture. Then, 0.9322 (4.00 mmol) of 2-methoxyterephthalate chloride powder was added all at once to the solution, followed by an additional 4.5 mL of anhydrous N-methyl-2-pyrrolidone, and the mixture was stirred at room temperature for 24 hours. This homogeneous solution was then added to 1000 mL of a pH 5 hydrochloric acid solution to deprotect the silyl groups and precipitate a fibrous polyhydroxyamide compound. The resulting polyhydroxyamide compound was collected by filtration and washed with deionized water. The washing was continued by adding an aqueous silver nitrate solution to the wash until the removal of chloride ions was confirmed. The resulting mixture was then dried in a vacuum dryer at 120°C for 12 hours to obtain the target polyhydroxyamide compound containing the structural unit represented by the above formula. This fibrous polyhydroxyamide compound was dissolved in DMSO-d6 and 1 ¹H-NMR measurements revealed no signal for the trimethylsilyl group (around δ0 ppm), suggesting that desilylation was complete. The intrinsic viscosity of the obtained polyhydroxyamide compound was 0.32 dL / g.

[0075] <Preparation of polyhydroxyamide solution, production of polyhydroxyamide film, and production of polybenzoxazole film> The fibrous polyhydroxyamide compound and dehydrated N-methyl-2-pyrrolidone were added to a 20 mL screw bottle and stirred for 24 hours to prepare a 25.2% by weight solution. This solution was then filtered through a glass filter to obtain a polyhydroxyamide solution. This solution was cast onto a glass substrate and dried at 100°C for 1 hour in a forced convection oven under atmospheric pressure to obtain a polyhydroxyamide film. The polyhydroxyamide film formed on the glass substrate was heated in a vacuum at 250°C for 1 hour, followed by 350°C for 1 hour to heat the polyhydroxyamide compound and dehydrate it into a polybenzoxazole film. The resulting polybenzoxazole film was then immersed in warm water, peeled from the glass substrate, and thoroughly dried in a vacuum oven.

[0076] (Comparative Example 3) <Attempt to polymerize a polyhydroxyamide compound containing a structural unit represented by the following formula>

[0077] [ka]

[0078] A 100 mL recovery flask was charged with 0.4325 g (2.00 mmol) of 4,4'-diamino-3,3'-dihydroxybiphenyl, 4.1 mL of dehydrated N-methyl-2-pyrrolidone adjusted to a 1% lithium chloride concentration by mass, and 8.00 mmol of pyridine. The flask was immediately sealed with a septum cap and dissolved. 8.00 mmol of trimethylsilyl chloride was added to this solution using a syringe and stirred at room temperature for 1 hour to silylate the amino and hydroxy groups. When 0.4060 g (2.00 mmol) of terephthalic acid chloride was quickly added to the solution, the solution became suspended and gelled, terminating the polymerization reaction and making evaluation impossible.

[0079] For Examples 2 and 3, and Comparative Examples 1 and 2, the intrinsic viscosity of the polyhydroxyamide, solubility in NMP, film thickness of the polyhydroxyamide film, and light transmittance T at 365 nm were examined. i , the glass transition temperature (T g), 5% mass loss temperature under nitrogen (T d 5 Table 1 summarizes the film thickness and average linear thermal expansion coefficient (average CTE). 3 to 6 show the infrared absorption spectra of the polyhydroxyamide films and polybenzoxazole films of Examples 2 and 3 and Comparative Examples 1 and 2. In Figures 3 to 6, the upper side shows the infrared absorption spectrum of the polybenzoxazole film, and the lower side shows the infrared absorption spectrum of the polyhydroxyamide film.

[0080] [Table 1]

[0081] The bis(aminophenol) compound used in Comparative Example 1, i.e., 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, has a chemical structure characterized by the introduction of a bulky trifluoromethyl group, which is geometrically flexible. A polyhydroxyamide compound synthesized by combining the bis(aminophenol) compound used in Comparative Example 1 with 4,4'-oxybisbenzoic acid chloride, which contains an ether bond, is expected to have high solubility in organic solvents. As shown in Table 1, the polyhydroxyamide compound of Comparative Example 1 dissolved in N-methyl-2-pyrrolidone at a high concentration of 38.0 mass%. However, as shown in Table 1, the average linear thermal expansion coefficient of the polybenzoxazole film obtained from the polyhydroxyamide compound of Comparative Example 1 was as high as 57.7 ppm / K, indicating insufficient thermal dimensional stability. This is thought to be because, even in the polybenzoxazole film obtained by thermally cyclizing the polyhydroxyamide of Comparative Example 1, which has a bent main chain of a polyhydroxyamide compound, the polybenzoxazole main chain was also significantly bent, and the orientation of the main chain in the film plane (in-plane orientation), which is necessary for low thermal expansion, was not promoted. Comparative Example 2 is a polyhydroxyamide compound synthesized by replacing the 4,4'-oxybisbenzoic acid chloride used in Comparative Example 1 with 2-methoxyterephthalic acid chloride, which exhibits a linear chemical structure. Because it is substituted with a bulky methoxy group, it is expected to maintain solubility in organic solvents. Furthermore, by replacing it with 2-methoxyterephthalic acid chloride, which has a linear chemical structure, the proportion of linear chemical structures in the polybenzoxazole main chain also increases, and low thermal expansion of the film can be expected. As shown in Table 1, the polyhydroxyamide compound of Comparative Example 2 dissolved in N-methyl-2-pyrrolidone at a concentration of 46.2% by mass, as expected. However, although the average linear thermal expansion coefficient of the polybenzoxazole film was slightly lower than that of Comparative Example 1, it was still large at 49.5 ppm / K, and the thermal dimensional stability was still not sufficient. This is thought to be because, even with the introduction of 2-methoxyterephthalic acid chloride, which has a linear chemical structure, the linearity of the entire polybenzoxazole main chain was still low, and in-plane orientation was not promoted. The bis(aminophenol) compound used in Comparative Example 3, namely 4,4'-diamino-3,3'-dihydroxybiphenyl, is characterized by its geometrically linear chemical structure. A polybenzoxazole film synthesized by combining it with terephthalic acid chloride, which also exhibits a linear structure, is expected to exhibit even lower thermal expansion compared to the polybenzoxazole film of Comparative Example 2. However, the solubility of the polyhydroxyamide compound of Comparative Example 3 in organic solvents was remarkably low, resulting in suspension and gelation during polymerization, halting the polymerization reaction. This is thought to be because the polyhydroxyamide compound of Comparative Example 3, polymerized from this bis(aminophenol) compound, developed a linear main chain structure due to the growth of the main chain from the para position, causing the amide and hydroxyl groups to aggregate through hydrogen bonding. The results of Comparative Examples 1 to 3 above show that it is difficult to achieve both the solubility of a polyhydroxyamide compound in an organic solvent and the low thermal expansion (thermal dimensional stability) of a polybenzoxazole film.

[0082] In contrast, the chemical structure of the bis(aminophenol) compound of Example 1 is characterized in that aminophenol is introduced via imide bonds on both sides of the cyclobutane ring. Because the chemical structure of this bis(aminophenol) compound of Example 1 is linear, a polybenzoxazole film synthesized by combining it with a dicarboxylic acid compound such as 4,4'-oxybisbenzoic acid chloride or its activated derivative can be expected to have low thermal expansion (excellent thermal dimensional stability). Furthermore, the polyhydroxyamide compounds of Examples 2 and 3, obtained using the bis(aminophenol) compound of Example 1, all showed excellent solubility in the organic solvent N-methyl-2-pyrrolidone. Specifically, as shown in Table 1, the polyhydroxyamide compound of Example 2 obtained by polymerizing the bis(aminophenol) compound of Example 1 with 4,4'-oxybisbenzoic acid chloride was soluble in N-methyl-2-pyrrolidone at room temperature, exhibiting a high solubility of 22.6% by mass. This is because the cyclobutane ring and the two imide rings fused to the cyclobutane ring were not coplanar, suppressing aggregation of the polymer main chain of the derived polyhydroxyamide compound, resulting in high solubility in organic solvents. Furthermore, in the bis(aminophenol) compound of Example 1, the imide bond was para-positioned relative to the hydroxy group, resulting in significant bending of the main chain of the polyhydroxyamide compound, further enhancing its solubility in organic solvents. Similarly, the polyhydroxyamide compound of Example 3 obtained by polymerizing the bis(aminophenol) compound of Example 1 with 2-methoxyterephthalic acid chloride was soluble in N-methyl-2-pyrrolidone at room temperature, exhibiting a high solubility of 20.2% by mass, as shown in Table 1. Furthermore, as shown in Table 1, the polybenzoxazole films obtained from the polyhydroxyamide compounds of Examples 2 and 3 had low mean linear thermal expansion coefficients of 31.8 ppm / K and 18.2 ppm / K, respectively, and were excellent in thermal dimensional stability. Furthermore, due to the presence of imide bonds, the films exhibited high glass transition temperatures of 349°C and 370°C, respectively, and high 5% mass loss temperatures under nitrogen of 450°C and 430°C, respectively, demonstrating high heat resistance. From the above results, it was found that by using the bis(aminophenol) compound of the present invention, polyhydroxyamide compounds and polybenzoxazole films containing structural units obtained using the bis(aminophenol) compound of the present invention and a dicarboxylic acid compound or an active derivative thereof as monomers can simultaneously achieve the high solubility of the polyhydroxyamide compound in organic solvents and the high heat resistance and excellent thermal dimensional stability (low thermal expansion) of the polybenzoxazole film.

Claims

1. A bis(aminophenol) compound represented by the following general formula (1): 【Chemistry 1】 In the above formula, R １ ~R ４ each independently represents a hydrogen atom or a methyl group.

2. The bis(aminophenol) compound according to claim 1, which is represented by the following general formula (2): 【Chemistry 2】

3. A polyhydroxyamide compound containing a structural unit represented by the following general formula (3): 【Transformation 3】 In the above formula, R １ ~R ４ each independently represents a hydrogen atom or a methyl group. １ represents a divalent aliphatic group, a divalent aromatic group, or a group formed by combining two or more of these groups. １ When is a group formed by combining two or more of these groups, the two groups to be combined are —O— or >SO ２ may be bonded via

4. The polyhydroxyamide compound according to claim 3, wherein the structural unit represented by the general formula (3) includes a structural unit represented by the following general formula (4): 【Chemistry 4】 Y １ represents Y in the general formula (3). １ is synonymous with.

5. A polyhydroxyamide solution obtained by dissolving the polyhydroxyamide compound according to claim 3 or 4 in an organic solvent.

6. 6. A method for producing a polybenzoxazole film, comprising: a step of applying the polyhydroxyamide solution according to claim 5 onto a substrate and then drying the applied solution to obtain a film on the substrate; and a step of heating the film on the substrate to dehydrate and ring-close the polyhydroxyamide compound, thereby converting the film into a polybenzoxazole film.

7. A polybenzoxazole film comprising a structural unit represented by the following general formula (5): 【Transformation 5】 In the above formula, R １ ~R ４ each independently represents a hydrogen atom or a methyl group. １ represents a divalent aliphatic group, a divalent aromatic group, or a group formed by combining two or more of these groups. １ When is a group formed by combining two or more of these groups, the two groups to be combined are —O— or >SO ２ may be bonded via

8. The polybenzoxazole film according to claim 7, wherein the structural unit represented by the general formula (5) includes a structural unit represented by the following general formula (6): 【Transformation 6】 Y １ represents Y in the above general formula (5). １ is synonymous with.

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