JP2020023671A - Polyimide precursor resin composition, polyimide resin composition and filmy matter thereof, laminate containing the same, and flexible device - Google Patents

Abstract

To provide a polyimide precursor resin composition that makes it possible to obtain a polyimide that has transparency and high Tg and can be easily peeled from a support substrate, by short-time heating in the air.SOLUTION: A polyimide precursor resin composition has (A) a polyimide precursor containing a structure with an aromatic tetracarboxylic acid residue, an aromatic diamine residue as the main component, (B) a compound of formula (2), and (C) a solvent, (B) being 30-4000 ppm relative to the resin composition (where Ris a group selected from a C1-10 alkyl group and a C6-15 aryl group, n is 2 or 3.)SELECTED DRAWING: None

Description

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

  Organic films are more flexible, less fragile, and lighter than glass. Recently, the trend to make the display flexible by replacing the substrate of the flat panel display with an organic film has been activated.

  Examples of the resin used for the organic film include polyester, polyamide, polyimide, polycarbonate, polyethersulfone, acryl, epoxy, and cycloolefin polymer. Among these, polyimide is suitable as a display substrate as a high heat-resistant resin. However, a general polyimide resin is colored brown or yellow due to a high aromatic ring density, has a low transmittance in a visible light region, and is difficult to use in a field where transparency is required.

  To address the problem of improving the transparency of such a polyimide, Patent Document 1 discloses 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 [benzamide) -4-hydroxyphenyl] hexafluoropropane (HFHA) has high heat resistance and light transmittance.

  Patent Document 2 discloses a technique for obtaining a flexible touch panel using a transparent polyimide resin film obtained by baking in air.

International Publication No. 2013/24849 International Publication No. WO2018 / 84067

  Patent Document 1 discloses that polyimide has high transparency and low birefringence.However, it is necessary to perform firing for a long time in an inert oven to form a polyimide film. There was a problem that it took time and cost for the film. In addition, in order to peel off from the supporting substrate, it is necessary to irradiate with an excimer laser, and there is also a problem that the peeling is costly.

  Patent Document 2 discloses that a transparent polyimide resin film can be obtained by performing baking in air for 30 minutes. However, the glass transition temperature of the transparent polyimide resin film described in Patent Document 2 is about 220 ° C. to 230 ° C., and there is a problem that the glass transition temperature is low. When a polyimide having a low glass transition temperature is used, for example, if a touch panel or a color filter is formed after forming an inorganic film on the polyimide resin film to improve the reliability of the panel, the inorganic film is formed because the glass transition temperature of the polyimide resin film is low. Wrinkles occur on the surface, and the surface smoothness decreases.

  Thus, there is no known method for efficiently obtaining a polyimide which is transparent, has a high glass transition temperature, and can be easily peeled from a glass supporting substrate.

  In view of the above problems, the present invention provides a polyimide precursor resin composition that can be obtained by heating a short time in the air to obtain a polyimide that is transparent, has a high glass transition temperature, and can be easily separated from a supporting substrate. The purpose is to do.

  In order to solve the above-described problems and achieve the object, the present invention provides (A) a polyimide precursor containing a structural unit represented by the general formula (1) as a main component, and (B) a polyimide precursor represented by the general formula (2). A polyimide precursor resin composition containing a compound represented by the formula (C) and a solvent, wherein (B) the content of the compound represented by the general formula (2) is 30 to 4000 ppm based on the polyimide precursor resin composition. Is a polyimide precursor resin composition.

(R ¹ represents an aromatic tetracarboxylic acid residue, R ² represents an aromatic diamine residue. X ¹ and X ² each independently represent a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. .)

(In the general formula (2), R ³ represents a group selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 15 carbon atoms. N represents 2 or 3.)

  According to the present invention, there is provided a polyimide precursor resin composition capable of obtaining a polyimide that is transparent, has a high glass transition temperature, and can be easily peeled from a glass support substrate by being heated in air for a short time. be able to. The polyimide resin composition obtained from the polyimide precursor resin composition of the present invention can be suitably used as a support substrate for a display such as an electronic device, for example, a touch panel or a color filter. By using such a supporting substrate, a display with high definition and high reliability can be manufactured.

Sectional drawing which shows an example of the color filter containing the polyimide resin film which concerns on embodiment of this invention. Schematic perspective view when evaluating the bending resistance of the laminate Schematic perspective view when evaluating the bending resistance of the laminate

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the following embodiments. Further, the drawings referred to in the following description merely schematically show shapes, sizes, and positional relationships to the extent that the contents of the present invention can be understood. That is, the present invention is not limited only to the shapes, sizes, and positional relationships illustrated in each drawing.

<Polyimide precursor resin composition>
The polyimide precursor resin composition according to the embodiment of the present invention comprises (A) a polyimide precursor containing a structural unit represented by the general formula (1) as a main component (hereinafter, simply referred to as “(A) polyimide precursor”). (B) a polyimide precursor resin composition containing (B) a compound represented by the general formula (2) and (C) a solvent, wherein (B) a compound represented by the general formula (2) Is 30 to 4000 ppm with respect to the polyimide precursor resin composition.

R ¹ represents an aromatic tetracarboxylic acid residue, and R ² represents an aromatic diamine residue. X ¹ and X ² each independently represent a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. )

In the general formula (2), R ³ represents a group selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 15 carbon atoms. n represents 2 or 3.

  In addition, "C1-10" shows "C1 or more, C10 or less". Similar descriptions in the present invention have the same meaning.

  The polyimide precursor resin composition according to the embodiment of the present invention preferably includes a polyimide precursor containing a structural unit represented by the general formula (1) as a main component and a compound represented by the general formula (2). The following effects can be obtained by including them in the ratio. By heating this polyimide precursor resin composition in air for a short time, a transparent polyimide resin film having a high glass transition temperature can be obtained. Further, the resin film can be easily separated from the supporting substrate.

[(A) polyimide precursor]
The structural unit represented by the general formula (1) is a repeating structural unit in the polyimide precursor resin according to the embodiment of the present invention. Hereinafter, these structural units may be referred to as “repeating structural units” or simply “repeating units”.

  Here, the main component means that the structural unit represented by the general formula (1) has 50 mol% or more of all structural units of the polymer. By including the structure represented by the general formula (1) in an amount of 50 mol% or more of the total structural units of the polymer, oxidation during heating in an air atmosphere is less likely to occur. Thereby, a transparent polyimide resin film can be obtained even when heated and baked in the air.

  In addition, all structural units are all the structural units which comprise the polyimide precursor which has a repeating unit represented by General formula (1). Specifically, it refers to the total amount (mol basis) of the repeating unit represented by the general formula (1). However, when the polyimide precursor includes a repeating unit structure other than the repeating unit represented by the general formula, a repeating unit represented by the general formula (1) and a repeating unit other than the repeating unit represented by the general formula (1) It is the total amount (mol basis) with the unit structure.

  More preferably, the content of the structural unit represented by the general formula (1) is 70 mol% or more of all the structural units of the polymer. The ratio of the unit structure of the polymer can be measured by mass spectrometry, pyrolysis gas chromatography (GC), NMR, or IR measurement of the polyimide precursor or polyimide.

Examples of the case where X ¹ and X ² in the general formula (1) are monovalent organic groups having 1 to 10 carbon atoms include a saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic group, and an alkylsilyl group. And the like. Examples of the saturated hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, and a 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 the aromatic group include a phenyl group. The aromatic group may be further substituted with a saturated hydrocarbon group, an unsaturated hydrocarbon group or a halogen atom. Examples of the alkylsilyl group include a trimethylsilyl group.

In the general formula (1), R ¹ is a residue of an aromatic tetracarboxylic acid or a derivative thereof, and R ² is a residue of an aromatic diamine. The carbon number of R ¹ and R ² is preferably 6 to 40.

Examples of the tetracarboxylic acid giving R ¹ include pyromellitic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 2,2 ', 3,3'-biphenyltetracarboxylic acid, 3,3', 4,4'-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, 3,3 ', 4,4'-diphenyl ether Tetracarboxylic acid, 2,2 ', 3,3'-diphenylethertetracarboxylic acid, 2,2-bis (4- (3,4-dicarboxyphenoxy) phenyl) propane, 9,9-bis [4- (3 , 4-Dicarboxyphenoxy) phenyl] fluorene and the like.

Further, it is preferable that R ¹ does not include the structure represented by the general formula (3). The structure represented by the general formula (3) is a bis (trifluoromethyl) methylene structure. When R ¹ does not include the structure of the general formula (3), yellowing due to oxidation during heating and firing in air can be suppressed, and a transparent polyimide resin film can be obtained.

  These tetracarboxylic acids may be used as they are, or may be used in the form of tetracarboxylic acid derivatives such as acid anhydrides, active esters and active amides. Of these, acid anhydrides are preferably used because by-products do not occur during polymerization. Also, two or more of these may be used.

R ¹ in the general formula (1) is preferably a tetravalent organic group represented by the following general formula (4).

Y ¹ is a direct bond or a divalent organic group having 1 to 3 carbon atoms which may be substituted with at least one selected from the group consisting of an oxygen atom, a sulfur atom, a sulfonyl group and a halogen atom. Or a divalent crosslinked structure selected from the group consisting of an organic group having 1 to 20 carbon atoms having an ester bond, an amide bond, a carbonyl group, a sulfide bond, and an aromatic ring.

  Examples of the compound giving the structure represented by the general formula (4) include, for example, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 2,2 ', 3,3'-biphenyltetracarboxylic acid, 3,3', 4,4'-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, 3,3 ', 4,4'-diphenyl ether Tetracarboxylic acid, 2,2 ′, 3,3′-diphenylethertetracarboxylic acid, 9,9-bis (3,4-dicarboxyphenyl) fluorene and the like can be mentioned.

R ¹ in the general formula (1) is particularly preferably one or more selected from the structures represented by the general formulas (5) to (7). By including the structure represented by the general formula (5), a polyimide having a high glass transition temperature can be obtained. In addition, by including the structure represented by the general formula (6), a polyimide having high transparency, small birefringence, and high glass transition temperature can be obtained. In addition, by including the structure represented by the general formula (7), a polyimide having high transparency and small birefringence can be obtained.

Examples of the diamine providing R ² include, for example, 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'-diaminodiphenylsulfone, 2,2'-bis (trifluoromethyl) benzidine, 3,3'-bis (trifluoromethyl) benzidine, 9,9-bis (4-aminophenyl) fluorene, 3-amino Phenyl-4-aminobenzenesulfonate, 4-aminophenyl-4-aminobenzenesulfonate, 9,9- Bis (3-fluoro-4-aminophenyl) fluorene, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [3- (3-aminophenoxy) phenyl] sulfone, 1,4-bis (4-amino Phenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 2,2′-bis (trifluoromethyl) -4,4′-diaminodiphenyl ether, 9,9-bis (3-fluoro-4-aminophenyl) fluorene and the like.

Further, it is preferable that R ² does not include the structure represented by the general formula (3). By R ² does not include the structure of the general formula (3), it is possible to suppress variations oxide yellow when firing in the air, it is possible to obtain a transparent polyimide resin film.

R ² in the general formula (1) is preferably a divalent organic group represented by any of the following general formulas (8) to (12). Examples of the compounds giving the structures represented by the general formulas (8) to (12) include, for example, 3,3′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfone, 2′-bis (trifluoromethyl) benzidine, 3,3′-bis (trifluoromethyl) benzidine, 2,2′-bis (trifluoromethyl) -4,4′-diaminodiphenyl ether, 9,9-bis ( 3-fluoro-4-aminophenyl) fluorene. By containing these compounds, a polyimide resin film having high heat resistance and high transparency can be obtained.

  In the formula (12), each Z independently represents a hydrogen atom or a fluorine atom, and at least one Z is a fluorine atom. m represents an integer of 1 or 2.

  Further, (A) the polyimide precursor contains a diamine residue having a sulfonyl group in an amount of 10 mol% to 90 mol% in 100 mol% of the polyimide precursor, and a diamine residue having a fluorine atom, The polyimide precursor preferably contains 10 mol% to 90 mol% in 100 mol% of the polyimide precursor, and contains a diamine residue having a sulfonyl group in an amount of 20 mol% to 80 mol% in 100 mol% of the polyimide precursor, and More preferably, the diamine residue having a fluorine atom contains at least 20 mol% and at most 80 mol% in 100 mol% of the polyimide precursor. By including a diamine residue having a sulfonyl group and a diamine residue having a fluorine atom within the above range, the amount of the compound of the general formula (2) contained in the cured film can be controlled to a preferable range, Both high glass transition temperature and good peelability can be achieved.

  Further, the use of a diamine having a sulfonic acid ester in the molecule is preferable because the glass transition temperature can be improved while maintaining the transparency and heat resistance of the polyimide. That is, the (A) polyimide precursor preferably further has a structural unit represented by the general formula (13).

R ¹ represents an aromatic tetracarboxylic acid residue. Y ² and Y ³ may be the same or different, and include an aromatic ring or an aromatic ring, an amide group, an ester group, an ether group, an alkylene group, an oxyalkylene group, a vinylene group and a haloalkylene group, and a thioether group. , A fluorenyl group, a sulfonate group, and a sulfonyl group.

  Examples of the diamine providing the structure represented by the general formula (13) include the structures represented by the general formulas (14) to (22).

  Among them, the structural unit represented by the general formula (13) preferably contains a structural unit represented by the following general formula (23). Thereby, the transparency of the polyimide resin can be improved without deteriorating the releasability from the glass substrate, and the glass transition temperature can be further increased. The diamine that gives this structure is 3-aminophenyl-4-aminobenzenesulfonate.

  (A) The polyimide precursor preferably contains the structural unit represented by the general formula (13) in a range of 1 mol% or more and 25 mol% or less, more preferably 2 mol% or more and 20 mol% or less.

  (A) The polyimide precursor may contain other structural units as long as the effects of the present invention are not impaired. Examples of other structural units include polyimide, which is a dehydrated ring-closure of polyamic acid, and dehydrated-ring-closure polybenzoxazole of polyhydroxyamide.

  Examples of the acid dianhydride used for other structural units include aromatic acid dianhydrides, alicyclic acid dianhydrides, and aliphatic acid dianhydrides described in WO2017 / 099183. Examples of the diamine compound used for the other structural unit include an aromatic diamine, an alicyclic diamine, or an aliphatic diamine described in International Publication WO2017 / 099183.

(A) The polyimide precursor may have a structure represented by the general formula (24) in R ¹ and / or R ² . When the polyimide precursor has the structure represented by the general formula (24), the residual stress generated between the polyimide resin film and the inorganic film obtained by using the same can be reduced. Therefore, substrate warpage when the polyimide resin film and the inorganic film are stacked on the substrate can be suppressed.

In the formula (24), R ⁴ and R ⁵ each independently represent a monovalent organic group having 1 to 20 carbon atoms. x shows the integer of 3-200.

Examples of the monovalent organic group having 1 to 20 carbon atoms in R ⁴ and R ⁵ include a hydrocarbon group, an amino group, an alkoxy group, and an epoxy group. Examples of the hydrocarbon group for R ⁴ and R ⁵ 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, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t- Examples thereof include a butyl group, a pentyl group, and a hexyl group. 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 include a phenyl group, a tolyl group, and a naphthyl group.

Examples of the alkoxy group for R ⁴ and R ⁵ include a methoxy group, an ethoxy group, a propoxy group, an isopropyloxy group, a butoxy group, a phenoxy group, a propenyloxy group, and a cyclohexyloxy group.

R ⁴ and R ⁵ in the general formula (24) 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 obtained 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 the general formula (24) is an integer of 3 to 200, preferably 10 to 200, more preferably 20 to 150, further preferably 30 to 100, and particularly preferably 30 to 60. When x is within the above range, the residual stress of the polyimide can be reduced, and the substrate warpage can be reduced. Moreover, it can suppress that a polyimide film becomes cloudy and that the mechanical strength of a polyimide film falls.

  The polyimide precursor resin having the structure represented by the general formula (24) can be obtained by using a silicone compound represented by the following general formula (23) as a monomer component.

In the formula (25), a plurality of R ⁶ are each independently a single bond or a divalent organic group having 1 to 20 carbon atoms, and a plurality of R ⁷ , R ⁸ and R ⁹ are each independently a carbon atom 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 ¹⁰ Is one group selected from the group consisting of R ¹⁰ is a monovalent organic group having 1 to 20 carbon atoms. y is an integer of 3-200, and z is an integer of 0-197.

  (A) When a polyimide precursor having a structural unit represented by the general formula (1) is cured by heating, the imide group concentration is preferably from 3.0 mmol / g to 4.5 mmol / g, and preferably 3.3 mmol / g. / G to 4.1 mmol / g is more preferable. When the imide group concentration is in the above range, a polyimide resin film having a high glass transition temperature, high transparency, and capable of suppressing crack generation during curing can be obtained. Here, the method of calculating the imide group concentration will be described below.

(Calculation of imide group concentration)
Assuming that the imidation ratio is 100 mol%, and since there are two imide groups per mol of the monomer, the imide group concentration (when the imidation ratio is assumed to be 100 mol%) is calculated using the following formula. Theoretical value).

Number of moles of imide group (mol): Number of moles of acid anhydride monomer or amine monomer (if either is small, number of moles) × 2
Polyimide weight (g) = total weight of acid anhydride monomer and amine monomer-number of moles of imide group x molecular weight of water (18.02 g / mol)
Imide group concentration (mmol / g) = moles of imide group × 1000 / polyimide weight In the polyimide precursor of (A), a part of the structural unit represented by the general formula (1) may be imidized. . By imidizing a part of the polyimide precursor, the viscosity stability of the resin solution during storage at room temperature can be improved. As the range of the imidation ratio of the polyimide precursor (A), 1% to 50% is preferable from the viewpoint of solubility in a solution and viscosity stability. The imidation ratio is more preferably 5% or more and 30% or less.

  In order to promote the imidation of the polyimide precursor, an imidization accelerator can be used. For example, by adding an imidization accelerator when polymerizing the polyimide precursor polymerization, the imidation rate of the polyimide precursor can be increased. The imidization accelerator referred to here is a compound having a function of enhancing nucleophilicity or electrophilicity, and specifically, a tertiary amine compound such as trimethylamine, triethylamine, tripropylamine, tributylamine; Carboxylic acid compounds such as hydroxyphenylacetic acid and 3-hydroxybenzoic acid; polyhydric phenol compounds such as 3,5-dihydroxyacetophenone and methyl 3,5-dihydroxybenzoate; pyridine, quinoline, isoquinoline, imidazole, benzimidazole; Heterocyclic compounds such as 2,4-triazole; and the like.

  Examples of the partially imidized (A) polyimide precursor include resins each having a repeating unit represented by the general formula (26), the general formula (27) and the general formula (28).

In the general formulas (26) to (28), R ¹¹ represents a divalent organic group, and R ¹² 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 ^{11 is} the same as the above-described diamine residue, and the tetravalent organic group for R ¹² is the same as the above-described tetracarboxylic acid residue.

  The numbers of the repeating units represented by the formulas (26), (27) and (28) in the polyimide precursor are p, q, and r, respectively.

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

  Here, “(2r + q) × 100 / (2p + 2q + 2r)” is the number of bonds (2r + q) of imide ring-closing bonds (2r + q) in the bonding part (reaction part between tetracarboxylic dianhydride and diamine compound) of the polyimide precursor. The ratio to the total number of bonded parts (2p + 2q + 2r) is shown. That is, “(2r + q) × 100 / (2p + 2q + 2r)” indicates the imidation ratio of the polyimide precursor.

  By setting the imidation ratio (value of “(2r + q) × 100 / (2p + 2q + 2r)”) of the polyimide precursor of (A) to 1 to 50%, more preferably 5 to 30%, The viscosity stability can be improved without deteriorating the solubility of the polyimide precursor in the solution.

  The imidation ratio (value of “(2r + q) × 100 / (2p + 2q + 2r)”) of the polyimide precursor (A) is measured by the following method.

-Measurement of imidation ratio of polyimide precursor-
Preparation of Polyimide Precursor Sample (a) A polyimide precursor composition to be measured is applied on a silicon wafer in a thickness of 1 μm or more and 10 μm or less to prepare a coating film sample.

  (B) The coating film sample is immersed in tetrahydrofuran (THF) for 20 minutes to replace the solvent in the coating film sample with tetrahydrofuran (THF). The solvent to be immersed is not limited to THF and 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.

(C) a coating film sample, removed from in THF, blowing _{N 2} gas into THF adhering to the coating surface of the sample, removed. The coating film sample is dried by treating at a temperature of 5 ° C. or more and 25 ° C. or less for 12 hours or more under a reduced pressure of 10 mmHg or less to prepare a polyimide precursor sample.

Preparation of 100% imidized standard sample (d) In the same manner as in (a) above, a polyimide precursor composition to be measured is applied on a silicon wafer to prepare a coating film sample.

  (E) The coating film sample is heated at 380 ° C. for 60 minutes to perform an imidization reaction to prepare a 100% imidized standard sample.

-Measurement and analysis (f) Using a Fourier transform infrared spectrophotometer (FT-730 manufactured by Horiba, Ltd.), measure the infrared absorption spectra of the 100% imidized standard sample and the polyimide precursor sample. Aromatic ring-derived absorption peak near 1500 cm ^-1 and 100% imidization standard sample (Ab ratio 'for (1500cm ^-1)), absorption peaks derived from an imide bond in the vicinity of ^{1780cm -1 (Ab' (1780cm -1} )) I ′ (100) is obtained.

(G) In the same manner, was measured on the polyimide precursor sample, relative to the aromatic ring derived absorption peak near ^{1500cm -1 (Ab (1500cm -1)} ), absorption peaks derived from imide bond near 1780 cm ^-1 (Ab ( The ratio I (x) of 1780 cm ⁻¹ )) is determined.

Then, using the measured absorption peaks I ′ (100) and I (x), the imidation ratio of the polyimide precursor is calculated based on the following equation.
Formula: Imidation rate (%) of polyimide precursor = I (x) × 100 / I ′ (100)
Formula: I ′ (100) = (Ab ′ (1780 cm ⁻¹ )) / (Ab ′ (1500 cm ⁻¹ ))
Formula: I (x) = (Ab (1780 cm ⁻¹ )) / (Ab (1500 cm ⁻¹ )).

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

  When the weight average molecular weight and the 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 obtained coating film.

  The weight-average molecular weight, number-average molecular weight and molecular weight distribution were measured using a DP-8020 type GPC apparatus manufactured by TOSOH (guard column: TSK guard colon ALPHA column: TSK-GEL α-M, developing solvent: N, N′-dimethylacetamide ( DMAc), 0.05M-LiCl, 0.05% phosphoric acid).

  (A) The polyimide precursor is a resin containing the structural unit represented by the chemical formula (1), and the terminal may be sealed with a terminal sealing agent. By reacting the terminal blocking agent, the molecular weight of the polyimide precursor can be adjusted to a preferable range.

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

  When the terminal monomer is an acid dianhydride, a monoamine, a monoalcohol, or the like can be used as a terminal blocking agent to block the acid anhydride group.

[(B) Compound represented by general formula (2)]
The compound represented by the general formula (2) is a cyclic compound having an imide structure. When the polyimide precursor resin composition containing no cyclic compound having an imide structure is placed in a preheated oven (direct in) so that heating can be performed in the air for a short time, the solvent is heated before the polyimide molecules are oriented. Is removed, the orientation of the polyimide molecules is disturbed, and the resulting polyimide resin film is in a state where the intermolecular interaction is small. As a result, a polyimide resin film having a low glass transition temperature is obtained.

  On the other hand, in the case of a polyimide precursor resin composition containing a cyclic compound having an imide structure as in the present invention, the cyclic compound having an imide structure interacts with a carboxyl group in the polyimide precursor resin by hydrogen bonding. Therefore, the polyimide precursor resin composition tends to remain in the film in the step of heating and curing. As a result, in the heat curing process in which the polyimide precursor resin is converted to polyimide, the cyclic compound having an imide structure acts as a plasticizer, and the polyimide resin can take the most stable conformation, and the polyimide resin The orientation of the film is promoted. As a result, the glass transition temperature of the obtained polyimide resin film increases.

  In addition, since the cyclic compound having an imide structure remaining in a trace amount in the polyimide resin film partially prevents the interaction between the hydroxyl group present on the surface of the glass substrate and the polyimide resin, the polyimide resin film is easily peeled from the glass support substrate. can do.

Specific examples of the alkyl group having 1 to 10 carbon atoms for R ³ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, and a hexyl group. Can be Specific examples of the aryl group having 6 to 15 carbon atoms include a phenyl group, a tolyl group, and a naphthyl group.

  Further, n in the general formula (2) represents 2 or 3. When n is the above value, the transparency of the obtained polyimide resin composition, the glass transition temperature is improved without deteriorating the gas generation, and a polyimide resin that can be easily peeled from the glass support substrate can be obtained. .

  Examples of the compound represented by the general formula (2) include N-methylsuccinimide (MSI), N-ethylsuccinimide (ESI), N-phenylsuccinimide (PSI), 1-methylpiperidine-2,6-dione, Ethyl piperidine-2,6-dione, 1-phenylpiperidine-2,6-dione and the like can be mentioned. Among them, N-methylsuccinimide is preferred from the viewpoint of improving the glass transition temperature and improving the releasability. N-methylsuccinimide is an oxidized form of N-methyl-2-pyrrolidone (NMP), and is generated, for example, by bubbling a gas containing oxygen into NMP. Of course, N-methylsuccinimide may be separately added to the polyimide precursor resin composition.

  The content of the compound represented by the general formula (2) (B) in the polyimide precursor resin composition according to the embodiment of the present invention is 30 to 4000 ppm in total with respect to the polyimide precursor resin composition. Yes, it is more preferably from 50 to 3000 ppm, still more preferably from 50 to 2500 ppm, and even more preferably from 100 to 2500 ppm. By containing the compound represented by the general formula (2) in the above range, the glass transition temperature of the polyimide resin film can be improved without deteriorating the yellowness, and the releasability from the glass substrate can be improved. .

[(C) solvent]
(C) The solvent is not particularly limited, and a known solvent can be used. Examples include N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-dimethylisobutylamide, 3-methoxy-N, N-dimethylpropionamide, 3-butoxy-N , N-dimethylpropionamide, γ-butyrolactone, ethyl lactate, 1,3-dimethyl-2-imidazolidinone, N, N′-dimethylpropyleneurea, 1,1,3,3-tetramethylurea, dimethylsulfoxide, Sulfolane, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, water, a solvent described in WO2017 / 099183, etc. may be used alone or in combination of two or more. Can. Among them, it is preferable to include an aprotic polar solvent such as N-methyl-2-pyrrolidone and N, N-dimethylformamide, and it is particularly preferable to include N-methyl-2-pyrrolidone. Since the solvent contains N-methylpyrrolidone, N-methylpyrrolidone can be oxidized in the course of polymerization of the polyimide precursor to produce N-methylsuccinimide, and the glass transition temperature and peelability of the resulting polyimide resin film can be reduced. Can be improved.

  (C) The content of the solvent is preferably at least 200 parts by weight, more preferably at least 300 parts by weight, preferably at most 2,000 parts by weight, more preferably at most 2,000 parts by weight, based on 100 parts by weight of the polyimide precursor (A). Is 1,500 parts by weight or less. When the content is in the range of 200 to 2,000 parts by weight, the concentration and viscosity are suitable for coating, and good film thickness uniformity can be obtained when coating is performed with a slit coater.

[Other ingredients]
The polyimide precursor resin composition according to the embodiment of the present invention may contain a surfactant. Examples of the surfactant include fluorosurfactants such as Florard (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.) Is raised. Further, organic siloxane surfactants such as KP341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow, Granol (trade name, manufactured by Kyoeisha Chemical Co., Ltd.), and BYK (trade name, manufactured by BYK Chemie Co., Ltd.). Can be Emulmin (a polyoxyalkylene lauriether, a polyoxyethylene lauryl ether, a polyoxyethylene oleyl ether and a polyoxyethylene cetyl ether surfactant such as Sanyo Chemical Industries, Ltd .; and a polyflow (trade name, Kyoeisha Chemical ( And the like.Acrylic polymer surfactants such as those manufactured by Co., Ltd.) are preferably contained in an amount of 0.001 to 1 part by weight based on 100 parts by weight of the resin composition.

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

  To the resin composition of the present invention, a coupling agent such as a silane coupling agent and a titanium coupling agent can be added for improving the adhesion to the substrate. Known coupling agents can be used as the coupling agent. These may be used in combination of two or more. 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.

<Production method of polyimide precursor resin composition>
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. Derivatives include acid anhydrides, active esters, and active amides of the tetracarboxylic acid. The reaction method of the polymerization reaction is not particularly limited as long as the desired polyimide precursor can be produced, and a known reaction method can be used.

  As a specific reaction method, a predetermined amount of all diamine components and a solvent are charged and dissolved in a reactor, and then a predetermined amount of an acid dianhydride component is charged, followed by stirring at room temperature to 120 ° C for 0.5 to 30 hours. And the like. Among them, using N-methylpyrrolidone as a solvent, when performing a reaction while bubbling a gas containing air, N-methylpyrrolidone is oxidized to generate N-methylsuccinimide, and the glass transition temperature of the obtained polyimide resin film is increased. It is preferable because it can be performed. Examples of the gas containing air include clean dry air containing about 20.9% by volume of oxygen and an oxygen / nitrogen mixed gas containing 1 to 21% by volume of oxygen.

  The above-mentioned solvent, surfactant, internal release agent, and coupling agent may be added to the polyimide precursor obtained by the above method.

  The water content in the polyimide precursor resin composition is preferably 0.05% by mass or more and 3.0% by mass or less. When the moisture content of the polyimide precursor resin composition is within the above range, the viscosity storage stability of the polyimide precursor resin composition can be improved. The water content here refers to a value measured at a liquid temperature of 23 ° C. and measured by the Karl Fischer method. In order to measure the moisture content by the Karl Fischer method, a Karl Fischer moisture content titrator (for example, “MKS-520” (trade name, manufactured by Kyoto Electronics Industry Co., Ltd.) or the like) is used and measured according to “JIS K0068 (2001)”. Based on the volume titration method, the moisture content is measured.

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

  The method of imidization is not particularly limited, and examples thereof include imidization by heating and chemical imidization.In particular, from the viewpoint of heat resistance of the obtained polyimide resin composition and transparency in the visible light region, imidization by heating is performed. Is preferred. The polyimide precursor resin composition film is heated in a range of 180 ° C. or more and 550 ° C. or less to be converted into a polyimide resin composition. This is called a thermal imidization step. Note that the thermal imidization step may be performed after a certain step after the step of evaporating the solvent from the coating film.

  In the step of evaporating the solvent from the coating film, specifically, the coating film may be vacuum-dried or heated. However, in consideration of the transparency of the film after imidization, it is preferable to evaporate the solvent without clouding. For drying, a hot plate, an oven, an infrared ray, a vacuum chamber, or the like is used.

  Above all, it is preferable to perform vacuum drying using a vacuum chamber, and it is more preferable to perform heating for drying further after vacuum drying, or to perform heating for drying while performing vacuum drying. As a result, the drying time can be reduced, and a uniform coating film can be obtained. The heating temperature for drying varies depending on the type and purpose of the object to be heated, and it is preferable to perform the heating in the range of room temperature to 170 ° C for 1 minute to several hours. The room temperature is usually from 20 to 30C, preferably 25C. Further, the drying step may be performed a plurality of times under the same conditions or 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. Since the polyimide resin composition of the present invention has high resistance to oxidation, a transparent polyimide resin film can be obtained by heating in an air atmosphere for 30 minutes to 2 hours using an oven.

  In addition, the time required to reach the heating temperature for thermal imidization is not particularly limited, and a heating method according to the heating method of the production line can be selected. For example, in an oven, the temperature of the polyimide precursor resin composition formed on the substrate may be raised from room temperature to a heating temperature for thermal imidization over 5 to 120 minutes, or 180 ° C in advance. The polyimide precursor resin composition formed on the substrate may be suddenly charged into an oven heated to a temperature of 550 ° C. or lower to perform heat treatment. Moreover, you may heat under reduced pressure as needed.

<Membrane of polyimide resin composition>
The film-like material of the polyimide resin composition according to the embodiment of the present invention (hereinafter, may be simply referred to as “polyimide resin film”) refers to (A) a film containing polyimide obtained by imidizing a polyimide precursor. It is.

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

  Examples of a method of forming a coating film by applying the polyimide precursor resin composition on a substrate include a roll coating method, a spin coating method, a slit coating method, and a method of applying using a doctor blade, a coater, and the like. Can be Note that the thickness and surface smoothness of the film may be controlled by repeating the application. Among them, the slit die coating method is preferred from the viewpoint of the surface smoothness of the coating film and the uniformity of the film thickness.

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

  Examples of the substrate include a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, a polybutylene terephthalate (PBT) film, a silicon wafer, a glass wafer, an oxide wafer, a glass substrate, a Cu substrate, and a SUS plate. Among them, a glass substrate is preferred from the viewpoint of surface smoothness and dimensional stability during heating. As the glass, non-alkali glass is preferable, and soda glass is preferable from the viewpoint of surface smoothness and peelability.

  In the step of evaporating the solvent from the coating film, specifically, the coating film may be vacuum-dried or heated. However, in consideration of the transparency of the film after imidization, it is preferable to evaporate the solvent without clouding. For drying, a hot plate, an oven, an infrared ray, a vacuum chamber, or the like is used.

  Above all, it is preferable to perform vacuum drying using a vacuum chamber, and it is more preferable to perform heating for drying further after vacuum drying, or to perform heating for drying while performing vacuum drying. As a result, the drying time can be reduced, and a uniform coating film can be obtained. The heating temperature for drying varies depending on the type and purpose of the object to be heated, and it is preferable to perform the heating in the range of room temperature to 170 ° C. for 1 minute to several hours. The room temperature is usually from 20 to 30C, preferably 25C. Further, the drying step may be performed a plurality of times under the same conditions or different conditions.

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

  Examples of the peeling method include a method of mechanically peeling the polyimide film by making a cut at the end with a cutter or the like, a method of immersing in water, a method of immersing in a chemical solution such as hydrochloric acid or hydrofluoric acid, or a method of irradiating from ultraviolet light to red. There is a method of irradiating the interface between the film-like material of the polyimide resin composition and the substrate with laser light in the wavelength range of external light, but the device is formed on the film-like material of the polyimide resin composition and then peeled off. When performing the separation, it is necessary to perform separation without damaging the device.Therefore, a method of mechanically separating the polyimide film by making a cut in the end of the polyimide film with a cutter or the like, or separation using an ultraviolet laser is used. preferable. Note that, in order to facilitate peeling, a release agent may be applied to the substrate or a sacrifice layer may be formed before applying the polyimide precursor resin composition to the substrate. Examples of the release agent include silicone-based, fluorine-based, aromatic polymer-based, and alkoxysilane-based release agents. Examples of the sacrificial layer include a metal film, a metal oxide film, and an amorphous silicon film.

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

  The tensile elastic modulus of the polyimide resin film according to the embodiment of the present invention is preferably 1.5 GPa or more and 3.5 GPa or less. When the tensile modulus is within the above range, breakage when the film is peeled from the substrate can be suppressed, and the residual stress can be further reduced.

  The elongation at break of the polyimide resin film according to the embodiment of the present invention is preferably 10% or more, more preferably 15% or more, and particularly preferably 20% or more. It is preferable that the elongation at break of the film is 10% or more because the film has excellent bending resistance.

  The glass transition temperature of the polyimide resin film according to the embodiment of the present invention is 240 ° C. or higher, preferably 250 ° C. or higher. Since the device is heated to 240 ° C. or higher during device fabrication, if the glass transition temperature is lower than 240 ° C., the film may be deformed when the film is used for such an application.

  The content of the compound represented by the general formula (2) (B) in the polyimide resin film according to the embodiment of the present invention is 0.3 to 2.4 ppm in total with respect to the weight of the polyimide resin film. Preferably, it is 0.3 to 2.0 ppm, more preferably 0.3 to 1.5 ppm.

  When the polyimide resin film contains the compound represented by the general formula (2) in the above range, the releasability from the glass substrate can be improved without greatly deteriorating the yellowness. Furthermore, since the glass transition temperature of the polyimide resin film can be increased, it is possible to suppress the occurrence of wrinkles in the inorganic film after forming the inorganic film on the polyimide resin film. In addition, since the stress generated at the interface between the polyimide resin film and the inorganic film is relieved, it is possible to suppress the occurrence of cracks in the inorganic film when the polyimide film is bent with the inorganic film formed on the film. It is possible to obtain a laminate having high flexibility.

<Laminate>
The laminate according to the embodiment of the present invention has a film-like material of the above polyimide resin composition and an inorganic film.

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

  Materials constituting the gas barrier layer include metal oxides, metal nitrides, metal oxynitrides, and metal carbonitrides. Examples of metal elements contained therein 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, the gas barrier layer preferably contains at least one of silicon oxide, silicon nitride, silicon oxynitride, and silicon carbonitride. By using these materials, a uniform and dense film is easily obtained, and the oxygen barrier property of the gas barrier layer is further improved.

  Further, from the viewpoint of further improving the oxygen barrier property, the gas barrier layer preferably contains a component represented by SiOhNi. h and i are values satisfying 0 <h ≦ 1, 0.55 ≦ i ≦ 1, and 0 ≦ h / i ≦ 1.

  An inorganic film in which a gas barrier layer is laminated in two or more layers, and a layer in contact with the film-like material of the polyimide resin composition among the inorganic films is SiOj (j is a value satisfying 0.5 ≦ j ≦ 2). Is preferably formed of the components represented by This is because damage to the polyimide film at the time of forming the first layer of the inorganic film is reduced, and thus deterioration in surface smoothness after the formation of the inorganic film and coloring during 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 on a supporting substrate.
(2) a step of removing a solvent from the applied polyimide precursor resin composition;
(3) a step of imidizing the polyimide precursor to obtain a film of the polyimide resin composition.
(4) a step of forming an inorganic film on the film of the polyimide resin composition;

  The steps (1) to (3) can be performed according to the method for producing a film-like material of the polyimide resin composition described above.

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

  The inorganic film can be formed by a vapor deposition method of forming a film by depositing a material from a gas phase, such as a sputtering method, a vacuum deposition method, an ion plating method, and a plasma CVD method. Among them, it is preferable to use a sputtering method or a plasma CVD method since a more uniform film having a high oxygen barrier property can be obtained.

  The number of layers of the inorganic film is not limited, and may be only one layer or two or more layers. From the viewpoint of compatibility between the bending resistance and the gas barrier property, two or more layers are preferable. Examples of the multilayer film include a gas barrier layer in which the first layer is made of SiN and a 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, and 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, and more preferably 500 nm or less.

  The laminate obtained through the above steps can be used after being separated from the substrate, or can be used without being separated.

  As an example of the peeling method, a method similar to the above-described method of peeling the polyimide resin composition film from the substrate 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 for electronic devices. More specifically, it can be used for a display device such as a liquid crystal display, an organic EL display, a touch panel, electronic paper, a color filter, a micro LED display, a solar cell, and a light receiving device such as a CMOS. These electronic devices are preferably flexible devices. A film-like material of the above-mentioned polyimide resin composition is preferably used as a substrate in these electronic devices, particularly as a flexible substrate.

  Hereinafter, the present invention will be described with reference to examples and the like, but the present invention is not limited to these examples.

<Material>
(Acid dianhydride)
BPDA: 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride ODPA: 3,3', 4,4'-diphenylethertetracarboxylic dianhydride 6FDA: 2,2-bis (3,4- Dicarboxyphenyl) hexafluoropropane dianhydride PMDA-HS: 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic dianhydride BSAA: 2,2-bis (4- (3,4-dicarboxyphenoxy) Phenyl) propane dianhydride.

(Diamine compound)
4,4'-DDS: 4,4'-diaminodiphenylsulfone 3,3'-DDS: 3,3'-diaminodiphenylsulfone TFMB: 2,2'-bis (trifluoromethyl) benzidine t-CHDA: trans- 1,4-diaminocyclohexane 4-ABS-3AP: 3-aminophenyl-4-aminobenzenesulfonate 6FODA: 2,2′-bis (trifluoromethyl) -4,4′-diaminodiphenyl ether FFDA: 9, 9-bis (3-fluoro-4-aminophenyl) fluorene.

(solvent)
NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone DMAc: N, N-dimethylacetamide.

(Compound represented by general formula (2))
MSI: N-methylsuccinimide PSI: N-phenylsuccinimide.

<Evaluation>
(1) Measurement of N-methylsuccinimide contained in varnish The amount of N-methylsuccinimide contained in the varnish was measured by the following procedure.

1. Preparation of standard solution
a) N-methylsuccinimide (0.0201 g) was weighed into a volumetric flask (20 mL), and the volume of the solution was fixed with N, N-dimethylacetamide (hereinafter, DMAc) to obtain a standard stock solution (concentration: 100 μg / mL).
b) The solution of a) was diluted with DMAc to prepare a standard solution.

2. Preparation of Sample Solution a) A varnish (0.2 g) was weighed into a volumetric flask (5 mL), and DMAc was added thereto to make the volume to 5 mL.
b) The solution was diluted 50-fold with DMAc to obtain a sample solution.

3. GC / MS analysis GC / MS measurement of the standard solution and the sample solution was performed under the following conditions, and the amount of N-methylsuccinimide contained in the varnish was quantified.
Apparatus: GC6890 (Agilent technologies)
MS: SX-102A (JEOL)
Column: Inert Cap Pure WAX, 30m x 0.25mm, film thickness 0.25m (GL Science)
Column temperature: 50 ° C (5 min) -20 ° C / min-250 ° C (5 min)
Carrier gas flow rate: 1 mL / min (helium, constant flow mode)
Split ratio: 1/20
Inlet temperature: 250 ° C
Injection volume: 1 μL
Ionization method: EI (electron ionization)
Measurement mode: SIM (selection ion detection)
Monitor ion: m / z 113.0480.

(2) Preparation of Polyimide Resin Film (On Glass Substrate-1) A spin coater MS-A200 manufactured by Mikasa Co., Ltd. was coated on a varnish of 100 mm × 100 mm × 0.7 mm thick soda glass substrate (AS manufactured by Asahi Glass Co., Ltd.). It was applied so that the film thickness after curing was 10 ± 0.5 μm. Thereafter, prebaking was performed using a hot plate. The hot plate was dried for 6 minutes using a preheated one at 120 ° C. The prebaked film thus obtained is cured in an oven (“IHPS-222”; manufactured by Espec Corp.) at 260 ° C. for 30 minutes in the air to form a film of the polyimide resin composition. (On a glass substrate-1) was produced.

(3) Preparation of polyimide resin film (peeling film) A cut is made with a single blade at a portion 1 cm from the four sides of the polyimide resin film (on the glass substrate) prepared in (2), and immersed in warm water heated to 60 ° C. for 60 minutes. Then, a polyimide resin film (peeling film) was obtained by peeling.

(4) Preparation of film-like material (on glass substrate-2) of polyimide resin composition A polyimide resin was prepared in the same manner as (2) except that a glass substrate (Tempax) having a thickness of 50 mm × 50 mm × 1.1 mm was used. A film of the composition (on a glass substrate-2) was prepared.

(4) Measurement of in-plane / out-of-plane birefringence Using a prism coupler (manufactured by METRICON, PC2010), measure the TE refractive index (n (TE)) and TM refractive index (n (TM)) at a wavelength of 632.8 nm. did. n (TE) and n (TM) are the refractive indices in the direction parallel and perpendicular to the polyimide film surface, respectively. In-plane / out-plane birefringence was calculated as the difference between n (TE) and n (TM) (n (TE) -n (TM)). Note that the polyimide resin film (peeling film) obtained in (3) was used for the measurement.

(5) Measurement of glass transition temperature (Tg) The measurement was performed under a nitrogen gas flow 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 temperature was raised to 150 ° C. at a rate of 5 ° C./min to remove the adsorbed water of the sample, and in the second stage, the sample was air-cooled to a room temperature at a rate of 5 ° C./min. In the third stage, the main measurement was performed at a heating rate of 5 ° C./min to determine the glass transition temperature. Note that the polyimide resin film (peeling film) obtained in (3) was used for the measurement.

(6) Measurement of 90 ° peel strength (90 ° peel test)
A film-like material (on a glass substrate-1) of the resin composition obtained in (2) was cut into a 10 mm width and a 100 mm length, and subjected to a dehydration bake treatment at 120 ° C. for 6 minutes using a hot plate. A 90 ° peel test was performed under the conditions of a tensile speed of 50 mm / min. Here, in the 90 ° peel test, a 90 ° peel strength (N) was measured using an adhesion tester (manufactured by Yamamoto Plating Test Equipment Co., Ltd.) based on JIS C6481 (1996, copper clad laminate test method for printed wiring boards). / Cm) was measured.

(7) Preparation of a laminate and confirmation of appearance after preparation of the laminate SiON (film formation temperature: 240 ° C., film thickness: 200 nm) on a film-like material (on a glass substrate-1) of the resin composition obtained in (2) ) Was formed by plasma CVD. Thereafter, confirmation was performed at a magnification of 50 times using an optical microscope (Nikon (manufactured by Nikon), OPTIPHOT300), and judgment was made by the following evaluation method.

Excellent (A): No wrinkles are seen on the entire surface, and the surface is smooth Excellent (B): Some wrinkles are observed, but the area of wrinkles is 15% or less of the whole Good (C): Some wrinkles Although wrinkles are observed, the area of the wrinkled area is more than 15% and 30% or less of the whole. Defective (D): The area of the wrinkled area is more than 30% of the whole.

(8) Evaluation of Flex Resistance of Laminate The flex resistance of a laminate having an inorganic film on a film of the polyimide resin composition was measured by the following method. First, the laminate prepared in (7) was peeled off at the glass-polyimide interface to obtain a laminate in which a polyimide resin film and a SiON film were laminated. The laminate was sampled at 100 mm × 140 mm, and the laminate was sampled at the center on the surface. A metal cylinder having a diameter of 30 mm is fixed, and the cylinder is placed along the cylinder at a holding angle of 0 ° (in a state where the sample is flat) (see FIG. 6), and the holding angle to the cylinder is 180 ° (turned back by the cylinder). In the range (see FIG. 7). The flex resistance was evaluated by using the presence or absence of cracks in the inorganic film before and after the bending operation as an index. After the test, 100 sheets were visually observed using an optical microscope (Nikon (manufactured by OPTIPHOT300)).

(9) Preparation of Color Filter Using Laminate [1] Preparation of Resin Black Matrix A black resin composition for a resin black matrix comprising a polyamic acid in which a black pigment is dispersed on SiON of the laminate prepared in (7). It was spin-coated and dried at 130 ° C. for 10 minutes on a hot plate to form a black resin coating film. A positive type photoresist (“SRC-100” manufactured by Shipley Co., Ltd.) is spin-coated, prebaked on a hot plate at 120 ° C. for 5 minutes, and irradiated with 100 mJ / cm ² (i-line conversion) ultraviolet rays using an ultra-high pressure mercury lamp to mask. After the exposure, using a 2.38% aqueous solution of tetramethylammonium hydroxide, the development of the photoresist and the etching of the black resin coating are simultaneously performed to form a pattern, the resist is peeled off with methyl cellosolve acetate, and the resist is removed in an oven. By heating at 60 ° C. for 60 minutes, the resin was imidized to form a resin black matrix in which carbon black was dispersed in a polyimide resin. When the thickness of the black matrix was measured, it was 1.4 μm.

[2] Preparation of colored layer Acrylic resin photosensitive red resist was applied to the resin laminate obtained by patterning the black matrix prepared in [1], and the film thickness at the black matrix opening after heat treatment was reduced to 2.0 μm. Spin coating was performed as described above, and pre-baked at 100 ° C. for 10 minutes on a hot plate to obtain a red colored layer. Next, using an ultraviolet exposure apparatus “PLA-5011” manufactured by Canon Inc., 100 mJ was applied to the black matrix opening portion and a partial region on the black matrix through a chrome photomask that transmits light in an island shape. / Cm ² (i-line conversion). After the exposure, the substrate was immersed in a developing solution composed of a 0.2% aqueous solution of tetramethylammonium hydroxide for development. Subsequently, the substrate was washed with pure water and heated in an oven at 230 ° C. for 30 minutes to produce a red pixel 4R. Similarly, a green pixel 4G made of an acrylic photosensitive green resist and a blue pixel 4B made of a photosensitive blue resist were prepared to obtain a color filter (FIG. 1). Subsequently, the rotation speed of the spinner was adjusted such that the thickness of the colored layer after the heat treatment became 2.5 μm, and the transparent resin composition was applied. Then, it heat-processed for 30 minutes in a 230 degreeC oven, and produced the overcoat layer.

(10) Confirmation of peeling of black matrix and colored pixels The black matrix and colored pixels of the color filter prepared in (9) were confirmed at 50 times magnification using an optical microscope (Nikon (manufactured by OPTIPHOT300)), and the following evaluation method was used. Was determined.

Excellent (A): no peeling of black matrix and colored pixels Excellent (B): partial peeling of black matrix and colored pixels (less than 5% of total)
Good (C): Black matrix and colored pixels partially peeled off (more than 5% and less than 15% of the whole)
Poor (D): Partial peeling of the black matrix and the colored pixels was present (15% or more of the whole).

(11) Confirmation of peelability after color filter production A cut was made with a cutter at a position 10 mm from the end of the color filter produced in (9), mechanical peeling was performed, and judgment was made by the following evaluation method.

  Shu (A): Peelable with little stress on the color filter. When the black matrix and the colored pixels were confirmed after peeling, no pixel defects were found.

Excellent (B): It is necessary to apply a little stress, but it can be peeled. When the black matrix and color pixels were confirmed after peeling, some pixel defects were found. (Defects less than 5% of the total)
Good (C): It is necessary to apply a little stress, but it can be peeled off. When the black matrix and the colored pixels were confirmed after peeling, some pixel defects were observed. (Defects are more than 5% and less than 25% of the total)
Poor (D): No peeling. Alternatively, peeling could not be performed unless a large stress was applied, and the peeled color filter had defects in 25% or more of the pixel regions.

Synthesis Example 1
90 g of NMP was put into a 200 mL four-necked flask, and heated and stirred at 55 ° C. while bubbling with dry air (containing 20.9 vol% of oxygen) at 1500 ml / min. 13.66 g (44.04 mmol) of ODPA, 4.92 g (19.82 mmol) of 3,3′-DDS, 7.76 g (24.22 mmol) of TFMB, and 30 g of NMP were put therein and 50 ° C. while bubbling with dry air. For 8 hours. Then, it was cooled to room temperature to obtain a varnish. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polyimide precursor were 94,500 and 27,000, respectively.

Synthesis Example 2
A varnish was obtained in the same manner as in Example 1, except that the flow rate of the dry air was changed to 800 ml / min. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyimide precursor were 96,500 and 28,000, respectively.

Synthesis Example 3
A varnish was obtained in the same manner as in Example 1, except that the flow rate of the dry air was changed to 400 ml / min. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyimide precursor were 98,500 and 29,000, respectively.

Synthesis Example 4
The monomers used were changed to 7.19 g (23.17 mmol) of ODPA, 8.04 g (15.44 mmol) of BSAA, 4.31 g (17.38 mmol) of 3,3′-DDS, and 6.80 g (21.24 mmol) of TFMB. A varnish was prepared in the same manner as in Synthesis Example 3 except for the above. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polyimide precursor were 98,000 and 30,000, respectively.

Synthesis Example 5
A varnish was obtained in the same manner as in Example 1, except that the flow rate of the dry air was changed to 200 ml / min. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyimide precursor were 99,700, 29,100, respectively.

Synthesis Example 6
A varnish was obtained in the same manner as in Synthesis Example 5, except that dry air (containing 20.9% by volume of oxygen) was changed to nitrogen gas containing 5.0% by volume of oxygen. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyimide precursor were 99,600, 30,100, respectively.

Synthesis Example 7
A varnish was obtained in the same manner as in Synthesis Example 5, except that dry air (containing 20.9% by volume of oxygen) was changed to nitrogen gas (oxygen content was less than 0.1 ppm by volume). The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyimide precursor were 95,500 and 27,800, respectively.

Synthesis Example 8
A varnish was obtained in the same manner as in Synthesis Example 7, except that the solvent used was changed from NMP to GBL. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyimide precursor were 88,500 and 25,700, respectively.

Synthesis Example 9
A varnish was obtained in the same manner as in Synthesis Example 7, except that the solvent used was changed from NMP to DMAc. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyimide precursor were 90,500 and 26,600, respectively.

Synthesis Example 10
The monomers used were 5.18 g (16.69 mmol) of ODPA, 11.46 g (38.94 mmol) of BPDA, 6.22 g (25.03 mmol) of 3,3′-DDS, and 3.49 g (30.59 mmol) of t-CHDA. A varnish was prepared in the same manner as in Synthesis Example 2 except that the varnish was changed to varnish. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polyimide precursor were 109,500 and 45,900, respectively.

Synthesis Example 11
90 g of NMP was put into a 200 mL four-necked flask, and heated and stirred at 55 ° C. while bubbling with dry air (containing 20.9% by volume) of 400 ml / min. There, 4.11 g (13.25 mmol) of ODPA, 9.10 g (30.92 mmol) of BPDA, 4.94 g (19.88 mmol) of 3,3′-DDS, 7.78 g (24.30 mmol) of TFMB, and 30 g of NMP were added. The mixture was heated and stirred at 50 ° C. for 8 hours while bubbling with dry air. Then, it was cooled to room temperature to obtain a varnish. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polyimide precursor were 89,500 and 26,900, respectively.

Synthesis Example 12
A varnish was prepared in the same manner as in Synthesis Example 11 except that dry air (containing 20.9% by volume of oxygen) was changed to nitrogen gas (oxygen content was less than 0.1 ppm by volume) and the flow rate was changed to 200 ml / min. Obtained. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyimide precursor were 95,500 and 27,800, respectively.

Synthesis Example 13
The monomers used were 4.11 g (13.25 mmol) of ODPA, 9.10 g (30.92 mmol) of BPDA, 3.84 g (15.46 mmol) of 3,3′-DDS, 7.78 g (24.30 mmol) of TFMB, and 4 A varnish was prepared in the same manner as in Synthesis Example 3 except that 1.51 g (4.42 mmol) of -ABS-3AP was changed. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polyimide precursor were 89,500 and 26,900, respectively.

Synthesis Example 14
The monomers used were changed to 3.54 g (11.42 mmol) of ODPA, 11.84 g (26.65 mmol) of 6FDA, 4.25 g (17.13 mmol) of 3,3′-DDS, and 6.71 g (20.94 mmol) of TFMB. A varnish was prepared in the same manner as in Synthesis Example 3 except for the above. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polyimide precursor were 89,500 and 26,900, respectively.

Synthesis Example 15
The monomers used were 4.56 g (14.69 mmol) of ODPA, 7.69 g (34.28 mmol) of PMDA-HS, 5.47 g (22.04 mmol) of 3,3′-DDS, 8.63 g (26.94 mmol) of TFMB. A varnish was prepared in the same manner as in Synthesis Example 3 except that the varnish was changed to varnish. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polyimide precursor were 85,500 and 25,900, respectively.

Synthesis Example 16
Same as Synthesis Example 3 except that the monomers used were changed to 13.11 g (42.26 mmol) of ODPA, 12.18 g (38.04 mmol) of TFMB, and 1.05 g (4.23 mmol) of 3,3′-DDS. Varnish. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polyimide precursor were 98,300 and 29,800, respectively.

Synthesis Example 17
Same as Synthesis Example 3 except that the monomers used were changed to 14.45 g (46.56 mmol) of ODPA, 1.49 g (4.66 mmol) of TFMB, and 10.41 g (41.91 mmol) of 4,4′-DDS. Varnish. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polyimide precursor were 84,500 and 25,700, respectively.

Synthesis Example 18
Same as Synthesis Example 3 except that the monomers used were changed to 14.47 g (43.40 mmol) of ODPA, 4.85 g (19.53 mmol) of 3,3′-DDS, and 8.03 g (23.87 mmol) of 6FODA. Varnish. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polyimide precursor were 94,900 and 27,900, respectively.

Synthesis Example 19
Same as Synthesis Example 3 except that the monomers used were changed to 12.90 g (41.59 mmol) of ODPA, 4.65 g (18.71 mmol) of 3,3′-DDS, and 8.79 g (22.87 mmol) of FFDA. Varnish. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polyimide precursor were 88,900 and 25,900, respectively.

Examples 1-6, 9-15, Comparative Examples 1-6:
The varnish used in accordance with Table 1 was changed, and the polyimide precursor resin composition and the polyimide resin film were evaluated by the above method. The varnish used in each example was obtained by filtering the varnish obtained in each synthesis example with a filter made of a resin made of tetrafluoroethylene resin (PTFE) having a pore diameter of 1 μm. The amount of MSI contained in each varnish was measured by the method described in (1).

Example 7
To 100 g of the varnish obtained in Synthesis Example 7, 50.0 mg of PSI (500 ppm based on the varnish) was added. Using the obtained varnish, a polyimide resin film was formed by the method described above and evaluated.

Example 8
To 100 g of the varnish obtained in Synthesis Example 7, 50.0 mg of 1-methylpiperidine-2,6-dione (500 ppm based on the varnish) was added. Using the obtained varnish, a polyimide resin film was formed by the above method and evaluated.

  Table 2 shows the evaluation results of Examples 1 to 15 and Comparative Examples 1 to 6. In Comparative Example 4, since cracks occurred during curing, evaluation after forming the laminate was not performed.

  In Examples 1 to 3, 5, 9, 10, and 12 to 15, no wrinkling was observed after the formation of the inorganic film. This is considered to be due to the fact that the Tg of the polyimide resin film used was sufficiently high and the resin film was not softened by heating during the formation of the inorganic film. Further, it is considered that the smoothness of the surface of the inorganic film was maintained by suppressing the generation of wrinkles, and the adhesion between the black matrix and the colored pixels and the inorganic film was excellent.

Reference Signs List 1 polyimide resin 2 gas barrier layer 3 black matrix 4R red pixel 4G green pixel 4B blue pixel 5 overcoat layer 6 color filter 7 metal column 8 laminate

Claims (12)

(A) a polyimide precursor containing a structural unit represented by the general formula (1) as a main component, (B) a compound represented by the general formula (2), and (C) a polyimide precursor resin composition containing a solvent And (B) a polyimide precursor resin composition in which the content of the compound represented by the general formula (2) is 30 to 4000 ppm based on the polyimide precursor resin composition.
(R ¹ represents an aromatic tetracarboxylic acid residue, R ² represents an aromatic diamine residue. X ¹ and X ² each independently represent a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. .)
(In the general formula (2), R ³ represents a group selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 15 carbon atoms. In addition, n represents 2 or 3.) (A) The polyimide precursor resin composition according to (1), wherein the structural unit represented by the general formula (1) does not include the structure represented by the general formula (3).
(B) The polyimide precursor resin composition according to claim 1 or 2, wherein the compound represented by the general formula (2) is N-methylsuccinimide. (A) When the polyimide precursor having the structural unit represented by the general formula (1) is cured by heating, the imide group concentration is from 3.0 mmol / g to 4.5 mmol / g. Or a polyimide precursor resin composition. The polyimide precursor resin composition according to any one of claims 1 to 4, wherein, in the general formula (1), R ¹ is a tetravalent organic group represented by the general formula (4).
(Y ¹ is a direct bond or a divalent organic group having 1 to 3 carbon atoms which may be substituted by one or more selected from the group consisting of an oxygen atom, a sulfur atom, a sulfonyl group and a halogen atom. Or a divalent crosslinked structure selected from the group consisting of an organic group having 1 to 20 carbon atoms having an ester bond, an amide bond, a carbonyl group, a sulfide bond, and an aromatic ring.) The polyimide precursor resin according to any one of claims 1 to 5, wherein R ¹ in the general formula (1) is at least one selected from structures represented by the following general formulas (5) to (7). Composition.
The polyimide precursor resin composition according to any one of claims 1 to 6, wherein in the general formula (1), R ² is a divalent organic group represented by any of the general formulas (8) to (12). object.
(In the formula (12), each Z independently represents a hydrogen atom or a fluorine atom, but at least one Z is a fluorine atom. M represents an integer of 1 or 2.) The polyimide precursor contains a diamine residue having a sulfonyl group in an amount of 10 mol% or more and 90 mol% or less in 100 mol% of the polyimide precursor, and a diamine residue having a fluorine atom is contained in the polyimide precursor. The polyimide precursor resin composition according to any one of claims 1 to 7, comprising 10 mol% to 90 mol% in 100 mol%. A polyimide resin film obtained by imidizing the polyimide precursor resin composition according to claim 1, wherein the content of the compound represented by the general formula (2) is the weight of the polyimide resin film. 0.3 to 2.4 ppm with respect to the polyimide resin film. A laminate comprising a glass substrate on one of the polyimide resin films according to claim 8. A laminate having an inorganic film on the polyimide resin film according to claim 8. A flexible device comprising the polyimide resin film according to claim 8.