Polyimide resin composition and polyimide film

Abstract

Provided are: a polyimide resin composition from which a polyimide film excellent in terms of transparency, light resistance and adhesion to a substrate can be obtained; and a polyimide film excellent in terms of transparency, light resistance and adhesion to a substrate.　A polyimide resin composition contains: a polyimide resin (I) including a repeating unit represented by formula (1); at least one compound (S) selected from the group consisting of a silsesquioxane compound (S1) and a phenylalkoxysilane (S2); and an organic solvent, wherein the content of the compound (S) relative to 100 parts by mass of the polyimide resin (I) is 1-45 parts by mass. (X represents a C4-39 tetravalent aliphatic group or aromatic group; Y represents a C4-39 divalent aromatic group; and Y includes at least one selected from the group consisting of a divalent group represented by formula (2) and a divalent group represented by formula (3). Z is a C1-8 aliphatic group, and n is 0-2.)

Description

Polyimide resin composition and polyimide film

[0001] This invention relates to polyimide resin compositions and polyimide films.

[0002] Polyimide resins are being explored for various applications in fields such as electrical and electronic components. In recent years, in particular, polyimide resins have been adopted as optical filter materials, replacing glass which was previously used, due to their characteristics of pigment dispersibility, heat resistance, and transparency. To apply polyimide resins as optical filter materials, transparency, heat resistance, and adhesion to the substrate are required. Attempts are being made to improve the raw materials, tetracarboxylic acid and diamine, as well as the manufacturing process, to meet these requirements.

[0003] For example, Patent Document 1 discloses a method for producing a polyimide resin composition by reacting 1,2,4,5-cyclohexanetetracarboxylic dianhydride with a mixture of 1-(4-aminophenyl)-1,3,3-trimethylphenylindan-6-amine and 1-(4-aminophenyl)-1,3,3-trimethylphenylindan-5-amine to obtain a polyimide that is colorless, transparent, heat resistant, and has excellent adhesion to a substrate, and then reacting it with an alkoxysilylamine compound.

[0004] International Publication No. 2024 / 034634

[0005] As described above, polyimides used in the field of optical filter materials require not only high transparency but also heat resistance and adhesion. Furthermore, for polyimides used in such applications, not only transparency but also light resistance, which prevents changes in transparency due to ultraviolet light, is considered important as a measure of resistance to the environment in which they are used. Thus, there has been a need for polyimides with higher transparency, heat resistance, adhesion, and also excellent light resistance. The present invention has been made in view of this situation, and the problem that the present invention aims to solve is to provide a polyimide resin composition that can produce a polyimide film with excellent transparency, light resistance, and adhesion to a substrate, and a polyimide film with excellent transparency, light resistance, and adhesion to a substrate.

[0006] The present inventors have found that a polyimide resin composition containing a polyimide resin having specific structural units and a specific amount of a silsesquioxane compound or phenylalkoxysilane can solve the above problems, and have completed the invention.

[0007] In other words, the present invention relates to the following [1] to

[10] . [1] A polyimide resin composition comprising a polyimide resin (I) containing repeating units represented by the following formula (1), at least one compound (S) selected from the group consisting of a silsesquioxane compound (S1) and a phenylalkoxysilane (S2), and an organic solvent, wherein the content of compound (S) is 1 to 45 parts by mass per 100 parts by mass of the polyimide resin (I). (In formula (1), X is a tetravalent aliphatic or aromatic group having 4 to 39 carbon atoms, Y is a divalent aromatic group having 4 to 39 carbon atoms, and Y includes at least one selected from the group consisting of a divalent group represented by formula (2) and a divalent group represented by formula (3). In formula (2), Z is an aliphatic group having 1 to 8 carbon atoms, and n is 0 to 2.) [2] The polyimide resin composition according to [1], wherein the silsesquioxane compound (S1) is a compound represented by the following composition formula (4). [R 1 SiO 1.5 ] ｍ (4) (In formula (4), R 1 m is at least one selected from the group consisting of hydroxyl groups, alkoxy groups, and aromatic groups, and m is between 4 and 100. Note that m is the average value.) [3] R 1 The polyimide resin composition according to [2] above, wherein the polyimide resin composition contains a hydroxyl group or an alkoxy group. [4]R 1 A polyimide resin composition according to [2] or [3], wherein X comprises an aromatic group. A polyimide resin composition according to any one of [1] to [4], wherein X comprises at least one selected from the group consisting of a tetravalent group represented by the following formula (5) and a tetravalent group represented by the following formula (6). [6] A polyimide film obtained by applying the polyimide resin composition according to any one of [1] to [5] on a support and heating it. [7] A method for producing a polyimide film, comprising applying the polyimide resin composition according to any one of [1] to [5] on a support and heating it. [8] A polyimide film containing a polyimide resin (I) containing a repeating unit represented by the following formula (1) and a silsesquioxane compound (S3), wherein the content of the silsesquioxane compound (S3) with respect to 100 parts by mass of the polyimide resin (I) is 1 to 45 parts by mass. (In formula (1), X is a tetravalent aliphatic group or aromatic group having 4 to 39 carbon atoms, Y is a tetravalent aromatic group having 4 to 39 carbon atoms, and Y includes at least one selected from the group consisting of a divalent group represented by formula (2) and a divalent group represented by formula (3). In formula (2), Z is an aliphatic group having 1 to 8 carbon atoms, and n is 0 to 2.) [9] The polyimide film according to [8] above, wherein the silsesquioxane compound (S3) is a compound represented by the following compositional formula (4). 1 [R 1.5 SiO ｍ 1 (4) (In formula (4), R is at least one selected from the group consisting of a hydroxy group, an alkoxy group, and an aromatic group, and m is 4 to 100. Note that m is an average value.)

[10] The polyimide film according to [8] or [9] above, which is for an optical filter.

[0008] According to the present invention, a polyimide resin composition capable of obtaining a polyimide film excellent in transparency, light resistance, and adhesion to a substrate, and a polyimide film excellent in transparency, light resistance, and adhesion to a substrate can be provided. Since the polyimide film has the above properties, the polyimide resin composition of the present invention is useful as a raw material for a film for an optical filter.

[0009] [Polyimide Resin Composition] The polyimide resin composition of the present invention contains a polyimide resin (I) containing repeating units represented by the following formula (1), at least one compound (S) selected from the group consisting of silsesquioxane compounds (S1) and phenylalkoxysilanes (S2), and an organic solvent, wherein the content of compound (S) is 1 to 45 parts by mass per 100 parts by mass of the polyimide resin (I). In other words, the polyimide resin composition of the present invention contains a polyimide resin (I), a compound (S), and an organic solvent, wherein the content of compound (S) is 1 to 45 parts by mass per 100 parts by mass of the polyimide resin (I), the polyimide resin (I) contains repeating units represented by the following formula (1), and the compound (S) is at least one selected from the group consisting of silsesquioxane compounds (S1) and phenylalkoxysilanes (S2). (In formula (1), X is a tetravalent aliphatic or aromatic group having 4 to 39 carbon atoms, Y is a divalent aromatic group having 4 to 39 carbon atoms, and Y includes at least one selected from the group consisting of divalent groups represented by formula (2) and divalent groups represented by formula (3). In formula (2), Z is an aliphatic group having 1 to 8 carbon atoms, and n is 0 to 2.)

[0010] The reason why a polyimide film with excellent transparency, light resistance, and adhesion to the substrate can be obtained by using the polyimide resin composition of the present invention is not entirely clear, but it is thought to be as follows: The polyimide resin containing the repeating unit represented by formula (1) is thought to exhibit the transparency of the silsesquioxane compound, etc., because the silsesquioxane compound obtained from phenylalkoxysilane is uniformly miscible in the polyimide resin, and the resulting polyimide film is thought to have high transparency. Furthermore, it is thought that the transparency of the polyimide film improves the transmittance of ultraviolet rays, and the silsesquioxane compound, etc., traps radical species generated by ultraviolet rays, thereby preventing degradation of the resin and enabling it to have high light resistance. Adhesion to the substrate is thought to be achieved by the aromatic groups of the silsesquioxane compound, etc., forming interactions with the polyimide resin, and further by the hydroxyl groups (silanol groups) of the silsesquioxane compound forming interactions or chemical bonds with the substrate. The aforementioned "silsesquioxane compounds, etc." include silsesquioxane compounds, polydiphenylsiloxanes, polyalkylphenylsiloxanes, and compounds having an Si-O skeleton that possesses both a siloxane structure and a silsesquioxane structure.

[0011] <Polyimide resin (I)> The polyimide resin (I) contained in the polyimide resin composition of the present invention contains repeating units represented by the following formula (1). (In formula (1), X is a tetravalent aliphatic or aromatic group having 4 to 39 carbon atoms, Y is a divalent aromatic group having 4 to 39 carbon atoms, and Y includes at least one selected from the group consisting of divalent groups represented by formula (2) and divalent groups represented by formula (3). In formula (2), Z is an aliphatic group having 1 to 8 carbon atoms, and n is 0 to 2.) The polyimide resin (I) contained in the polyimide film described later is the same as the polyimide resin (I) described in this section, and the preferred polyimide resin is also the same.

[0012] In polyimide resin, a "repeating unit" refers to an imide unit containing a constituent unit derived from one tetracarboxylic dianhydride and a constituent unit derived from one diamine. In formula (1), X is a tetravalent aliphatic or aromatic group having 4 to 39 carbon atoms, preferably a tetravalent aliphatic or aromatic group having 6 to 12 carbon atoms, and more preferably a tetravalent aliphatic group having 6 carbon atoms. By having X be the aforementioned group, the transparency, light resistance, and adhesion to the substrate of the resulting polyimide film can be further enhanced. In this specification, an aromatic group means a group containing one or more aromatic rings, and an aliphatic group means a group that does not contain aromatic rings.

[0013] In formula (1), Y is a divalent aromatic group having 4 to 39 carbon atoms, and Y includes at least one selected from the group consisting of divalent groups represented by formula (2) and divalent groups represented by formula (3). Preferably, Y includes a divalent group represented by formula (3). By including a divalent group represented by formula (3) in Y, the transparency, light resistance, and adhesion to the substrate of the resulting polyimide film can be further improved.

[0014] When Y contains a divalent group represented by formula (2) and a divalent group represented by formula (3), the molar ratio of the divalent group represented by formula (2) to the divalent group represented by formula (3) in Y (formula (2) / formula (3)) is preferably 20 / 80 to 90 / 10, more preferably 30 / 70 to 70 / 30, even more preferably 40 / 60 to 60 / 40, and even more preferably 45 / 55 to 55 / 45.

[0015] In formula (2), Z is an aliphatic group having 1 to 8 carbon atoms, preferably an aliphatic group having 1 to 3 carbon atoms, and more preferably an aliphatic group having 3 carbon atoms. In formula (2), n is 0 to 2, preferably 0 or 1, and more preferably 1. Note that n is an integer. The divalent group represented by formula (2) having the above structure can further improve the transparency, light resistance, and adhesion to the substrate of the resulting polyimide film.

[0016] The ratio of the total divalent group represented by formula (2) to the divalent group represented by formula (3) in Y is preferably 70 mol% or more and 100 mol% or less. More preferably 80 mol% or more and 100 mol% or less, even more preferably 90 mol% or more and 100 mol% or less, even more preferably 95 mol% or more and 100 mol% or less, and even more preferably 99 mol% or more and 100 mol% or less.

[0017] In formula (1), X preferably includes at least one selected from the group consisting of a tetravalent group represented by the following formula (5) and a tetravalent group represented by the following formula (6), more preferably includes a tetravalent group represented by the following formula (5) or a tetravalent group represented by the following formula (6), and even more preferably includes a tetravalent group represented by the following formula (5).

[0018] The total ratio of the tetravalent group represented by formula (5) and the tetravalent group represented by formula (6) in X is preferably 40 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, even more preferably 70 mol% or more, even more preferably 80 mol% or more, and even more preferably 90 mol% or more, from the viewpoint of obtaining a polyimide film with excellent transparency, light resistance, and adhesion to the substrate. The upper limit is 100 mol% or less.

[0019] The ratio of the tetravalent group represented by formula (5) in X is preferably 40 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, even more preferably 70 mol% or more, even more preferably 80 mol% or more, and even more preferably 90 mol% or more, from the viewpoint of obtaining a polyimide film with excellent transparency, light resistance, and adhesion to the substrate. The upper limit is 100 mol% or less.

[0020] <Constituent Units of Polyimide Resin> The polyimide resin contains repeating units represented by formula (1), and the constituent units of the resin are described below.

[0021] The polyimide resin preferably has constituent units A derived from tetracarboxylic dianhydride and constituent units B derived from diamine. In the polyimide resin, constituent units A and B form an imide structure. Since the polyimide resin contains repeating units represented by formula (1), it is preferable that constituent unit A includes constituent unit (A1) derived from a compound represented by the following formula (a1), and constituent unit B includes at least one selected from the group consisting of constituent unit (B2) derived from a compound represented by the following formula (b2) and constituent unit (B3) derived from a compound represented by the following formula (b3). (In formula (a1), X is a tetravalent aliphatic or aromatic group having 4 to 39 carbon atoms. In formula (b2), Z is an aliphatic group having 1 to 8 carbon atoms, and n is 0 to 2.)

[0022] (Constituent Unit A) Constituent unit A is a constituent unit derived from a tetracarboxylic dianhydride, and preferably is a constituent unit (A1) derived from the compound represented by formula (a1). Constituent unit A is preferably a constituent unit derived from a tetracarboxylic dianhydride having a tetravalent aliphatic group or aromatic group having 4 to 39 carbon atoms. Note that the tetravalent aliphatic group having 4 to 39 carbon atoms includes those having a cyclic structure.

[0023] The constituent unit (A1) includes constituent units derived from aromatic tetracarboxylic dianhydrides, constituent units derived from alicyclic tetracarboxylic dianhydrides, and constituent units derived from aliphatic tetracarboxylic dianhydrides. Preferably, it is at least one selected from the group consisting of constituent units derived from aromatic tetracarboxylic dianhydrides and constituent units derived from alicyclic tetracarboxylic dianhydrides, and more preferably, it is a constituent unit derived from alicyclic tetracarboxylic dianhydrides. In this specification, aromatic tetracarboxylic dianhydrides mean tetracarboxylic dianhydrides containing one or more aromatic rings, alicyclic tetracarboxylic dianhydrides mean tetracarboxylic dianhydrides containing one or more alicyclic rings but not aromatic rings, and aliphatic tetracarboxylic dianhydrides mean tetracarboxylic dianhydrides containing neither aromatic rings nor alicyclic rings.

[0024] Examples of the alicyclic tetracarboxylic dianhydride that provides a structural unit derived from an alicyclic tetracarboxylic dianhydride include cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA), dicyclohexyl-3,4,3',4'-tetracarboxylic dianhydride (H-BPDA), cyclohexane-1,2,3,4-tetracarboxylic dianhydride, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5',6,6'-tetracarboxylic anhydride (CpODA), 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclopentanetetracarboxylic dianhydride, 3,3',4,4'-bicyclohexyltetracarboxylic dianhydride, 2,2-propylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo[4.4.0]decane-2,3,6,7-tetracarboxylic dianhydride, and the like. Preferably, it is cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA).

[0025] Aromatic tetracarboxylic dianhydrides that provide constituent units derived from aromatic tetracarboxylic dianhydrides include 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, biphenyltetracarboxylic dianhydride (BPDA), 4,4'-oxydiphthalic anhydride (ODPA), and 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride (DSD). A) 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), pyromellitic anhydride (PMDA), 4,4-bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-ylcarbonyloxy)biphenyl (BP-TME), 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorenodioanhydride (BPF-PA), 2,3,6,7-naphthalenetetracarboxylic acid 2,3 : 6,7-dianhydride (NTCDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 9,9-bis(trifluoromethyl)-9H-xanthene-2,3,6,7-tetracarboxylic dianhydride (6FCDA), 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, 9,9' Examples include bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), hydroquinone diphthalic anhydride (HQDEA), ethylene glycol bis(trimellitate) dianhydride (TMEG), p-phenylene bis(trimellitate) dianhydride (TAHQ), and the like, with 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride being preferred.

[0026] Examples of the aliphatic tetracarboxylic dianhydrides include 1,2,3,4-butanetetracarboxylic dianhydride. Among these, the structural unit (A1) preferably contains at least one selected from the group consisting of the structural unit (A5) derived from the compound represented by the following formula (a5) and the structural unit (A6) derived from the compound represented by the following formula (a6), and more preferably contains the structural unit (A5) derived from the compound represented by the following formula (a5). The structural unit (A1) is more preferably at least one selected from the group consisting of the structural unit (A5) derived from the compound represented by the following formula (a5) and the structural unit (A6) derived from the compound represented by the following formula (a6), and still more preferably is the structural unit (A5) derived from the compound represented by the following formula (a5). The compound represented by the formula (a5) is cyclohexane-1,2,4,5-tetracarboxylic dianhydride (HPMDA). By using the structural unit (A5) derived from the compound represented by the formula (a5) as a structural unit of the polyimide resin, the transparency, light resistance, and adhesion to the substrate of the obtained polyimide film can be further enhanced. The compound represented by the formula (a6) is 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride. By using the structural unit (A6) derived from the compound represented by the formula (a6) as a structural unit of the polyimide resin, the transparency, light resistance, and adhesion to the substrate of the obtained polyimide film can be further enhanced.

[0027] From the viewpoint of obtaining a polyimide film excellent in transparency, light resistance, and adhesion to the substrate, the ratio of the structural unit (A1) in the structural unit A is preferably 40 mol% or more, more preferably 50 mol% or more, still more preferably 60 mol% or more, even more preferably 70 mol% or more, even more preferably 80 mol% or more, and even more preferably 90 mol% or more. The upper limit is 100 mol% or less. The structural unit A may consist only of the structural unit (A1).

[0028] The ratio of the total of constituent units (A5) and (A6) within constituent unit (A1) is preferably 40 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, even more preferably 70 mol% or more, even more preferably 80 mol% or more, and even more preferably 90 mol% or more, from the viewpoint of obtaining a polyimide film with excellent transparency, light resistance, and adhesion to the substrate. The upper limit is 100 mol% or less.

[0029] From the viewpoint of obtaining a polyimide film with excellent transparency, light resistance, and adhesion to the substrate, the ratio of constituent unit (A5) to constituent unit (A1) is preferably 40 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, even more preferably 70 mol% or more, even more preferably 80 mol% or more, and even more preferably 90 mol% or more. The upper limit is 100 mol% or less.

[0030] Constituent unit A may include constituent units other than constituent unit (A1). Such constituent units are not particularly limited, but include constituent units derived from aromatic tetracarboxylic dianhydrides other than constituent unit (A1), constituent units derived from alicyclic tetracarboxylic dianhydrides other than constituent unit (A1), and constituent units derived from aliphatic tetracarboxylic dianhydrides other than constituent unit (A1).

[0031] (Constituent Unit B) Constituent unit B preferably includes at least one selected from the group consisting of constituent unit (B2) derived from the compound represented by formula (b2) and constituent unit (B3) derived from the compound represented by formula (b3), and more preferably includes constituent unit (B3) derived from the compound represented by formula (b3). Constituent unit B is more preferably at least one selected from the group consisting of constituent unit (B2) derived from the compound represented by formula (b2) and constituent unit (B3) derived from the compound represented by formula (b3), and even more preferably is constituent unit (B3) derived from the compound represented by formula (b3). By using at least one selected from the group consisting of constituent unit (B2) and constituent unit (B3) as a constituent unit of the polyimide resin, the transparency, light resistance, and adhesion to the substrate of the resulting polyimide film can be further improved.

[0032] In formula (b2), Z is an aliphatic group having 1 to 8 carbon atoms, and n is 0 to 2. In formula (b2), Z is an aliphatic group having 1 to 8 carbon atoms, preferably an aliphatic group having 1 to 3 carbon atoms, and more preferably an aliphatic group having 3 carbon atoms. In formula (b2), n is 0 to 2, preferably 0 or 1, and more preferably 1. n is an integer. The compound represented by formula (b2) having the above structure can further improve the transparency, light resistance, and adhesion to the substrate of the resulting polyimide film.

[0033] Examples of constituent units (B2) include 1,3-bis[2-(3-aminophenyl)-2-propyl]benzene, 1,3-bis[2-(3-aminophenyl)-2-hexafluoropropyl]benzene, 2,2-bis(4-aminophenyl)hexafluoropropane (HFDA), 4,4'-diaminodiphenylmethane (DDM), 2,2-bis(3-aminophenyl)propane, 2,2-bis(4-aminophenyl)propane, 1,3-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene (BisAM), 1,4-bis(4-amino-α,α-dimethylbenzyl)benzene (BisAP), and the like, with 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene (BisAM) being preferred.

[0034] Examples of constituent units (B3) include 5-amino-1,3,3-trimethyl-1-(4-aminophenyl)-indan (TMDA) and 6-amino-1,3,3-trimethyl-1-(4-aminophenyl)-indan (6-TMDM), with 5-amino-1,3,3-trimethyl-1-(4-aminophenyl)-indan (TMDA) being preferred.

[0035] When constituent unit B includes constituent unit (B2) and constituent unit (B3), the molar ratio ((B2) / (B3)) of constituent unit (B2) to constituent unit (B3) in constituent unit B is preferably 20 / 80 to 90 / 10, more preferably 30 / 70 to 70 / 30, even more preferably 40 / 60 to 60 / 40, and even more preferably 45 / 55 to 55 / 45.

[0036] The ratio of the total of constituent units (B2) and constituent units (B3) in constituent unit B is preferably 70 mol% or more and 100 mol% or less. More preferably it is 80 mol% or more and 100 mol% or less, even more preferably 90 mol% or more and 100 mol% or less, even more preferably 95 mol% or more and 100 mol% or less, and even more preferably 99 mol% or more and 100 mol% or less.

[0037] Constituent unit B may include constituent units other than constituent units (B2) and (B3). Such constituent units are not particularly limited, but include constituent units derived from aromatic diamines other than constituent units (B2) and (B3), constituent units derived from alicyclic diamines, and constituent units derived from aliphatic diamines. Aromatic diamines that give constituent units derived from aromatic diamines other than constituent units (B2) and (B3) include bis[4-(3-aminophenoxy)phenyl]sulfone (BAPS-M), 1,3-bis(3-aminophenoxy)benzene (TPE-M), 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA), and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (2,2'-TFMB), 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-5,5'-diaminobiphenyl, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (HFBAPP), 4,4'-diaminodiphenyl ether (4,4'-ODA), 3,4' -diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone (4,4'-DDS), 3,3'-diaminodiphenyl sulfone (3,3'-DDS), 4,4'-diamino-2,2'-dimethylbiphenyl (mTB), 9,9-bis(4-aminophenyl)fluorene (BAFL), 4,4'-diaminobiphenyl (benzidine), 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diaminodiphenyl sulfone Fido, 4,4'-diaminobenzophenone, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl (BODA), 1,1-bis[4-(4-aminophenoxy)phenyl]cyclohexane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1,Examples include 3-bis(4-aminophenoxy)benzene, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]sulfone, 4,4-diaminobenzanilide, 4-aminobenzoic acid-4-aminophenyl, 3,4-diaminobenzanilide, etc. Examples of alicyclic diamines include 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), 1,4-bis(aminomethyl)cyclohexane, 1,3-cyclohexyldiamine, 1,4-cyclohexyldiamine, isophoronediamine, bis(aminomethyl)norbornane, 4,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexyl ether, and 2,2-bis(4-aminocyclohexyl)propane. Examples of aliphatic diamines include ethylenediamine and hexamethylenediamine.

[0038] In this specification, aromatic diamine means a diamine containing one or more aromatic rings, alicyclic diamine means a diamine containing one or more alicyclic rings but not an aromatic ring, and aliphatic diamine means a diamine that does not contain either an aromatic ring or an alicyclic ring. The constituent units optionally included in constituent unit B may be one type or two or more types.

[0039] (Method for producing polyimide resin) The polyimide resin may be produced by any method, but the following method is preferred. There are no particular restrictions on the method of reacting the tetracarboxylic acid component and the diamine component in this production method, and known methods can be used. Specific reaction methods include: (1) charging the tetracarboxylic acid component, the diamine component, and an organic solvent into a reactor, stirring at 0 to 80°C for 0.5 to 30 hours, and then raising the temperature to carry out the imidation reaction; (2) charging the diamine component and an organic solvent into a reactor and dissolving them, then charging the tetracarboxylic acid component, stirring at 10 to 110°C for 0.5 to 30 hours as needed, and then raising the temperature to carry out the imidation reaction; and (3) charging the tetracarboxylic acid component, the diamine component, and an organic solvent into a reactor and immediately raising the temperature to carry out the imidation reaction.

[0040] In the imidation reaction, it is preferable to carry out the reaction while removing the water generated during production using a Dean-Stark apparatus or similar device. By performing such an operation, the degree of polymerization and the imidation rate can be further increased.

[0041] In the above imidation reaction, known imidation catalysts can be used. Examples of imidation catalysts include base catalysts and acid catalysts. Examples of base catalysts include organic base catalysts such as pyridine, quinoline, isoquinoline, α-picoline, β-picoline, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethylamine, tripropylamine, tributylamine, triethylenediamine, imidazole, N,N-dimethylaniline, N,N-diethylaniline, and 1,4-diazabicyclo[2.2.2]octane; and inorganic base catalysts such as potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate. Examples of acid catalysts include crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, methylbenzoic acid, oxybenzoic acid, terephthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, and naphthalenesulfonic acid. The above imidation catalysts may be used alone or in combination of two or more. Of the above, from the viewpoint of ease of handling, a base catalyst is preferred, an organic base catalyst is more preferred, one or more selected from triethylamine, 1,4-diazabicyclo[2.2.2]octane and triethylenediamine is even more preferred, one or more selected from triethylamine and 1,4-diazabicyclo[2.2.2]octane is even more preferred, triethylamine is even more preferred, and the combined use of triethylamine and 1,4-diazabicyclo[2.2.2]octane is even more preferred.

[0042] The temperature of the imidation reaction is preferably 120 to 250°C, more preferably 160 to 200°C, from the viewpoint of the reaction rate and suppression of gelation, etc. The reaction time is preferably 0.5 to 10 hours after the start of distillation of the generated water. Furthermore, the amount of the diamine component relative to the amount of the tetracarboxylic acid component is preferably 0.9 to 1.1 moles.

[0043] By the above method, a polyimide resin solution is obtained in which a polyimide resin having an imide structure is dissolved in a solvent. The concentration of the polyimide resin in the obtained solution is preferably 1 to 50% by mass, more preferably 3 to 35% by mass, and even more preferably 5 to 30% by mass.

[0044] The number-average molecular weight of the polyimide resin obtained by the above manufacturing method is preferably 5,000 to 500,000, from the viewpoint of the mechanical strength of the resulting polyimide film. Similarly, the weight-average molecular weight (Mw) is preferably 10,000 to 800,000, and more preferably 100,000 to 300,000. Next, the raw materials used in this manufacturing method will be described.

[0045] [Tetracarboxylic Acid Component] The tetracarboxylic acid component used as a raw material in this manufacturing method is preferably a tetracarboxylic dianhydride as described in the section on (constituent unit A) above. The tetracarboxylic dianhydride used as the tetracarboxylic acid component in this manufacturing method may be in any form: dianhydride, tetracarboxylic acid (free acid), or alkyl ester of tetracarboxylic acid, but is preferably a dianhydride. The tetracarboxylic acid component used as a raw material in this manufacturing method includes at least one compound represented by formula (a1) (a compound that gives constituent unit (A1)). Furthermore, it is preferable that the compound represented by formula (a1) includes at least one selected from the group consisting of the compound represented by formula (a5) (a compound that gives constituent unit (A5)) and the compound represented by formula (a6) (a compound that gives constituent unit (A6)).

[0046] The tetracarboxylic acid component may include tetracarboxylic acid components other than the compound represented by formula (a1). Such tetracarboxylic acid components are not particularly limited, but include aromatic tetracarboxylic dianhydrides other than the compound represented by formula (a1), alicyclic tetracarboxylic dianhydrides other than the compound represented by formula (a1), and aliphatic tetracarboxylic dianhydrides. Specific examples of tetracarboxylic acid components other than the compound represented by formula (a1) include the tetracarboxylic dianhydrides described in the section (Constituent Unit A) above. One tetracarboxylic acid component may be used, or two or more may be used.

[0047] [Diamine component] The diamine component used as a raw material in this manufacturing method is preferably the diamine described in the section (constituent unit B) above. The diamine used as a raw material in this manufacturing method may be in the form of a diamine or a diisocyanate corresponding to a diamine, but it is preferably a diamine. The diamine component used as a raw material in this manufacturing method preferably includes at least one selected from the group consisting of a compound represented by formula (b2) (a compound that gives constituent unit (B2)) and a compound represented by formula (b3) (a compound that gives constituent unit (B3)).

[0048] The diamine component may include diamine components other than the compound represented by formula (b2) and the compound represented by formula (b3). Such diamine components are not particularly limited, but include aromatic diamines, alicyclic diamines, and aliphatic diamines other than the compound represented by formula (b2) and the compound represented by formula (b3). Specific examples of diamine components other than the compound represented by formula (b2) and the compound represented by formula (b3) include the diamines described in the section (Constituent Unit B) above. One type of diamine component may be used, or two or more types may be used.

[0049] [End-Sealing Agent] In addition to the tetracarboxylic acid component and diamine component mentioned above, an end-sealing agent may also be used in the production of polyimide resin. Monoamines or dicarboxylic acids are preferred as end-sealing agents. The amount of end-sealing agent to be introduced is preferably 0.0001 to 0.1 moles, and more preferably 0.001 to 0.06 moles, per mole of tetracarboxylic acid component. Examples of monoamine end-sealing agents include methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, 3-methylbenzylamine, 3-ethylbenzylamine, aniline, 3-methylaniline, and 4-methylaniline. Of these, benzylamine and aniline are preferred. Dicarboxylic acid end-sealing agents are preferred, and a portion of them may be ring-closed. Examples include phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, 2,3-benzophenone dicarboxylic acid, 3,4-benzophenone dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, and 4-cyclohexene-1,2-dicarboxylic acid. Of these, phthalic acid and phthalic anhydride are more preferred.

[0050] [Organic solvents used in the production of polyimide resin] The organic solvent used in the production of the polyimide resin can be any solvent that can dissolve the polyimide resin to be produced. Examples include amide solvents, lactone solvents, phosphorus-containing solvents, sulfur-containing solvents, ketone solvents, ester solvents, phenol solvents, ether solvents, carbonate solvents, etc.

[0051] Specific examples of amide solvents include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 1,3-dimethylimidazolidinone, and tetramethylurea. Specific examples of lactone solvents include γ-butyrolactone and γ-valerolactone. Specific examples of phosphorus-containing solvents include hexamethylphosphoricamide and hexamethylphosphinetriamide. Specific examples of sulfur-containing solvents include dimethyl sulfone, dimethyl sulfoxide, and sulfolane. Specific examples of ketone solvents include acetone, methyl ethyl ketone, cyclohexanone, and methylcyclohexanone. Specific examples of ester solvents include acetic acid (2-methoxy-1-methylethyl).

[0052] Specific examples of phenolic solvents include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, and 3,5-xylenol. Specific examples of etheric solvents include 1,2-dimethoxyethane, bis(2-methoxyethyl) ether, 1,2-bis(2-methoxyethoxy)ethane, bis[2-(2-methoxyethoxy)ethyl] ether, tetrahydrofuran, and 1,4-dioxane. Specific examples of carbonateic solvents include diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, and propylene carbonate. Among the above organic solvents, amide solvents or lactone solvents are preferred, lactone solvents are more preferred, and γ-butyrolactone is even more preferred. The above solvents may be used individually or in combination of two or more.

[0053] <Organic solvent> The polyimide resin composition of the present invention contains a polyimide resin (I), at least one compound (S) selected from the group consisting of a silsesquioxane compound (S1) and a phenylalkoxysilane (S2), and an organic solvent. That is, the polyimide resin (I) and compound (S) are dissolved in the organic solvent. The organic solvent is not particularly limited, as long as it is capable of dissolving the polyimide resin (I) and compound (S), but it is preferable to use the above-mentioned compounds alone or in a mixture of two or more as the solvent used in the production of the polyimide resin (I). The polyimide resin composition of the present invention may be obtained by adding compound (S) to the above-mentioned polyimide resin solution after the production of the polyimide resin (I), or by further mixing compound (S) and a diluent solvent with the polyimide resin solution.

[0054] Examples of organic solvents contained in the polyimide resin composition of the present invention include amide solvents, lactone solvents, phosphorus-containing solvents, sulfur-containing solvents, ketone solvents, ester solvents, phenol solvents, ether solvents, and carbonate solvents.

[0055] Specific examples of amide solvents include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 1,3-dimethylimidazolidinone, and tetramethylurea. Specific examples of lactone solvents include γ-butyrolactone and γ-valerolactone. Specific examples of phosphorus-containing solvents include hexamethylphosphoricamide and hexamethylphosphinetriamide. Specific examples of sulfur-containing solvents include dimethyl sulfone, dimethyl sulfoxide, and sulfolane. Specific examples of ketone solvents include acetone, methyl ethyl ketone, cyclohexanone, and methylcyclohexanone. Specific examples of ester solvents include acetic acid (2-methoxy-1-methylethyl).

[0056] Specific examples of phenolic solvents include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, and 3,5-xylenol. Specific examples of etheric solvents include 1,2-dimethoxyethane, bis(2-methoxyethyl) ether, 1,2-bis(2-methoxyethoxy)ethane, bis[2-(2-methoxyethoxy)ethyl] ether, tetrahydrofuran, and 1,4-dioxane. Specific examples of carbonateic solvents include diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, and propylene carbonate. Among the above organic solvents, amide solvents or lactone solvents are preferred, lactone solvents are more preferred, and γ-butyrolactone is even more preferred. The above organic solvents may be used individually or in combination of two or more.

[0057] <Compound (S)> The polyimide resin composition of the present invention contains at least one compound (S) selected from the group consisting of silsesquioxane compounds (S1) and phenylalkoxysilanes (S2).

[0058] The content of compound (S) per 100 parts by mass of the polyimide resin (I) is 1 to 45 parts by mass. That is, the total content of silsesquioxane compound (S1) and phenylalkoxysilane (S2) per 100 parts by mass of the polyimide resin (I) is 1 to 45 parts by mass. The content of compound (S) per 100 parts by mass of the polyimide resin (I) is preferably 2 to 45 parts by mass, more preferably 3 to 45 parts by mass, even more preferably 5 to 45 parts by mass, even more preferably 10 to 45 parts by mass, even more preferably 15 to 45 parts by mass, even more preferably 25 to 45 parts by mass, and even more preferably 35 to 45 parts by mass. By having the content of compound (S) per 100 parts by mass of the polyimide resin (I) within the above range, the resulting polyimide film will have excellent transparency, light resistance, and adhesion to the substrate. Furthermore, from the viewpoint of further improving the transparency (haze) of the obtained polyimide film, the content of compound (S) per 100 parts by mass of polyimide resin (I) is preferably 2 to 45 parts by mass, more preferably 3 to 45 parts by mass, even more preferably 3 to 35 parts by mass, even more preferably 3 to 25 parts by mass, and even more preferably 5 to 25 parts by mass.

[0059] (Silsesquioxane compound (S1)) The polyimide resin composition of the present invention contains a silsesquioxane compound (S1), which makes it possible to obtain a polyimide film with excellent transparency, light resistance, and adhesion to the substrate. Furthermore, since the silsesquioxane compound (S1) retains the structure of the silsesquioxane compound even after the polyimide film is manufactured, it is preferable that a film can be obtained that does not degas during film formation, is smooth, and does not contain air bubbles or other impurities. The molecular weight of the silsesquioxane compound (S1) is preferably 300 to 6000, more preferably 500 to 6000, even more preferably 600 to 6000, even more preferably 700 to 5000, even more preferably 800 to 5000, even more preferably 900 to 5000, even more preferably 1000 to 4000, and even more preferably 1000 to 2000 from the viewpoint of ease of handling. By having the molecular weight of the silsesquioxane compound (S1) within the above range, the resulting polyimide film exhibits excellent transparency, light resistance, and adhesion to the substrate.

[0060] Furthermore, if the silsesquioxane compound (S1) has a random or ladder-type structure, the molecular weight of the silsesquioxane compound (S1) is the weight-average molecular weight obtained by gel filtration chromatography, converted to standard polystyrene (PS). Also, if the silsesquioxane compound has a cage-type structure, since most molecules have a single structure (molecular weight), the molecular weight of the silsesquioxane compound (S1) is the molecular weight calculated from the molecular formula. When the silsesquioxane compound (S1) has a random structure or a ladder structure, the molecular weight of the silsesquioxane compound having a random structure or ladder structure is more preferably 600 to 6000, more preferably 700 to 5000, more preferably 800 to 5000, more preferably 900 to 5000, more preferably 1000 to 4000, and more preferably 1000 to 2000 from the standpoint of ease of handling. When the silsesquioxane compound (S1) has a cage-type structure, the molecular weight of the cage-type silsesquioxane compound (S1) is more preferably 600 to 6000, more preferably 600 to 4000, more preferably 600 to 2000, more preferably 600 to 1500, more preferably 700 to 1000, and more preferably 700 to 900 from the standpoint of availability. By having the molecular weight of the silsesquioxane compound (S1) within the above range, the resulting polyimide film will have excellent transparency, light resistance, and adhesion to the substrate.

[0061] The silsesquioxane compound (S1) is preferably a compound having a structural unit represented by the following formula (4a). (R 1 SiO 1.5 ) (4a) (In formula (4a), R 1 (This is at least one selected from the group consisting of hydroxyl groups, alkoxy groups, and aromatic groups.)

[0062] In equation (4a), R 1is at least one selected from the group consisting of a hydroxyl group, an alkoxy group, and an aromatic group, preferably R 1 R comprises a hydroxyl group or an alkoxy group, and more preferably R 1 It further contains an aromatic group. That is, R 1 It is preferable that it contains a hydroxyl group or an alkoxy group and an aromatic group, and more preferably a hydroxyl group or an alkoxy group and an aromatic group.

[0063] Examples of alkoxy groups include methoxy, ethoxy, propoxy, and butoxy groups, preferably methoxy or ethoxy groups, and more preferably ethoxy groups. Examples of aromatic groups include phenyl, tolyl, and xylyl groups, preferably phenyl or tolyl groups, and more preferably phenyl groups.

[0064] The silsesquioxane compound (S1) is more preferably a compound represented by the following compositional formula (4). Note that compositional formula (4) is a compositional formula showing the main skeletal portion of the silsesquioxane compound, and the molecular terminus of the silsesquioxane compound may contain a portion to which two or three hydroxyl groups, alkoxy groups, or aromatic groups are bonded to a silicon atom. [R 1 SiO 1.5 ] m (4) (In formula (4), R 1 m is at least one selected from the group consisting of hydroxyl groups, alkoxy groups, and aromatic groups, and m is between 4 and 100. (m is the average value.)

[0065] In equation (4), R 1 is at least one selected from the group consisting of a hydroxyl group, an alkoxy group, and an aromatic group, preferably R 1 R comprises a hydroxyl group or an alkoxy group, and more preferably R 1 It further contains an aromatic group. That is, R 1 It is preferable that it contains a hydroxyl group or an alkoxy group and an aromatic group, and more preferably a hydroxyl group or an alkoxy group and an aromatic group.

[0066] Examples of alkoxy groups include methoxy, ethoxy, propoxy, and butoxy groups, preferably methoxy or ethoxy groups, and more preferably ethoxy groups. Examples of aromatic groups include phenyl, tolyl, and xylyl groups, preferably phenyl or tolyl groups, and more preferably phenyl groups.

[0067] In formula (4), m is 4 to 100, preferably 7 to 100, more preferably 8 to 80, even more preferably 9 to 80, even more preferably 10 to 70, even more preferably 13 to 50, and even more preferably 13 to 30. When the silsesquioxane compound (S1) contains multiple silsesquioxane compounds, m is the average value (corresponding to the number-average degree of polymerization).

[0068] The content of the silsesquioxane compound (S1) in the polyimide resin composition per 100 parts by mass of the polyimide resin (I) is preferably 1 to 45 parts by mass. The content of the silsesquioxane compound (S1) per 100 parts by mass of the polyimide resin (I) is more preferably 2 to 45 parts by mass, even more preferably 3 to 45 parts by mass, even more preferably 5 to 45 parts by mass, even more preferably 10 to 45 parts by mass, even more preferably 15 to 45 parts by mass, even more preferably 25 to 45 parts by mass, and even more preferably 35 to 45 parts by mass. By having the content of the silsesquioxane compound (S1) per 100 parts by mass of the polyimide resin (I) within the above range, the resulting polyimide film will have excellent transparency, light resistance, and adhesion to the substrate. Furthermore, from the viewpoint of further improving the transparency (haze) of the resulting polyimide film, the content of the silsesquioxane compound (S1) per 100 parts by mass of the polyimide resin (I) is preferably 2 to 45 parts by mass, more preferably 3 to 45 parts by mass, even more preferably 3 to 35 parts by mass, even more preferably 3 to 25 parts by mass, and even more preferably 5 to 25 parts by mass.

[0069] (Phenylalkoxysilane (S2)) By containing phenylalkoxysilane (S2) in the polyimide resin composition of the present invention, a polyimide film with excellent transparency, light resistance, and adhesion to the substrate can be obtained. When a polyimide film is produced from the polyimide resin composition, phenylalkoxysilane (S2) is converted into a silsesquioxane compound, etc., by de-alcoholization condensation. Therefore, the polyimide resin composition of the present invention may contain compounds other than phenylalkoxysilane (S2) that can serve as raw materials for silsesquioxane compounds, etc., but it is preferable that the compound that can serve as a raw material for silsesquioxane compounds, etc., is mainly phenylalkoxysilane (S2). Examples of compounds other than phenylalkoxysilane (S2) that can serve as raw materials for silsesquioxane compounds, etc., include tetraalkoxysilane, monoalkyltrialkoxysilane, dialkyldialkoxysilane, etc., and silanes containing silanol groups obtained by hydrolysis of the alkoxy group are also included in the above compounds. The aforementioned "silsesquioxane compounds, etc." include, in addition to silsesquioxane compounds, polydiphenylsiloxanes, polyalkylphenylsiloxanes, and compounds having an Si-O skeleton that possesses both a siloxane structure and a silsesquioxane structure. Preferably, the silsesquioxane compounds, etc. are at least one selected from the group consisting of, in addition to silsesquioxane compounds, polydiphenylsiloxanes, polyalkylphenylsiloxanes, and compounds having an Si-O skeleton that possesses both a siloxane structure and a silsesquioxane structure. More preferably, they are at least one selected from the group consisting of silsesquioxane compounds, polydiphenylsiloxanes, and polyalkylphenylsiloxanes. Even more preferably, they are at least one selected from the group consisting of silsesquioxane compounds and polydiphenylsiloxanes, and even more preferably, they are silsesquioxane compounds.The proportion of phenylalkoxysilane (S2) in the compounds that can be used as raw materials for silsesquioxane compounds, etc., is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 99% by mass or more, and may be 100% by mass, with 100% by mass being even more preferable. It is even more preferable that the compounds that can be used as raw materials for silsesquioxane compounds, etc., consist solely of phenylalkoxysilane (S2). Phenylalkoxysilane (S2) is preferable because it has excellent solubility in resin compositions, allowing for the acquisition of a homogeneous polyimide film.

[0070] Phenylalkoxysilane (S2) is preferably at least one selected from the group consisting of diphenyldialkoxysilane, monophenyltrialalkoxysilane (phenyltrialalkoxysilane), and alkylphenyldialkoxysilane, more preferably at least one selected from the group consisting of diphenyldialkoxysilane and monophenyltrialalkoxysilane, and even more preferably monophenyltrialalkoxysilane. The phenylalkoxysilane (S2) in the polyimide resin composition of the present invention also includes silanes containing silanol groups obtained by hydrolysis of the alkoxy group. Examples of alkoxy groups in phenylalkoxysilane (S2) include methoxy, ethoxy, propoxy, and butoxy groups, and is preferably at least one selected from the group consisting of methoxy and ethoxy groups, with methoxy being more preferable. Therefore, phenylalkoxysilane (S2) is more specifically preferably at least one selected from the group consisting of diphenyldimethoxysilane, monophenyltrimethoxysilane, phenyldiethoxysilane, and monophenyltriethoxysilane, more preferably at least one selected from the group consisting of diphenyldimethoxysilane and monophenyltrimethoxysilane, and even more preferably monophenyltrimethoxysilane. By including the above compound as phenylalkoxysilane (S2) in the polyimide resin composition, the resulting polyimide film exhibits excellent transparency, light resistance, and adhesion to the substrate.

[0071] The content of phenylalkoxysilane (S2) in the polyimide resin composition per 100 parts by mass of the polyimide resin (I) is preferably 1 to 45 parts by mass. The content of phenylalkoxysilane (S2) per 100 parts by mass of the polyimide resin (I) is more preferably 2 to 45 parts by mass, even more preferably 3 to 45 parts by mass, even more preferably 5 to 45 parts by mass, even more preferably 10 to 45 parts by mass, even more preferably 15 to 45 parts by mass, even more preferably 25 to 45 parts by mass, and even more preferably 35 to 45 parts by mass. By having the content of phenylalkoxysilane (S2) per 100 parts by mass of the polyimide resin (I) within the above range, the resulting polyimide film will have excellent transparency, light resistance, and adhesion to the substrate. Furthermore, from the viewpoint of further improving the transparency (haze) of the resulting polyimide film, the content of phenylalkoxysilane (S2) per 100 parts by mass of polyimide resin (I) is preferably 2 to 45 parts by mass, more preferably 3 to 45 parts by mass, even more preferably 3 to 35 parts by mass, even more preferably 3 to 25 parts by mass, and even more preferably 5 to 25 parts by mass.

[0072] <Composition and properties of the polyimide resin composition> The polyimide resin composition of the present invention contains a polyimide resin (I) comprising repeating units represented by formula (1), at least one compound (S) selected from the group consisting of silsesquioxane compounds (S1) and phenylalkoxysilanes (S2), and an organic solvent.

[0073] The solid content concentration of the polyimide resin composition (total of polyimide resin (I) and compound (S)) is preferably 3 to 50% by mass, more preferably 5 to 45% by mass, even more preferably 10 to 40% by mass, even more preferably 15 to 40% by mass, even more preferably 20 to 35% by mass, and even more preferably 20 to 30% by mass. Since the polyimide resin is solvent-soluble, it can be made into a stable, high-concentration solution at room temperature, and by using the above concentration, a polyimide film of a thickness suitable for optical filter applications can be efficiently obtained.

[0074] The content of the organic solvent in the polyimide resin composition is preferably 50 to 97% by mass, more preferably 55 to 95% by mass, even more preferably 60 to 90% by mass, even more preferably 60 to 85% by mass, even more preferably 65 to 80% by mass, and even more preferably 70 to 80% by mass. Since the polyimide resin is solvent-soluble, it can be made into a stable, high-concentration solution at room temperature, and by adjusting the content of the organic solvent, a polyimide film of a thickness suitable for optical filter applications can be efficiently obtained.

[0075] The viscosity of the polyimide resin composition is preferably 0.1 to 100 Pa·s, and more preferably 0.1 to 20 Pa·s. The viscosity of the polyimide resin composition is the value measured at 25°C using an E-type viscometer. Furthermore, the polyimide resin composition of the present invention may contain various additives such as inorganic fillers, adhesion promoters, release agents, flame retardants, ultraviolet stabilizers, surfactants, leveling agents, defoaming agents, fluorescent whitening agents, crosslinking agents, polymerization initiators, and photosensitive agents, to the extent that they do not impair the required properties of the resulting polyimide film. The method for producing the polyimide resin composition of the present invention is not particularly limited, and known methods can be applied. For example, it can be obtained by adding compound (S) to a solution of polyimide resin obtained by the above-described production method, and adjusting the concentration by mixing in further organic solvents as needed.

[0076] [Polyimide Film] The polyimide film of the present invention preferably contains a polyimide resin (I) having repeating units represented by the following formula (1), and a silsesquioxane compound (S3), wherein the content of the silsesquioxane compound (S3) is 1 to 45 parts by mass per 100 parts by mass of the polyimide resin (I). (In formula (1), X is a tetravalent aliphatic or aromatic group having 4 to 39 carbon atoms, Y is a tetravalent aromatic group having 4 to 39 carbon atoms, and Y includes at least one selected from the group consisting of divalent groups represented by formula (2) and divalent groups represented by formula (3). In formula (2), Z is an aliphatic group having 1 to 8 carbon atoms, and n is 0 to 2.)

[0077] The polyimide resin (I) contained in the polyimide film of the present invention is the same as the polyimide resin (I) described in the section on [Polyimide Resin Composition], and the preferred polyimide resin (I) is also the same.

[0078] The silsesquioxane compound (S3) is the same as the silsesquioxane compound (S1) described in the section on [Polyimide Resin Composition], and the preferred silsesquioxane compound (S3) is also the same as the preferred silsesquioxane compound (S1) described in the section on [Polyimide Resin Composition].

[0079] The content of the silsesquioxane compound (S3) per 100 parts by mass of the polyimide resin (I) is 1 to 45 parts by mass. The content of the silsesquioxane compound (S3) per 100 parts by mass of the polyimide resin (I) is preferably 2 to 45 parts by mass, more preferably 3 to 45 parts by mass, even more preferably 5 to 45 parts by mass, even more preferably 10 to 45 parts by mass, even more preferably 15 to 45 parts by mass, even more preferably 25 to 45 parts by mass, and even more preferably 35 to 45 parts by mass. By having the content of the silsesquioxane compound (S3) per 100 parts by mass of the polyimide resin (I) within the above range, the polyimide film will have excellent transparency, light resistance, and adhesion to the substrate. Furthermore, from the viewpoint of further improving the transparency (haze) of the polyimide film, the content of the silsesquioxane compound (S3) per 100 parts by mass of the polyimide resin (I) is preferably 2 to 45 parts by mass, more preferably 3 to 45 parts by mass, even more preferably 3 to 35 parts by mass, even more preferably 3 to 25 parts by mass, and even more preferably 5 to 25 parts by mass.

[0080] The thickness of the polyimide film of the present invention can be appropriately selected depending on the application, but is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 7 μm or more. It is also preferably 250 μm or less, more preferably 100 μm or less, even more preferably 50 μm or less, and even more preferably 20 μm or less. Among these, it is even more preferable that the thickness of the polyimide film be between 1 μm and 20 μm. The thickness of the polyimide film being within the above range enables practical use as a self-supporting film. The thickness of the polyimide film can be easily controlled by adjusting the solid content concentration and viscosity of the polyimide resin composition.

[0081] The preferred physical properties of the polyimide film of the present invention are as follows: When the thickness of the polyimide film is 7 μm, the yellow index (YI) is preferably 0.59 or less, more preferably 0.55 or less, even more preferably 0.50 or less, and even more preferably 0.48 or less. When the thickness of the polyimide film is 7 μm, the haze is preferably 0.3 or less, more preferably 0.2 or less, and even more preferably 0.1 or less. The glass transition temperature (Tg) is preferably 240°C or higher, more preferably 300°C or higher, even more preferably 350°C or higher, even more preferably 370°C or higher, and even more preferably 380°C or higher. The above physical properties in the present invention can be specifically measured by the method described in the examples.

[0082] As described above, the polyimide film of the present invention is useful as a display film because it has excellent transparency, light resistance, and adhesion to the substrate. Therefore, the polyimide film of the present invention is preferably used for optical filters.

[0083] The polyimide film of the present invention also includes a polyimide film containing a polyimide resin (I) containing repeating units represented by the following formula (1), a silsesquioxane compound, etc., wherein the content of the silsesquioxane compound, etc. is 1 to 45 parts by mass per 100 parts by mass of the polyimide resin (I). The silsesquioxane compound, etc. is preferably a silsesquioxane compound, and more preferably a silsesquioxane compound (S3). A more preferred silsesquioxane compound is the same as silsesquioxane compound (S3).

[0084] In other words, the polyimide film of the present invention includes, in addition to a polyimide film containing the silsesquioxane compound (S3), a polyimide resin (I) containing at least one compound selected from the group consisting of polydiphenylsiloxane, polyalkylphenylsiloxane, and compounds having an Si-O skeleton having both a siloxane structure and a silsesquioxane structure, and a repeating unit represented by the following formula (1), wherein the content of the compound etc. per 100 parts by mass of the polyimide resin (I) is 1 to 45 parts by mass. (In formula (1), X is a tetravalent aliphatic or aromatic group having 4 to 39 carbon atoms, Y is a tetravalent aromatic group having 4 to 39 carbon atoms, and Y includes at least one selected from the group consisting of divalent groups represented by formula (2) and divalent groups represented by formula (3). In formula (2), Z is an aliphatic group having 1 to 8 carbon atoms, and n is 0 to 2.)

[0085] The at least one compound selected from the group consisting of polydiphenylsiloxane, polyalkylphenylsiloxane, and compounds having an Si-O skeleton having both a siloxane structure and a silsesquioxane structure, contained in the polyimide film, is preferably at least one compound selected from the group consisting of polydiphenylsiloxane and polyalkylphenylsiloxane, and more preferably polydiphenylsiloxane.

[0086] Polyimide films containing polydiphenylsiloxane can be obtained from a polyimide resin composition containing diphenyldialkoxysilane as the phenylalkoxysilane (S2). Polyimide films containing polyalkylphenylsiloxane can be obtained from a polyimide resin composition containing diphenyldialkoxysilane as the phenylalkoxysilane (S2), and also containing dialkyldialkoxysilane, alkylphenyldialkoxysilane, etc. Polyimide films containing compounds having an Si-O skeleton that has both a siloxane structure and a silsesquioxane structure can be obtained from a polyimide resin composition containing diphenyldialkoxysilane and monophenyltrialkoxysilane as the phenylalkoxysilane (S2), etc.

[0087] [Method for Manufacturing Polyimide Film] The polyimide film of the present invention is preferably manufactured using the polyimide resin composition described above. Specifically, the polyimide film of the present invention is preferably a polyimide film obtained by coating the polyimide resin composition onto a support and heating it. Therefore, the polyimide film of the present invention has excellent transparency, light resistance, and adhesion to the substrate.

[0088] There are no particular limitations on the method for producing a polyimide film using the polyimide resin composition, but preferably, the polyimide resin composition is applied to a support and heated. Examples of the support include glass plates, metal plates, and plastics. The support preferably has a smooth surface. After applying the polyimide resin composition to the support and forming it into a film, organic solvents such as reaction solvents and diluent solvents contained in the polyimide resin composition are removed by heating. If the polyimide resin composition contains phenylalkoxysilane (S2), it is further converted to a silsesquioxane compound or the like by de-alcoholization condensation, and then peeled off from the support to produce a polyimide film.

[0089] The heating temperature when drying the polyimide resin composition to obtain a polyimide film is preferably 100 to 350°C, more preferably 130 to 300°C. The heating time is usually 1 minute to 6 hours, preferably 5 minutes to 2 hours, more preferably 15 minutes to 1 hour. By using such temperatures and times, the physical properties of the resulting polyimide film will be good. Examples of heating atmospheres include air, nitrogen gas, oxygen gas, hydrogen gas, and nitrogen / hydrogen mixed gas. However, in order to suppress discoloration of the resulting polyimide film, nitrogen gas with an oxygen concentration of 100 ppm or less, and nitrogen / hydrogen mixed gas containing a hydrogen concentration of 0.5% or less are preferred.

[0090] As described above, the polyimide film obtained by the above manufacturing method is useful as a display film because it has excellent transparency, light resistance, and adhesion to the substrate. Therefore, the polyimide film obtained by the above manufacturing method is preferably used for optical filters.

[0091] The present invention will be specifically described below with reference to examples. However, the present invention is not limited in any way by these examples.

[0092] <Physical Properties and Evaluation of Polyimide Films> The physical properties of the films obtained in the examples and comparative examples were measured by the following methods. (1) Film Thickness The film thickness was measured using a micrometer manufactured by Mitutoyo Corporation.

[0093] (2) Glass transition temperature (Tg) Using a thermomechanical analyzer "TMA / SS6100" (manufactured by Hitachi High-Tech Science Co., Ltd.), the elongation of the test specimen was measured in tensile mode under the conditions of a sample size of 3 mm x 20 mm, a load of 50 mN, a nitrogen gas flow (flow rate of 200 mL / min), and a heating rate of 10 °C / min. The point at which the inflection point of the elongation was observed was determined as the glass transition temperature.

[0094] (3) Yellow Index (YI) The YI was measured in accordance with JIS K7136:2000 (D light source, 65°) using a color and turbidity simultaneous measuring instrument (COH7700, manufactured by Nippon Denshoku Industries Co., Ltd.). The smaller the YI value, the better the colorless and transparent properties.

[0095] (4) Haze was measured in accordance with JIS K7136:2000 using a color and turbidity simultaneous measuring instrument (COH7700, manufactured by Nippon Denshoku Industries Co., Ltd.). The smaller the haze value, the better the colorless and transparent properties.

[0096] (5) Yellow Index (YI) and ΔYI after UV irradiation test The YI after UV irradiation test was evaluated using a xenon fade meter tester under the following conditions. The YI was measured in the same manner as described in "(3) Yellow Index (YI)" above. Light source: Xenon lamp black panel Temperature: 65°C Humidity: 50% RH Irradiance: 120 W / m ２ Wavelength range: 300-400 nm (cut off below 295 nm) Test time: 300 hours ΔYI is YI before UV irradiation test YI ０ And YI after the test is YI １ The following formula was used to calculate ΔYI = YI １ -YI ０ The smaller the value of ΔYI, the better the light resistance.

[0097] (6) Adhesion to glass substrate The adhesion to the glass was evaluated in accordance with ASTM D3359 under the following conditions: Cross-cut: 1 mm x 1 mm, 100 pieces Peel test: Peel test using adhesive tape compliant with ASTM D3359 Evaluation: In accordance with ASTM D3359, the adhesion was on a 6-point scale from 5B for the best adhesion to 0B for the worst adhesion. Adhesion is better as it approaches 5B, and 5B indicates sufficient adhesion.

[0098] The tetracarboxylic acid and diamine components used in the examples and comparative examples, as well as their abbreviations, are as follows: <Tetracarboxylic acid component> HPMDA: Cyclohexane-1,2,4,5-tetracarboxylic dianhydride (compound represented by formula (a5)) <Diamine component> TMDA: 5-amino-1,3,3-trimethyl-1-(4-aminophenyl)-indan (compound represented by formula (b3). The amino group is bonded to positions 5 and 4 of the benzene ring.) BisAM: 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene (compound represented by formula (b2). n is 1, Z is an isopropylidene group, the isopropylidene group is bonded to positions 1 and 3 of the central benzene ring, and both amino groups are bonded to position 4 of the benzene ring.)

[0099] The silsesquioxane compounds used in the examples and comparative examples are as follows: Silsesquioxane compound 1: Random structure. R in formula (4) 1 The group consists of a hydroxyl group and a phenyl group, and the molecular weight is 1300. Silsesquioxane compound 2: Random structure. R in formula (4) 1 The group consists of a hydroxyl group, an ethoxy group, and a phenyl group, and has a molecular weight of 1000. The molecular weights of silsesquioxane compound 1 and silsesquioxane compound 2 are weight-average molecular weights determined by gel filtration chromatography measurements under the following conditions, converted to standard polystyrene (PS).

[0100] (Gel Filtration Chromatography Measurement Conditions) The silsesquioxane compound was diluted with the mobile phase solvent shown below to a concentration of 0.1% by mass of the silsesquioxane compound, and a measurement solution was prepared. Using the measurement solution, gel filtration chromatography was performed under the following conditions, and the weight-average molecular weight of the silsesquioxane compound was determined as a polystyrene (PS) equivalent. Apparatus: Shodex 101 Column: TSKgel G2000H ＸＬ &TSKgel G4000H ＸＬ Column temperature: 40°C; Mobile phase: Tetrahydrofuran (THF); Mobile phase flow rate: 1.0 mL / min; Molecular weight standard: Polystyrene (PS) (manufactured by Tosoh Corporation)

[0101] The abbreviations for the solvents and catalysts used in the examples and comparative examples are as follows: GBL: γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation) TEA: triethylamine (manufactured by Kanto Chemical Co., Ltd.) TEDA: 1,4-diazabicyclo[2.2.2]octane (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0102] <Preparation of Polyimide Resin Composition and Polyimide Film> Example 1 A 300 mL five-necked round-bottom flask equipped with a stainless steel crescent-shaped stirring blade, nitrogen inlet tube, condenser, thermometer, and glass end cap was filled with 36.117 g (0.135 mol) of TMDA and 79.652 g of GBL. The mixture was stirred at a system temperature of 50°C, under a nitrogen atmosphere, at a rotation speed of 200 rpm to obtain a solution. To this solution, 30.426 g (0.135 mol) of HPMDA and 14.935 g of GBL were added, followed by the addition of 0.685 g (0.00677 mol) of TEA, 0.03063 g (0.000271 mol) of TEDA, and 4.978 g of GBL. The mixture was then heated with a mantle heater to raise the reaction system temperature to 190°C, stirred for 6 hours, and diluted with 138.935 g of GBL to obtain a solution containing polyimide resin. To the obtained solution, 12.300 g (20% by mass relative to the polyimide resin) of silsesquioxane compound 1 was added to obtain a polyimide resin composition. Subsequently, the obtained polyimide resin composition was applied to a glass plate by spin coating, held at 80°C for 20 minutes on a hot plate, and then heated in a hot air dryer at 160°C for 120 minutes under an air atmosphere to evaporate the solvent and obtain a polyimide film. Table 1 shows the composition, physical properties, and evaluation results of the polyimide film.

[0103] Examples 2-5, 7 and Comparative Example 2 A polyimide resin composition was obtained in the same manner as in Example 1, except that the amount or type of silsesquioxane compound was changed as shown in Table 1. A polyimide film was obtained using the obtained polyimide resin composition in the same manner as in Example 1. The composition, physical properties, and evaluation results of the polyimide film are shown in Table 1.

[0104] Examples 6 and 10 A polyimide resin composition was obtained in the same manner as in Example 1, except that the amount and type of diamine component were changed as shown in Table 1. A polyimide film was obtained using the obtained polyimide resin composition in the same manner as in Example 1. The composition, physical properties, and evaluation results of the polyimide film are shown in Table 1.

[0105] Example 8 A 300 mL five-necked round-bottom flask equipped with a stainless steel crescent-shaped stirring blade, a nitrogen inlet tube, a Dean-Stark condenser, a thermometer, and a glass end cap was filled with 36.117 g (0.135 mol) of TMDA and 79.652 g of GBL. The mixture was stirred at 200 rpm under a nitrogen atmosphere at a system temperature of 50°C to obtain a solution. To this solution, 30.426 g (0.135 mol) of HPMDA and 14.935 g of GBL were added, followed by the addition of 0.685 g (0.00677 mol) of TEA, 0.03063 g (0.000271 mol) of TEDA, and 4.978 g of GBL. The mixture was then heated with a mantle heater to raise the reaction system temperature to 190°C, stirred for 6 hours, and diluted with 138.935 g of GBL to obtain a solution containing polyimide resin. To the obtained solution, 12.300 g (20% by mass relative to the polyimide resin) of phenyltrimethoxysilane was added to obtain a polyimide resin composition. Subsequently, the obtained polyimide resin composition was applied to a glass plate by spin coating, held at 80°C for 20 minutes on a hot plate, and then heated in a hot air dryer at 160°C for 120 minutes under an air atmosphere to evaporate the solvent and obtain a polyimide film. Table 1 shows the composition, physical properties, and evaluation results of the polyimide film.

[0106] Example 9 A polyimide resin composition was obtained in the same manner as in Example 8, except that phenyltrimethoxysilane was replaced with diphenyldimethoxysilane. A polyimide film was obtained using the obtained polyimide resin composition in the same manner as in Example 8. The composition, physical properties, and evaluation results of the polyimide film are shown in Table 1.

[0107] Comparative Example 1 A polyimide resin composition was obtained in the same manner as in Example 1, except that a silsesquioxane compound was not used. A polyimide film was obtained using the obtained polyimide resin composition in the same manner as in Example 1. The composition, physical properties, and evaluation results of the polyimide film are shown in Table 1.

[0108] Comparative Example 3 A polyimide resin composition was obtained in the same manner as in Example 6, except that a silsesquioxane compound was not used. A polyimide film was obtained using the obtained polyimide resin composition in the same manner as in Example 6. The composition, physical properties, and evaluation results of the polyimide film are shown in Table 1.

[0109] Comparative Example 4 A polyimide resin composition was obtained in the same manner as in Example 10, except that a silsesquioxane compound was not used. A polyimide film was obtained using the obtained polyimide resin composition in the same manner as in Example 10. The composition, physical properties, and evaluation results of the polyimide film are shown in Table 1.

[0110]

[0111] As shown in Table 1, the polyimide film obtained using the polyimide resin composition of the example exhibits excellent transparency, as evidenced by the low YI and haze values. Furthermore, the film exhibits excellent light resistance, as evidenced by the low YI value after irradiation with ultraviolet light. The film also exhibits excellent adhesion to glass substrates.

[0112] The polyimide resin composition of the present invention is useful as a raw material for optical filter films because it can produce polyimide films with transparency, light resistance, and adhesion to substrates. Furthermore, the polyimide film of the present invention is useful as an optical filter film because it has excellent transparency, light resistance, and adhesion to substrates.

Claims

1. A polyimide resin composition comprising a polyimide resin (I) containing repeating units represented by the following formula (1), at least one compound (S) selected from the group consisting of silsesquioxane compounds (S1) and phenylalkoxysilanes (S2), and an organic solvent, wherein the content of compound (S) is 1 to 45 parts by mass per 100 parts by mass of the polyimide resin (I). (In formula (1), X is a tetravalent aliphatic or aromatic group having 4 to 39 carbon atoms, Y is a divalent aromatic group having 4 to 39 carbon atoms, and Y includes at least one selected from the group consisting of divalent groups represented by formula (2) and divalent groups represented by formula (3). In formula (2), Z is an aliphatic group having 1 to 8 carbon atoms, and n is 0 to 2.) 2. The polyimide resin composition according to claim 1, wherein the silsesquioxane compound (S1) is a compound represented by the following composition formula (4). [R 1 SiO 1.5 ] ｍ (4) (In formula (4), R 1 m is at least one selected from the group consisting of hydroxyl groups, alkoxy groups, and aromatic groups, and m is between 4 and 100. (Note that m is the average value.) 3. R 1 The polyimide resin composition according to claim 2, wherein the group comprises a hydroxyl group or an alkoxy group.

4. R 1 The polyimide resin composition according to claim 2 or 3, wherein the aromatic group is included.

5. The polyimide resin composition according to any one of claims 1 to 4, wherein X comprises at least one selected from the group consisting of a tetravalent group represented by the following formula (5) and a tetravalent group represented by the following formula (6).

6. A polyimide film obtained by coating a polyimide resin composition according to any one of claims 1 to 5 onto a support and heating it.

7. A method for producing a polyimide film, comprising applying a polyimide resin composition according to any one of claims 1 to 5 onto a support and heating it.

8. A polyimide film containing a polyimide resin (I) having repeating units represented by the following formula (1), and a silsesquioxane compound (S3), wherein the content of the silsesquioxane compound (S3) is 1 to 45 parts by mass per 100 parts by mass of the polyimide resin (I). (In formula (1), X is a tetravalent aliphatic or aromatic group having 4 to 39 carbon atoms, Y is a tetravalent aromatic group having 4 to 39 carbon atoms, and Y includes at least one selected from the group consisting of divalent groups represented by formula (2) and divalent groups represented by formula (3). In formula (2), Z is an aliphatic group having 1 to 8 carbon atoms, and n is 0 to 2.) 9. The polyimide film according to claim 8, wherein the silsesquioxane compound (S3) is a compound represented by the following compositional formula (4). [R 1 SiO 1.5 ｍ (4) (In formula (4), R 1 is at least one selected from the group consisting of a hydroxy group, an alkoxy group, and an aromatic group, and m is 4 to 100. Note that m is an average value.)​ 10. The polyimide film according to claim 8 or 9, for use as an optical filter.

Images