JP7375318B2 - Polyimide precursor resin compositions, polyimide resin compositions and films thereof, laminates containing the same, and flexible devices - Google Patents

Description

The present invention relates to a polyimide precursor resin composition, a polyimide resin composition, a film-like product thereof, a laminate containing the same, and a flexible device.

Organic films have the advantage of being more flexible, less likely to break, and lighter than glass. Recently, there has been an active movement to make displays more flexible by replacing the substrates of flat panel displays with organic films.

Examples of the resin used for the organic film include polyester, polyamide, polyimide, polycarbonate, polyether sulfone, acrylic, epoxy, and cycloolefin polymer. Among these, polyimide is a highly heat-resistant resin suitable for use as a display substrate. However, common polyimide resins are colored brown or yellow due to their high aromatic ring density and have low transmittance in the visible light region, making it difficult to use them in fields where transparency is required.

In order to solve the problem of improving the transparency of polyimide, Patent Document 1 discloses that an alicyclic acid dianhydride and an amine having a hydroxyl group, specifically 2,2-bis[3-(3-amino It is described that a polyimide film using benzamido)-4-hydroxyphenyl]hexafluoropropane (HFHA) has high heat resistance and light transmittance.

Furthermore, Patent Document 2 discloses that 2,2-bis(trifluoromethyl)benzidine (hereinafter also referred to as TFMB) is used to improve transmittance and hue transparency, and a silicone component such as silicone diamine is further introduced. A method for reducing residual stress is disclosed.

International Publication No. 2013/24849 Patent No. 5948545

Although it is disclosed that the polyimide of Patent Document 1 has high transparency, there is a problem that a large residual stress is generated at the interface with the glass substrate during the film forming process of the polyimide film.

Further, Patent Document 2 discloses a polyimide precursor resin composition containing silicone having reactive functional groups such as amines and acid anhydrides at both ends, but the reactive functional group portions are easily thermally decomposed; There was a problem in that the amount of gas degassed during heating was large.

At present, there is no known method for maintaining transparency and reducing the residual stress generated at the interface with the glass substrate without deteriorating the amount of outgassing.

In view of the above problems, the present invention aims to provide a polyimide precursor resin composition that can maintain transparency and reduce residual stress generated at the interface with a glass substrate without worsening the amount of outgassing. purpose.

In order to solve the above-mentioned problems and achieve the objects, the present invention provides (A) a polyimide precursor containing a unit structure represented by general formula (1), (B) a polyimide precursor represented by general formula (2). A polyimide precursor resin composition containing a compound and/or a compound represented by general formula (3), and (C) a solvent, wherein the (B) is added to 100 parts by mass of the (A) polyimide precursor. A polyimide precursor resin composition containing a total of 0.01 to 0.5 parts by mass of a compound represented by general formula (2) and a compound represented by general formula (3).

(In general formula (1), R ¹ represents a tetravalent organic group, and R ² represents a divalent organic group. X ¹ and X ² each independently represent a hydrogen atom, a carbon number of 1 to 10 (Indicates a monovalent organic group or a monovalent alkylsilyl group with 1 to 10 carbon atoms.)

(In general formula (2), a plurality of R ³ 's may be the same or different, and include an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and Represents a group selected from aryl groups having 6 to 15 carbon atoms. Also, n represents an integer of 1 to 38.)

(In general formula (3), a plurality of R ⁴ 's may be the same or different, and include an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and Represents a group selected from aryl groups having 6 to 15 carbon atoms, and each of the plural R ^5s may be the same or different, and represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an acyl group having 2 to 6 carbon atoms, and Represents a group selected from aryl groups having 6 to 15 carbon atoms. Also, m represents an integer of 3 to 40.)

According to the present invention, it is possible to provide a polyimide precursor resin composition that maintains transparency and can reduce residual stress generated at the interface with a glass substrate without deteriorating the amount of outgassing. The polyimide resin composition obtained from the polyimide precursor resin composition of the present invention can be suitably used as a support substrate for displays such as electronic devices, such as touch panels, color filters, liquid crystal elements, and organic EL elements. By using such a support substrate, it is possible to create a display with high definition and high reliability.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail with drawing. Note that the present invention is not limited to the following embodiments. Furthermore, the figures referred to in the following description merely schematically illustrate the shape, size, and positional relationship to the extent that the content of the present invention can be understood. That is, the present invention is not limited to the shapes, sizes, and positional relationships illustrated in each figure.

<Polyimide precursor resin composition>
The polyimide precursor resin composition according to the embodiment of the present invention includes (A) a polyimide precursor containing a unit structure represented by general formula (1), (B) a compound represented by general formula (2), and A polyimide precursor resin composition containing a compound represented by the general formula (3) and (C) a solvent, wherein the compound represented by the general formula (B) is added to 100 parts by mass of the polyimide precursor (A). A polyimide precursor resin composition containing a total of 0.01 to 0.5 parts by mass of the compound represented by (2) and the compound represented by the general formula (3).

In the general formula (1), R ¹ represents a tetravalent organic group, and R ² represents a divalent organic group. X ¹ and X ² each independently represent a hydrogen atom, a monovalent organic group having 1 to 10 carbon atoms, or a monovalent alkylsilyl group having 1 to 10 carbon atoms.

In general formula (2), a plurality of R ³ 's may be the same or different, and include an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a carbon Represents a group selected from 6 to 15 aryl groups. Further, n represents an integer from 1 to 38.

In general formula (3), a plurality of R ⁴ 's may be the same or different, and include an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a carbon Represents a group selected from 6 to 15 aryl groups, each of which has a plurality of R ^5s may be the same or different, and represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an acyl group having 2 to 6 carbon atoms, and a carbon Represents a group selected from 6 to 15 aryl groups. Further, m represents an integer of 3 to 40.

Note that "carbon number 1 to 10" indicates "carbon number 1 or more and carbon number 10 or less". Similar descriptions in the present invention have similar meanings.

The polyimide precursor resin composition according to the embodiment of the present invention contains the above polyimide precursor and a siloxane compound represented by the general formula (2) and/or the general formula (3) in a preferable ratio, It has the following effects. The residual stress generated at the interface between the film-like material of the resin composition and the glass substrate can be reduced without deteriorating the transparency or degassing amount of the polyimide resin composition obtained by imidization. Moreover, the adhesion between the film-like material of the resin composition and the glass substrate can be improved.

The siloxane compound represented by the general formula (2) is a cyclic siloxane compound, and when hydrolyzed, becomes a linear siloxane compound having a silanol group at the end. Further, the compound represented by the general formula (3) is a linear siloxane compound, and the terminal thereof is a silanol group or an alkoxy group. Those having an alkoxy group at the end become linear siloxane compounds having a silanol group at the end by hydrolysis.

By interacting these silanol groups with the polyimide precursor resin or the polyimide resin, a microlayer separation structure can be formed in which the flexible siloxane structure portion is the island portion and the polyimide resin is the sea portion. When the microlayer separation structure is formed, the stress generated in the film forming process can be efficiently absorbed by the island portion, so that a film with low residual stress and suppressed warpage can be obtained.

[(A) Polyimide precursor containing unit structure represented by general formula (1)]
Examples of cases where X ^{1 and} Examples include. Examples of the saturated hydrocarbon group include alkyl groups such as methyl group, ethyl group, and tert-butyl group. The saturated hydrocarbon group may be further substituted with a halogen atom. Examples of the unsaturated hydrocarbon group include a vinyl group, an ethynyl group, a biphenyl group, and a phenylethynyl group. Examples of aromatic groups include phenyl groups. The aromatic group may be further substituted with a saturated hydrocarbon group, an unsaturated hydrocarbon group, or a halogen atom. Examples of alkylsilyl groups include trimethylsilyl groups.

In general formula (1), R ¹ is a residue of a tetracarboxylic acid or a derivative thereof. The number of carbon atoms in R ¹ is preferably 1 to 40. Examples of R ¹ include a tetravalent aromatic group, an alicyclic aliphatic group, and a chain aliphatic group.

The tetracarboxylic acid that provides R ¹ is not particularly limited, and any known tetracarboxylic acid can be used. Examples include pyromellitic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, 2,2',3,3'-biphenyltetracarboxylic acid. acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane, bis(3,4-dicarboxyphenyl)sulfone, bis(3 ,4-dicarboxyphenyl)ether, 2,2-bis(4-(3,4-dicarboxyphenoxy)phenyl)propane, cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1 , 2,4,5-cyclohexanetetracarboxylic acid, cyclopentanone bisspironorbornane tetracarboxylic acid, and the tetracarboxylic acid described in International Publication No. 2017/099183.

These tetracarboxylic acids can be used as they are, or in the form of acid anhydrides, active esters, or active amides. Among these, acid anhydrides are preferably used because they do not produce by-products during polymerization. Moreover, you may use 2 or more types of these.

From the viewpoint of heat resistance, R ¹ is preferably a group represented by any of the following formulas (4) to (7), and from the viewpoint of transparency, it is a group represented by any of the following formulas (8) to (10). More preferably, it is a group represented by any of the following.

In formulas (4) to (10), R ⁶ each independently represents a hydrogen atom or an electron-withdrawing group. X ³ is a direct bond, ester bond, amide bond, ether bond, sulfonyl group, sulfinyl group, or sulfide bond, or a divalent organic group having 1 to 3 carbon atoms that may be substituted with a halogen atom shows. a's each independently represent 1 or 2, b's each independently represent an integer from 1 to 3, and c represents an integer from 0 to 3.

The electron-withdrawing group used herein has a Hammett substituent constant (para position, σp) which is usually larger than 0, preferably 0.01 or more, and more preferably 0.1 or more. It is preferably 0.5 or more, particularly preferably 0.5 or more. Hammett's substituent constants are described, for example, in "Chemistry Handbook" edited by the Chemical Society of Japan, revised 5th edition, Volume II, Maruzen Co., Ltd., February 2004, p. 380.

Examples of the electron-withdrawing group include a halogen atom, a cyano group, a hydrogen atom or a carbonyl group having a substituent, a nitro group, a perfluoroalkyl group such as a trifluoromethyl group, a sulfonyl group, and the like. Examples of the halogen atom include a fluorine atom, a bromine atom, a chlorine atom, and an iodine atom.

In general formula (1), R ² is a diamine residue. The number of carbon atoms in R ² is preferably 1 to 40. Examples of R ² include an aromatic group, an alicyclic aliphatic group, and a chain aliphatic group.

There are no particular restrictions on the diamine that provides R ² , and any known diamine can be used. Examples include m-phenylenediamine, p-phenylenediamine, 4,4'-diaminobenzanilide, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2'-dimethyl-4,4'- Diaminobiphenyl, 2,2'-di(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 2,2'-bis(trifluoromethyl)benzidine, 3,3'-bis(trifluoromethyl)benzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether, 3,3'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether, 9,9-bis(4-aminophenyl)fluorene, 3-aminophenyl-4-aminobenzenesulfonate, 4-aminophenyl-4-aminobenzene Sulfonate, 9,9-bis(3-fluoro-4-aminophenyl)fluorene, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[3-(3-aminophenoxy)phenyl]sulfone, 1, 4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, bis(3-amino-4-hydroxyphenyl)hexafluoro Examples include propane, ethylene diamine, propylene diamine, butane diamine, cyclohexane diamine, 4,4'-methylenebis(cyclohexylamine), norbornane diamine, and the diamine described in International Publication No. 2017/099183.

These diamines can be used as they are or in the form of corresponding trimethylsilylated diamines. Moreover, you may use 2 or more types of these.

From the viewpoint of heat resistance, ^R2 is more preferably a group represented by either the following formula (11) or (12), and from the viewpoint of transparency, it is a group represented by the following formula (13). More preferably, it is a group.

In formulas (11) to (12), R ⁷ each independently represents a hydrogen atom or an electron-withdrawing group. X ⁴ is a direct bond, ester bond, amide bond, ether bond, sulfonyl group, sulfinyl group, or sulfide bond, or a divalent organic group having 1 to 3 carbon atoms that may be substituted with a halogen atom shows. d represents an integer of 1 to 3, e represents 1 or 2, f each independently represents an integer of 0 to 4, and g represents an integer of 0 to 3.

Moreover, it is preferable that the polyimide precursor according to the embodiment of the present invention contains a residue of a diamine represented by the general formula (16).

In the general formula (16), R ¹⁰ is a substituted or unsubstituted phenyl group, and s represents an integer of 1 or more and 4 or less.

R ¹⁰ is preferably a phenyl group or a phenyl group substituted with a phenyl group. For example, R ¹⁰ is a phenyl group or a biphenyl group.

Since the diamine residue represented by the general formula (16) always has a structure containing a carboxyl group, strong hydrogen bonds are formed between molecules and intermolecular interactions are strengthened, resulting in a high glass transition temperature and poor mechanical strength. It becomes possible to obtain excellent polyimide. In addition, the carboxyl group acts as an acid catalyst, leading to ring opening of the cyclic siloxane compound represented by general formula (2) and hydrolysis of the terminal of the siloxane compound represented by general formula (3) (alkoxy group hydrolysis) is promoted. As a result, the effect of forming the above-mentioned microlayer separation structure becomes stronger, and the stress generated during the film formation process can be efficiently absorbed in the island portion, resulting in a film with lower residual stress and less warpage. can be obtained.

A diamine containing a residue represented by general formula (16) is represented by, for example, the following general formula (18).

Specific examples of the diamine represented by general formula (18) are 3,5-diaminobenzoic acid, 3,4-diaminobenzoic acid, 2,3-diaminobenzoic acid, or 2,6-diaminobenzoic acid. , but not limited to.

The polyimide precursor according to the embodiment of the present invention contains diamine residues represented by general formula (16) in an amount of 0.5 mol% or more and 50 mol% of all the diamine residues contained in the polyimide precursor (A). The content is preferably 1 mol% or more and 40 mol% or less, and even more preferably 1 mol% or more and 30 mol% or less.

Among these, it is preferable that R ¹ and/or R ² in general formula (1) contain an aromatic ring to which an electron-withdrawing group is bonded. As a result, the acidity of the carboxyl group possessed by the polyimide precursor resin increases (pKa decreases), and the ring-opening of the cyclic siloxane compound represented by the general formula (2) and the ring-opening of the cyclic siloxane compound represented by the general formula (3) occur. Hydrolysis of the terminals of the siloxane compound (hydrolysis of alkoxy groups) is promoted. As a result, the effect of forming the above-mentioned microlayer separation structure becomes greater.

The above effect is more prominent when the distance between the electron-withdrawing group and the carboxyl group is short, so it is more preferable that R ¹ contains an aromatic ring to which an electron-withdrawing group is bonded. Specifically, it is preferable that R ¹ in general formula (1) contains at least one type selected from the structures represented by formulas (14) and (15). Furthermore, it is particularly preferable that the unit structure containing the structure is contained in an amount of 25 mol% or more in 100 mol% of the total structure represented by the general formula (1). Note that the ratio of unit structures of a polymer can be measured by mass spectrometry, pyrolysis gas chromatography (GC), NMR, or IR measurement of a polyimide precursor or polyimide.

In formula (14), R ⁸ represents a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and at least one of the plurality of R ⁸ is a fluorine atom or a trifluoromethyl group. In formula (15), X ⁵ represents either C(CF ₃ ), SO ₂ or SO, and R ⁹ represents a hydrogen atom, a fluorine atom or a trifluoromethyl group.

Examples of the compound represented by formula (14) include 1,4-difluoropyromellitic dianhydride and 1,4-ditrifluoromethylpyromellitic dianhydride. Further, examples of the compound represented by formula (15) include diphenylsulfone-3,3',4,4'-tetracarboxylic dianhydride (DSDA), 2,2-bis(3,4-dicarboxyphenyl ) hexafluoropropanihydride (6FDA), and the like.

Moreover, it is preferable that the polyimide precursor (A) contains a triamine skeleton. Triamine has three amino groups and forms a branched molecular chain by combining with three tetracarboxylic dianhydride components. The triamine skeleton introduces a branched structure into the molecular chain of polyamic acid to form a branched polyamic acid. Thereby, it becomes possible to improve the viscosity of the varnish in which the polyamic acid resin is dissolved, and it is possible to improve the uniformity of the film thickness when coating is performed using a slit. In addition, the molecular weight of polyimide resin obtained from a polyimide precursor with a branched structure is larger than that of one without a branched structure, so it is possible to improve the interaction with the inorganic film formed on the polyimide resin due to the cluster effect. It is possible.

Specific examples of triamine compounds that provide a triamine skeleton that do not have an aliphatic group include 2,4,4'-triamino diphenyl ether (TAPE), 1,3,5-tris(4-aminophenoxy)benzene ( TAPOB), tris(4-aminophenyl)amine, 1,3,5-tris(4-aminophenyl)benzene, 3,4,4'-triaminodiphenyl ether, etc. Examples of those having the amine include tris(2-aminoethyl)amine (TAEA) and tris(3-aminopropyl)amine.

As described above, the triamine constitutes a branch of the crosslinked structure in the molecular chain of the polyimide resin. If this triamine is thermally decomposed, the crosslinked structure of the polyimide resin will be lost. Therefore, as the triamine component, it is preferable to use a component that does not have an aliphatic group and is difficult to thermally decompose. That is, it is preferable to use 2,4,4'-triamino diphenyl ether (TAPE), 1,3,5-tris(4-aminophenoxy)benzene (TAPOB), and the like.

The polyimide precursor (A) may have a structure represented by general formula (19) in the tetracarboxylic acid residue and/or diamine residue constituting the polyimide. Since the polyimide precursor has the structure represented by the general formula (19), residual stress generated between the polyimide resin film obtained using the polyimide precursor and the inorganic film can be reduced. Therefore, it is possible to suppress substrate warpage when a polyimide resin film and an inorganic film are laminated on a substrate.

In formula (19), R ¹² and R ¹³ each independently represent a monovalent organic group having 1 to 20 carbon atoms. x represents an integer from 3 to 200.

Examples of the monovalent organic group having 1 to 20 carbon atoms in R ¹² and R ¹³ include a hydrocarbon group, an amino group, an alkoxy group, and an epoxy group. Examples of the hydrocarbon group for R ¹² and R ¹³ include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms.

The alkyl group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 10 carbon atoms, and specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t- Examples include butyl group, pentyl group, hexyl group, and the like. The cycloalkyl group having 3 to 20 carbon atoms is preferably a cycloalkyl group having 3 to 10 carbon atoms, and specific examples include a cyclopentyl group and a cyclohexyl group. The aryl group having 6 to 20 carbon atoms is preferably an aryl group having 6 to 12 carbon atoms, and specific examples thereof include phenyl group, tolyl group, naphthyl group, and the like.

Examples of the alkoxy group for R ¹² and R ¹³ include methoxy group, ethoxy group, propoxy group, isopropyloxy group, butoxy group, phenoxy group, propenyloxy group, and cyclohexyloxy group.

R ¹² and R ¹³ in general formula (19) are preferably a monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms or an aromatic group having 6 to 10 carbon atoms. This is because the resulting polyimide film has both high heat resistance and low residual stress. Here, the monovalent aliphatic hydrocarbon having 1 to 3 carbon atoms is preferably a methyl group, and the aromatic group having 6 to 10 carbon atoms is preferably a phenyl group.

x in general formula (19) is an integer of 3 to 200, preferably 10 to 200, more preferably 20 to 150, still more preferably 30 to 100, particularly preferably 30 to 60. When m is within the above range, residual stress in the polyimide can be reduced. Moreover, it is possible to suppress the polyimide film from becoming cloudy and from decreasing the mechanical strength of the polyimide film.

A polyimide resin having a structure represented by the general formula (19) can be obtained by using a silicone compound represented by the following general formula (20) as a monomer component.

In formula (20), a plurality of R ^14s are each independently a single bond or a divalent organic group having 1 to 20 carbon atoms, and a plurality of R ^{15 s} , R ¹⁶ and R ¹⁷ are each independently a carbon A monovalent organic group of numbers 1 to 20, L ¹ , L ² and L ³ are each independently an amino group, an acid anhydride group, a carboxyl group, a hydroxy group, an epoxy group, a mercapto group, and R ¹⁸ It is one group selected from the group consisting of. R ¹⁸ is a monovalent organic group having 1 to 20 carbon atoms. y is an integer from 3 to 200, and z is an integer from 0 to 197.

Further, in the polyimide precursor (A), a part of the unit structure represented by the general formula (1) may be imidized. By imidizing a portion of the polyimide precursor, residual stress generated between the polyimide resin film and the inorganic film can be reduced, and the viscosity stability of the resin solution during storage at room temperature can be improved. The range of imidization rate of the polyimide precursor (A) is preferably 1% to 50% from the viewpoint of reducing residual stress, solubility in solution, and viscosity stability. The imidization rate is more preferably 5% or more and 30% or less.

An imidization accelerator can be used to promote imidization of the polyimide precursor. For example, the imidization rate of the polyimide precursor can be increased by adding an imidization promoter during polymerization of the polyimide precursor. The imidization accelerator mentioned here is a compound that has the function of increasing nucleophilicity and electrophilicity. Specifically, tertiary amine compounds such as trimethylamine, triethylamine, tripropylamine, and tributylamine; 4-hydroxy Carboxylic acid compounds such as phenylacetic acid and 3-hydroxybenzoic acid; polyhydric phenol compounds such as 3,5-dihydroxyacetophenone and methyl 3,5-dihydroxybenzoate, pyridine, quinoline, isoquinoline, imidazole, benzimidazole, 1,2 , 4-triazole, and other heterocyclic compounds;

Examples of the partially imidized polyimide precursor (A) include resins each having repeating units represented by general formula (21), general formula (22), and general formula (23).

In the general formulas (21) to (23), R ¹⁹ represents a divalent organic group, and R ²⁰ represents a tetravalent organic group. W ¹ and W ² each independently represent a hydrogen atom, a monovalent organic group having 1 to 10 carbon atoms, or a monovalent alkylsilyl group having 1 to 10 carbon atoms. The divalent organic group for R ¹⁹ is the same as the diamine residue described above, and the tetravalent organic group for R ²⁰ is the same as the tetracarboxylic acid residue described above.

Let the numbers of repeating units represented by formulas (21), (22), and (23) in the polyimide precursor be p, q, and r, respectively.

It is preferable that p represents an integer of 1 or more, q and r each independently represent an integer of 0 or 1 or more, and satisfy the relationship 1%≦(2r+q)×100/(2p+2q+2r)≦50%, More preferably, the following relationship is satisfied: 5%≦(2r+q)×100/(2p+2q+2r)≦30%.

Here, "(2r+q)×100/(2p+2q+2r)" is the number of bonding sites (2r+q) that undergo imide ring closure at the bonding site of the polyimide precursor (reaction site between tetracarboxylic dianhydride and diamine compound). The ratio to the total number of bonds (2p+2q+2r) is shown. That is, "(2r+q)×100/(2p+2q+2r)" indicates the imidization rate of the polyimide precursor.

By setting the imidization rate (value of "(2r+q)×100/(2p+2q+2r)") of the polyimide precursor of (A) to 1 to 50%, more preferably 5 to 30%, (A) can be improved. The residual stress generated between the polyimide resin film and the inorganic film can be reduced and the viscosity stability can be improved without deteriorating the solubility of the polyimide precursor in the solution.

The imidization rate (value of "(2r+q)×100/(2p+2q+2r)") of the polyimide precursor (A) is measured by the following method.

-Measurement of imidization rate of polyimide precursor-
- Preparation of polyimide precursor sample (i) A polyimide precursor composition to be measured is coated on a silicon wafer to a film thickness of 1 μm or more and 10 μm or less to prepare a coating film sample.

(ii) The paint film sample is immersed in tetrahydrofuran (THF) for 20 minutes to replace the solvent in the paint film sample with tetrahydrofuran (THF). The solvent to be immersed is not limited to THF, but can be selected from solvents that do not dissolve the polyimide precursor and are miscible with the solvent component contained in the polyimide precursor composition. Specifically, alcohol solvents such as methanol and ethanol, and ether compounds such as dioxane can be used.

(iii) The paint film sample is taken out from the THF, and N ₂ gas is sprayed onto the THF adhering to the surface of the paint film sample to remove it. The coating film sample is dried by processing at a temperature of 5° C. or higher and 25° C. or lower for 12 hours or more under a reduced pressure of 10 mmHg or lower to prepare a polyimide precursor sample.

- Preparation of 100% imidized standard sample (iv) Similarly to (i) above, the polyimide precursor composition to be measured is applied onto a silicon wafer to prepare a coating film sample.

(v) Heat the coating film sample at 380° C. for 60 minutes to perform an imidization reaction to prepare a 100% imidized standard sample.

- Measurement and analysis (vi) Using a Fourier transform infrared spectrophotometer (FT-730 manufactured by Horiba, Ltd.), measure the infrared absorption spectra of the 100% imidized standard sample and polyimide precursor sample. Ratio of the absorption peak derived from the imide bond (Ab' (1780 cm -1 )) near 1780 cm ^-1 to the absorption peak derived from the aromatic ring (Ab' (1500 cm ^-1 )) near 1500 cm ^-1 of a 100% imidized ^standard sample Find I'(100).

(vii) In the same manner, a polyimide precursor sample was measured, and the absorption peak derived from the imide bond (Ab (1500 cm ^-1 )) near 1780 cm ^-1 was compared to the absorption peak derived from the aromatic ring (Ab (1500 cm ^-1 )) near 1500 cm -1 . Find the ratio I(x) of 1780 cm ⁻¹ )).

Then, using each of the measured absorption peaks I'(100) and I(x), the imidization rate of the polyimide precursor is calculated based on the following formula.
・Formula: Imidization rate (%) of polyimide precursor = I(x)×100/I'(100)
・Formula: I'(100)=(Ab'(1780cm ^-1 ))/(Ab'(1500cm ^-1 ))
-Formula: I(x)=(Ab(1780cm ^-1 ))/(Ab(1500cm ^-1 )).

The weight average molecular weight (Mw) of the polyimide precursor (A) is preferably 10,000 to 1,000,000, more preferably 10,000 to 500,000, even more preferably 20,000 to 400,000. The number average molecular weight (Mn) of the polyimide precursor (A) is 5,000 to 1,000,000, preferably 5,000 to 500,000, particularly preferably 15,000 to 300,000.

When the weight average molecular weight and number average molecular weight of the polyimide precursor are within the above ranges, it is possible to increase the strength of the film obtained after curing without deteriorating the flatness of the resulting coating film.

The weight average molecular weight, number average molecular weight, and molecular weight distribution were determined using a TOSOH DP-8020 GPC device (guard column: TSK guard column ALPHA column: TSK-GEL α-M, developing solvent: N,N'-dimethylacetamide ( DMAc), 0.05M-LiCl, 0.05% phosphoric acid added).

The polyimide precursor (A) is a resin containing a unit structure represented by the chemical formula (1), and the ends thereof may be capped with an end capping agent. By reacting with the terminal capping agent, the molecular weight of the polyimide precursor can be adjusted to a preferable range.

When the terminal monomer is a diamine compound, dicarboxylic anhydride, monocarboxylic acid, monocarboxylic acid chloride compound, monocarboxylic acid active ester compound, dialkyl dicarbonate, etc. are added to the terminal to block the amino group. It can be used as a sealant.

When the terminal monomer is an acid dianhydride, monoamine, monoalcohol, etc. can be used as a terminal capping agent in order to cap the acid anhydride group.

[(B) Siloxane compound represented by general formula (2) or (3)]
In general formulas (2) and (3), examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, Examples include pentyl group and hexyl group. Specific examples of the cycloalkyl group having 3 to 20 carbon atoms include a cyclopentyl group and a cyclohexyl group. Specific examples of the aryl group having 6 to 12 carbon atoms include phenyl group, tolyl group, and naphthyl group.

R ³ and R ⁴ in general formulas (2) and (3) are preferably a monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms or an aromatic group having 6 to 10 carbon atoms. This is because the resulting polyimide resin composition has both high heat resistance and low residual stress. Here, the monovalent aliphatic hydrocarbon having 1 to 3 carbon atoms is preferably a methyl group, and the aromatic group having 6 to 10 carbon atoms is preferably a phenyl group. Among these, methyl group is more preferable because it has excellent resistance to thermal decomposition and excellent residual stress reduction effect.

Furthermore, examples of the alkyl group in R ⁵ in the general formula (3) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group. Examples of the acyl group include an acetyl group. Examples of the aryl group include phenyl group, 4-tolyl group, 4-hydroxyphenyl group, 4-methoxyphenyl group, 4-t-butylphenyl group, and 1-naphthyl group.

Furthermore, n in general formula (2) represents an integer of 1 to 38, and m in general formula (3) represents an integer of 3 to 40. When n and m are within the above ranges, residual stress can be reduced without deteriorating the transparency of the resulting polyimide resin composition. In addition, it is known that polydimethylsiloxane molecules have a helical structure in which six Si-O bonds make one revolution, and when this helical structure is adopted, the stress generated during the film formation process is efficiently absorbed, resulting in residual stress. n in general formula (2) is particularly preferably 4 or more, and m in general formula (3) is particularly preferably 6 or more. Further, from the viewpoint of reducing haze of the polyimide resin composition obtained by imidization, n in general formula (2) is particularly preferably 13 or less, more preferably 10 or less, and even more preferably 8 or less. Similarly, from the viewpoint of reducing haze of the polyimide resin composition obtained by imidization, m in general formula (3) is particularly preferably 15 or less.

Examples of the cyclic siloxane compound represented by the general formula (2) include hexamethylcyclotrisiloxane (D3-Me), hexaphenylcyclotrisiloxane (D3-Ph), octamethylcyclotetrasiloxane (D4-Me), octaphenyl Cyclotetrasiloxane (D4-Ph), decamethylcyclopentasiloxane (D5-Me), dodecamethylcyclohexasiloxane (D6-Me), tetradecamethylcycloheptasiloxane (D7-Me), hexadecamethylcyclooctasiloxane ( D8-Me), octadecamethylcyclononasiloxane (D9-Me), and the like.

Among the linear siloxane compounds represented by the general formula (3), those with terminal silanol include manufactured by Azumax Co., Ltd., number average molecular weight 3,000), DMS-S12 (manufactured by Azumax Co., Ltd., number average molecular weight 400-700), DMS-S14 (manufactured by Azumax Co., Ltd., number average molecular weight 700-1500), PDS-1615 (manufactured by Azumax Co., Ltd., number average molecular weight 700-1500), Co., Ltd., number average molecular weight: 900 to 1,000), PDS-9931 (manufactured by Azumax Co., Ltd., number average molecular weight: 1,000 to 1,400), and the like. In addition, linear siloxane compounds whose terminal ends have been converted to alkoxy groups are produced by acting on these terminal silanol siloxanes with a primary alcohol compound such as methanol or ethanol in the presence of a catalyst such as an acid or a base to cause a dehydration condensation reaction. Obtainable. Such terminal alkoxysiloxane compounds can also be preferably used.

Silanol groups are highly reactive functional groups, so when a compound with a terminal silanol group is added to a polyimide precursor resin composition, the siloxane compounds or the siloxane compounds and the polyimide precursor resin composition may react. , storage stability may deteriorate. Therefore, from the viewpoint of storage stability of the polyimide precursor resin composition, it is particularly preferable to use a linear siloxane compound or a cyclic siloxane compound having an alkoxy group at the end.

The content of (B) the siloxane compound represented by general formula (2) and/or (3) in the polyimide precursor resin composition according to the embodiment of the present invention is based on 100 parts by weight of (A) polyimide precursor. On the other hand, the total amount is 0.01 to 0.5 part by mass, more preferably 0.05 part to 0.3 part by mass. By including the siloxane compound in the above range, the residual stress of the polyimide resin composition can be reduced without increasing the amount of outgassing.

[(C) Solvent]
There are no particular limitations on the solvent (C), and known solvents can be used. Examples include N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylisobutyramide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N , N-dimethylpropionamide, γ-butyrolactone, ethyl lactate, 1,3-dimethyl-2-imidazolidinone, N,N'-dimethylpropylene urea, 1,1,3,3-tetramethylurea, dimethyl sulfoxide, Sulfolane, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, water, the solvents described in International Publication No. 2017/099183, and the like can be used alone or in combination of two or more. Among these, aprotic polar solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide are preferred. This is because when these are used, the polyimide precursor resin can be dissolved without inhibiting the hydrolysis reaction of the siloxane compound.

The content of the solvent is preferably 100 parts by weight or more, more preferably 200 parts by weight or more, and preferably 2,000 parts by weight or less, more preferably 1 part by weight, based on 100 parts by weight of the polyimide precursor (A). , 500 parts by weight or less. If it is in the range of 100 to 2,000 parts by weight, the concentration and viscosity will be suitable for coating, and good film thickness uniformity can be obtained when coating with a slit coater.

[(D) Tetracarboxylic acid compound]
The polyimide precursor resin composition according to the embodiment of the present invention preferably contains a tetracarboxylic acid compound represented by general formula (17).

In the formula, R ¹¹ represents a tetravalent aromatic residue containing at least one 6-membered carbon ring, and the four carboxyl groups are directly connected to different carbon atoms in this residue, and two of the four carboxyl groups are directly connected to different carbon atoms in this residue. Each is bonded to an adjacent carbon atom within a six-membered carbon ring.

Further, the polyimide precursor resin composition according to the embodiment of the present invention contains 0.01 to 1.0 parts by weight of the tetracarboxylic acid compound represented by the general formula (17) per 100 parts by weight of the polyimide precursor resin. The content is preferably 0.01 to 0.5 parts by weight, and more preferably 0.01 to 0.5 parts by weight.

When the polyimide precursor resin composition contains the tetracarboxylic acid compound represented by general formula (17) in the above range, the amount of carboxylic acid present in the system increases, and the cyclic carboxylic acid compound represented by general formula (2) increases. Ring opening of the siloxane compound and hydrolysis of the terminal of the siloxane compound represented by the general formula (3) (hydrolysis of the alkoxy group) are promoted. As a result, the effect of forming the above-mentioned microlayer separation structure becomes stronger, and the stress generated during the film formation process can be efficiently absorbed in the island portion, resulting in a film with low residual stress and suppressed warping. be able to. In addition, since the tetracarboxylic acid compound represented by the general formula (17) is incorporated into the polyimide precursor resin during the film forming process, the residual stress is smaller without worsening the amount of outgassing, and the occurrence of warping is further suppressed. A thin film can be obtained.

In general formula (17), preferable specific examples of R ¹¹ include the following.

X ⁶ in the formula represents a direct bond or a divalent group represented by either.

[Other ingredients]
The polyimide precursor resin composition according to the embodiment of the present invention may contain a surfactant. Examples of surfactants include fluorine-based surfactants such as Florado (trade name, manufactured by Sumitomo 3M Co., Ltd.), Megafac (trade name, manufactured by DIC Corporation), and Sulfuron (trade name, manufactured by Asahi Glass Co., Ltd.). can be given. In addition, KP341 (product name, manufactured by Shin-Etsu Chemical Co., Ltd.), DBE (product name, manufactured by Chisso Corporation), Polyflow, Granol (product name, manufactured by Kyoeisha Chemical Co., Ltd.), BYK (product name, manufactured by Kyoeisha Chemical Co., Ltd.), Examples include organic siloxane surfactants such as those manufactured by ). Examples include polyoxyalkylene lauri ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, and polyoxyethylene cetyl ether surfactants such as Emulmin (Sanyo Chemical Industries, Ltd.).Furthermore, Polyflow (trade name, Kyoeisha Chemical Co., Ltd.) Examples include acrylic polymer surfactants such as those manufactured by Co., Ltd.).

The surfactant is preferably contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the resin composition.

The resin composition of the present invention may contain an internal mold release agent. Examples of internal mold release agents include long chain fatty acids.

A coupling agent such as a silane coupling agent or a titanium coupling agent may be added to the resin composition of the present invention in order to improve adhesiveness with a base material. As the above-mentioned coupling agent, known ones can be used. Two or more of these may be used in combination. The amount used at this time is preferably 0.01% by weight or more and 2% by weight or less based on the polyimide precursor.

Polyimide precursors such as polyamic acid, polyamic acid ester, and polyamic acid silyl ester can be synthesized by reacting a diamine compound with a tetracarboxylic acid or a derivative thereof. Examples of derivatives include acid anhydrides, active esters, and active amides of the tetracarboxylic acid. The reaction method for the polymerization reaction is not particularly limited as long as the desired polyimide precursor can be produced, and any known reaction method can be used.

A specific reaction method is to charge a predetermined amount of all the diamine components and solvent into a reactor and dissolve them, then add a predetermined amount of the acid dianhydride component, and stir at room temperature to 120°C for 0.5 to 30 hours. Examples include methods to do so.

The aforementioned siloxane compound is added to the solution of the polyimide precursor obtained by the above method, and the mixture is stirred at room temperature to 60° C. for 0.5 to 30 hours. At this time, the aforementioned solvent, surfactant, internal mold release agent, and coupling agent may be added.

The moisture content in the polyimide precursor resin composition is preferably 0.05% by mass or more, more preferably 0.1% by mass or more. By setting the moisture content of the polyimide precursor resin composition to the lower limit value or more, it is possible to reduce the residual stress of the resulting polyimide resin composition without deteriorating the storage stability of the polyimide precursor resin composition. can. Furthermore, the moisture content in the polyimide precursor resin composition is preferably 3.0% by mass or less, more preferably 2.0% by mass or less. When the moisture content of the polyimide precursor resin composition is equal to or less than the above-mentioned upper limit, hydrolysis of the polyimide precursor resin can be suppressed and storage stability can be improved. The moisture content here refers to a value measured by the Karl Fischer method with the liquid temperature adjusted to 23°C. To measure the moisture content using the Karl Fischer method, use a Karl Fischer moisture titration device (for example, “MKS-520” (trade name, manufactured by Kyoto Electronics Industry Co., Ltd.)), and use a Based on this, the moisture content is measured using the volumetric titration method.

<Polyimide resin composition>
The polyimide resin composition according to the embodiment of the present invention is obtained by imidizing the above polyimide precursor resin composition.

The imidization method is not particularly limited, but examples include imidization by heating and chemical imidization. Among them, from the viewpoint of heat resistance of the resulting polyimide resin composition and transparency in the visible light region, imidization by heating is is preferred. The polyimide precursor resin composition film is heated in a range of 180° C. or higher and 550° C. or lower to convert it into a polyimide resin composition. This is called a thermal imidization process. Note that the thermal imidization step may be performed after some other step is performed after the step of evaporating the solvent from the coating film.

Specifically, the step of evaporating the solvent from the coating film may be performed by vacuum drying or heating the coating film, but in consideration of the transparency of the film after imidization, it is preferable to evaporate the solvent without causing cloudiness. For drying, use a hot plate, oven, infrared rays, vacuum chamber, etc.

Among these, it is preferable to perform vacuum drying using a vacuum chamber, and it is more preferable to further perform heating for drying after vacuum drying, or to perform heating for drying while vacuum drying. This makes it possible to shorten the drying treatment time, and furthermore, it is possible to obtain a uniform coating film. The heating temperature for drying varies depending on the type and purpose of the object to be heated, and is preferably carried out at a temperature ranging from room temperature to 170° C. for 1 minute to several hours. Room temperature is usually 20 to 30°C, preferably 25°C. Furthermore, the drying step may be performed multiple times under the same conditions or under different conditions.

The atmosphere in the thermal imidization step is not particularly limited, and may be air or an inert gas such as nitrogen or argon. However, since the polyimide resin composition of the present invention is required to be colorless and transparent, it is preferable to perform thermal imidization by heating in an atmosphere with an oxygen concentration of 3% or less. In general, by lowering the oxygen concentration, it is possible to reduce oxidation coloring of polyimide films during heating and maintain high transparency. However, on the other hand, it is difficult to control oxygen concentration on the order of ppm at manufacturing sites. Often. The polyimide resin composition of the present invention is preferable if the oxygen concentration during heat curing is 3% or less, since higher transparency can be maintained.

Further, the time required to reach the heating temperature for thermal imidization is not particularly limited, and a temperature raising method can be selected depending on the heating type of the production line. For example, the polyimide precursor resin composition formed on the base material may be heated in an oven from room temperature to the heating temperature for thermal imidization over 5 to 120 minutes, or the temperature may be raised to 180°C in advance. The polyimide precursor resin composition formed on the base material may be suddenly put into an oven heated to a temperature of 550° C. or less to perform the heat treatment. Further, if necessary, heating may be performed under reduced pressure.

<Membrane of polyimide resin composition>
The film-like material of the polyimide resin composition according to the embodiment of the present invention is a film containing polyimide obtained by imidizing the polyimide precursor (A).

A film-like material of a polyimide resin composition can be obtained, for example, by the following method. The method includes a step of coating the polyimide precursor resin composition on a substrate to form a coating film, a step of evaporating the solvent from the coating film, and a step of imidizing the polyimide precursor.

Examples of methods for coating the polyimide precursor resin composition on a substrate to form a coating include roll coating, spin coating, slit coating, and coating using a doctor blade, coater, etc. It will be done. Note that the thickness, surface smoothness, etc. of the film may be controlled by repeating coating. Among these, the slit die coating method is preferred from the viewpoint of surface smoothness and film thickness uniformity of the coating film.

The thickness of the coating film is appropriately selected depending on the desired use and is not particularly limited, but is, for example, 1 to 500 μm, preferably 2 to 250 μm, particularly preferably 5 to 125 μm.

Substrates include polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, polybutylene terephthalate (PBT) film, silicon wafer, glass wafer, oxide wafer, glass substrate (including alkali-free glass substrate), Cu substrate, and Examples include SUS board. Among these, alkali-free glass is preferred from the viewpoint of surface smoothness and dimensional stability during heating.

Specifically, the step of evaporating the solvent from the coating film may be performed by vacuum drying or heating the coating film, but in consideration of the transparency of the film after imidization, it is preferable to evaporate the solvent without causing cloudiness. For drying, use a hot plate, oven, infrared rays, vacuum chamber, etc.

Among these, it is preferable to perform vacuum drying using a vacuum chamber, and it is more preferable to further perform heating for drying after vacuum drying, or to perform heating for drying while vacuum drying. This makes it possible to shorten the drying treatment time, and furthermore, it is possible to obtain a uniform coating film. The heating temperature for drying varies depending on the type and purpose of the object to be heated, and is preferably carried out at a temperature ranging from room temperature to 170° C. for 1 minute to several hours. Room temperature is usually 20 to 30°C, preferably 25°C. Furthermore, the drying step may be performed multiple times under the same conditions or under different conditions.

The film obtained through the above film forming process can be used after being peeled off from the substrate, or can be used as it is without being peeled off.

Examples of peeling methods include immersion in water, immersion in a chemical solution such as hydrochloric acid or hydrofluoric acid, and laser light in the wavelength range from ultraviolet to infrared light to the interface between the polyimide resin composition film and the substrate. However, when peeling is performed after creating a device on a polyimide resin composition film, it is necessary to perform the peeling without damaging the device, so ultraviolet light is used. Peeling using a laser is preferred. Note that in order to facilitate peeling, a release agent may be applied to the substrate or a sacrificial layer may be formed before applying the polyimide precursor resin composition to the substrate. Examples of the mold release agent include silicone-based, fluorine-based, aromatic polymer-based, alkoxysilane-based, and the like. Examples of the sacrificial layer include a metal film, a metal oxide film, an amorphous silicon film, and the like.

The thickness of the resulting film is appropriately selected depending on the desired use, but is preferably 1 to 100 μm, more preferably 5 to 30 μm, particularly preferably 7 to 20 μm.

The tensile modulus of the film obtained from the polyimide resin composition of the present invention is preferably 1.5 GPa or more and 2.5 GPa or less. When the tensile modulus is within the above range, it is possible to suppress breakage when the film is peeled from the substrate and further reduce residual stress.

The elongation at break of the film obtained from the polyimide resin composition of the present invention is preferably 10% or more, more preferably 15% or more, particularly preferably 20% or more. It is preferable that the elongation at break of the membrane is 10% or more because it has excellent bending resistance.

The glass transition temperature of the film obtained from the polyimide resin composition of the present invention is 250°C or higher, preferably 300°C or higher. Since the film is heated to 250° C. or higher during device fabrication, if the glass transition temperature is less than 250° C., the film may be deformed when used for such purposes.

<Laminated body>
A laminate according to an embodiment of the present invention includes a film-like material of the polyimide resin composition and an inorganic film.

Examples of inorganic films include gas barrier layers. The gas barrier layer plays a role in preventing the permeation of water vapor, oxygen, and the like. In order to suppress deterioration of electronic devices due to moisture and oxygen, it is preferable to provide gas barrier properties by providing a gas barrier layer on the film-like material of the polyimide resin composition.

Materials constituting the gas barrier layer include metal oxides, metal nitrides, metal oxynitrides, and metal carbonitrides. Examples of the metal elements contained in these include aluminum (Al), silicon (Si), titanium (Ti), tin (Sn), zinc (Zn), zirconium (Zr), indium (In), and niobium (Nb). , molybdenum (Mo), tantalum (Ta), calcium (Ca), and the like.

In particular, it is preferable that the gas barrier layer contains at least one of silicon oxide, silicon nitride, silicon oxynitride, and silicon carbonitride. This is because by using these materials, it becomes easier to obtain a uniform and dense film, and the oxygen barrier properties of the gas barrier layer are further improved.

Moreover, from the viewpoint of further improving oxygen barrier properties, it is preferable that the gas barrier layer contains a component represented by SiOhNi. h and i are values that satisfy 0<h≦1, 0.55≦i≦1, and 0≦h/i≦1.

An inorganic film in which two or more gas barrier layers are laminated, and among these inorganic films, the layer in contact with the film-like material of the polyimide resin composition is SiOj (j is a value satisfying 0.5≦j≦2). ) is preferably formed from the components represented by This is because damage to the polyimide film when forming the first layer of the inorganic film is reduced, so deterioration of surface smoothness after the formation of the inorganic film and discoloration during the formation of the inorganic film can be suppressed.

The method for manufacturing a laminate according to the embodiment of the present invention includes, for example, the following steps (1) to (4).
(1) A step of applying a polyimide precursor resin composition onto a support substrate.
(2) A step of removing the solvent from the applied polyimide precursor resin composition.
(3) A step of imidizing a polyimide precursor to obtain a film-like material of a polyimide resin composition.
(4) A step of forming an inorganic film on the film-like material of the polyimide resin composition.

Steps (1) to (3) can be carried out in accordance with the method for producing a film-like product of a polyimide resin composition described above.

In step (4), an inorganic film is formed, for example, as follows.

The inorganic film can be produced by, for example, a vapor deposition method such as a sputtering method, a vacuum evaporation method, an ion plating method, or a plasma CVD method, in which a material is deposited in a gas phase to form a film. Among these, it is preferable to use the sputtering method or the plasma CVD method because a more uniform film with high oxygen barrier properties can be obtained.

There is no limit to the number of layers of the inorganic film, and it may be one layer or a multilayer of two or more layers, but a multilayer of two or more layers is preferable from the viewpoint of achieving both flexibility and gas barrier properties. Examples of multilayer films include a gas barrier layer in which the first layer is made of SiN and the second layer is made of SiO, and a gas barrier layer in which the first layer is made of SiON and the second layer is made of SiO.

The total thickness of the inorganic film is preferably 10 nm or more, more preferably 100 nm or more, from the viewpoint of improving oxygen barrier properties. On the other hand, from the viewpoint of improving the bending resistance of the device, the total thickness of the inorganic film is preferably 1 μm or less, more preferably 500 nm or less.

The laminate obtained through the above steps can be used after being peeled off from the substrate, or can be used as is without being peeled off.

As an example of the peeling method, a method similar to the method for peeling the film-like material of the polyimide resin composition from the substrate described above can be used.

<Application>
The polyimide precursor resin composition according to the embodiment of the present invention and the laminate obtained therefrom can be used in electronic devices. More specifically, it can be used for display devices such as liquid crystal displays, organic EL displays, touch panels, electronic paper, color filters, and micro LED displays, and light receiving devices such as solar cells and CMOS. Preferably, these electronic devices are flexible devices. The film-like material of the polyimide resin composition described above is preferably used as a substrate in these electronic devices, especially as a flexible substrate.

The manufacturing process of a flexible device includes a process of forming a circuit necessary for a display device or a light receiving device on a laminate formed on a substrate. For example, an amorphous silicon TFT can be formed on a flexible substrate. Furthermore, structures necessary for a device can be formed thereon by known methods. As described above, the laminate on which the circuit and the like are formed can be peeled off from the substrate using a known method such as laser irradiation to obtain a flexible device.

The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

<Materials>
(acid dianhydride)
BPDA: 3,3'4,4'-biphenyltetracarboxylic dianhydride BSAA: 2,2-bis(4-(3,4-dicarboxyphenoxy)phenyl)propane dianhydride 6FDA: 2,2-bis (3,4-dicarboxyphenyl)hexafluoropropanihydride.

(Diamine compound)
CHDA: trans-1,4-diaminocyclohexane 4,4'-DDS: 4,4'-diaminodiphenylsulfone 6FODA: 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether 3, 5-DABA: 3,5-diaminobenzoic acid

(solvent)
NMP: N-methyl-2-pyrrolidone.

(siloxane compound)
D3-Me: hexamethylcyclotrisiloxane (formula (2), n=1)
D4-Me: octamethylcyclotetrasiloxane (formula (2), n=2)
D4-Ph: octaphenylcyclotetrasiloxane (formula (2), n=2)
D6-Me: dodecamethylcyclohexasiloxane (formula (2), n=4)
D9-Me: octadecamethylcyclononasiloxane (formula (2), n=7)
X-21-5841: Methyl silicone oil modified with silanol at both ends (formula (3), m=13)
KF-9701: Methyl silicone oil modified with silanol at both ends (formula (3), m=39).

(Alkali-soluble resin)
Alkali-soluble resin (A): 0.4 equivalent of glycidyl methacrylate added to the carboxyl group of a copolymer consisting of methacrylic acid/methyl methacrylate/styrene = 54/23/23 (mol%). (Weight average molecular weight (Mw): 29,000).

(conductive particles)
A-1: Silver particles with a surface carbon coating layer having an average thickness of 1 nm and a primary particle diameter of 40 nm (manufactured by Nisshin Engineering Co., Ltd.)
A-2: Silver particles with a primary particle diameter of 0.7 μm (manufactured by Mitsui Kinzoku Co., Ltd.).

<Evaluation>
(1) Measurement of moisture content of varnish Using a Karl Fischer moisture content titration device “MKS-520” (trade name, manufactured by Kyoto Electronics Co., Ltd.), water content in a solution at 23°C was measured according to the volumetric titration method of JIS K0068. Moisture was measured. However, if the resin precipitated in the titration solvent, a 1:4 mixed solution of Aquamicron GEX (manufactured by Mitsubishi Chemical Corporation) and N-methylpyrrolidone was used as the titration solvent.

(2) Measurement of imidization rate The imidization rate of the polyimide precursor contained in the varnish was measured by the following method.

- Preparation of polyimide precursor sample (i) A polyimide precursor composition to be measured was applied onto a silicon wafer to a film thickness of 1 μm or more and 10 μm or less to prepare a coating film sample.

(ii) The coating sample was immersed in tetrahydrofuran (THF) for 20 minutes to replace the solvent in the coating sample with tetrahydrofuran (THF).

(iii) The paint film sample was taken out from the THF, and N ₂ gas was sprayed onto the THF adhering to the surface of the paint film sample to remove it. The coating film sample was dried by processing at a temperature of 5° C. or higher and 25° C. or lower for 12 hours or more under a reduced pressure of 10 mmHg or lower to prepare a polyimide precursor sample.

- Preparation of 100% imidized standard sample (iv) In the same manner as in (i) above, the polyimide precursor composition to be measured was applied onto a silicon wafer to prepare a coating film sample.

(v) The coating film sample was heated at 380° C. for 60 minutes in a nitrogen atmosphere to perform an imidization reaction to prepare a 100% imidization standard sample.

- Measurement and analysis (vi) Using a Fourier transform infrared spectrophotometer (FT-730 manufactured by Horiba, Ltd.), the infrared absorption spectra of the 100% imidized standard sample and the polyimide precursor sample were measured. Ratio of the absorption peak derived from the imide bond (Ab' (1780 cm -1 )) near 1780 cm ^-1 to the absorption peak derived from the aromatic ring (Ab' (1500 cm ^-1 )) near 1500 cm ^-1 of a 100% imidized ^standard sample I'(100) was calculated.

(vii) In the same manner, a polyimide precursor sample was measured, and the absorption peak derived from the imide bond (Ab (1500 cm ^-1 )) near 1780 cm ^-1 was compared to the absorption peak derived from the aromatic ring (Ab (1500 cm ^-1 )) near 1500 cm -1 . The ratio I(x) of 1780 cm ⁻¹ )) was determined.

Then, using the measured absorption peaks I'(100) and I(x), the imidization rate of the polyimide precursor was calculated based on the following formula.
・Formula: Imidization rate (%) of polyimide precursor = I(x)×100/I'(100)
・Formula: I'(100)=(Ab'(1780cm ^-1 ))/(Ab'(1500cm ^-1 ))
-Formula: I(x)=(Ab(1780cm ^-1 ))/(Ab(1500cm ^-1 )).

(3) Change in viscosity of varnish The varnish obtained in each synthesis example was placed in a clean bottle (manufactured by Aicello Co., Ltd.) and stored at 23°C for 7 days, and the rate of change in viscosity before and after that was calculated from the following formula.

(Viscosity change rate/%) = 100 x ((viscosity after storage) - (viscosity before storage)) / (viscosity before storage)
The viscosity was measured using a viscometer RE-215/U (manufactured by Toki Sangyo Co., Ltd.) according to JIS K7117-2 (1999). The attached constant temperature bath was set at 23.0°C, and the measurement temperature was always kept constant.

(4) Preparation of polyimide resin composition film (on glass substrate-1) Apply varnish to a 300 mm x 350 mm x 0.5 mm thick glass substrate 26 (AN-100 manufactured by Asahi Glass Co., Ltd.) using a slit coater (Toray Co., Ltd.). (manufactured by Engineering Co., Ltd.) to give a film thickness of 10±0.5 μm after curing. Thereafter, prebaking was performed using a heating vacuum dryer and a hot plate. The heated vacuum dryer heated the upper plate to 60°C and the lower plate to 40°C, and dried under conditions such that the internal pressure was reduced to 60 Pa over 150 seconds. Drying was carried out for 6 minutes using a hot plate preheated to 120°C. The pre-baked film thus obtained was heated to 400°C over 80 minutes under a nitrogen stream (oxygen concentration 100 ppm or less) using an inert oven (INH-21CD manufactured by Koyo Thermo Systems Co., Ltd.). The mixture was held for 30 minutes and cooled to 50°C at a rate of 5 to 8°C/min to produce a polyimide resin composition film (on glass substrate-1).

(5) Preparation of polyimide resin composition film (on glass substrate-2) A 50 mm x 50 mm x 1.1 mm thick glass substrate (Tempax) was coated with a spin coater MS-A200 manufactured by Mikasa Co., Ltd. The varnish was spin-coated so that the film thickness after curing was 10±0.5 μm. Thereafter, a prebaking process was performed at 120° C. for 6 minutes using a hot plate D-SPIN manufactured by Dainippon Screen Co., Ltd. The prebaked film was heated to 400°C at a rate of 4°C/min under a nitrogen stream (oxygen concentration 100 ppm or less) using an inert oven (INH-21CD manufactured by Koyo Thermo Systems Co., Ltd.), held for 30 minutes, and heated to 5 to 8°C. /min to 50° C. to produce a film-like material (on glass substrate-2) of the polyimide resin composition.

(6) Preparation of film-like material of polyimide resin composition (on silicon substrate)
A varnish was spin-coated onto a 6-inch silicon substrate using a coating and developing device Mark-7 manufactured by Tokyo Electron Ltd. so that the film thickness after curing was 10±0.5 μm. Thereafter, a prebaking process was performed at 120° C. for 6 minutes using a Mark-7 hot plate. The prebaked film was heated to 400°C at a rate of 4°C/min under a nitrogen stream (oxygen concentration 100 ppm or less) using an inert oven (INH-21CD manufactured by Koyo Thermo Systems Co., Ltd.), held for 30 minutes, and heated to 5 to 8°C. /min to 50° C. to produce a film-like material (on a silicon substrate) of the polyimide resin composition.

(7) Measurement of light transmittance (T) The light transmittance at a wavelength of 450 nm was measured using an ultraviolet-visible spectrophotometer (MultiSpec1500, manufactured by Shimadzu Corporation). Note that the film-like material (on glass substrate-2) of the polyimide resin composition prepared in (5) was used for the measurement.

(8) Measurement of haze value Using a direct reading haze computer (manufactured by Suga Test Instruments Co., Ltd. HGM2DP, C light source), the haze value ( %) was measured. Note that the average value of three measurements was used as each value.

(9) Measurement of 1% weight loss temperature (Td1) Measurement was performed under a nitrogen stream using a thermogravimetric measuring device (TGA-50, manufactured by Shimadzu Corporation). The temperature was raised under the following conditions. In the first step, the sample was heated to 150° C. at a temperature increase rate of 3.5° C./min to remove adsorbed water from the sample, and in the second step, it was cooled to room temperature at a temperature decreasing rate of 10° C./min. In the third stage, the main measurement was performed at a temperature increase rate of 10° C./min to determine the 1% thermogravimetric loss temperature. Note that the film-like material (on glass substrate-1) of the polyimide resin composition prepared in (4) was used for the measurement.

(10) Measurement of glass transition temperature (Tg) and coefficient of linear expansion (CTE) Measurement was performed under a nitrogen stream using a thermomechanical analyzer (EXSTAR6000TMA/SS6000, manufactured by SII Nanotechnology Co., Ltd.). The temperature was raised under the following conditions. In the first stage, the sample was heated to 150°C at a temperature increase rate of 5°C/min to remove adsorbed water from the sample, and in the second stage, it was air-cooled to room temperature at a cooling rate of 5°C/min. In the third stage, main measurements were performed at a temperature increase rate of 5° C./min to determine the glass transition temperature. Furthermore, the coefficient of linear expansion (CTE) was determined from the average of the coefficients of linear expansion from 50 to 200°C in the third stage. Note that the film-like material (on glass substrate-1) of the polyimide resin composition prepared in (4) was used for the measurement.

(11) Measurement of 90° peel strength (90° peel test)
The film-like material of the resin composition obtained in (4) (on the glass substrate -1) was cut into pieces 10 mm wide and 100 mm long, and heated at 120°C for 6 minutes using a hot plate D-SPIN manufactured by Dainippon Screen Co., Ltd. After performing the dehydration baking treatment, a 90° peel test was conducted at a pulling speed of 50 mm/min. In the 90° peel test, the 90° peel strength (N /cm) was measured.

(12) Measurement of residual stress Measurement was performed using a thin film stress measuring device FLX-3300-T manufactured by KLA-Tencor. The measurement was performed using the polyimide resin composition film (on a silicon substrate) prepared in (6), and the polyimide resin composition film was placed in a room with a room temperature of 23°C and a humidity of 55% before measurement. It was left undisturbed for 24 hours.

(13) Creation of touch panel and evaluation of heat and humidity resistance A touch panel was created using the method described below, and then a heat and humidity test was conducted.

○Preparation of conductive composition Production example 1: Preparation of conductive composition (AE-1) 80 g of conductive particles (A-1), surfactant (“DISPERBYK” (registered trademark) 21116: DIC Corporation) 4.06 g of PGMEA, 98.07 g of PGMEA, and 98.07 g of DPM were mixed and treated with a homogenizer at 1200 rpm for 30 minutes. Furthermore, the mixture was dispersed using a high-pressure wet medialess atomization device Nanomizer (manufactured by Nanomizer Co., Ltd.) to obtain a silver dispersion having a silver content of 40% by mass.

20 g of alkali-soluble resin (A) as an organic compound, 0.6 g of ethyl acetoacetate aluminum diisopropylate (ALCH: manufactured by Kawaken Fine Chemicals Co., Ltd.) as a metal chelate compound, and a photopolymerization initiator (NCI-831: manufactured by Kawaken Fine Chemicals Co., Ltd.). ) manufactured by ADEKA) and 12.0 g of PE-3A were mixed, 132.6 g of PGMEA and 52.6 g of DPM were added and stirred to obtain an organic liquid I for a conductive composition.

The silver dispersion liquid and organic liquid I were mixed at a mass ratio of 72.6/27.4 to obtain a conductive composition (AE-1).

○Preparation of insulating composition Production example 2: Preparation of insulating composition (OA-1) In a clean bottle, 50.0 g of cardo-based resin (V-259ME: manufactured by Nippon Steel Sumitomo Chemical Co., Ltd.) and a crosslinking monomer ( TAIC: manufactured by Nippon Kasei Co., Ltd.) 18.0 g, crosslinking monomer (M-315: manufactured by Toagosei Co., Ltd.) 10.0 g, epoxy compound (PG-100: manufactured by Osaka Gas Chemical Co., Ltd.) 20.0 g , 0.2 g of a photopolymerization initiator (OXE-01: manufactured by BASF Corporation) was added, and the mixture was stirred for 1 hour to obtain an insulating composition OA-1.

○Creation of touch panel (formation of first wiring layer)
Conductive composition AE-1 was applied onto the polyimide resin composition film prepared in (4) using a spin coater (Mikasa Co., Ltd. "1H-360S (trade name)") at 300 rpm. Spin coating was performed for 10 seconds and at 500 rpm for 2 seconds. Thereafter, prebaking was performed at 100° C. for 2 minutes using a hot plate (“SCW-636 (trade name)” manufactured by Dainippon Screen Mfg. Co., Ltd.) to produce a prebaked film. Using a parallel light mask aligner (“PLA-501F (trade name)” manufactured by Canon Inc.) and using an ultra-high pressure mercury lamp as a light source, the prebaked film was exposed through a desired mask. Thereafter, using an automatic developing device ("AD-2000 (product name)" manufactured by Takizawa Sangyo Co., Ltd.), shower development was performed for 60 seconds with a 0.045% by mass potassium hydroxide aqueous solution, and then rinsed with water for 30 seconds. , pattern processing was performed.

The patterned substrate was cured in an oven at 250° C. for 30 minutes in air (oxygen concentration 21%) to form a first wiring layer.

(Formation of first insulating layer)
The insulating composition OA-1 was spin coated on the substrate on which the first wiring layer was formed using a spin coater at 650 rpm for 5 seconds. Thereafter, a prebaked film was prepared by prebaking at 100° C. for 2 minutes using a hot plate. Using a parallel light mask aligner and an ultra-high pressure mercury lamp as a light source, the prebaked film was exposed through a desired mask. Thereafter, using an automatic developing device, shower development was performed for 60 seconds with a 0.045% by mass potassium hydroxide aqueous solution, followed by rinsing with water for 30 seconds, and pattern processing was performed. The patterned substrate was cured in an oven at 250° C. for 60 minutes in air (oxygen concentration 21%) to form an insulating layer.

(Formation of second wiring layer)
A second wiring layer was formed on the substrate on which the first insulating layer was formed in the same manner as the first wiring layer.

(Formation of second insulating layer)
A second insulating layer was formed on the substrate on which the second wiring layer was formed in the same manner as the first insulating layer.

Finally, a touch panel was obtained by cutting the periphery of the region where the first wiring layer and the second wiring layer were formed from the upper surface with a single blade, and mechanically peeling from the cut end surface.

○Evaluation of heat and humidity resistance For measurement of heat and humidity resistance, an insulation deterioration characteristic evaluation system "ETAC SIR13" (manufactured by Kusumoto Kasei Co., Ltd.) was used. Electrodes were attached to the ends of the first wiring layer and the second wiring layer, respectively, and the touch panel was placed in a high-temperature, high-humidity bath set at 85° C. and 85% RH. After 5 minutes had passed since the environment inside the tank had stabilized, a voltage was applied between the electrodes of the first wiring layer and the second wiring layer, and the change in insulation resistance over time was measured. A voltage of 10 V was applied using the first wiring layer as the positive electrode and the second wiring layer as the negative electrode, and the resistance value for 500 hours was measured at 5 minute intervals. When the measured resistance value reached the fifth power of 10 or less, it was determined that a short circuit occurred due to poor insulation, the printing pressure was stopped, and the test time up to that point was taken as the short circuit time. Moisture and heat resistance was evaluated according to the following evaluation criteria, and a rating of 2 or higher was considered to be a pass.
6: Short circuit time is 400 hours or more 5: Short circuit time is 300 hours or more and less than 400 hours 4: Short circuit time is 200 hours or more and less than 300 hours 3: Short circuit time is 100 hours or more and less than 200 hours 2: Short circuit time is 50 hours or more and less than 200 hours Less than hours 1: Short circuit time less than 50 hours.

Synthesis example 1:
A thermometer and a stirring bar with stirring blades were set in a 300 mL four-necked flask. Next, 160 g of NMP was added under a stream of dry nitrogen, and the temperature was raised to 60°C. After raising the temperature, 10.53 g (92.18 mmol) of CHDA was added while stirring, and the mixture was washed with 20 g of NMP. After confirming that CHDA was dissolved, 18.98 g (64.52 mmol) of BPDA and 14.39 g (27.65 mmol) of BSAA were added and washed with 20 g of NMP. After 4 hours, it was cooled to obtain a varnish. When the imidization rate of the polyimide precursor resin was measured using the obtained varnish, it was found to be 15%.

Synthesis example 2:
A thermometer and a stirring bar with stirring blades were set in a 300 mL four-necked flask. Next, 160 g of NMP was added under a stream of dry nitrogen, and the temperature was raised to 35°C. After raising the temperature, 10.53 g (92.18 mmol) of CHDA was added while stirring, and the mixture was washed with 20 g of NMP. After confirming that CHDA was dissolved, 18.98 g (64.52 mmol) of BPDA and 14.39 g (27.65 mmol) of BSAA were added and washed with 20 g of NMP. After 4 hours, it was cooled to obtain a varnish. When the imidization rate of the polyimide precursor resin was measured using the obtained varnish, it was found to be 3%.

Synthesis example 3:
A thermometer and a stirring bar with stirring blades were set in a 300 mL four-necked flask. Next, 160 g of NMP was added under a stream of dry nitrogen, and the temperature was raised to 60°C. After raising the temperature, 10.53 g (92.18 mmol) of CHDA and 0.126 g (1.84 mmol) of imidazole were added while stirring, and the mixture was washed with 20 g of NMP. After confirming that CHDA and imidazole were dissolved, 18.98 g (64.52 mmol) of BPDA and 14.39 g (27.65 mmol) of BSAA were added and washed with 20 g of NMP. Thereafter, the temperature was raised to 80°C, stirred for 4 hours, and cooled. When the imidization rate of the polyimide precursor resin was measured using the obtained varnish, it was found to be 40%.

Synthesis example 4:
A thermometer and a stirring bar with stirring blades were set in a 300 mL four-necked flask. Next, 160 g of NMP was added under a stream of dry nitrogen, and the temperature was raised to 60°C. After raising the temperature, 10.53 g (92.18 mmol) of CHDA and 0.044 g (0.65 mmol) of imidazole were added while stirring, and the mixture was washed with 20 g of NMP. After confirming that CHDA and imidazole were dissolved, 18.98 g (64.52 mmol) of BPDA and 14.39 g (27.65 mmol) of BSAA were added and washed with 20 g of NMP. Thereafter, the temperature was raised to 80°C, stirred for 4 hours, and cooled. When the imidization rate of the polyimide precursor resin was measured using the obtained varnish, it was found to be 25%.

Purification Example 1: Reduction of cyclic siloxane compound The amount of cyclic siloxane compound (D4-Me) contained in unpurified X-22-9409 was measured by gas chromatography (GC) and found to be 3000 ppm. 500 g of this unpurified X-22-9409 was placed in a flask, and purified by stripping at 250° C./1330 Pa for 3 hours while blowing nitrogen gas. The amount of the cyclic siloxane compound (D4-Me) contained in the purified X-22-9409 (hereinafter referred to as X-22-9409A) was measured by GC and found to be 60 ppm.

Synthesis example 5:
A thermometer and a stirring bar with stirring blades were set in a 300 mL four-necked flask. Next, 160 g of NMP was added under a stream of dry nitrogen, and the temperature was raised to 60°C. After raising the temperature, 9.810 g (85.91 mmol) of CHDA and 2.349 g of X-22-9409A were added while stirring, and the mixture was washed with 20 g of NMP. After confirming that CHDA was dissolved, 18.06 g (61.38 mmol) of BPDA and 13.69 g (26.30 mmol) of BSAA were added and washed with 20 g of NMP. It was cooled after 4 hours. The amount of cyclic siloxane oligomer contained in the obtained varnish was measured by GC and was found to be 1 ppm or less. (The amount of cyclic siloxane oligomer relative to the polyimide precursor resin in the varnish is less than 0.01 wt%.) When the imidization rate of the polyimide precursor resin was measured using the obtained varnish, it was 14%.

Synthesis example 6:
A thermometer and a stirring bar with stirring blades were set in a 300 mL four-necked flask. Next, 160 g of NMP was added under a stream of dry nitrogen, and the temperature was raised to 60°C. After raising the temperature, 10.37 g (90.82 mmol) of CHDA was added while stirring, and the mixture was washed with 20 g of NMP. After confirming that CHDA was dissolved, 13.36 g (45.41 mmol) of BPDA and 20.17 g (45.41 mmol) of 6FDA were added, followed by washing with 20 g of NMP. It was cooled after 4 hours. When the imidization rate of the polyimide precursor resin was measured using the obtained varnish, it was found to be 17%.

Synthesis example 7:
A thermometer and a stirring bar with stirring blades were set in a 300 mL four-necked flask. Next, 160 g of NMP was added under a stream of dry nitrogen, and the temperature was raised to 60°C. After raising the temperature, 8.508 g (74.51 mmol) of CHDA and 6.167 g (24.84 mmol) of 4,4'-DDS were added while stirring, and the mixture was washed with 20 g of NMP. After confirming that CHDA and 4,4'-DDS were dissolved, 29.23 g (99.34 mmol) of BPDA was added and washed with 20 g of NMP. It was cooled after 4 hours. When the imidization rate of the polyimide precursor resin was measured using the obtained varnish, it was found to be 13%.

Synthesis example 8:
A thermometer and a stirring bar with stirring blades were set in a 300 mL four-necked flask. Next, 160 g of NMP was added under a stream of dry nitrogen, and the temperature was raised to 60°C. After raising the temperature, 8.105 g (70.97 mmol) of CHDA and 7.955 g (23.66 mmol) of 6FODA were added while stirring, and the mixture was washed with 20 g of NMP. After confirming that CHDA and 6FODA were dissolved, 27.84 g (94.63 mmol) of BPDA was added and washed with 20 g of NMP. It was cooled after 4 hours. When the imidization rate of the polyimide precursor resin was measured using the obtained varnish, it was found to be 15%.

Synthesis example 9:
A thermometer and a stirring bar with stirring blades were set in a 300 mL four-necked flask. Next, 160 g of NMP was added under a stream of dry nitrogen, and the temperature was raised to 60°C. After raising the temperature, 7.761 g (67.97 mmol) of CHDA, 7.935 g (23.60 mmol) of 6FODA, and 0.431 g (2.832 mmol) of 3,5-DABA were added while stirring, and the mixture was washed with 20 g of NMP. After confirming that CHDA, 6FODA, and 3,5-DABA were dissolved, 27.78 g (94.40 mmol) of BPDA was added and washed with 20 g of NMP. It was cooled after 4 hours. When the imidization rate of the polyimide precursor resin was measured using the obtained varnish, it was found to be 15%.

Example 1:
To 100 g of the varnish obtained in Synthesis Example 1, 0.018 g of the siloxane compound D3-Me (0.1 part by mass based on 100 parts by mass of the polyimide precursor) was added. Using the obtained varnish, a polyimide resin film was formed by the method described above and evaluated.

Examples 2 to 25, Comparative Examples 1 to 6:
Evaluation was performed in the same manner as in Example 1, except that the varnish used, the siloxane compound and amount added, and the tetracarboxylic acid compound and amount added were changed according to Table 1. In addition, the upward arrow in the acid dianhydride and diamine columns in the table indicates that the composition is the same as the one above.

However, in Examples 13 and 14, 2.73 g and 3.47 g of water were added to the varnish obtained in the same manner as in Example 1, respectively, and the mixture was stirred at 25° C. for 15 minutes. The moisture content of these varnishes was 2.8% by weight and 3.5% by weight, respectively.

Further, in Example 15, the following varnish was used. 10 g of Molecular Sieve 4A (manufactured by Nacalai Tesque), which is a dehydrating agent, was added to the varnish obtained in the same manner as in Example 1, the mixture was tightly stoppered, and the mixture was allowed to stand at 25° C. for 24 hours. Thereafter, the molecular sieve was removed by filtration using a PTFE filter with a pore size of 1 μm to obtain a varnish. The moisture content of this varnish was 0.05% by weight.

The evaluation results of Examples 1 to 25 and Comparative Examples 1 to 6 are shown in Table 2.

Example 26
Using the varnish obtained in Example 1, a polyimide resin composition film (on glass substrate-1) was created by the method described in (4), and SiON (film forming temperature: 350°C, A film with a thickness of 150 nm) was formed by plasma CVD. Thereafter, a touch panel was produced by the method described in (13).

Example 27
A touch panel was produced in the same manner as in Example 26 except that the varnish obtained in Example 8 was used.

Example 28
A touch panel was produced in the same manner as in Example 26 except that the varnish obtained in Example 15 was used.

Example 29
A touch panel was produced in the same manner as in Example 26 except that the varnish obtained in Example 18 was used.

Example 30
A touch panel was produced in the same manner as in Example 26 except that the varnish obtained in Example 19 was used.

Example 31
A touch panel was produced in the same manner as in Example 26 except that the varnish obtained in Example 23 was used.

Comparative example 7
A touch panel was produced in the same manner as in Example 26 except that the varnish obtained in Comparative Example 1 was used.

Table 2 shows the evaluation results of the touch panels obtained in Examples 26 to 31 and Comparative Example 7. In Examples 26 to 31, since the polyimide resin composition contains a siloxane compound, residual stress generated at the interface between the barrier layer and the polyimide resin composition film is also reduced, and cracks generated in the barrier layer during the heat and humidity test are reduced. It is thought that this was because the moisture and heat resistance was suppressed.

Claims (17)

A polyimide precursor resin composition containing (A) a polyimide precursor containing a unit structure represented by general formula (1), (B) a compound represented by general formula (2) , and (C) a solvent. Based on 100 parts by mass of the polyimide precursor (A), 0.0% of the compound represented by the general formula (2) (B) was added. A polyimide precursor resin composition characterized in that it contains 01 to 0.5 parts by mass and has a moisture content value of 0.05% by mass or more as measured by Karl Fischer method.

(In general formula (1), R ¹ represents a tetravalent organic group, and R ² represents a divalent organic group. X ¹ and X ² each independently represent a hydrogen atom, a carbon number of 1 to 10 (Indicates a monovalent organic group or a monovalent alkylsilyl group with 1 to 10 carbon atoms.)

(In general formula (2), a plurality of R ³ 's may be the same or different, and include an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and Represents a group selected from aryl groups having 6 to 15 carbon atoms. Also, n represents an integer of 1 to 38. ) The polyimide precursor resin composition according to claim 1, wherein the imidization rate of the polyimide precursor (A) is 1% or more and 50% or less. The polyimide precursor resin composition according to claim 1 or 2, which has a moisture content value of 3.0% by mass or less as measured by the Karl Fischer method. R ¹ in general formula (1) is a group represented by any one of formulas (4) to (10), and R ² in general formula (1) is any one of formulas (11) to (13). The polyimide precursor resin composition according to any one of claims 1 to 3, which is a divalent group represented by:

(In formulas (4) to (10), R ⁶ each independently represents a hydrogen atom or an electron-withdrawing group. X ³ represents a direct bond, ester bond, amide bond, ether bond, sulfonyl group, sulfinyl group or a sulfide bond, or a divalent organic group having 1 to 3 carbon atoms which may be substituted with a halogen atom.a each independently represents 1 or 2, and b each represents (Independently represents an integer from 1 to 3, and c represents an integer from 0 to 3.)

(In formulas (11) to (13), R ⁷ each independently represents a hydrogen atom or an electron-withdrawing group. X ⁴ represents a direct bond, ester bond, amide bond, ether bond, sulfonyl group, sulfinyl group or a sulfide bond, or a divalent organic group having 1 to 3 carbon atoms which may be substituted with a halogen atom. d represents an integer of 1 to 3, and e represents 1 or 2. , f each independently represents an integer from 0 to 4, and g represents an integer from 0 to 3.) The polyimide precursor resin composition according to any one of claims 1 to 4, wherein R ¹ and/or R ² in general formula (1) contains an aromatic ring to which an electron-withdrawing group is bonded. The polyimide precursor resin composition according to any one of claims 1 to 5, wherein R ¹ in general formula (1) contains an aromatic ring to which an electron-withdrawing group is bonded. The polyimide precursor resin composition according to any one of claims 1 to 6, wherein R ¹ in general formula (1) contains at least one type selected from structures represented by the following formulas (14) and (15). .

(In formula (14), R ⁸ represents a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and at least one of the plurality of R ⁸ is a fluorine atom or a trifluoromethyl group. In formula (15), X ⁵ represents either C(CF ₃ ), SO ₂ or SO, and R ⁹ represents a hydrogen atom, a fluorine atom or a trifluoromethyl group.) The polyimide precursor resin composition according to any one of claims 1 to 7, wherein R ² in general formula (1) contains a structure represented by the following formula (16).

(In general formula (16), R ¹⁰ is a substituted or unsubstituted phenyl group, and s represents an integer of 1 to 4.) The polyimide precursor resin composition according to any one of claims 1 to 8, further comprising (D) a tetracarboxylic acid compound represented by general formula (17).

(In the formula, R ¹¹ represents a tetravalent aromatic residue containing at least one carbon 6-membered ring, and the four carboxyl groups are directly connected to different carbon atoms in this residue, and among the four (Two pairs form a pair and are bonded to adjacent carbon atoms in a six-membered carbon ring.) (D) The content of the tetracarboxylic acid compound represented by general formula (17) is 0.01 to 1.0 parts by mass based on 100 parts by mass of the (A) polyimide precursor. polyimide precursor resin composition. The polyimide precursor resin composition according to any one of claims 1 to 10, wherein n in general formula (2) is 4 to 13. The polyimide precursor resin composition according to any one of claims 1 to 11, wherein R ³ in general formula (2) is a methyl group or a phenyl group. The polyimide precursor resin composition according to any one of claims 1 to 12 , wherein the solvent (C) is an aprotic polar solvent. A polyimide resin composition obtained by imidizing the polyimide precursor resin composition according to any one of claims 1 to 13 . A film-like product of a polyimide resin composition obtained by imidizing the polyimide precursor resin composition according to any one of claims 1 to 13 . A laminate comprising a film-like material of the polyimide resin composition according to claim 15 and an inorganic film. A flexible device comprising the laminate according to claim 16 .