TW201335239A - Resin composition and polyimide resin film using the same, display substrate and manufacturing method thereof - Google Patents

Abstract

A resin composition of the invention contains (a) a polyimide precursor, (b) an alkoxysilane compound, and (c) an organic solvent. Compared with the (a) polyimide precursor, a content of (b) ranges from 0.01 mass% to 2 mass%. Compared with the (a) polyimide precursor, a preferable content of the (b) alkoxysilane compound ranges from 0.02 mass% to 2 mass%, and a more preferable content ranges from 0.05 mass% to 1 mass%.

Description

Resin composition, polyimine resin film using the same, display substrate and manufacturing method thereof

The present invention relates to a resin composition which has both moderate adhesion and good peelability. Further, it relates to a polyimide film using a resin composition of the present invention, a display substrate, and a method for producing the same.

In recent years, small and medium-sized displays typified by smart phones or tablet terminals are expanding in market size. The display substrate used in these small and medium-sized displays can be obtained by forming a thin film transistor (TFT) or the like on a glass substrate. However, on the other hand, the glass substrate is excellent in heat resistance and dimensional stability, and on the other hand, when the weight is reduced and the thickness is reduced, there is a problem that the strength is lowered.

Therefore, a plastic substrate is proposed as a substrate instead of a glass substrate. Since the plastic substrate is easy to form and has high toughness and has high bending property, it is suitable for weight reduction and thinning of a semiconductor element, and is effectively used as a flexible substrate.

Method package for manufacturing display substrate using thinned plastic substrate A step of forming a plastic substrate on a support; a step of forming a semiconductor element such as a TFT on the plastic substrate; and a step of peeling the plastic substrate from the support.

For example, Patent Document 1 describes a method of manufacturing a display substrate in which a plastic substrate is placed on a hard carrier substrate (support) via a peeling layer, and a pixel circuit and a display layer are formed thereon, and then the hard carrier substrate is used. Shoot and peel off.

With the flexible display substrate manufactured by this method, a lightweight and thin substrate can be formed.

On the other hand, in the case of forming a TFT, processing at a high temperature of 200 ° C or higher is required. However, the plastic substrate tends to have poor heat resistance and dimensional stability as compared with the glass substrate. Therefore, in Patent Document 1, a plastic layer containing parylene is used as a heat resistance. However, the formation of a plastic layer containing parylene has a problem of complicated processes.

Further, in the method of manufacturing a display substrate described in Patent Document 1, since it is necessary to peel the plastic substrate by laser, an excimer laser device or the like is required.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-512568

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2011-11455

Therefore, a method of providing a decane coupling layer between an inorganic layer (support) and a polyimide layer as a plastic substrate has been proposed (for example, Patent Document 2). Patent literature In the method of 2, the laser is not required in the stripping step, and the polyimide film is physically peeled off from the support.

However, in the production method of Patent Document 2, since it is necessary to form two layers such as a decane coupling layer and a polyimine layer, the steps are complicated.

Accordingly, an object of the present invention is to provide a resin composition capable of forming a polyimide film (plastic substrate) which is sufficiently formed with a support when forming a semiconductor element such as a TFT. The adhesion is excellent, and the self-supporting body can be peeled off by a physical method without using a laser. Further, an object of the present invention is to provide a resin composition which can form a polyimide film having good mechanical properties and heat resistance.

Further, an object of the present invention is to provide a polyimide film using a resin composition and a method for producing a display substrate. Further, it is an object of the invention to provide a display substrate formed by the manufacturing method.

In general, when a composition in which a decane coupling agent is applied to a member to be bonded to form a layer or film of a composition, the adhesion strength of the formed layer or film to the adherend is remarkably increased, and Improve the tendency of adhesion. Further, in order to increase the adhesion, it is necessary to increase the amount of the decane coupling agent to some extent, and to remove the layer or film from the adherend without using a decane coupling agent. The present inventors have found that, contrary to the prior art methods of use, moderate (b) alkoxydecane compounds in a small amount of a decane coupling agent can be formulated in a (a) polyimine precursor to exhibit moderate adhesion strength. The present invention has thus been completed.

The present invention relates to the following.

<1> A resin composition comprising (a) a polyimine precursor, (b) an alkoxydecane compound, (c) an organic solvent, and (a) a polyimine precursor, (b) The content of the alkoxydecane compound is 0.01% by mass to 2% by mass.

<2> The resin composition as described above, wherein the (a) polyimine precursor is a polyamic acid having a structural unit represented by the general formula (1): (In the formula (1), R ¹ represents a divalent organic group having an aromatic ring, and R ² represents a tetravalent organic group having an aromatic ring).

<3> The resin composition as described above, wherein the content of the (b) alkoxydecane compound is from 0.02% by mass to 2% by mass based on the (a) polyimine precursor.

<4> The resin composition as described above, wherein the content of the (b) alkoxydecane compound is 0.05% by mass to 1% by mass based on the (a) polyimine precursor.

<5> The resin composition as described above, wherein the (b) alkoxydecane compound is any one of the compounds represented by the formula (2) or the formula (3): (In the general formula (2) and the general formula (3), R ¹ and R ² each independently represent a monovalent organic group).

<6> The resin composition as described above, wherein the (a) polyimine precursor has a weight average molecular weight of from 15,000 to 200,000.

<7> The resin composition as described above, which is used in a method for producing a display substrate comprising the steps of: coating a resin composition on a support and heating to form a polyimide film; a step of forming a semiconductor element on the imide resin film; and a step of peeling off the polyimide film formed of the semiconductor element from the support.

<8> A polyimine resin film obtained by heating the resin composition as described above.

<9> A method for producing a display substrate, comprising the steps of: applying a resin composition as described above to a support and heating to form a polyimide film; in the polyimide resin a step of forming a semiconductor element on the film; and a step of peeling off the polyimide film formed of the semiconductor element from the support.

<10> A display substrate formed by the method of manufacturing a display substrate as described above.

According to the present invention, it is possible to provide a resin composition capable of forming a polyimide film (plastic substrate) having a sufficient adhesion to a support when forming a semiconductor element such as a TFT. Sex and self-supporting When laser is not used, it can be perfectly peeled off by physical means (good peelability). Further, it is possible to provide a resin composition capable of forming a polyimide film which is thermally expanded even when exposed to a high temperature when a semiconductor element is formed. When the thermal expansion of the polyimide film is small, dimensional variations can be suppressed when a semiconductor element such as a TFT is formed. Further, the polyimide resin film using the resin composition of the present invention is excellent in mechanical properties and heat resistance.

Further, the present invention can provide a method of manufacturing a display substrate using the resin composition. Further, the present invention can provide a display substrate formed by the manufacturing method.

1‧‧‧ glass substrate

2‧‧‧Resin composition film

3‧‧‧ Polyimine resin film

4‧‧‧TFT electrode layer

5‧‧‧Liquid display device layer

6‧‧‧ cover film

Fig. 1 is a cross-sectional view showing an embodiment of a method of manufacturing a display substrate of the present invention.

Fig. 2 is a cross-sectional view showing an embodiment of a method of manufacturing a display substrate of the present invention.

3 is a cross-sectional view showing an embodiment of a method of manufacturing a display substrate of the present invention.

4 is a cross-sectional view showing an embodiment of a method of manufacturing a display substrate of the present invention.

(resin composition)

The resin composition of the present invention contains (a) a polyimine precursor, and (b) an alkoxy group. The content of the (b) is from 0.01% by mass to 2% by mass based on the (a) polyimine precursor, the decane compound and (c) the organic solvent. Each component is described below.

((a) Polyimine precursors)

The resin composition of the present invention contains (a) a polyimine precursor. By containing a polyimine precursor, a polyimide film having excellent heat resistance and mechanical properties can be formed.

From the viewpoint of heat resistance and mechanical properties, the (a) polyimine precursor is preferably a polyamic acid having a structural unit represented by the general formula (1).

(In the formula (1), R ¹ represents a divalent organic group having an aromatic ring, and R ² represents a tetravalent organic group having an aromatic ring.)

(a) Polyimine precursors are usually obtained by polymerizing a tetracarboxylic dianhydride with a diamine. This polymerization can be carried out by mixing the two in an organic solvent.

Examples of the tetracarboxylic dianhydride used for the synthesis of the (a) polyimine precursor include pyromellitic dianhydride, cyclohexyltetracarboxylic dianhydride, and 3,3',4,4'-biphenyltetracarboxylic acid. Acid dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenone Tetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,4'-sulfonyl diphthalic acid Anhydride, 2,2-bis(3,4-dicarboxyphenyl)propane II An anhydride or the like may be used in combination of two or more kinds.

The diamine used for the synthesis of the (a) polyimine precursor may be exemplified by p-phenylenediamine, m-phenylenediamine, benzidine, and 3,3'-dimethyl-4,4'-diaminobiphenyl. , 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 2,2'-diethyl- 4,4'-diaminobiphenyl, p-xylylene diamine, m-xylylenediamine, 1,5-diaminonaphthalene, 3,3'-dimethoxy Anthranil, 4,4'- (or 3,4'-, 3,3'-, 2,4'-)diaminodiphenylmethane, 4,4'- (or 3,4'-, 3,3'-, 2,4'-)diaminodiphenyl ether, 4,4'-(or 3,4'-,3,3'-,2,4'-)diaminodiphenyl碸, 4,4'-(or 3,4'-,3,3'-,2,4'-)diaminodiphenyl sulfide, 4,4'-benzophenone diamine, 3,3 '-benzophenone diamine, 4,4'-bis(4-aminophenoxy)phenylhydrazine, 4,4'-bis(4-aminophenoxy)biphenyl, 1,4- Bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,1,1,3,3,3-hexafluoro-2,2-dual (4 -aminophenyl)propane, 2,2'-bis(trifluoromethyl)benzidine, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 3,3-di Methyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenyl Alkane, 4,4'-bis(3-aminophenoxy)phenylindole, 3,3'-diaminodiphenylanthracene, 2,2'-bis(4-aminophenyl)propane, 5,5'-methylene-bis-(o-amine benzoic acid), 3,5-diaminobenzoic acid, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3 Aromatic diamines such as '-dimethyl-4,4'-diaminobiphenyl-6,6'-disulfonic acid, 2,6-diaminopyridine, 2,4-diaminopyridine, 2 ,4-diamino-s-triazine, 2,7-diaminobenzofuran, 2,7-diaminocarbazole, 3,7-diaminophenothiazine, 2,5-diamino Heterocyclic diamines such as -1,3,4-thiadiazole, 2,4-diamino-6-phenyl-s-triazine, trimethylenediamine, tetramethylenediamine, hexamethylene Further, these may be used in combination of two or more kinds, such as bis-diamine, 2,2-dimethylpropanediamine, and 1,4-cyclohexanediamine.

The organic solvent used for the synthesis of the (a) polyimine precursor may be exemplified by N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, γ. - Butyrolactone, ε-caprolactone, γ-caprolactone, γ-valerolactone, dimethyl hydrazine, 1,4-dioxane, cyclohexanone, etc., and these may be used in combination of 2 or more types. .

The weight average molecular weight of the (a) polyimine precursor is preferably from 5,000 to 300,000, more preferably from 10,000 to 300,000, from the viewpoint of the elongation of the cured film and the solubility in a solvent. , especially good for 15,000 ~ 200,000. The weight average molecular weight can be measured by gel permeation chromatography (Gel Permeation Chromatography) and converted by a standard polystyrene calibration curve.

Further, the polyimine precursor represented by the formula (1) is a divalent organic group having an aromatic ring, and R ¹ as a residue of the above diamine (one of which is removed from the diamine) The divalent organic group represented by any one of the following structural formulas (4) to (6) is preferable.

(In the general formula (4) and the general formula (5), R' each independently represents a monovalent alkyl group. Further, part or all of the hydrogen atoms in the alkyl group of R' may be substituted by a halogen atom (fluorine, chlorine, bromine, or iodine). )

When R ^{1 in the} formula (1) is a divalent organic group represented by any one of the structural formulae (3) to (6), it is excellent in mechanical properties or heat resistance, and the coefficient of thermal expansion can be lowered.

Here, R' in the general formula (4) and the general formula (5) which represent a monovalent alkyl group is preferably an alkyl group having 1 to 3 carbon atoms. Further, part or all of the hydrogen atom of the alkyl group may be substituted by a halogen atom.

When R ¹ of the formula (1) is a divalent organic group represented by any one of the structural formulae (3) to (6), the diamine used in the synthesis of the (a) polyimine precursor can be enumerated. : p-phenylenediamine, m-phenylenediamine, benzidine, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diamine Biphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl. The diamine is preferably used in an amount of 40% by mass or more, more preferably 60% by mass or more, and particularly preferably 80% by mass, based on the total amount of the diamine used in the synthesis of the (a) polyimine precursor. ~100% by mass.

Further, in the structural unit represented by the formula (1), R ² having a tetravalent organic group having an aromatic ring is preferably a tetravalent group represented by the following structural formula (7) or structural formula (8). Organic base.

When R ² is any of the above groups, it is excellent in mechanical properties or heat resistance, and the coefficient of thermal expansion can be lowered.

When R ² of the formula (1) is a tetravalent organic group represented by the structural formula (7) or the structural formula (8), the tetracarboxylic dianhydride used in the synthesis of the (a) polyimine precursor can be enumerated. : pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride. The tetracarboxylic dianhydride is preferably used in an amount of 40% by mass or more, more preferably 60% by mass or more, based on the total amount of the tetracarboxylic dianhydride used in the synthesis of the (a) polyimine precursor. Good use 80% to 100% by mass.

The (a) polyimine precursor is preferably contained in an amount of from 5 to 100% by mass based on the entire resin composition.

((b) alkoxydecane compound)

The resin composition of the present invention contains 0.01% by mass to 2% by mass of the (b) alkoxydecane compound with respect to the (a) polyimine precursor.

By containing 0.01% by mass to 2% by mass of the (b) alkoxydecane compound, it is possible to provide a resin composition capable of forming a polyimide film (plastic substrate), which is a polyimide substrate (plastic substrate) When a semiconductor element such as a TFT is formed, it has sufficient adhesion to the support, and does not use a laser when peeling off from the support, but can be perfectly peeled off by a physical method (good peelability).

When the content of the (b) alkoxydecane compound is 0.01% by mass or more, a sufficient adhesion to the support can be imparted, and the content of the (b) alkoxydecane compound is 2% by mass or less. It can impart good peelability and impart good heat resistance and mechanical properties to the polyimide film. The content of the (b) alkoxydecane compound is preferably 0.02% by mass to 2% by mass, more preferably 0.05% by mass to 1% by mass, even more preferably 0.05% by mass, based on the (a) polyimine precursor. ~0.5% by mass, particularly preferably 0.1% by mass to 0.5% by mass.

As a method of confirming the content of the (b) alkoxydecane compound in the resin composition, ¹ H NMR (Nuclear Magnetic Resonance) can be mentioned.

(b) The alkoxydecane compound is preferably a compound represented by the formula (2) or the formula (3).

(In the general formula (2) and the general formula (3), R ¹ and R ² each independently represent a monovalent organic group)

The compound represented by the formula (2) or the formula (3) may, for example, be 3-ureidopropyltriethoxydecane or bis(2-hydroxyethyl)-3-aminopropyltriethoxydecane. 3-glycidoxypropyltrimethoxydecane, phenyltrimethoxydecane, γ-aminopropyltriethyl Oxydecane, γ-aminopropyltrimethoxydecane, γ-aminopropyltripropoxydecane, γ-aminopropyltributoxydecane, γ-aminoethyltriethoxydecane , γ-aminoethyltrimethoxydecane, γ-aminoethyltripropoxydecane, γ-aminoethyltributoxydecane, γ-aminobutyltriethoxydecane, γ- Ethyl butyl trimethoxy decane, γ-aminobutyl tripropoxy decane, γ-aminobutyl tributoxy decane, and the like, and these may be used in combination of two or more kinds. Among these, from the viewpoint of providing a polyimide-imide resin film having sufficient adhesion to the support and having good peelability when peeled off from the support, 3-ureidopropyltriethoxysilane is preferably used. Any of bis(2-hydroxyethyl)-3-aminopropyltriethoxydecane, 3-glycidoxypropyltrimethoxydecane, and phenyltrimethoxydecane, preferably 3- Ureapropyl triethoxy decane.

((c) organic solvent)

The resin composition of the present invention contains (c) an organic solvent. By containing (c) an organic solvent, the coatability on the support and the uniformity of the polyimide film are improved.

(c) The organic solvent may be an organic solvent remaining when the (a) polyimine precursor is synthesized, and a further organic solvent may be used in order to adjust the viscosity of the resin composition.

When (c) the organic solvent is an organic solvent remaining when the (a) polyimine precursor is synthesized, (c) the organic solvent may, for example, be N-methyl-2-pyrrolidone or N,N-dimethylmethyl. Indoleamine, N,N-dimethylacetamide, γ-butyrolactone, ε-caprolactone, γ-caprolactone, γ-valerolactone, dimethyl azine, 1,4-dioxin Alkane, cyclohexanone, etc.

In addition, in order to adjust the viscosity of the resin composition, (c) organic In the case of a solvent, the above solvent may be used, and propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl cellosolve, butyl cellosolve, toluene, and the like may also be used. Toluene, ethanol, isopropyl alcohol, n-butanol, etc. may be used in combination of two or more kinds.

In the resin composition of the present invention, the content of the (a) polyacetimimine precursor is (g) the content of the organic solvent in terms of mass ratio (from the viewpoint of formation of a good film coating property, etc.). a) the mass of the polyimine precursor / (c) the mass of the organic solvent), preferably 5/95 to 95/5, more preferably 20/80 to 80/20, and particularly preferably 30/70~ 50/50. Further, the mass ratio ((a) the mass of the polyimine precursor/(c) the mass of the organic solvent) can be calculated by adding a resin composition to a metal or glass dish to accurately measure The total mass of the resin composition and the dish is such that the organic solvent is scattered at a temperature near the boiling point of the organic solvent, and the total mass of the resin composition after the treatment and the treated resin is accurately measured, and the dish and the resin composition before and after the treatment The total mass of each dish was subtracted from the mass of the dish, and the mass of the resin composition after the treatment was divided by the mass of the resin composition before the treatment. At this time, the temperature is such that the polyimide ring of the polyamidene precursor is condensed below the temperature of the polyimine. It is usually 150 ° C or lower, preferably set to a lower temperature.

(other ingredients)

The resin composition of the present invention can impart photosensitivity as needed. For example, when a negative photosensitive property is imparted, it can be formulated with a polyacrylic acid (a hydrogen atom of a carboxylic acid bonded to R ² in the general formula (1)) as a polyimide precursor. The acryloyl group-based amine imparts photosensitivity. Examples of such an amine include N,N-diethylaminopropyl methacrylate, N,N-dimethylaminopropyl methacrylate, and N,N-diethylaminopropyl acrylate. N,N-diethylaminoethyl methacrylate or the like is not limited to this range. When a negative photosensitive property is imparted, it is generally more preferable to use a photopolymerization initiator such as a radical polymerization initiator of 0.01% by mass to 10% by mass based on the total amount of the resin composition.

The resin composition of the present invention may contain other components (such as an adhesion aid, an acid generator, etc.) as needed within the range of not impairing heat resistance and mechanical properties.

The resin composition of the present invention is preferably a method for producing a display substrate comprising the steps of: applying the resin composition to a support and heating to form a polyimide film; in the poly a step of forming a semiconductor element on the amine resin film; and a step of peeling the polyimide film formed of the semiconductor element from the support.

The polyimine resin film of the present invention is excellent in adhesion to a support (for example, 50 kg/cm ² to 950 kg/cm ² , stud pull evaluation method), and thus can be used in polyimine. A semiconductor element such as a TFT is simply formed on the resin film. Further, the polyimide film of the present invention has a low coefficient of thermal expansion (for example, a thermal expansion coefficient of 15 × 10 ^-6 /K or less at 100 ° C to 200 ° C), and a high glass transition temperature (for example, 250 ° C or more). Therefore, when a semiconductor element such as a TFT is formed, dimensional deviation can be suppressed even when exposed to a high temperature.

(polyimine resin film)

The polyimide film of the present invention can be formed by heating the resin composition of the present invention. By heating, the polyimine precursor in the resin composition becomes polypyrene The amine imparts good mechanical properties and heat resistance to the polyimide film.

The polyimide film of the present invention is a so-called plastic substrate.

(Method of Manufacturing Display Substrate)

The method for producing a display substrate of the present invention comprises the steps of: applying a resin composition of the present invention to a support and heating to form a polyimide film; forming a polyimide film on the polyimide film; a step of separating a semiconductor element; and a step of peeling the polyimide film formed of the semiconductor element from the support.

In the present specification, the display substrate is not particularly limited, and refers to a substrate on which a semiconductor element such as a TFT is formed on a plastic substrate (a polyimide film in the present invention).

The step of applying the resin composition of the present invention to the support is not particularly limited as long as it can form a uniform thickness on the support, and for example, it can be die-coated or spin-coated, and screen-printed. Coating.

The support to which the resin composition of the present invention is applied may be any one which is self-supporting and has heat resistance, and may be rough and smooth on the surface on which the resin composition is applied. That is, it is not particularly limited if it is difficult to be deformed at a high temperature required for exposure to the manufacturing steps of the display substrate. Specifically, a material having a glass transition temperature of 200 ° C or higher, preferably 250 ° C or higher is preferably used, and examples of such a support include glass. The thickness of the support is preferably from 0.3 mm to 5.0 mm, more preferably from 0.5 mm to 3.0 mm, and particularly preferably from 0.7 mm to 1.5 mm.

The resin composition film formed by the step of applying the resin composition onto the support is then preferably subjected to a drying step. Staged by drying step The solvent in the resin composition is removed, whereby the roughness of the surface of the polyimide film after heat hardening can be suppressed. The drying step is preferably carried out at 80 ° C to 150 ° C for 30 seconds to 5 minutes using a hot plate.

The polyimide film can be formed by heating the resin composition film. borrow By this heating step, the quinone imine ring of the polyimide precursor in the resin composition is ring-closed, and imparts good mechanical properties and heat resistance to the polyimide film. The heating step may be any device that can control the temperature rise rate and the environment during hardening, and can maintain the specific temperature for a fixed time. The temperature in the heating step is preferably from 100 ° C to 500 ° C, more preferably from 200 ° C to 475 ° C, and particularly preferably from 250 ° C to 450 ° C. Further, the heating time is preferably from 1 minute to 6 hours, more preferably from 3 minutes to 4 hours, and particularly preferably from 15 minutes to 2 hours.

The thickness of the polyimide film of the present invention is preferably from 1 μm to 50 Mm. By having a thickness of 1 μm or more, the polyimide film has good mechanical properties and can suppress occurrence of defects on the polyimide film in the peeling step of the self-supporting body. Further, by having a thickness of 50 μm or less, the surface roughness of the polyimide film caused by the uniform vaporization of the solvent during drying can be suppressed. The thickness of the polyimide film is preferably from 3 μm to 40 μm, particularly preferably from 5 μm to 30 μm.

A method of manufacturing a display substrate of the present invention comprises: a polyimide resin A step of forming a semiconductor element such as a TFT on the film. The polyimine resin film obtained in the present invention is excellent in heat resistance and mechanical properties. Therefore, a method of forming a semiconductor element or the like is not particularly limited, and a method of forming a semiconductor element differs depending on the type of element used in the display substrate. .

For example, in the manufacture of TFT liquid crystal display devices (TFT Liquid Crystal In the case of a display device, a TFT such as an amorphous germanium can be formed thereon. The TFT includes a gate metal layer, a tantalum nitride gate dielectric layer, and an Indium Tin Oxide (ITO) pixel electrode. Further, a structure required for the liquid crystal display can be formed thereon by a known method.

The polyimide film is peeled off from the support after forming the semiconductor element. peel The method of the separation is not particularly limited, and the polyimide film having the resin composition of the present invention has excellent peelability and mechanical properties, and thus can be perfectly peeled off by a physical method. Further, it is also possible to perform peeling by irradiating a laser or the like from the side of the support.

The display substrate in the present invention may be exemplified by a flexible wiring board and a liquid crystal cell. Pieces, electronic paper. In particular, it is preferably applied to a device that is intended to be thinned and flexible.

Here, the manufacturer of the display substrate using the present invention is shown using a diagram. A manufacturing example of a flexible liquid crystal display substrate.

As shown in FIG. 1, the glass substrate 1 is prepared as a support by spin coating. The resin composition of the present invention was applied onto a glass substrate 1, and then baked by a hot plate at 130 ° C for 2 minutes to form a film having a thickness of about 5 μm to obtain a resin composition film 2 . Next, as shown in FIG. 2, the polyimide was heat-hardened at 200 ° C for 30 minutes using a hardening furnace, followed by heat-hardening at 350 ° C for 60 minutes, and the polyamidene precursor ruthenium in the resin composition was imidized to form a solid. Polyimide resin film 3 of a resin film. The film thickness of the polyimide film 3 was 3 μm. On the polyimide film 3, as shown in Fig. 3, the TFT electrode layer 4 is formed in accordance with a known method. Then at The liquid crystal display element layer 5 and the cover film layer 6 are formed thereon according to a known method. Then, as shown in FIG. 4, the polyimide film 3 of the TFT electrode layer 4 or the like is formed by physical separation from the glass substrate 1. According to this method, a flexible liquid crystal display substrate excellent in reliability can be obtained.

The thermal expansion coefficient of the polyimide film of the present invention is preferably 50 × 10 ^-6 /K or less, more preferably 30 × 10 ^-6 /K or less, particularly preferably 30 × 10 ^-6 /K or less, in the range of 100 ° C to 200 ° C. The body (for example, a glass substrate) has the same degree of thermal expansion. When the thermal expansion coefficient of the support is equal to the thermal expansion coefficient of the polyimide film, the peeling, warpage, and dimensional deviation of the support and the polyimide film are less likely to occur in the process of forming the semiconductor element. A highly reliable display substrate can be provided.

The coefficient of thermal expansion can be cut out by using a polyimine film after dehydration ring closure For the measurement of 5 mm × 15 mm, the temperature was raised from 25 ° C to 450 ° C at 5 ° C per minute using a Thermal Mechanical Analyzer (for example, manufactured by Rigaku Co., Ltd.).

The elongation at break of the polyimide film is preferably 5% or more (25 ° C). More preferably, it is 10% or more, and particularly preferably 15% or more. The elongation at break can be measured by using a polygraph film having a dehydration ring closure of 10 mm × 60 mm, and measuring it by an autograph (for example, manufactured by Shimadzu Corporation). When the elongation at break is 5% or more, even if it is bent, there is a possibility that flexibility can be further imparted.

The elastic modulus (tensile elastic modulus) of the polyimide resin is preferably 1 GPa. The above (25 ° C), more preferably 1.5 GPa or more, and particularly preferably 2 GPa or more. Elastic modulus The sample was cut into a sample of 10 mm × 60 mm by dehydration-closed polyimine film, and was measured by an automatic mapper (for example, manufactured by Shimadzu Corporation). When the modulus of elasticity is 1 GPa or more, the coefficient of thermal expansion tends to be small. Therefore, the deformation at the time of high-temperature exposure is small, that is, the dimensional deviation is hard to occur, and the reliability of various devices using the polyimide resin of the present invention is obtained. The tendency to improve.

Next, the adhesion between the formed polyimide resin and the substrate (pile plug pull-down evaluation method) is preferably 50 kg/cm ² or more, 950 kg/cm ² or less, more preferably 300 kg/cm ² or less. When the adhesion is weaker than this range, peeling of the semiconductor element and the support is likely to occur in formation and build-up, and when the adhesion is exceeded, the polyimide film or the polyimide may be peeled off from the support. The possibility of damage caused by semiconductor components.

[Examples]

(Synthesis Example 1: Synthesis of Polyimine Precursor Solution A)

In a 200 ml flask under a nitrogen atmosphere, 6.79 g of p-phenylenediamine and 174 g of N-methylpyrrolidone were charged, and the mixture was heated and stirred at 40 ° C for 15 minutes to dissolve the monomer.

Then, 19.01 g of the homobiphenyltetracarboxylic dianhydride (2,3,3',4'-biphenyltetracarboxylic acid 2,3:3',4'-dianhydride) was added, followed by stirring for 30 minutes to obtain a viscosity of 1100. mPa. s (25 ° C) polyimine precursor solution A. The polyimine precursor has a weight average molecular weight of 70,000. In the obtained polyimine precursor solution A, the content of the polyimine precursor was 13% by mass.

(Synthesis Example 2: Synthesis of Polyimine Precursor Solution B)

In a 200 ml flask under a nitrogen atmosphere, put p-phenylenediamine 10.85 g, two 0.10 g of aminodiphenyl ether and 164 g of N-methylpyrrolidone were dissolved by heating at 40 ° C for 15 minutes to dissolve the monomer. Then, 11.88 g of the homobiphenyltetracarboxylic dianhydride and 13.21 g of the pyromellitic dianhydride were added, followed by stirring for 30 minutes to obtain a viscosity of 1200 mPa. s (25 ° C) polyimine precursor solution B. The polyamidene precursor solution B had a weight average molecular weight of 65,000. In the obtained polyimine precursor solution B, the content of the polyimine precursor was 18% by mass.

(Synthesis Example 3: Synthesis of Polyimine Precursor Solution C)

In a 200 ml flask under a nitrogen atmosphere, 7.22 g of p-phenylenediamine, 0.07 g of diaminodiphenyl ether, and 173 g of N-methylpyrrolidone were charged, and the mixture was heated and stirred at 40 ° C for 15 minutes to dissolve the monomer. Then, 19.64 g of the homobiphenyltetracarboxylic dianhydride and 0.07 g of the pyromellitic dianhydride were added, followed by stirring for 30 minutes to obtain a viscosity of 13,000 mPa. Liquid polyimine precursor C of s (25 ° C). The polyimine precursor had a weight average molecular weight of 72,000. The content of the polyimide precursor was 13% by mass.

(Synthesis Example 4: Synthesis of Polyimine Precursor Solution D)

In a 200 ml flask under a nitrogen atmosphere, 11.33 g of p-phenylenediamine, 0.11 g of diaminodiphenyl ether, and 164 g of N-methylpyrrolidone were charged, and the mixture was heated and stirred at 40 ° C for 15 minutes to dissolve the monomer. Then, 6.20 g of the benzil carboxylic acid dianhydride and 18.37 g of the pyromellitic dianhydride were added, followed by stirring for 30 minutes to obtain a viscosity of 1200 mPa. Liquid polyimine precursor D of s (25 ° C). The polyimine precursor has a weight average molecular weight of 60,000. The content of the polyimine precursor was 18% by mass.

(Example 1)

Add 0.013 g of UCT-801 to the polyimine precursor solution A 100 g (3- After a 50% methanol solution of urea propyl triethoxy decane (the same applies hereinafter), the mixture was stirred for 3 hours to obtain a resin composition 1. Further, the content of the alkoxydecane compound was 0.05% by mass based on the (a) polyimine precursor.

The obtained resin composition 1 was applied by spin coating on a 6-inch wafer, and then baked (dried) by a hot plate at 130 ° C for 2 minutes to form a film having a thickness of 18 μm. Subsequently, it was heat-hardened at 200 ° C for 30 minutes in a hardening furnace, and then heat-hardened at 450 ° C for 60 minutes to carry out oxime imidization of the polyimide precursor in the resin composition to obtain a polyimide film. The film thickness of the polyimide film after heat curing was 10 μm. The polyimide resin film was measured for adhesion to the ruthenium substrate, thermal properties, and mechanical properties, and the results are shown in Table 1.

(evaluation of adhesion)

The adhesion was measured by a plug pull-down evaluation method (column plug tensile peel strength measurement) using a Romulus (film adhesion strength measuring machine) manufactured by Quad Group. Specifically, a ruthenium substrate in which a polyimide film formed by the above method was formed was cut into a sample piece of 1 cm square, and a stud pin with an epoxy resin was erected in the center thereof. The jig was fixed, and heat-hardened by an oven at 150 ° C for 1 hour, and an epoxy resin stud pin was fixed to the polyimide film to prepare a sample for evaluation. The sample for evaluation was placed on a Romulus, the load was increased at a rate of 5 kg/min, and a tensile load was applied in a vertical direction, and the strength at which the polyimide film was peeled off from the substrate was defined as the peel strength.

(evaluation of peelability)

Cutting into the slit by a razor on the polyimide film formed on the substrate of the crucible, Physical peeling was attempted and evaluated by A to D shown below.

"A": excellent in peeling property, and it is naturally peeled off by cutting it into a slit by a razor.

"B": good peelability (can be easily peeled off by tweezers), but it was not peeled off naturally by cutting into the slit by a razor.

"C": peelable (by peeling off the tweezers), but burdening the film which causes a burden (elongation or deformation, partial breakage) on the polyimide film.

"D": Cannot be peeled off.

(Evaluation of heat resistance (thermal expansion rate and temperature at which 1% is reduced)

The thermal property was measured by a thermomechanical analyzer manufactured by Rigaku Co., Ltd., and a polyimide film of 5 mm × 15 mm cut out was measured at a temperature of 5 ° C per minute from 25 ° C to 450 ° C at 100 ° C ~ The coefficient of thermal expansion in the range of 200 ° C and the temperature at which the mass is reduced by 1%.

(Evaluation of mechanical properties (elongation at break and modulus of elasticity))

The mechanical properties are the polyimine resin film cut out to 10 mm × 60 mm, and the elongation at break and the modulus of elasticity (the Young's modulus for stretching) were measured using an automatic mapper manufactured by Shimadzu Corporation. , tensile modulus of elasticity).

(Example 2)

After adding 0.052 g of UCT-801 to the polyimine precursor solution A 100 g, the mixture was stirred for 3 hours to obtain a resin composition 2. Further, the content of the alkoxydecane compound was 0.2% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution A).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimine resin was obtained. The film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are summarized in Table 1.

(Example 3)

After adding 0.13 g of UCT-801 to 100 g of the polyimine precursor solution A, the mixture was stirred for 3 hours to obtain a resin composition 3. Further, the content of the alkoxydecane compound was 0.5% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution A).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

(Example 4)

After adding 0.26 g of UCT-801 to the polyimine precursor solution A 100 g, the mixture was stirred for 3 hours to obtain a resin composition 4. Further, the content of the alkoxydecane compound was 1.0% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution A).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

(Example 5)

After 0.018 g of UCT-801 was added to the polyimine precursor solution B 100 g, the mixture was stirred for 3 hours to obtain a resin composition 5. Further, the content of the alkoxydecane compound was 0.05% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

(Example 6)

After 0.072 g of UCT-801 was added to the polyimine precursor solution B 100 g, the mixture was stirred for 3 hours to obtain a resin composition 6. Further, the content of the alkoxydecane compound was 0.2% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

(Example 7)

After adding 0.18 g of UCT-801 to 100 g of the polyimine precursor solution B, the mixture was stirred for 3 hours to obtain a resin composition 7. Further, the content of the alkoxydecane compound was 0.5% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 2.

(Example 8)

After adding 0.072 g of SIB1140.0 (50% methanol solution of bis(2-hydroxyethyl)-3-aminopropyltriethoxydecane) to the polyimine precursor solution B 100 g, stirring 3 In an hour, the resin composition 8 was obtained. Further, the content of the alkoxydecane compound was 0.2% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 2.

(Example 9)

After 0.18 g of SIB1140.0 was added to the polyimine precursor solution B 100 g, the mixture was stirred for 3 hours to obtain a resin composition 9. Further, the content of the alkoxydecane compound was 0.5% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 2.

(Embodiment 10)

After 0.36 g of SIB1140.0 was added to the polyimine precursor solution B 100 g, the mixture was stirred for 3 hours to obtain a resin composition 10. Further, the content of the alkoxydecane compound was 1.0% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 2.

(Example 11)

After 0.072 g of KBM-103 (phenyltrimethoxydecane) was added to the polyimine precursor solution B 100 g, the mixture was stirred for 3 hours to obtain a resin composition 11. Further, the content of the alkoxydecane compound was 0.4% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 2.

(Embodiment 12)

After adding 0.18 g of KBM-103 to the polyimine precursor solution B 100 g, the mixture was stirred for 3 hours to obtain a resin composition 12. Further, the content of the alkoxydecane compound was 1.0% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 2.

(Example 13)

After 0.36 g of KBM-103 was added to the polyimine precursor solution B 100 g, the mixture was stirred for 3 hours to obtain a resin composition 13. Further, the content of the alkoxydecane compound was 2.0% by mass based on the polyimide intermediate precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 2.

(Example 14)

After adding 0.072 g of KBM-403 (3-glycidoxypropyltriethoxydecane) to 100 g of the polyimine precursor solution B, the mixture was stirred for 3 hours to obtain a resin composition 14. Further, the content of the alkoxydecane compound was 0.4% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 2.

(Example 15)

After adding 0.18 g of KBM-403 to the polyimine precursor solution B 100 g, the mixture was stirred for 3 hours to obtain a resin composition 15. Further, the content of the alkoxydecane compound was 1.0% by mass based on the polyimine precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 3.

(Embodiment 16)

After 0.36 g of KBM-403 was added to the polyimine precursor solution B 100 g, the mixture was stirred for 3 hours to obtain a resin composition 16. Further, the content of the alkoxydecane compound was 2.0% by mass based on the polyimide intermediate precursor (polyimine precursor component in the polyimine precursor solution B).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 3.

(Example 17)

After adding 0.14 g of UCT-801 to the liquid polyimine precursor C 100 g, the mixture was stirred for 3 hours to obtain a liquid polyimine precursor resin composition 17.

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

(Embodiment 18)

After adding 0.27 g of UCT-801 to 100 g of the liquid polyimine precursor C, the mixture was stirred for 3 hours to obtain a liquid polyimine precursor resin composition 18.

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide film was evaluated. The results of the price adhesion, thermal properties, and mechanical properties are summarized in Table 1.

(Embodiment 19)

After adding 0.54 g of UCT-801 to the liquid polyimine precursor C 100 g, the mixture was stirred for 3 hours to obtain a liquid polyimine precursor resin composition 19.

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

(Embodiment 20)

After adding 0.18 g of UCT-801 to the liquid polyimine precursor D 100 g, the mixture was stirred for 3 hours to obtain a liquid polyimine precursor resin composition 20.

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

(Example 21)

After adding 0.36 g of UCT-801 to the liquid polyimine precursor D 100 g, the mixture was stirred for 3 hours to obtain a liquid polyimine precursor resin composition 21.

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

(Example 22)

After adding 0.54 g of UCT-801 to the liquid polyimine precursor D 100 g, the mixture was stirred for 3 hours to obtain a liquid polyimine precursor resin composition 22.

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

(Comparative Example 1)

The polyimine precursor solution A was formed into a film by the method described in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 3.

(Comparative Example 2)

The polyimine precursor solution B was formed into a film by the method described in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 3.

(Comparative Example 3)

Pretreatment with decane coupling agent (0.1-amino-1-methoxy-2-propanol solution of 3-aminopropyltriethoxy decane was spin-coated on a 6-inch wafer at 130 ° C After baking the solvent to remove the solvent, thereby forming a single layer film of 3-aminopropyltriethoxydecane, the polyimine precursor solution A was coated by spin coating. The film was baked by a hot plate at 130 ° C for 2 minutes to form a film having a thickness of 18 μm. Subsequently, the film was heat-hardened at 200 ° C for 30 minutes in a curing oven, and then heat-cured at 450 ° C for 60 minutes to carry out oxime imidization to obtain a polyimide film. The film thickness after imidization was 10 μm.

The obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 3.

(Comparative Example 4)

The polyimine precursor solution B was coated by spin coating on a 6-inch wafer pretreated with a decane coupling agent, and then baked by a hot plate at 130 ° C for 2 minutes to a thickness of 18 Film formation was carried out in a manner of μm. Then, use a hardening furnace to heat at 200 ° C After hardening for 30 minutes and then heat-hardening at 450 ° C for 60 minutes, hydrazine imidization was carried out to obtain a resin film containing a polyimide film.

The film thickness after imidization was 10 μm.

The obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 3.

(Comparative Example 5)

After 0.78 g of UCT-801 was added to the polyimine precursor solution A 100 g, the mixture was stirred for 3 hours to obtain a resin composition. Further, the content of the alkoxydecane compound was 3.0% by mass based on the polyimide intermediate precursor (polyimine precursor component in the polyimine precursor solution A).

Film formation was carried out in the same manner as in Example 1, and the obtained polyimide resin film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

(Comparative Example 6)

The liquid polyimine precursor C was formed into a film by the method described in Example 1, and the obtained polyimide film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

(Comparative Example 7)

The liquid polyimine precursor D was formed into a film by the method described in Example 1, and the obtained polyimide film was evaluated for adhesion, thermal properties, and mechanical properties, and the results are shown in Table 1.

As shown in the examples 1 to 22, the resin film containing a resin composition containing 0.01% by mass to 2% by mass of an alkoxydecane compound has adhesiveness, peelability, and heat resistance (thermal expansion coefficient, reduction of 1). Excellent in terms of temperature (% of mass) and mechanical properties (elongation at break, and modulus of elasticity). The polyimide film of Examples 1 to 17 can easily form a semiconductor element such as a TFT even if it is a film of 10 μm, and can be easily peeled off from the support.

On the other hand, in Comparative Example 1 and Comparative Example 2 in which a resin composition containing no decane coupling agent was used, the adhesion was lowered. In addition, a comparative example in which a wafer is pretreated by a decane coupling agent instead of using a resin composition containing a decane coupling agent In 3 and Comparative Example 4, the peelability was inferior. Further, in Comparative Example 5 using a 3% by mass decane coupling agent, the releasability was poor.

The embodiments and/or the embodiments of the present invention have been described in detail above, but the embodiments and/or embodiments of the present invention are readily described without departing from the novel spirit and effect of the invention. Apply a lot of changes. Therefore, these numerous modifications are included in the scope of the present invention.

The contents of the documents described in the present specification and the Japanese Patent Application Laid-Open No.

1‧‧‧ glass substrate

3‧‧‧ Polyimine resin film

4‧‧‧TFT electrode layer

5‧‧‧Liquid display device layer

6‧‧‧ cover film

Claims (10)

A resin composition comprising (a) a polyimine precursor, (b) an alkoxydecane compound, (c) an organic solvent, and the above (b) alkane relative to the (a) polyimine precursor The content of the oxydecane compound is 0.01% by mass to 2% by mass. The resin composition according to claim 1, wherein the (a) polyimine precursor is a polyamic acid having a structural unit represented by the general formula (1): (In the formula (1), R ¹ represents a divalent organic group having an aromatic ring, and R ² represents a tetravalent organic group having an aromatic ring). The resin composition according to claim 1, wherein the content of the (b) alkoxydecane compound is from 0.02% by mass to 2% by mass based on the (a) polyimine precursor. The resin composition according to claim 1, wherein the content of the (b) alkoxydecane compound is 0.05% by mass to 1% by mass based on the (a) polyimine precursor. The resin composition according to claim 1, wherein the (b) alkoxydecane compound is any one of the compounds represented by the formula (2) or the formula (3): (In the general formula (2) and the general formula (3), R ¹ and R ² each independently represent a monovalent organic group). The resin composition according to claim 1, wherein the (a) polyimine precursor has a weight average molecular weight of from 15,000 to 200,000. The resin composition according to any one of claims 1 to 6, which is used in a method of producing a display substrate comprising the steps of: applying a resin composition to a support and heating to form a poly a step of forming a bismuth imide resin film; a step of forming a semiconductor element on the polyimide film; and a step of peeling the polyimine resin film on which the semiconductor element is formed from the support. A polyimine resin film obtained by heating the resin composition according to any one of claims 1 to 6. A method of manufacturing a display substrate, comprising the steps of: applying a resin composition according to any one of claims 1 to 6 to a support and heating to form a polyimine a step of forming a resin film on the polyimide film; and a step of peeling the polyimine resin film on which the semiconductor element is formed from the support. A display substrate formed by the method of manufacturing a display substrate according to claim 9 of the patent application.