Polyimide resin, photosensitive resin composition, resin film and electronic device

Abstract

A modified polyimide resin including a structure represented by general formula (I). A polyimide resin including a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine compound, wherein the structural unit A includes, at a ratio of 60 mol% or more, a structural unit derived from a compound having a specific structure.

Description

[Technical field]

[0001] The present invention relates to a polyimide resin, a photosensitive resin composition, a resin film, and an electronic device. [Background technology]

[0002] In general, polyimide resins obtained by the reaction of tetracarboxylic dianhydride with diamine have excellent properties such as heat resistance, mechanical properties, electrical properties, and chemical resistance, and are widely used in the electrical and electronics industry. However, since most aromatic polyimide resins have poor solubility in organic solvents, polyimide is usually produced by applying a polyamic acid solution, which is a polyimide precursor, and dehydrating and ring-closing the solution by high-temperature heating. Imidization by dehydration and ring-closing involves the elimination and evaporation of water, and the temperature during thermal imidization reaches 180 to 400°C, which makes it prone to malfunctions and makes it difficult to process, limiting its applications.

[0003] One method for solving the above problem is to use polyimide soluble in organic solvents. Polyimide soluble in organic solvents can be processed by simply volatilizing the organic solvent, and many studies have been conducted, mainly by devising polymerization components. One method for improving solubility is the introduction of an alicyclic structure. For example, a polyimide resin containing a 1,2,4,5-cyclohexanetetracarboxylic acid skeleton has been disclosed (see Patent Documents 1 and 2). Patent Document 1 discloses a polyimide resin containing a 1,2,4,5-cyclohexanetetracarboxylic acid skeleton and having a sufficiently high solubility in organic solvents. Patent Document 2 discloses a method for producing a solvent-soluble polyimide by polycondensing an aliphatic tetracarboxylic acid dianhydride, an aliphatic tetracarboxylic acid or a derivative thereof with a diamine compound in a solvent. In addition, a solvent-soluble polyimide obtained by copolymerizing a specific alicyclic tetracarboxylic acid dianhydride with an alicyclic diamine and an aromatic diamine has also been disclosed (see Patent Document 3). On the other hand, Patent Document 4 discloses a polyimide resin that contains a specific aromatic diamine, 4,4'-oxybis[3-(trifluoromethyl)benzeneamine] (6FODA), and has sufficiently high solubility in organic solvents. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-168800 A [Patent Document 2] JP 2005-15629 A [Patent Document 3] JP 2015-134842 A [Patent Document 4] China Patent Application Publication No. 102807675 Summary of the Invention [Problem to be solved by the invention]

[0005] Photosensitive polyimide resins with excellent heat resistance and insulating properties are widely used for surface protection films and interlayer insulating films of semiconductor elements in electronic devices, and wiring protection insulating films of circuit boards. Insulating materials for semiconductor integrated circuits and the like are required to have higher pattern developability than ever before in photolithography in view of recent trends toward higher density and higher integration, and it is important to widen the difference in solubility between exposed and unexposed areas, so that the base polyimide resin is required to have high solvent solubility. The polyimide resins in the above Patent Documents 1 to 4 still have insufficient solvent solubility, and further ingenuity is required.

[0006] In view of the above circumstances, an object of the present invention is to provide a polyimide resin having excellent solvent solubility, a photosensitive resin composition containing the polyimide resin, a resin film thereof, and an electronic device containing the resin film. [Means for solving the problem]

[0007] Means for Solving the Problems The present inventors have conducted intensive research to solve the above problems and have found that by using a specific tetracarboxylic dianhydride and a specific diamine compound as raw materials for a polyimide resin, a polyimide resin having superior solvent solubility to that of conventional polyimide resins can be obtained. That is, the present invention provides the following polyimide resin, photosensitive resin composition, resin film, and electronic device.

[0008] [1] A modified polyimide resin having a structure represented by the following general formula (I): [ka] In the general formula (I), E has at least one group selected from the group consisting of an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and an organosiloxane group, and is a divalent group having 2 to 39 carbon atoms. Q contains 60 mol % or more of a structure represented by the following general formula (II), and may contain a tetravalent group having 4 to 10 carbon atoms and having a cyclic structure, a non-cyclic structure, or a combination of a cyclic structure and a non-cyclic structure, in addition to the structure represented by the general formula (II). n represents the number of repeating units. The terminal of the general formula (I) is either a group represented by the following formula (III) or formula (IV) or a hydrogen atom, and at least one of the terminals is a group represented by formula (III) or formula (IV): [ka] [In the general formula (II), X represents one selected from the group consisting of a single bond and a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. The divalent aromatic hydrocarbon group represented by X may be substituted with a substituent, and the above carbon number represents the number of carbon atoms forming an aromatic ring. When X represents a single bond, multiple R 1 each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, or a nitro group, or two R 1 When X is a divalent aromatic hydrocarbon group, multiple R 1 Each of R independently represents at least one selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 10 carbon atoms. 2 each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; m represents an integer of 0 to 4; * represents a bond.] [ka] [In the general formula (III) and (IV), X 11 and X 22 Y each independently represents a group having 2 to 15 carbon atoms and may have at least one group selected from the group consisting of an ester bond and a double bond. 1 and Y 2 are each independently a hydrogen atom or a methyl group. [2] The modified polyimide resin according to the above [1], wherein the weight average molecular weight of the modified polyimide resin is 70,000 or less. [3] The modified polyimide resin according to [1] or [2] above, wherein the modified polyimide resin has a weight average molecular weight of 5,000 or more. [4] The modified polyimide resin according to any one of the above [1] to [3], wherein the modified polyimide resin has a light transmittance of 50% or more at any wavelength of 200 to 400 nm.

[0009] [5] A polyimide resin for a photosensitive resin composition, comprising a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine compound, wherein the structural unit A contains a structural unit derived from a compound represented by the following formula (1) in a ratio of 60 mol % or more: [ka] In the general formula (1), X represents one member selected from the group consisting of a single bond and a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. The divalent aromatic hydrocarbon group represented by X may be substituted with a substituent, and the above carbon number represents the number of carbon atoms forming an aromatic ring. When X represents a single bond, multiple R 1 each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, or a nitro group, or two R 1 When X is a divalent aromatic hydrocarbon group, multiple R 1Each of R independently represents at least one selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 10 carbon atoms. 2 each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. m represents an integer of 0 to 4. [6] The polyimide resin according to [5] above, wherein the structural unit B comprises a structural unit B1 derived from at least one compound selected from the group consisting of compounds represented by the following formulas: [ka] [7] The polyimide resin according to the above [5] or [6], wherein the structural unit B comprises a structural unit B2 derived from at least one compound selected from the group consisting of compounds represented by the following formulas: [ka] [8] The polyimide resin according to the above [7], wherein the structural unit B2 contains a structural unit derived from a compound represented by formula (2). [ka] [9] The polyimide resin according to any one of the above [6] to [8], wherein the structural unit B contains 60 mol % or more of the structural unit B1 or the structural unit B2.

[10] The polyimide resin according to any one of the above [5] to [9], which has a weight average molecular weight of 70,000 or less.

[0010]

[11] A polyimide varnish comprising at least one polyimide resin selected from the modified polyimide resin according to any one of the above [1] to [4] and the polyimide resin according to any one of the above [5] to

[10] , and an organic solvent.

[12] A molded article obtained by molding the polyimide varnish described in

[11] above.

[13] The molded article according to the above

[12] , which is in the form of a membrane, film or sheet.

[14] A photosensitive resin composition comprising at least one polyimide resin selected from the modified polyimide resin (A) described in any one of the above [1] to [4] and the polyimide resin described in any one of the above [5] to

[10] , and at least one compound (B) selected from the group consisting of a photopolymerization initiator, a solvent, and a photopolymerizable compound.

[15] The photosensitive resin composition according to the above

[14] , wherein the photopolymerizable compound contains a polyfunctional radically polymerizable monomer.

[16] The photosensitive resin composition according to

[14] or

[15] above, further comprising a sensitizer.

[17] The light from a high-pressure mercury lamp with wavelengths below 365 nm cut off is used at an exposure dose of 1,500 to 2,500 mJ / cm 2 The photosensitive resin composition according to any one of the above

[14] to

[16] , wherein after exposure under the above conditions, the residual film rate in the unexposed area is 40% or less.

[18] The photosensitive resin composition according to any one of the above

[14] to

[17] , which is for forming an insulating film.

[19] A resin film comprising the photosensitive resin composition according to any one of the above

[14] to

[18] or a cured product of the photosensitive resin composition.

[20] The resin film according to

[19] above, having a film thickness of 10 to 85 μm.

[21] An electronic device comprising the resin film described in

[20] above. Effect of the Invention

[0011] According to the present invention, it is possible to obtain a polyimide resin having excellent solvent solubility, a photosensitive resin composition containing the polyimide resin, a resin film thereof, and an electronic device containing the resin film. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A detailed description will be given of an embodiment for carrying out the present invention (hereinafter, simply referred to as "the present embodiment"). The following present embodiment is an example for explaining the present invention, and does not limit the contents of the present invention. The present invention can be carried out by appropriately modifying it within the scope of its gist. In this specification, the provisions that are considered to be preferable can be adopted arbitrarily, and it can be said that a combination of preferable provisions is more preferable. In this specification, the description "XX to YY" means "XX or more and YY or less."

[0013] In this specification, "(meth)acrylate" means both "acrylate" and "methacrylate". The same applies to other similar terms (such as "(meth)acrylic acid" and "(meth)acryloyl group").

[0014] [Polyimide resin] <Structural unit A> The polyimide resin of the present embodiment is a polyimide resin containing a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine compound, and is characterized in that the structural unit A contains a structural unit derived from a compound represented by the following formula (1) in a ratio of 60 mol % or more. [ka] In the general formula (1), X represents one member selected from the group consisting of a single bond and a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, and is preferably a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. The divalent aromatic hydrocarbon group represented by X may be substituted with a substituent, and the above carbon number indicates the number of carbon atoms forming an aromatic ring. When X is a single bond, multiple R 1 each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, or a nitro group, or two R 1 When X is a divalent aromatic hydrocarbon group, multiple R 1 Each of R independently represents at least one selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 10 carbon atoms. 2each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. m represents an integer of 0 to 4.

[0015] In the above general formula (1), the divalent aromatic hydrocarbon group having 6 to 30 carbon atoms that can be selected as X may be substituted or unsubstituted. In this specification, "6 to 30 carbon atoms" refers to the number of carbon atoms forming an aromatic ring, and does not include the number of carbon atoms in the substituent if the group has a substituent. If the divalent aromatic hydrocarbon group has more than 30 carbon atoms, the polyimide resin tends to be colored when formed from the compound represented by formula (1) as a raw material, which is not preferable. From the viewpoints of transparency and ease of purification, the divalent aromatic hydrocarbon group has preferably 6 to 18 carbon atoms, more preferably 6 to 12 carbon atoms.

[0016] The divalent aromatic hydrocarbon group is not particularly limited, and may be, for example, an aromatic hydrocarbon group obtained by removing two hydrogen atoms from an aromatic compound selected from the group consisting of benzene, naphthalene, anthracene, phenanthrene, triphenylene, pyrene, chrysene, biphenyl, terphenyl, quaterphenyl, and quinquephenyl, and a group in which at least one hydrogen atom in the aromatic hydrocarbon group is substituted with a substituent (e.g., 2,5-dimethyl-1,4-phenylene group, 2,3,5,6-tetramethyl-1,4-phenylene group), etc. The position at which the two hydrogen atoms are removed from the aromatic compound is not particularly limited, and for example, when the aromatic hydrocarbon group is a phenylene group, it may be any of the ortho, meta, and para positions. The aromatic compound may have a substituent, and the divalent aromatic hydrocarbon group derived from the aromatic compound may have a substituent derived from the compound.

[0017] The substituent that the divalent aromatic hydrocarbon group in X in the above formula (1) may have is not particularly limited. Examples include alkyl groups, alkoxy groups, and halogen atoms. Among these substituents, from the viewpoint of obtaining a polyimide resin with better solvent solubility and high processability, an alkyl group or alkoxy group having 1 to 10 carbon atoms is more preferred. If the carbon number of the substituent is 10 or less, it is preferable because it does not adversely affect the solvent solubility of the resulting polyimide resin. The carbon number of the alkyl group and alkoxy group suitable as the substituent is more preferably 1 to 6, even more preferably 1 to 5, even more preferably 1 to 4, and particularly preferably 1 to 3, from the viewpoint of obtaining a polyimide resin with better solvent solubility. The alkyl group and alkoxy group that can be selected as the substituent may each be linear or branched.

[0018] When X in formula (1) is a single bond, multiple R 1 each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, or a nitro group, or two R 1 When X is a divalent aromatic hydrocarbon group, multiple R 1 each independently represents at least one selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 10 carbon atoms.

[0019] R 1 The alkyl group represented by R is an alkyl group having 1 to 10 carbon atoms, regardless of the type of X, and may be linear or branched. 1 When the number of carbon atoms in the alkyl group represented by R is 10 or less, the solvent solubility of the resulting polyimide resin is not adversely affected. 1 The alkyl group represented by the formula (I) preferably has 1 to 6 carbon atoms, more preferably 1 to 5 carbon atoms, further preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms.

[0020] When X in the above formula (1) is a single bond, as described above, 1Among them, two R 1 The groups may be attached to form a methylidene group (=CH2).

[0021] Multiple R in formula (1) 1 From the viewpoints that excellent solvent solubility can be obtained when producing a polyimide, raw materials are easily available, and purification is easier, regardless of the type of X, each of R is preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, and further preferably a hydrogen atom or a methyl group. 1 may be the same or different regardless of the type of X, but are preferably the same from the viewpoint of ease of purification, etc.

[0022] A plurality of R in the above formula (1) 2 From the viewpoint of obtaining a polyimide resin having excellent solvent solubility, the alkyl group having 1 to 10 carbon atoms that can be selected as R preferably has 1 to 6 carbon atoms, more preferably 1 to 5 carbon atoms, further preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. 2 The alkyl group that may be selected as may be linear or branched.

[0023] A plurality of R in the above formula (1) 2 From the viewpoints of obtaining excellent solvent solubility when producing a polyimide, easy availability of raw materials, and easier purification, R are each preferably independently selected from a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, and an isopropyl group, and are particularly preferably a hydrogen atom or a methyl group. 2 may be the same or different, but from the viewpoint of ease of purification, etc., it is preferable that they are the same.

[0024] In one aspect of this embodiment, multiple R 1 and R 2 It is particularly preferable that all of R in formula (1) are hydrogen atoms. 1 and R2 When all of the groups are hydrogen atoms, when a polyimide is produced using the compound as a monomer, excellent solvent solubility tends to be obtained.

[0025] Examples of the compound (tetracarboxylic dianhydride) represented by the above formula (1) where X is a single bond include the same tetracarboxylic dianhydrides as those described in WO 2017 / 030019. Examples of the compound (tetracarboxylic dianhydride) represented by the above formula (1) where X is the divalent aromatic hydrocarbon group include the same tetracarboxylic dianhydrides as those described in WO 2015 / 163314. The compound represented by the above formula (1) is such that X is the divalent aromatic hydrocarbon group and a plurality of R 1 and R 2 are each a hydrogen atom, X is an aromatic hydrocarbon group obtained by eliminating two hydrogen atoms from an aromatic compound selected from the group consisting of benzene, naphthalene, anthracene, phenanthrene, triphenylene, pyrene, chrysene, biphenyl, terphenyl, quaterphenyl, and quinquephenyl, and 1 and R 2 are each a hydrogen atom, and X is an aromatic hydrocarbon group in which two hydrogen atoms have been eliminated from benzene, and 1 and R 2 are more preferably a compound in which X is an aromatic hydrocarbon group having two hydrogen atoms removed from the para-position of benzene (i.e., a 1,4-phenylene group), and 1 and R 2 are particularly preferably hydrogen atoms.

[0026] The polyimide resin of the present embodiment is required to contain 60 mol % or more of the structural unit derived from the compound represented by the above formula (1) as the structural unit A derived from the tetracarboxylic dianhydride. If the amount of the structural unit derived from the compound represented by the formula (1) in the structural unit A is less than 60 mol %, the resulting polyimide resin will have poor solvent solubility. The ratio of the structural unit derived from the compound represented by formula (1) in the structural unit A is more preferably 70 mol % or more, even more preferably 80 mol % or more, even more preferably 95 mol % or more, and particularly preferably 100 mol %.

[0027] As the tetracarboxylic acid other than the compound represented by formula (1) contained in the structural unit A, any one can be used. For example, cyclohexane tetracarboxylic acid, cyclohexane tetracarboxylic acid esters, cyclohexane tetracarboxylic acid dianhydride, cyclobutane tetracarboxylic acid, cyclobutane tetracarboxylic acid esters, cyclobutane tetracarboxylic acid dianhydride, cyclopentane tetracarboxylic acid, cyclopentane tetracarboxylic acid esters, cyclopentane tetracarboxylic acid dianhydride, bicyclopentane tetracarboxylic acid dianhydride, etc. are mentioned. Among them, cyclohexane tetracarboxylic acid dianhydride, cyclobutane tetracarboxylic acid dianhydride, and cyclopentane tetracarboxylic acid dianhydride are more preferable. Among the above, cyclohexane tetracarboxylic acid dianhydride is more preferable. The above-mentioned various tetracarboxylic acid components include positional isomers.

[0028] More preferred specific examples of the tetracarboxylic acid component include 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid methyl ester, 1,2,3,4-butanetetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,3,4-butanetetracarboxylic acid methyl ester, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid methyl ester, and 1,2,4,5-cyclopentanetetracarboxylic acid. , 1,2,4,5-cyclopentane tetracarboxylic acid dianhydride, 1,2,4,5-cyclopentane tetracarboxylic acid methyl ester, 3-carboxymethyl-1,2,4-cyclopentane tricarboxylic acid, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid methyl ester, dicyclohexyl tetracarboxylic acid, dicyclohexyl tetracarboxylic acid dianhydride, and dicyclohexyl tetracarboxylic acid methyl ester. Among these, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, and 1,2,4,5-cyclohexanetetracarboxylic acid methyl ester are particularly preferred because they are advantageous in that they can be easily increased in molecular weight when producing a polyimide resin and a flexible film can be easily obtained.

[0029] <Structural unit B> The structural unit B is derived from a diamine compound, and examples thereof include at least one type selected from the group consisting of compounds represented by the following formulas. [ka] [ka]

[0030] Among the above, it is more preferable to contain a structural unit B1 derived from at least one compound selected from the group consisting of compounds represented by the following formulas. [ka]

[0031] It is further preferable that the structural unit B contains a structural unit B2 derived from at least one compound selected from the group consisting of compounds represented by the following formulas: [ka]

[0032] Among these, when the structural unit B2 contains a structural unit derived from a compound represented by the following formula (2), the resulting polyimide resin has superior solvent solubility, which is preferable. [ka]

[0033] The polyimide resin of the present embodiment preferably contains 60 mol % or more of the above-mentioned structural unit B1 or structural unit B2 as the diamine-derived structural unit B. If the ratio of the structural unit B1 or the structural unit B2 in the structural unit B is 60 mol % or more, a polyimide resin having excellent solvent solubility can be obtained. The ratio of the structural unit B1 or the structural unit B2 in the structural unit B is more preferably 70 mol% or more, even more preferably 80 mol% or more, still more preferably 95 mol% or more, and particularly preferably 100 mol%. In particular, it is preferable that the structural unit B contains the structural unit B2 as the structural unit B, and that the structural unit B2 contains a structural unit derived from a diamine represented by formula (2) in the above ratio.

[0034] The weight average molecular weight of the polyimide resin is preferably 70,000 or less. If the weight average molecular weight is 70,000 or less, it has better solvent solubility and is suitable for forming a cured film. The weight average molecular weight is preferably 60,000 or less, more preferably 50,000 or less, even more preferably 45,000 or less, even more preferably 40,000 or less, and even more preferably 30,000 or less. Since a cured film having desired mechanical properties can be obtained, the weight average molecular weight of the polyimide resin is preferably 5,000 or more. The weight average molecular weight of the polyimide resin is more preferably 10,000 or more, even more preferably 13,000 or more, and even more preferably 15,000 or more. By having the weight average molecular weight of the polyimide resin in the above range, it is possible to obtain a resin composition having a low residual film rate in the unexposed part and excellent developability, for example, when the resin is made into a photosensitive resin composition, in addition to the solvent solubility. Here, the weight average molecular weight is a weight average molecular weight calculated from absolute molecular weight measurement by GPC-light scattering method.

[0035] <Method of manufacturing polyimide resin> The polyimide resin of this embodiment contains a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine compound, and the raw materials, tetracarboxylic dianhydride and diamine compound, are as described above. The polyimide resin of this embodiment can be obtained by reacting the above tetracarboxylic acid with a diamine component. The polyimide resin of this embodiment can have an amino group at the terminal.

[0036] The organic solvent used when reacting the tetracarboxylic acid component with the diamine component is not particularly limited, but is preferably at least one selected from the group consisting of cyclic ethers, cyclic ketones, cyclic esters, amides, and ureas. Specific examples of suitable solvents are not particularly limited, but include at least one selected from the group consisting of aprotic polar organic solvents such as γ-butyrolactone, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, hexamethylphosphoramide, cyclopentanone, cyclohexanone, 1,3-dioxolane, 1,4-dioxane, tetramethylurea, and tetrahydrofuran. Among these, it is more preferable to use at least one selected from the group consisting of γ-butyrolactone, N,N-dimethylacetamide, N,N-dimethylformamide, and N-methyl-2-pyrrolidone.

[0037] An imidization catalyst can be used when reacting the tetracarboxylic acid component with the diamine component. The imidization catalyst is preferably a tertiary amine compound, and specifically, at least one selected from the group consisting of trimethylamine, triethylamine (TEA), tripropylamine, tributylamine, triethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, triethylenediamine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, imidazole, pyridine, quinoline, and isoquinoline can be used.

[0038] The reaction temperature is, for example, in the range of 160 to 200°C, preferably in the range of 170 to 190°C, and more preferably in the range of 180 to 190°C. If the temperature is 160°C or higher, imidization and high molecular weight can be more effectively promoted. If the temperature is 200°C or lower, the solution viscosity can be more appropriately maintained, and problems such as the resin being burned onto the wall of the reaction vessel can be further prevented. In some cases, an azeotropic dehydrating agent such as toluene or xylene may be used. The reaction pressure is usually normal pressure, but the reaction can be carried out under pressure as necessary. The reaction temperature is preferably maintained for at least 1 hour, more preferably 3 hours or more. If the reaction temperature is maintained for 1 hour or more, imidization and high molecular weight can be more effectively promoted. There is no particular upper limit to the reaction time, but the reaction can be carried out within a range of, for example, 10 hours or less.

[0039] In the production of the polyimide resin of this embodiment, it is preferable to react "A moles" of the tetracarboxylic acid component with "B moles" of the diamine component in the range of 0.80≦A / B≦0.99, and more preferably in the range of 0.85≦A / B≦0.95. By making A / B≦0.99, it is possible to make the terminal of the polyimide have an excess of diamine, and it is possible to obtain a polyimide resin having an amino group at the terminal, and a polyimide resin having a molecular weight with sufficient solvent solubility is obtained. If 0.80≦A / B, it is possible to obtain a polyimide resin having a molecular weight that exhibits sufficient flexibility. The closer A / B is to 1.0, the higher the molecular weight of the resulting polyimide resin will be. By appropriately adjusting A / B, it is possible to obtain a polyimide resin with the desired molecular weight.

[0040] <Polyimide varnish> In one aspect of the present embodiment, a polyimide varnish is provided, which contains at least one polyimide resin selected from the above polyimide resin and the modified polyimide resin described below, and an organic solvent. The polyimide resin is as described above. The modified polyimide resin will be described below. The organic solvent is not particularly limited as long as it dissolves the polyimide resin or the modified polyimide resin. It is preferable to use the above-mentioned compounds alone or in a mixture of two or more kinds as the reaction solvent used in the production of the polyimide resin. The polyimide varnish of the present embodiment may be a polyimide solution itself in which a polyimide resin obtained by a polymerization method or a modified polyimide resin is dissolved in a reaction solvent, or may be a polyimide solution diluted by further adding a solvent.

[0041] Since the polyimide resin or modified polyimide resin of this embodiment has excellent solvent solubility, a highly concentrated varnish that is stable at room temperature can be obtained. The polyimide varnish of this embodiment preferably contains 5 to 40 mass % of the polyimide resin described in detail, more preferably 10 to 30 mass %. The viscosity of the polyimide varnish is preferably 1 to 200 Pa·s, more preferably 1 to 100 Pa·s. The viscosity of the polyimide varnish is a value measured at 25°C using an E-type viscometer.

[0042] The polyimide varnish of the present embodiment may contain various additives such as inorganic fillers, adhesion promoters, release agents, flame retardants, UV stabilizers, surfactants, leveling agents, defoamers, fluorescent brightening agents, crosslinking agents, polymerization initiators, and photosensitizers, within the scope of not impairing the required properties of the polyimide film. The method for producing the polyimide varnish is not particularly limited, and any known method can be applied.

[0043] [Molded body] According to one aspect of the present embodiment, there is provided a molded article obtained by molding the polyimide varnish. Specifically, the molded article may be in the form of a membrane, film, or sheet. The above molded article is excellent in optical isotropy, flexibility and chemical resistance. The method for producing the molded product is not particularly limited, and a known method can be used. For example, the polyimide varnish of the present embodiment is applied onto a smooth support such as a glass plate, a metal plate, or a plastic plate, and molded into a membrane, film, or sheet, and then the organic solvents contained in the varnish, such as a reaction solvent or a dilution solvent, are removed by heating.

[0044] Examples of the coating method include known coating methods such as spin coating, slit coating, blade coating, etc. Among these, slit coating is preferred from the viewpoint of workability, since it controls the intermolecular orientation and improves chemical resistance.

[0045] A method for removing the organic solvent contained in the varnish by heating is preferably to evaporate the organic solvent at a temperature of 150°C or less to make it tack-free, and then to dry it at a temperature equal to or higher than the boiling point of the organic solvent used (not particularly limited, but preferably 200 to 500°C). It is also preferable to dry it in an air atmosphere or a nitrogen atmosphere. The pressure of the drying atmosphere may be reduced pressure, normal pressure, or increased pressure. The method for peeling off a film formed on a support, for example a polyimide film, from the support is not particularly limited, but examples include a laser lift-off method, a method using a sacrificial layer for peeling (a method in which a release agent is applied in advance to the surface of the support), and a method of adding a release agent.

[0046] The thickness of the membrane-, film- or sheet-shaped molded article of this embodiment can be appropriately selected depending on the application, etc., and is preferably in the range of 1 to 250 μm, more preferably 5 to 100 μm, even more preferably 8 to 80 μm, and even more preferably 10 to 80 μm. If the thickness is in the range of 1 to 250 μm, it can be practically used as a free-standing film. The thickness of the molded article can be easily controlled by adjusting the solids concentration and viscosity of the polyimide varnish.

[0047] The membranous, film-like, or sheet-like molded article in this embodiment is suitably used as a film for various components such as color filters, flexible displays, semiconductor parts, and optical components, and is particularly suitably used as a substrate for image display devices such as liquid crystal displays and OLED displays.

[0048] [Modified polyimide resin and photosensitive resin composition] The present embodiment provides a modified polyimide resin having a structure represented by the following general formula (I), and a photosensitive resin composition comprising at least one polyimide resin selected from the modified polyimide resin (A) and the polyimide resin of the present embodiment described above, and at least one compound (B) selected from the group consisting of a photopolymerization initiator, a solvent, and a photopolymerizable compound. [ka] In the general formula (I), E has at least one group selected from the group consisting of an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and an organosiloxane group, and is a divalent group having 2 to 39 carbon atoms. Q contains 60 mol % of a structure represented by the following general formula (II), and may contain a tetravalent group having 4 to 10 carbon atoms and having a cyclic structure, a non-cyclic structure, or a combination of a cyclic structure and a non-cyclic structure, in addition to the structure represented by the general formula (II). n represents the number of repeating units. The terminal of the general formula (I) is either a group represented by the following formula (III) or formula (IV), or a hydrogen atom, and at least one of the terminals is a group represented by formula (III) or formula (IV): [ka] In the general formula (II), X represents one selected from the group consisting of a single bond and a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. The divalent aromatic hydrocarbon group represented by X may be substituted with a substituent, and the above carbon number represents the number of carbon atoms forming an aromatic ring. When X represents a single bond, multiple R 1each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, or a nitro group, or two R 1 When X is a divalent aromatic hydrocarbon group, multiple R 1 Each of R independently represents at least one selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 10 carbon atoms. 2 each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; m represents an integer of 0 to 4; * represents a bond.] [ka] [In the general formula (III) and (IV), X 11 and X 22 Y each independently represents a group having 2 to 15 carbon atoms and may have at least one group selected from the group consisting of an ester bond and a double bond. 1 and Y 2 are each independently a hydrogen atom or a methyl group.

[0049] X and R in general formula (II) 1 , R 2 Specific examples of m are the same as those described in detail for the polyimide resin, and the preferred examples are also the same. Combinations of the preferred examples are also equally preferred.

[0050] The modified polyimide resin of the present embodiment is required to contain a polyimide resin (A) in which Q in the general formula (I) contains 60 mol % or more of the structural unit represented by the general formula (II) as described above. If the ratio of the structural unit represented by the general formula (II) in Q in the general formula (I) is less than 60 mol %, the solvent solubility of the photosensitive resin composition is poor, which is not preferable. The proportion of the constitutional unit represented by the above general formula (II) is more preferably 70 mol % or more, even more preferably 80 mol % or more, still more preferably 95 mol % or more, and particularly preferably 100 mol %.

[0051] Q other than the general formula (II) preferably has at least a cyclic structure, and as described above with respect to the polyimide resin, may contain a structural unit derived from any tetracarboxylic acid. Examples of the cyclic structure include tetravalent groups formed by removing four hydrogen atoms from cyclohexane, cyclopentane, cyclobutane, bicyclopentane, and stereoisomers thereof. Preferred examples are as described above, and examples of structural units include the following structures. Among the following, a tetravalent group formed by removing four hydrogen atoms from cyclohexane is preferred. [ka] [In the formula, * indicates a bond.]

[0052] In general formula (I), E is a divalent group having 2 to 39 carbon atoms and at least one group selected from the group consisting of an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and an organosiloxane group. The main chain of E may be interrupted by at least one group selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S-.

[0053] More specifically, E may be a divalent group formed by removing two hydrogen atoms from a compound such as cyclohexane, dicyclohexylmethane, dimethylcyclohexane, isophorone, norbornane, and their alkyl-substituted and halogen-substituted derivatives; benzene, naphthalene, biphenyl, diphenylmethane, diphenyl ether, diphenyl sulfone, benzophenone, and their alkyl-substituted and halogen-substituted derivatives; or organo(poly)siloxane. E preferably has a cyclic structure, and more preferably has at least one selected from an alicyclic hydrocarbon group and an aromatic ring. E more preferably has an aromatic ring as an aromatic hydrocarbon group.

[0054] The divalent group having 2 to 39 carbon atoms represented by E is more specifically shown below. [ka] [In the formula, * indicates a bond.]

[0055] More specifically, the divalent group having 2 to 39 carbon atoms represented by E is preferably at least one group (Ia) selected from the group consisting of the structures shown below. [ka] [In the formula, * indicates a bond.]

[0056] It is more preferable that the group corresponding to the exemplified E contains at least one group (Ib) selected from the group consisting of the structures shown below. [ka] [In the formula, * indicates a bond.]

[0057] It is particularly preferable that E in the general formula (I) has a group represented by the following formula (Ic). [ka] [In the formula, * indicates a bond.]

[0058] In terms of solvent solubility, the modified polyimide resin contained in the photosensitive resin composition of the present embodiment preferably has a ratio of at least one structural unit selected from (Ia), (Ib), and (Ic) as E in general formula (I) of 60 mol % or more. The ratio of at least one of the constituent units selected from the above (Ia), (Ib) and (Ic) in E in the general formula (I) is more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 95 mol% or more, and particularly preferably 100 mol%. Among them, it is preferable that the constituent unit derived from the diamine represented by the formula (Ic) is contained in the above ratio.

[0059] n, which indicates the number of repeating units of the structural unit represented by formula (I), is preferably 5 or more, more preferably 10 or more, and even more preferably 15 or more, and is preferably 250 or less, more preferably 200 or less, and even more preferably 150 or less. When n is 15 or more, a cured film having desired mechanical properties can be obtained. When n is 250 or less, sufficient solvent solubility can be ensured.

[0060] The modified polyimide resin (A) of this embodiment has either a group represented by the above general formula (III) or general formula (IV) or a hydrogen atom at its terminal, and at least one of the terminals is a group represented by general formula (III) or general formula (IV). The modified polyimide resin (A) may have a structure represented by general formula (III) or general formula (IV) at one terminal, or may have a structure represented by general formula (III) or general formula (IV) at both terminals. X in general formula (III) or general formula (IV) 11 Or X 22 The group represented by the following formula (1) has 2 to 15 carbon atoms and may have at least one group selected from the group consisting of an ester bond and a double bond. 1 Or Y 2 is a hydrogen atom or a methyl group.

[0061] More specifically, the structure represented by the above general formula (III) or general formula (IV) corresponds to a structure obtained by reacting the terminal amine of a polyimide resin with a functional group-containing compound. Such a functional group-containing compound may be a compound having an isocyanate group or an epoxy group and a (meth)acrylic group. Examples of such compounds include 2-isocyanatoethyl methacrylate, 2-isocyanatoethyl acrylate, 1,1-bis(acryloyloxymethyl)ethyl isocyanate, glycidyl methacrylate, glycidyl acrylate, and allyl glycidyl ether. The structure represented by general formula (III) or general formula (IV) may have a structure in which the compound reacts with an amine terminal.

[0062] The modified polyimide resin (A) preferably has a weight average molecular weight of 70,000 or less. If the weight average molecular weight is 70,000 or less, the solvent solubility of the resin composition is not adversely affected, and the resin composition is suitable for forming a cured film. The weight average molecular weight is more preferably 60,000 or less, even more preferably 50,000 or less, even more preferably 45,000 or less, even more preferably 40,000 or less, and particularly preferably 30,000 or less. Since a cured film having desired mechanical properties can be obtained, the weight average molecular weight of the modified polyimide resin (A) is preferably 5,000 or more. The weight average molecular weight of the modified polyimide resin (A) is more preferably 10,000 or more, even more preferably 13,000 or more, and even more preferably 15,000 or more. By having the weight average molecular weight of the modified polyimide resin (A) in the above range, a resin composition having a low residual film rate in the unexposed area and excellent developability can be obtained. Here, the weight average molecular weight is a weight average molecular weight calculated from absolute molecular weight measurement by GPC-light scattering method.

[0063] <Method for preparing modified polyimide resin (A)> The modified polyimide resin (A) contained in the photosensitive resin composition of the present embodiment can be obtained by a production method including the following steps (1) and (2): Step (1): A tetracarboxylic acid component and a diamine component are reacted to obtain a polyimide resin having amino groups at the terminals. Step (2): The polyimide resin having an amino group at its terminal obtained in the above step (1) is reacted with the above functional group-containing compound (a compound having an isocyanate group or an epoxy group, and a (meth)acrylic group). The above step (1) is the same as the above-mentioned method for producing a polyimide resin, including the same raw materials, preferred materials, and reaction conditions.

[0064] <Process (2)> Step (2) is a step of modifying the terminals of the polyimide resin obtained in the above step (1). Specifically, as described above, polyimide is reacted with the above functional group-containing compound (a compound having an isocyanate group or an epoxy group and a (meth)acrylic group) to obtain a modified polyimide resin having a (meth)acrylic group at the terminal. The functional group-containing compound that modifies the terminal of the polyimide resin is a compound having an isocyanate group or an epoxy group and a (meth)acrylic group, and specific examples thereof include 2-isocyanatoethyl methacrylate, 2-isocyanatoethyl acrylate, 1,1-bis(acryloyloxymethyl)ethyl isocyanate, glycidyl methacrylate, glycidyl acrylate, and allyl glycidyl ether. These functional group-containing compounds may be used alone or in combination of two or more. The functional group-containing compound is preferably used in a molar ratio of 0.1 to 30 times the polyimide resin having an amino group at the terminal. The reaction temperature in step (2) is preferably in the range of 30 to 100°C, and the reaction time is preferably 1 to 5 hours.

[0065] When reacting the amino group terminal of the polyimide resin with the isocyanate group or epoxy group of the functional group-containing compound, the reaction may be performed as is, or may be performed in the presence of a catalyst as necessary. Examples of the catalyst include amine compounds such as triethylamine, organic phosphorus compounds such as triphenylphosphine, etc., which may be used alone or in combination of two or more. A polymerization inhibitor may be used to suppress side reactions during the reaction. Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, and methylhydroquinone, etc., which may be used alone or in combination of two or more. The content of the polyimide resin in the photosensitive resin composition according to this embodiment, when the total solid content of the photosensitive resin composition is taken as 100 mass%, is preferably 30 mass% or more, more preferably 40 mass% or more, even more preferably 50 mass% or more, even more preferably 60 mass% or more, even more preferably 70 mass% or more, and is preferably 90 mass% or less, more preferably 80 mass% or less. In this embodiment, the total solid content of the photosensitive resin composition refers to components that remain as solids when the photosensitive resin composition is cured, excluding components that volatilize when heated, such as solvents, etc. On the other hand, even if the components are liquid, components that are incorporated into the resin film when cured by heating are included in the total solid content. Furthermore, the content of the modified polyimide resin (A) in the photosensitive resin composition according to this embodiment is, relative to 100 parts by mass of the content of the polyimide resin contained in the photosensitive resin composition, preferably 50 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 80 parts by mass or more, even more preferably 90 parts by mass or more, and even more preferably 100 parts by mass or less.

[0066] The modified polyimide resin (A) contained in the photosensitive resin composition of this embodiment has a light transmittance at any wavelength of 200 to 400 nm of preferably 50% or more, more preferably 55% or more, even more preferably 60% or more, even more preferably 70% or more, even more preferably 80% or more, and even more preferably 90% or more. The modified polyimide resin (A) contained in the photosensitive resin composition of this embodiment has a light transmittance at a wavelength of 365 nm of preferably 50% or more, more preferably 55% or more, even more preferably 60% or more, even more preferably 70% or more, even more preferably 80% or more, and even more preferably 90% or more. In this embodiment, the light transmittance of the modified polyimide resin (A) is the light transmittance when the modified polyimide resin (A) is made into a solution with a solid content concentration of 3 mass%. The modified polyimide resin (A) contained in the photosensitive resin composition of the present embodiment has high light transmittance at the above wavelength and excellent solvent solubility. Therefore, the photopolymerization initiator that can be contained in the composition acts effectively, so that a cured film can be obtained efficiently. In addition, by using the modified polyimide resin (A) having a specific structure and a specific terminal structure and a specific molecular weight, when a cured film is formed from the composition described below, the residual film rate of the unexposed part is low, it has excellent developability, and the occurrence of cracks can be effectively suppressed.

[0067] The photosensitive resin composition in this embodiment contains at least one polyimide resin selected from the modified polyimide resin (A) and the polyimide resin of this embodiment described above, and at least one compound (B) selected from the group consisting of a photopolymerization initiator, a solvent, and a photopolymerizable compound. It is also preferable that the photosensitive resin composition in this embodiment further contains a sensitizer.

[0068] Examples of the solvent include N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N-benzyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphortriamide, N-acetyl-ε-caprolactam, dimethylimidazolidinone, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, γ-butyrolactone, etc. These solvents may be used alone or in combination of two or more. By using an appropriate solvent, the photosensitive resin composition of the present embodiment can be used in a solution (varnish) state, which is convenient for forming a film.

[0069] As the photopolymerizable compound, a polyfunctional radically polymerizable monomer, for example, a di- or higher functional (meth)acrylic monomer, can be used. Examples of (meth)acrylic monomers include tricyclodecane dimethanol diacrylate, tricyclodecane dimethanol dimethacrylate, polypropylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, tris-(2-acryloxyethyl)isocyanurate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexaacrylate, etc. These photopolymerizable compounds may be used alone or in combination of two or more. The flexibility of the photosensitive resin composition can be controlled by the structure of the photopolymerizable compound to be mixed. These photopolymerizable compounds are preferably mixed in a ratio of 5 to 500 parts by mass with respect to the solid content in the solution containing the modified polyimide resin having a (meth)acrylic group at the end. The content of the photopolymerizable compound in the photosensitive resin composition according to this embodiment is preferably 5 parts by mass or more and 500 parts by mass or less when the amount of the polyimide resin contained in the photosensitive resin composition is 100 parts by mass.

[0070] The photopolymerization initiator is not particularly limited and known ones can be used. For example, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-methyl-1- Examples of the photopolymerization initiator include (4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide. These photopolymerization initiators may be used alone or in combination of two or more. The photopolymerization initiator is preferably mixed in a ratio of 0.1 to 10 parts by mass relative to the solid content in the solution containing the modified polyimide resin (A) having a (meth)acrylic group at its end. The content of the photopolymerization initiator in the photosensitive resin composition according to this embodiment is preferably 0.1 parts by mass or more and 10 parts by mass or less when the amount of the polyimide resin contained in the photosensitive resin composition is taken as 100 parts by mass.

[0071] The sensitizer is not particularly limited, and known sensitizers can be used. For example, an amino group-containing sensitizer can be mentioned, and a compound having an amino group and a phenyl group in the same molecule can be preferably exemplified. More specifically, benzophenone compounds such as 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, 2-aminobenzophenone, 4-aminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, and 3,4-diaminobenzophenone; 2-(p-dimethylaminophenyl)benzoxazole, 2-(p-diethylaminophenyl)benzoxazole, 2-(p-dimethylaminophenyl)benzo[4,5]benzoxazole, 2-(p-dimethylaminophenyl)benzo[6,7]benzoxazole, and 2,5-bis(p-diethylaminophenyl)-1,3,4-oxadiazole. p-Dialkylaminophenyl group-containing compounds such as 2-(p-dimethylaminophenyl)benzothiazole, 2-(p-diethylaminophenyl)benzothiazole, 2-(p-dimethylaminophenyl)benzimidazole, 2-(p-diethylaminophenyl)benzimidazole, 2,5-bis(p-diethylaminophenyl)-1,3,4-thiadiazole, (p-dimethylaminophenyl)pyridine, (p-diethylaminophenyl)pyridine, (p-dimethylaminophenyl)quinoline, (p-diethylaminophenyl)quinoline, (p-dimethylaminophenyl)pyrimidine, and (p-diethylaminophenyl)pyrimidine can be mentioned. These sensitizers can be used alone or in combination of two or more kinds. The sensitizer is preferably mixed in a ratio of 0.001 to 10 parts by mass based on the solid content in the solution containing the modified polyimide resin (A) having a (meth)acrylic group at its end. The content of the sensitizer in the photosensitive resin composition according to the present embodiment is preferably 0.001 to 10 parts by mass based on 100 parts by mass of the polyimide resin contained in the photosensitive resin composition.

[0072] The photosensitive resin composition of the present embodiment is not particularly limited, but can be prepared as follows. A photosensitive resin composition is obtained by mixing at least one polyimide resin (A) having a structure represented by general formula (I) and a terminal structure represented by general formula (III) or (IV) selected from the polyimide resins of the present embodiment described above with at least one compound (B) selected from the group consisting of a solvent, a photopolymerization initiator, and a photopolymerizable compound. If necessary, a sensitizer may be mixed as described above. The photosensitive resin composition of the present embodiment is particularly suitable for use in forming an insulating film.

[0073] [Resin film] The photosensitive resin composition according to the present embodiment can be used to form a resin film such as a photoresist used in manufacturing an electronic device or a permanent film (cured film) constituting an electronic device. That is, the resin film according to the present embodiment is made of the photosensitive resin composition or a cured product of the photosensitive resin composition. The photoresist is formed, for example, from a resin film obtained by applying the photosensitive resin composition according to this embodiment onto a substrate and removing the solvent as necessary. The permanent film is constituted by a hardened film obtained by exposing and developing the resin film, patterning it into a desired shape, and then hardening it by heat treatment or the like. The permanent film can be suitably used as an insulating film such as a surface protective film or an interlayer insulating film. In order to obtain the resin film in this embodiment, a solution containing the above-mentioned photosensitive resin composition is applied onto a substrate. The method for applying the composition onto the substrate is not particularly limited, and specific examples thereof include an inkjet method, a spin coating method, a casting method, a microgravure method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, and a die coating method.

[0074] When applying onto a substrate, it is preferable to adjust the solid content concentration of the photosensitive resin composition of the present embodiment to be in the range of 5 to 50 mass %. As a solvent used during application, an aprotic polar solvent is preferable from the viewpoint of solubility. Specifically, N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N-benzyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphortriamide, N-acetyl-ε-caprolactam, dimethylimidazolidinone, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, γ-butyrolactone, and the like can be mentioned as suitable examples. These solvents may be used alone or in combination of two or more kinds. In order to further improve the application property, a solvent such as toluene, xylene, diethyl ketone, methoxybenzene, or cyclopentanone may be mixed within a range that does not adversely affect the solubility of the polymer.

[0075] Examples of the substrate include glass, silicon wafers, metal foils, and plastic films. Among the substrates, silicon wafers and copper foils are preferably used. The photosensitive resin composition of the present embodiment applied onto the substrate is irradiated with light (usually ultraviolet light) through a photomask having a predetermined pattern. After irradiation, the unexposed areas are dissolved and removed with a developer to obtain a desired relief pattern. The cumulative amount of UV radiation is 500 to 8,000 mJ / cm 2 It is preferable that:

[0076] In the resin pattern forming method using the photosensitive resin composition of this embodiment, it is preferable to use an organic solvent as the developer. The developer is not particularly limited as long as it dissolves the photosensitive resin composition of this embodiment. Specifically, suitable examples include N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N-benzyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphortriamide, N-acetyl-ε-caprolactam, dimethylimidazolidinone, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, γ-butyrolactone, and the like. These developers may be used alone or in combination of two or more.

[0077] The relief pattern formed by development is then washed with a rinse solution to remove the developing solvent. Suitable examples of the rinse solution include methanol, ethanol, isopropyl alcohol, water, and the like, which are well miscible with the developing solution. The relief pattern obtained by the above-mentioned treatment is heated at a temperature selected from the range of 80 to 250° C. to dry the solvent, and a cured film obtained by curing the photosensitive resin composition of the present embodiment can be obtained. According to the present embodiment, a resin composition is used that has excellent developability, that is, the exposed portion is sufficiently cured, and the unexposed portion is sufficiently removed due to the high solvent solubility of the modified polyimide resin contained in the photosensitive resin composition, so that the resulting relief pattern can be obtained with high resolution.

[0078] Specifically, the cured film obtained by curing the photosensitive resin composition according to this embodiment is exposed to light from a high-pressure mercury lamp from which wavelengths of less than 365 nm have been cut off at an exposure dose (accumulated irradiation dose) (calculated from the illuminance at 365 nm) of 1,500 to 2,500 mJ / cm 2 The residual film ratio of the unexposed portion after exposure under the above conditions is preferably 40% or less, more preferably 30% or less, and even more preferably 10% or less. The exposure light source is not particularly limited, but for example, a high-pressure mercury lamp can be used, and exposure is performed at 365 nm to achieve the above exposure amount.

[0079] In this specification, the term "unexposed portion remaining film ratio" refers to a value calculated from the following definition. The details of the measurement method will be described in detail in the Examples. Unexposed area remaining film ratio (%) = [mass of unexposed area after development / mass of unexposed area before development] x 100 The cured film obtained by curing the photosensitive resin composition according to this embodiment has a residual film rate in exposed areas of preferably 70% or more, more preferably 80% or more, and even more preferably 85% or more.

[0080] In this specification, the term "exposed area remaining film ratio" refers to a value calculated from the following definition. The details of the measurement method will be described in detail in the Examples. Residual film rate of exposed area (%) = [mass of exposed area after development / mass of exposed area before development] x 100

[0081] The thickness of the cured film obtained by this embodiment is preferably 10 to 85 μm. When the thickness is within the above range, it can be used as an excellent insulating film. As the thickness increases (i.e., the amount of the photosensitive resin composition applied to the substrate increases), problems often occur, particularly with the solvent solubility of the polyimide resin. However, according to this embodiment, by using a polyimide resin (modified polyimide resin) having a specific structure and a specific terminal structure and a specific molecular weight range, it is possible to achieve both excellent solvent solubility and transparency even in such a situation. Therefore, the cured film of the present embodiment can be suitably used, for example, in insulating film applications where application of high voltage is expected. The cured film obtained from the photosensitive resin composition of the present embodiment, which contains the modified polyimide resin (A) having a specific structure and a specific terminal structure and a specific molecular weight, can effectively suppress the occurrence of cracks and has excellent physical properties.

[0082] [Application] The photosensitive resin composition and cured film of the present embodiment can be used in various applications, such as surface protection films and interlayer insulating films for semiconductor elements in electronic devices, and wiring protection insulating films for circuit boards, and are particularly suitable for high-density, high-integration applications. The surface protective film is an insulating film formed on the surface of an electronic component or an electronic device, or on the surface of a wiring board, for protecting the surface, and the type of the insulating film is not particularly limited. Examples of such a surface protective film include a passivation film or a buffer coat layer provided on a semiconductor element, or a cover coat provided on a flexible substrate. The interlayer insulating film refers to an insulating film provided in a multilayer structure, and the type is not particularly limited. Examples of the interlayer film include those used in semiconductor device applications, such as an interlayer insulating film constituting a multilayer wiring structure of a semiconductor element, and a build-up layer or core layer constituting a wiring substrate. Examples of the interlayer film include those used in display device applications, such as a planarizing film covering a thin film transistor in a display device, a liquid crystal alignment film, a protrusion provided on a color filter substrate of a liquid crystal display device, or a partition wall for forming a cathode of an organic EL element.

[0083] [Electronic equipment] The electronic device according to the present embodiment includes the resin film according to the present embodiment. The electronic device according to the present embodiment is not particularly limited as long as it has a resin film formed from the photosensitive resin composition according to the present embodiment, and examples thereof include a display device having the resin film according to the present embodiment as a planarizing film or a microlens, a semiconductor device having a multilayer wiring structure using the resin film according to the present embodiment as an interlayer insulating film, a semiconductor device using the resin film according to the present embodiment as a surface protective film for a semiconductor element or a wiring substrate, a semiconductor device using the resin film according to the present embodiment as a build-up layer or core layer constituting a wiring substrate, etc. Among these, the semiconductor device is preferable as the electronic device according to the present embodiment. The electronic device according to this embodiment can be manufactured based on known information, except for using the resin film according to this embodiment. The electronic device according to this embodiment includes a resin film having excellent developability, and therefore has a good patterning shape, is less susceptible to dielectric breakdown, and is highly reliable.

[0084] According to the present embodiment, a polyimide resin having high transparency and excellent solvent solubility and therefore excellent developability, a photosensitive resin composition containing the polyimide resin, a resin film thereof, and an electronic device containing the resin film can be obtained without the need for a heating step. The resin composition has low cure shrinkage, so that the occurrence of cracks in the obtained cured film can be effectively suppressed. EXAMPLES

[0085] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples in any way. The evaluation methods employed in the present examples and comparative examples are as follows.

[0086] (1) Weight average molecular weight The weight average molecular weight (Mw) was determined by GPC analysis using the following apparatus and conditions: Equipment: Viscotek TDAmax (Malvern Panalytical Ltd.) Column: T6000M × 2 (Malvern Panalytical Ltd.) Eluent: dimethylformamide with 20 mM lithium bromide Flow rate: 1.0ml / min Column temperature: 40℃ Detector: RI (Refractive Index Detector), RALS (Light Scattering Detector), LALS (Light Scattering Detector)

[0087] (2) Film loss rate The varnishes obtained in each of Synthesis Examples 1 to 3 described below were applied onto a silicon wafer using a spin coater, and then heated at 100°C for 60 minutes to remove the solvent. The mass of the varnish at this point (the point at which the solvent was removed under the above conditions) was taken as the mass before immersion. After immersing in γ-butyrolactone as a developer for 2 minutes, the wafer was washed using methanol as a rinse liquid, and the solvent was removed under air circulation until there was no change in mass. The mass of the film remaining on the silicon wafer after the solvent removal was taken as the mass after immersion, and the film loss rate was calculated using the following formula. The higher this value, the better the solubility. Film loss rate (%) = [(mass before immersion - mass after immersion) / mass before immersion] x 100

[0088] (3) Residual film rate in unexposed areas (%) In the following examples and comparative examples, a varnish containing a photosensitive resin composition containing a polyimide resin is prepared. The varnish obtained in each example and comparative example was applied to a silicon wafer using a spin coater, and then heated at 100°C for 60 minutes to remove the solvent. The mass of the varnish at this point (the point at which the solvent was removed under the above conditions) was taken as the pre-development mass of the unexposed area. After immersing in γ-butyrolactone as a developer for 5 minutes, the wafer was washed using methanol as a rinse solution, and the solvent was removed under air circulation until there was no change in mass. The mass of the film remaining on the silicon wafer after the solvent removal was taken as the post-development mass of the unexposed area, and the unexposed area remaining film ratio was calculated by the following formula. Unexposed area remaining film ratio (%) = [mass of unexposed area after development / mass of unexposed area before development] x 100

[0089] (4) Residual film rate in exposed area (%) In the following examples and comparative examples, a varnish containing a photosensitive resin composition containing a polyimide resin is prepared. The varnish obtained in each example and comparative example was applied to a silicon wafer using a spin coater, and then heated at 100°C for 60 minutes to remove the solvent. The mass of the varnish at this point (the point at which the solvent was removed under the above conditions) was taken as the pre-development mass of the exposed area. After UV irradiation and immersion in γ-butyrolactone developer for 5 minutes, the wafer was washed using methanol as a rinse solution, and the solvent was removed under air flow until no mass change occurred. The mass of the film remaining on the silicon wafer after the solvent removal was taken as the post-development mass of the exposed area, and the remaining film ratio was calculated by the following formula. Residual film rate of exposed area (%) = [mass of exposed area after development / mass of exposed area before development] x 100

[0090] The equipment and conditions used for the development in (3) and (4) above are as follows. Ultraviolet irradiation device: ECS-1511U (manufactured by iGraphics Co., Ltd.) Illuminance: 670~700mW / cm 2 Accumulative irradiation dose: 2,400mJ / cm 2 Developer: γ-butyrolactone Development time: 5 minutes Rinse solution: Methanol Silicon wafer: 4-inch silicon wafer (Advantec Co., Ltd.)

[0091] (5)Light transmittance The modified polyimide resin obtained in the synthesis example was dissolved in γ-butyrolactone to obtain a polyimide resin solution with a solid content concentration of 3% by mass. The light transmittance of this polyimide resin solution at a wavelength of 365 nm was then measured using a spectrophotometer (product name: U3900H) manufactured by Hitachi, Ltd. and a cell with an optical path length of 10 mm.

[0092] Example 1 In a 500 ml five-neck flask equipped with a nitrogen inlet tube, a stirrer, a thermometer, and a condenser, 38.7103 g (0.115 mol) of 4,4'-oxybis[3-(trifluoromethyl)benzenamine] (hereinafter, 6FODA), 44.6270 g (0.109 mol) of 5,5'-(1,4-phenylene)bis(hexahydro-4,7-methanoisobenzofuran-1,3-dione) (hereinafter, BzDA) represented by the following formula, and 102.15 g of γ-butyrolactone (hereinafter, GBL) were added under nitrogen introduction, and the mixture was heated to 90°C with stirring. To this was added 1.106g (0.011mol) of triethylamine (TEA) and reacted at 190℃ for 5 hours, after which it was diluted with 82.87g of GBL to obtain 249.6g of polyimide varnish with a solid content of 30% by mass. Measurement by GPC showed that the weight average molecular weight of the polyimide obtained in this synthesis example was 20,113, and the film loss rate after immersion in GBL for 2 minutes was 83%. The results are shown in Table 1. [ka]

[0093] Comparative Example 1 In a 500 ml five-neck flask equipped with a nitrogen inlet tube, a stirrer, a thermometer, and a condenser, 117.7875 g (0.350 mol) of 6FODA, 74.5592 g (0.333 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride (hereinafter, HPMDA), and 235.11 g of GBL were added under nitrogen introduction and heated to 90 ° C. with stirring. 1.690 g (0.017 mol) of TEA was added thereto and reacted at 190 ° C. for 5 hours, and then diluted with 184.99 g of GBL to obtain 585.1 g of polyimide varnish with a solid content concentration of 30 mass %. As a result of GPC measurement, the weight average molecular weight of the polyimide obtained in this synthesis example was 23,077, and the film loss rate after immersion in GBL for 2 minutes was 40%. The results are shown in Table 1.

[0094] Comparative Example 2 Into a 500 ml five-neck flask equipped with a nitrogen inlet tube, a stirrer, a thermometer, and a condenser, 90.401 g (0.26 mol) of 1,4-bis[2-(4-aminophenyl)-2-propyl]benzene (hereinafter, BiS-AP), 29.959 g (0.11 mol) of 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine (hereinafter, TMDA), 82.943 g (0.37 mol) of HPMDA, and 249.0 g of GBL were added under nitrogen introduction, and the mixture was heated to 90°C with stirring. To this, 18.72g (0.19mol) of TEA and 0.083g (0.74mmol) of triethylenediamine (hereinafter referred to as TEDA) were added, and the mixture was reacted at 190°C for 5 hours, after which it was diluted with 512.3g of DMAc to obtain 952g of polyimide varnish with a solid content concentration of 20% by mass. As a result of measurement by GPC, the weight average molecular weight of the polyimide obtained in this synthesis example was 75,600. The film state after immersion in GBL for 2 minutes was almost unchanged, and it was confirmed that the solubility was poor. The results are shown in Table 1.

[0095] Comparative Example 3 A polyimide varnish having a solid content concentration of 20 mass% was obtained in the same manner as in Comparative Example 2, except that the amount of Bis-AP was changed to 76.4579 g (0.221 mol), the amount of HPMDA was changed to 94.1895 g (0.420 mol), the amount of TEA was changed to 2.129 g (0.022 mol), the amount of TEDA was changed to 0.000 g (0.00 mmol), and the amount of DMAc was changed to 666.09 g, and 90.8831 g (0.221 mol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane (hereinafter, BAPP) was used instead of TMDA. As a result of measurement by GPC, the weight average molecular weight of the polyimide obtained in this comparative example was 25,082. The film loss rate after immersion in GBL for 2 minutes was 15%. The results are shown in Table 1.

[0096] Comparative Example 4 261 g of polyimide varnish with a solid content concentration of 30 mass% was obtained in the same manner as in Example 1, except that the amount of 6FODA was 41.0665 g (0.122 mol), CpODA was 45.8347 g (0.116 mol) as an acid dianhydride, the amount of TEA was 0.586 g (0.006 mol), the amount of GBL was 106.24 g, and the amount of GBL for dilution was 86.55 g. As a result of GPC measurement, the weight average molecular weight of the polyimide obtained in this synthesis example was 28,408, and the film loss rate after immersion in GBL for 2 minutes was 9%. The results are shown in Table 1.

[0097] [Table 1]

[0098] Example 2 In a 500 mL four-neck flask equipped with a stirrer, a thermometer, and a cooler, 100.13 g of the polyimide varnish obtained in Example 1 and 3.00 g of 2-isocyanatoethyl acrylate (Karens AOI, manufactured by Showa Denko K.K.) were placed and reacted at 50°C for 5 hours. The reaction solution was then dropped into water to precipitate polyimide, which was then dried overnight at 70°C to obtain a modified polyimide resin. The light transmittance of the obtained modified polyimide resin at a wavelength of 365 nm was 93.1%. 4.6 g of this modified polyimide resin was dissolved in 7.0 g of GBL, and 1.16 g of Viscoat 802 (Osaka Organic Chemical Industry Co., Ltd., tri-PE-A), 0.069 g of 1-hydroxycyclohexyl phenyl ketone (BASF, IRGACURE (Omnirad) 184), and 0.162 g of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (BASF, IRGACURE (Omnirad) 819) were added and stirred until dissolved, to obtain a photosensitive resin composition (photosensitive resin varnish). This photosensitive resin composition was applied onto a silicon wafer and dried at 100°C for 60 minutes. The wafer was then immersed in GBL for 5 minutes, rinsed with methanol, and the solvent was removed under air flow until no mass change occurred, and the unexposed remaining film ratio was calculated. The unexposed remaining film ratio at this time was 0%. The photosensitive resin composition was applied onto a silicon wafer and dried at 100°C for 60 minutes. Then, using an iMini Grandage (ECS-1511U) manufactured by iGraphics Co., Ltd. and a high-pressure mercury lamp (light from a high-pressure mercury lamp with wavelengths less than 365 nm cut off) as the light source, the exposure dose (accumulated exposure dose) at an exposure wavelength of 365 nm (calculated from the illuminance at 365 nm) was 1,500 to 2,500 mJ / cm. 2 The film was exposed to light under the conditions of 100% to form a cured film, then immersed in GBL for 5 minutes, rinsed with methanol, and the solvent was removed under air circulation until there was no change in mass, and the exposed area residual film ratio was calculated. The exposed area residual film ratio at this time was 100%. The results are shown in Table 2.

[0099] Comparative Examples 5 to 7 A photosensitive resin composition was prepared in the same manner as in Example 2 above, except for the formulation shown in the table below, and its properties were evaluated. The results are also shown in Table 2.

[0100] [Table 2]

[0101] It can be seen that the cured film containing the photosensitive resin composition according to the present embodiment has excellent developability compared to the comparative example. It should be noted that although there is a difference in the crosslinking agent in the formulation, the remaining film rate is measured by exposing the entire surface in the examples and comparative examples, and therefore such a difference does not affect the results. The photosensitive resin composition according to this embodiment contains a polyimide resin having excellent solvent solubility, and therefore has the advantage that patterning can be performed in a short time.

Claims

1. A modified polyimide resin comprising a structure represented by the following general formula (I): 【Chemistry 1】 {In general formula (I), E contains a group represented by the following formula (I-c). Q contains 60 mol % or more of a structure represented by the following general formula (II), and may contain a tetravalent group having a cyclic structure, a non-cyclic structure, or a cyclic structure and a non-cyclic structure and having 4 to 10 carbon atoms, in addition to the structure represented by general formula (II). n represents the number of repeating units. The terminal of general formula (I) is either a group represented by the following formula (III) or formula (IV), or a hydrogen atom, and at least one of the terminals is a group represented by formula (III) or formula (IV): 【Chemistry 2】 [In the formula, * indicates a bond.] 【Chemistry 3】 In the general formula (II), X represents one selected from the group consisting of divalent aromatic hydrocarbon groups having 6 to 30 carbon atoms. The divalent aromatic hydrocarbon group represented by X may be substituted with a substituent, and the above carbon number represents the number of carbon atoms forming an aromatic ring. １ Each independently represents at least one selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 10 carbon atoms. ２ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; m represents an integer of 0 to 4; * represents a bond. 【Chemistry 4】 [In general formulas (III) and (IV), X １１ and X ２２ Each of Y is independently a group having 2 to 15 carbon atoms, and may have at least one group selected from the group consisting of an ester bond and a double bond. １ and Y ２ are each independently a hydrogen atom or a methyl group.

2. 2. The modified polyimide resin according to claim 1, wherein the weight average molecular weight of the modified polyimide resin is 70,000 or less.

3. 3. The modified polyimide resin according to claim 1, wherein the weight average molecular weight of the modified polyimide resin is 5,000 or more.

4. The modified polyimide resin according to any one of claims 1 to 3, wherein the modified polyimide resin has a light transmittance of 50% or more at any wavelength of 200 to 400 nm.

5. A polyimide resin for a photosensitive resin composition comprising a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine compound, wherein the structural unit A comprises a structural unit derived from a compound represented by the following formula (1) in a ratio of 60 mol % or more, and the structural unit B comprises a structural unit derived from a compound represented by the following formula (2): 【Chemistry 5】 In the general formula (1), X represents one selected from the group consisting of divalent aromatic hydrocarbon groups having 6 to 30 carbon atoms. The divalent aromatic hydrocarbon group represented by X may be substituted with a substituent, and the above carbon number represents the number of carbon atoms forming an aromatic ring. １ Each independently represents at least one selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 10 carbon atoms. ２ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; and m represents an integer of 0 to 4. 【Chemistry 6】

6. 6. The polyimide resin according to claim 5, wherein the structural unit B further comprises a structural unit B1 derived from at least one compound selected from the group consisting of compounds represented by the following formulas: 【Chemistry 7】

7. 7. The polyimide resin according to claim 5, wherein the structural unit B further comprises a structural unit B2 derived from at least one compound selected from the group consisting of compounds represented by the following formulas: 【Chemistry 8】

8. The polyimide resin according to claim 5, wherein the structural unit B contains 60 mol % or more of a structural unit derived from a compound represented by formula (2).

9. 7. The polyimide resin according to claim 6, wherein the structural unit B comprises 60 mol % or more of a structural unit derived from the compound represented by formula (2) and the structural unit B1 in total.

10. 8. The polyimide resin according to claim 7, wherein the structural unit B contains 60 mol % or more of a total of the structural unit derived from the compound represented by formula (2) and the structural unit B2.

11. The polyimide resin according to any one of claims 5 to 10, having a weight average molecular weight of 70,000 or less.

12. A polyimide varnish comprising at least one polyimide resin selected from the modified polyimide resin according to any one of claims 1 to 4 and the polyimide resin according to any one of claims 5 to 11, and an organic solvent.

13. A molded body obtained by molding the polyimide varnish described in claim 12.

14. The molded article according to claim 13, which is in the form of a membrane, a film or a sheet.

15. A photosensitive resin composition comprising at least one polyimide resin selected from the modified polyimide resin (A) according to any one of claims 1 to 4 and the polyimide resin according to any one of claims 5 to 11, and at least one compound (B) selected from the group consisting of a photopolymerization initiator, a solvent, and a photopolymerizable compound.

16. The photosensitive resin composition according to claim 15 , wherein the photopolymerizable compound comprises a polyfunctional radically polymerizable monomer.

17. The photosensitive resin composition according to claim 15 or 16, further comprising a sensitizer.

18. The light from a high-pressure mercury lamp with wavelengths of less than 365 nm cut off is used at an exposure dose of 1,500 to 2,500 mJ / cm ２ The photosensitive resin composition according to any one of claims 15 to 17, wherein a residual film rate in an unexposed area after exposure under the above conditions is 40% or less.

19. The photosensitive resin composition according to any one of claims 15 to 18, which is for forming an insulating film.

20. A resin film comprising the photosensitive resin composition according to any one of claims 15 to 19 or a cured product of the photosensitive resin composition.

21. The resin film according to claim 20, having a film thickness of 10 to 85 μm.

22. An electronic device comprising the resin film described in claim 21.

Images