WO2015046128A1 - Heat-resistant resin film and method for menufacturing same, heating furnace and process for producing image display device - Google Patents

Abstract

A heat-resistant resin film which when heated in a helium stream at 450°C for 30 minutes, generates 0.01 to 4μg/cm² of outgas. A method for manufacturing a heat-resistant resin film which comprises a step for applying a solution that contains a heat-resistant resin precursor to a substrate and a multistage heating step for subjecting the resulting coating to multistage heating, characterized in that the multistage heating step includes, at least, (A) a first heating step for heating the coating in an atmosphere having an oxygen concentration of 10vol% or more at a temperature higher than 200°C and (B) a second heating step for heating the resulting coating in an atmosphere having an oxygen concentration of 3vol% or less at a temperature higher than that in the first heating step, in this order.

Description

Heat resistant resin film and method for manufacturing the same, heating furnace, and method for manufacturing image display device

The present invention relates to a heat resistant resin film and a manufacturing method thereof, a heating furnace, and a manufacturing method of an image display device.

Heat-resistant resins such as polyimide, polybenzoxazole, polybenzothiazole, and polybenzimidazole are used in various fields including semiconductor applications due to their excellent electrical insulation, heat resistance, and mechanical properties. Recently, application of image display devices such as organic EL displays, electronic paper, and color filters to substrates has also expanded, and it is possible to manufacture a flexible image display device that is resistant to impact.

In order to use a heat-resistant resin as a substrate of an image display device, gas permeability such as oxygen and water vapor is high, and it is usual to use a gas barrier film such as a silicon nitride film in a laminated manner. Various methods for forming the gas barrier film have been studied, but a vacuum process such as plasma enhanced chemical vapor deposition (PECVD) is often used. For this reason, it is preferable that the outgas from the heat resistant resin is as small as possible so that the film formation in the vacuum process does not become defective.

In general, heat-resistant resins are often insoluble in solvents and infusible, so that direct molding is difficult. Therefore, in the formation of a heat-resistant resin film, a solution containing a precursor of a heat-resistant resin (hereinafter referred to as varnish) is usually applied to a support and is converted into a heat-resistant resin film by heating. Yes. For example, in the case of polyimide, a polyimide film can be obtained by coating a solution containing polyamic acid as a precursor on a support and heating at a temperature of 180 to 600 ° C. As a heating method, the heating may be performed in one stage, or may be performed in multiple stages. For example, Patent Document 1 reports a method of heating in multiple stages.

JP 2000-248077 A

In order to improve the mechanical properties of the heat resistant resin film, it is often effective to increase the heating temperature within a range not exceeding the thermal decomposition temperature of the heat resistant resin. However, if the heating temperature is increased in the atmosphere, oxygen molecules in the atmosphere cause the oxidation of the resin and the decomposition due to it, making it difficult to obtain good mechanical properties. For this reason, it is usually recommended to perform heating in an inert gas atmosphere such as nitrogen or argon, or in a vacuum atmosphere.

However, when heated in an inert atmosphere, the outgas component tends to remain in the heat resistant resin film, and it is difficult to reduce the outgas of the heat resistant resin film. In addition, when heating in an inert atmosphere, there is a problem that costs (power, gas) are higher than when heating in the air. Furthermore, it takes time to replace the heating atmosphere from the atmosphere to an inert gas or vacuum before heating, and there is a problem that productivity of the heat resistant resin film is lowered.

This invention makes it a subject to solve the said problem. That is, it is an object to provide a heat-resistant resin film with little outgas and high mechanical properties. In addition, it is an object of the present invention to provide a method for producing a heat-resistant resin film with less outgassing without impairing the mechanical properties of the heat-resistant resin film even if the process of heating in an inert atmosphere is shortened.

One of the features of the present invention is a heat resistant resin film in which outgas generated during heating at 450 ° C. for 30 minutes in a helium stream is 0.01 to 4 μg / cm ² .

One of the characteristics of the present invention is a method for producing a heat-resistant resin film comprising a step of applying a solution containing a precursor of a heat-resistant resin on a support, and a step of heating in multiple stages, The step of heating in multiple stages is (A) a first heating step of heating at a temperature higher than 200 ° C. in an atmosphere having an oxygen concentration of 10% by volume or more, and (B) an atmosphere having an oxygen concentration of 3% by volume or less. And a second heating step for heating at a temperature higher than that of the first heating step, in the order described above.

Further, one of the features of the present invention is a temperature measuring unit for measuring the temperature in the furnace, a temperature adjusting unit for adjusting the temperature in the furnace, an oxygen concentration measuring unit for measuring the oxygen concentration in the furnace, A heating furnace comprising: a gas flow rate adjustment unit that adjusts the flow rate of the heating atmosphere gas into the furnace; and a control unit that controls the temperature adjustment unit and the gas flow rate adjustment unit, wherein the control unit includes the The furnace that controls the gas flow rate adjusting unit according to the oxygen concentration in the furnace measured by the oxygen concentration measuring unit and that is measured by the temperature measuring unit after the oxygen concentration reaches a predetermined oxygen concentration It is a heating furnace which controls the said temperature adjustment part so that the inside temperature may become predetermined | prescribed temperature.

According to the present invention, it is possible to provide a heat resistant resin film with less outgas and high mechanical properties.

1 is a schematic view of a heating furnace 1. FIG.

<Heat resistant resin film>
One of the features of the present invention is a heat resistant resin film in which outgas generated during heating at 450 ° C. for 30 minutes in a helium stream is 0.01 to 4 μg / cm ² . The outgas generated during heating at 450 ° C. for 30 minutes under a helium stream here can be determined by measuring with the following apparatus and conditions.

Measuring device: heating section “Small-4” (manufactured by Toray Research Center, Inc.), GC / MS “QP5050A (7)” (manufactured by Shimadzu Corporation)
Heating conditions: Temperature is raised from room temperature at 10 ° C / min and held for 30 minutes after reaching 450 ° C.
Measurement atmosphere: under helium air flow (50 mL / min).

The heat resistant resin film of the present invention needs to have an outgas of 0.01 to 4 μg / cm ² measured while being held for 30 minutes after reaching 450 ° C. by the above method. If it is 4 μg / cm ² or less, film formation defects in a vacuum process such as plasma enhanced chemical vapor deposition (PECVD) are reduced. More preferably, it is 2 μg / cm ² or less, and further preferably 1 μg / cm ² .

On the other hand, when the heat-resistant resin film formed on the glass substrate is peeled from the glass substrate using a laser, the outgas generated from the heat-resistant resin film is accumulated at the interface with the glass, so that the peeling is facilitated. For this reason, the outgas of the heat resistant resin film is required to be 0.01 μg / cm ² or more. More preferably, it is 0.02 μg / cm ² or more, and further preferably 0.04 μg / cm ² or more.

Furthermore, the heat resistant resin film of the present invention preferably has a maximum tensile stress of 200 MPa or more. The maximum tensile stress here can be determined by measuring with the following equipment and conditions in accordance with Japanese Industrial Standards (JIS K 7127: 1999).

Measuring device: Tensilon Universal Material Testing Machine “RTM-100” (Orientec Co., Ltd.)
Measurement sample shape: Ribbon shape Measurement sample size: Length> 70 mm, width 10 mm
Pulling speed: 50mm / min
Distance between chucks at the start of the test: 50 mm
Experimental temperature: 0 to 35 ° C
Number of samples: 10
Calculation method of measurement results: Arithmetic average value of measured values of 10 samples If the maximum tensile stress is 200 MPa or more, it has appropriate mechanical characteristics as a substrate of an image display device such as an organic EL display, electronic paper, and a color filter. More preferably, it is 250 MPa or more. Further, it is preferably 800 MPa or less, more preferably 600 MPa or less. If it is 800 MPa or less, it has the flexibility as a flexible substrate.

<Heat resistant resin>
The heat-resistant resin in the present invention refers to a resin having no melting point or decomposition temperature below 300 ° C., and includes polyimide, polybenzoxazole, polybenzothiazole, polybenzimidazole, polyamide, polyethersulfone, polyetheretherketone, and the like. Including. Among these, the heat resistant resin that can be preferably used in the present invention is polyimide, polybenzoxazole, polybenzimidazole, or polybenzothiazole, and more preferably polyimide. If the heat-resistant resin is polyimide, when manufacturing an image display device using a heat-resistant resin film, heat resistance (outgas characteristics, glass transition temperature, etc.) with respect to the temperature of the manufacturing process, and toughness to the image display device after manufacture It is possible to have a mechanical property suitable for imparting.

Polyimide is a resin having a structure represented by the chemical formula (1).

In chemical formula (1), X represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms, and Y represents a divalent diamine residue having 2 or more carbon atoms. m represents a positive integer.

X is preferably a tetravalent hydrocarbon group having 2 to 80 carbon atoms. X may be a tetravalent organic group having 2 to 80 carbon atoms containing hydrogen and carbon as essential components and containing one or more atoms selected from boron, oxygen, sulfur, nitrogen, phosphorus, silicon and halogen. Each atom of boron, oxygen, sulfur, nitrogen, phosphorus, silicon and halogen is preferably independently in a range of 20 or less, more preferably in a range of 10 or less.

Examples of tetracarboxylic acids that give X include the following. Examples of the aromatic tetracarboxylic acid include monocyclic aromatic tetracarboxylic acid compounds such as pyromellitic acid and 2,3,5,6-pyridinetetracarboxylic acid;
Various isomers of biphenyltetracarboxylic acid such as 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 2,2 ′, 3,3 ′ -Biphenyltetracarboxylic acid, 3,3 ', 4,4'-benzophenone tetracarboxylic acid, 2,2', 3,3'-benzophenone tetracarboxylic acid, etc .;
Bis (dicarboxyphenyl) compounds such as 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 2,2-bis (2,3-dicarboxyphenyl) hexafluoropropane, 2,2- Bis (3,4-dicarboxyphenyl) propane, 2,2-bis (2,3-dicarboxyphenyl) propane, 1,1-bis (3,4-dicarboxyphenyl) ethane, 1,1-bis ( 2,3-dicarboxyphenyl) ethane, bis (3,4-dicarboxyphenyl) methane, bis (2,3-dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) sulfone, bis (3 4-dicarboxyphenyl) ether and the like;
Bis (dicarboxyphenoxyphenyl) compounds such as 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (2,3-dicarboxyphenoxy) ) Phenyl] hexafluoropropane, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane, 2,2-bis [4- (2,3-dicarboxyphenoxy) phenyl] propane, , 2-bis [4- (3,4-dicarboxyphenoxy) phenyl] sulfone, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] ether and the like;
Various isomers of naphthalene or condensed polycyclic aromatic tetracarboxylic acid such as 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7- Naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, etc .; bis (trimellitic acid monoester anhydride) compounds such as p-phenylenebis (Trimellitic acid monoester acid anhydride), p-biphenylenebis (trimellitic acid monoester acid anhydride), ethylene bis (trimellitic acid monoester acid anhydride), bisphenol A bis (trimellitic acid monoester acid anhydride) Thing) etc.

Examples of the aliphatic tetracarboxylic acid include a chain aliphatic tetracarboxylic acid compound such as butanetetracarboxylic acid;
Alicyclic tetracarboxylic acid compounds such as cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, bicyclo [2.2.1. ] Heptanetetracarboxylic acid, bicyclo [3.3.1. ] Tetracarboxylic acid, bicyclo [3.1.1. ] Hept-2-enetetracarboxylic acid, bicyclo [2.2.2. ] Octane tetracarboxylic acid, adamatane tetracarboxylic acid and the like.

These tetracarboxylic acids can be used as they are or in the form of acid anhydrides, active esters, and active amides. Two or more of these may be used.

In applications where heat resistance is required, it is preferable to use 50% by mole or more of aromatic tetracarboxylic acid based on the total tetracarboxylic acid. Among these, it is preferable that X is mainly composed of a tetravalent tetracarboxylic acid residue represented by the chemical formula (2) or (3).

That is, it is preferable to use pyromellitic acid or 3,3 ′, 4,4′-biphenyltetracarboxylic acid as a main component. In the present invention, the main component means that 50 mol% or more of the total tetracarboxylic acid is used. More preferably, 80 mol% or more is used. If it is a polyamic acid obtained from these tetracarboxylic acids, even if it heats in air | atmosphere, there will be little deterioration. Therefore, in the method for producing a heat-resistant resin film which is one of the features of the present invention, (A) a first heating step of heating at a temperature higher than 200 ° C. in an atmosphere having an oxygen concentration of 10% by volume or more, Further, it may be performed at a temperature higher than 300 ° C.

In addition, by using silicon-containing tetracarboxylic acids such as dimethylsilanediphthalic acid and 1,3-bis (phthalic acid) tetramethyldisiloxane, adhesion to the support, oxygen plasma used for cleaning, etc., UV ozone Resistance to processing can be increased. These silicon-containing tetracarboxylic acids are preferably used in an amount of 1 to 30 mol% of the total tetracarboxylic acids.

In the tetracarboxylic acid exemplified above, part of the hydrogen contained in the tetracarboxylic acid residue is a hydrocarbon group having 1 to 10 carbon atoms such as a methyl group or an ethyl group, or a carbon group having 1 to 3 carbon atoms such as a trifluoromethyl group. It may be substituted with 10 fluoroalkyl groups, groups such as F, Cl, Br, and I. Furthermore, when substituted with an acidic group such as OH, COOH, SO ₃ H, CONH ₂ , or SO ₂ NH ₂ , the solubility of the resin in an aqueous alkali solution is improved, so that it is used as a photosensitive resin composition described later. Preferred in some cases.

Y is preferably a divalent hydrocarbon group having 2 to 80 carbon atoms. Y may be a divalent organic group having 2 to 80 carbon atoms, which contains hydrogen and carbon as essential components and contains one or more atoms selected from boron, oxygen, sulfur, nitrogen, phosphorus, silicon and halogen. Each atom of boron, oxygen, sulfur, nitrogen, phosphorus, silicon and halogen is preferably independently in a range of 20 or less, more preferably in a range of 10 or less.

Examples of diamines that give Y include the following. Examples of the diamine compound containing an aromatic ring include monocyclic aromatic diamine compounds such as m-phenylenediamine, p-phenylenediamine, and 3,5-diaminobenzoic acid;
Naphthalene or condensed polycyclic aromatic diamine compounds such as 1,5-naphthalenediamine, 2,6-naphthalenediamine, 9,10-anthracenediamine, 2,7-diaminofluorene, etc .;
Bis (diaminophenyl) compounds or various derivatives thereof such as 4,4′-diaminobenzanilide, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3-carboxy-4,4′-diaminodiphenyl ether 3-sulfonic acid-4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 3,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfone, 3, 4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 4-aminobenzoic acid 4-aminophenyl ester, 9,9-bis (4-aminophenyl) fluorene, 1,3-bis (4-anilino) Tetramethyldisiloxane and the like;
4,4'-diaminobiphenyl or various derivatives thereof, such as 4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diamino Biphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-diethyl-4,4′-diaminobiphenyl, 2,2 ′, 3,3′-tetramethyl-4,4′- Diaminobiphenyl, 3,3 ′, 4,4′-tetramethyl-4,4′-diaminobiphenyl, 2,2′-di (trifluoromethyl) -4,4′-diaminobiphenyl, etc .;
Bis (aminophenoxy) compounds such as bis (4-aminophenoxyphenyl) sulfone, bis (3-aminophenoxyphenyl) sulfone, bis (4-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] Ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (4-aminophenoxy) ) Benzene, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, etc .;
Bis (3-amino-4-hydroxyphenyl) compounds such as bis (3-amino-4-hydroxyphenyl) hexafluoropropane, bis (3-amino-4-hydroxyphenyl) sulfone, bis (3-amino-4) -Hydroxyphenyl) propane, bis (3-amino-4-hydroxyphenyl) methylene, bis (3-amino-4-hydroxyphenyl) ether, bis (3-amino-4-hydroxy) biphenyl, 9,9-bis ( 3-amino-4-hydroxyphenyl) fluorene and the like;
Bis (aminobenzoyl) compounds such as 2,2′-bis [N- (3-aminobenzoyl) -3-amino-4-hydroxyphenyl] hexafluoropropane, 2,2′-bis [N- (4-amino Benzoyl) -3-amino-4-hydroxyphenyl] hexafluoropropane, 2,2'-bis [N- (3-aminobenzoyl) -3-amino-4-hydroxyphenyl] propane, 2,2'-bis [N- (4-aminobenzoyl) -3-amino-4-hydroxyphenyl] propane, bis [N- (3-aminobenzoyl) -3-amino-4-hydroxyphenyl] sulfone, bis [N- (4-aminobenzoyl) -3 -Amino-4-hydroxyphenyl] sulfone, 9,9-bis [N- (3-aminobenzoyl) -3-amino-4-hydroxyphenyl Enyl] fluorene, 9,9-bis [N- (4-aminobenzoyl) -3-amino-4-hydroxyphenyl] fluorene, N, N′-bis (3-aminobenzoyl) -2,5-diamino-1, 4-dihydroxybenzene, N, N′-bis (4-aminobenzoyl) -2,5-diamino-1,4-dihydroxybenzene, N, N′-bis (3-aminobenzoyl) -4,4′-diamino −3,3-dihydroxybiphenyl, N, N′-bis (4-aminobenzoyl) -4,4′-diamino-3,3-dihydroxybiphenyl, N, N′-bis (3-aminobenzoyl) -3, 3′-diamino-4,4-dihydroxybiphenyl, N, N′-bis (4-aminobenzoyl) -3,3′-diamino-4,4-dihydroxybiphenyl and the like;
Heterocycle-containing diamine compounds such as 2- (4-aminophenyl) -5-aminobenzoxazole, 2- (3-aminophenyl) -5-aminobenzoxazole, 2- (4-aminophenyl) -6-amino Benzoxazole, 2- (3-aminophenyl) -6-aminobenzoxazole, 1,4-bis (5-amino-2-benzoxazolyl) benzene, 1,4-bis (6-amino-2-benzo Oxazolyl) benzene, 1,3-bis (5-amino-2-benzoxazolyl) benzene, 1,3-bis (6-amino-2-benzoxazolyl) benzene, 2,6-bis ( 4-aminophenyl) benzobisoxazole, 2,6-bis (3-aminophenyl) benzobisoxazole, 2,2′-bis [(3-aminophenyl) -5-benzene Nzooxazolyl] hexafluoropropane, 2,2′-bis [(4-aminophenyl) -5-benzoxazolyl] hexafluoropropane, bis [(3-aminophenyl) -5-benzoxazolyl], bis [ (4-aminophenyl) -5-benzoxazolyl], bis [(3-aminophenyl) -6-benzoxazolyl], bis [(4-aminophenyl) -6-benzoxazolyl] and the like;
Alternatively, a compound in which a part of hydrogen bonded to the aromatic ring contained in these diamine compounds is substituted with hydrocarbon or halogen.

Examples of the aliphatic diamine compound include linear diamine compounds such as ethylenediamine, propylenediamine, butanediamine, pentanediamine, hexanediamine, octanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tetramethylhexanediamine, 1, 12- (4,9-dioxa) dodecanediamine, 1,8- (3,6-dioxa) octanediamine, 1,3-bis (3-aminopropyl) tetramethyldisiloxane and the like;
Alicyclic diamine compounds such as cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), isophoronediamine and the like;
Polyoxyethyleneamine, polyoxypropyleneamine, and their copolymer compounds known as Jeffamine (trade name, manufactured by Huntsman Corporation).

These diamines can be used as they are or as the corresponding trimethylsilylated diamines. Two or more of these may be used.

In applications where heat resistance is required, it is preferable to use an aromatic diamine compound in an amount of 50 mol% or more of the entire diamine compound. Among these, it is preferable that Y is mainly composed of a divalent diamine residue represented by the chemical formula (4).

That is, it is preferable to use p-phenylenediamine as a main component. In the present invention, the main component means that 50 mol% or more of the entire diamine compound is used. More preferably, 80 mol% or more is used. A polyamic acid obtained using p-phenylenediamine is less deteriorated even when heated in air. For this reason, in the method for producing a heat resistant resin film which is one of the features of the present invention, (A) a first heating step of heating at a temperature higher than 200 ° C. in an atmosphere having an oxygen concentration of 10% by volume or more, Further, it may be performed at a temperature higher than 300 ° C.

It is particularly preferable that X in the chemical formula (1) is composed mainly of a tetravalent tetracarboxylic acid residue represented by the chemical formula (2) or (3), and Y is a divalent compound represented by the chemical formula (4). The main component is a diamine residue. The polyamic acid leading to the polyimide having such a structure is particularly less deteriorated even when heated in the air. For this reason, in the method for producing a heat resistant resin film which is one of the features of the present invention, (A) a first heating step of heating at a temperature higher than 200 ° C. in an atmosphere having an oxygen concentration of 10% by volume or more, Furthermore, even if it carries out at temperature higher than 300 degreeC, the maximum tensile stress of the heat resistant resin film obtained can be kept high.

Further, by using a silicon-containing diamine such as 1,3-bis (3-aminopropyl) tetramethyldisiloxane or 1,3-bis (4-anilino) tetramethyldisiloxane as the diamine component, adhesion to the support is achieved. And resistance to oxygen plasma used for cleaning and UV ozone treatment can be increased. These silicon-containing diamine compounds are preferably used in an amount of 1 to 30 mol% of the total diamine compound.

In the diamine compound exemplified above, a part of hydrogen contained in the diamine compound is a hydrocarbon group having 1 to 10 carbon atoms such as a methyl group or an ethyl group, or a fluoroalkyl group having 1 to 10 carbon atoms such as a trifluoromethyl group. , F, Cl, Br, I and the like may be substituted. Furthermore, when substituted with an acidic group such as OH, COOH, SO ₃ H, CONH ₂ , or SO ₂ NH ₂ , the solubility of the resin in an aqueous alkali solution is improved, so that it is used as a photosensitive resin composition described later. Preferred in some cases.

The weight average molecular weight of the precursor of the heat-resistant resin in the present invention is preferably adjusted to 100000 or less, more preferably 80000 or less, and still more preferably 50000 or less in terms of polystyrene using gel permeation chromatography. If it is this range, even if it is a high concentration varnish, it can suppress more that a viscosity increases. Further, the weight average molecular weight is preferably 2000 or more, more preferably 3000 or more, and further preferably 5000 or more. If the weight average molecular weight is 2000 or more, the viscosity when used as a varnish will not be excessively lowered, and better coating properties can be maintained.

In the chemical formula (1), m represents the number of repeating polyimide units, and may be in a range satisfying the weight average molecular weight of the heat resistant resin in the present invention. m is preferably 5 or more, more preferably 10 or more. Moreover, it is preferably 500 or less, more preferably 200 or less.

The precursor of the heat-resistant resin in the present invention can be used as a varnish by further dissolving in a solvent. As described later, a film containing a precursor of a heat resistant resin can be formed by applying such varnish on various supports. A heat resistant resin film can be produced by converting the precursor of the heat resistant resin contained in the film into a heat resistant resin. Solvents include aprotic polar solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, propylene glycol monomethyl ether, propylene Glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether and other ethers, acetone, methyl ethyl ketone, diisobutyl ketone, diacetone alcohol, cyclohexanone and other ketones, ethyl acetate, propylene glycol monomethyl ether Esters such as acetate and ethyl lactate, toluene, Emissions, etc. aromatic hydrocarbons such as alone or mixture of two or more thereof may be used.

The content of the solvent is preferably 50 parts by mass or more, more preferably 100 parts by mass or more, preferably 2000 parts by mass or less, more preferably 1500 parts by mass with respect to 100 parts by mass of the heat-resistant resin precursor. It is as follows. If it is the range which satisfy | fills this condition, it will become a viscosity suitable for application | coating and the film thickness after application | coating can be adjusted easily.

The solution containing the precursor of the heat-resistant resin in the present invention preferably contains at least one of (a) a photoacid generator, (b) a compound containing a phenolic hydroxyl group, and (c) a surfactant.

The varnish in the present invention can be made into a photosensitive resin composition by further containing (a) a photoacid generator. By containing the photoacid generator, an acid is generated in the light irradiation part, the solubility of the light irradiation part in the alkaline aqueous solution is increased, and a positive relief pattern in which the light irradiation part is dissolved can be obtained. In addition, by containing a photoacid generator and an epoxy compound or a thermal cross-linking agent described later, the acid generated in the light irradiation part accelerates the cross-linking reaction of the epoxy compound or the heat cross-linking agent, and the light irradiation part becomes insoluble. The relief pattern can be obtained.

Examples of photoacid generators include quinonediazide compounds, sulfonium salts, phosphonium salts, diazonium salts, and iodonium salts. Two or more of these may be contained, and a highly sensitive photosensitive resin composition can be obtained.

The quinonediazide compound includes a polyhydroxy compound in which a sulfonic acid of quinonediazide is bonded with an ester, a polyamino compound in which a sulfonic acid of quinonediazide is bonded to a sulfonamide, and a sulfonic acid of quinonediazide in an ester bond and / or sulfone. Examples include amide-bonded ones. It is preferable that 50 mol% or more of the total functional groups of these polyhydroxy compounds and polyamino compounds are substituted with quinonediazide.

In the present invention, quinonediazide is preferably a 5-naphthoquinonediazidesulfonyl group or a 4-naphthoquinonediazidesulfonyl group. The 4-naphthoquinonediazide sulfonyl ester compound has absorption in the i-line region of a mercury lamp and is suitable for i-line exposure. The 5-naphthoquinonediazide sulfonyl ester compound has an absorption extending to the g-line region of a mercury lamp and is suitable for g-line exposure. In the present invention, it is preferable to select a 4-naphthoquinone diazide sulfonyl ester compound or a 5-naphthoquinone diazide sulfonyl ester compound depending on the wavelength to be exposed. In addition, a naphthoquinone diazide sulfonyl ester compound containing a 4-naphthoquinone diazide sulfonyl group and a 5-naphthoquinone diazide sulfonyl group in the same molecule may be contained, or the 4-naphthoquinone diazide sulfonyl ester compound and the 5 -It may contain a naphthoquinonediazide sulfonyl ester compound.

Of the photoacid generators, sulfonium salts, phosphonium salts, and diazonium salts are preferable because they moderately stabilize the acid component generated by exposure. Of these, sulfonium salts are preferred. Furthermore, it can also contain a sensitizer etc. as needed.

In the present invention, the content of the photoacid generator is preferably 0.01 to 50 parts by mass with respect to 100 parts by mass of the precursor of the heat resistant resin from the viewpoint of increasing sensitivity. Of these, the quinonediazide compound is preferably 3 to 40 parts by mass. The total amount of sulfonium salt, phosphonium salt and diazonium salt is preferably 0.5 to 20 parts by mass.

The photosensitive resin composition in the present invention contains a thermal crosslinking agent represented by the following chemical formula (31) or a thermal crosslinking agent having a structure represented by the following chemical formula (32) (hereinafter also referred to as a thermal crosslinking agent). May be. These thermal cross-linking agents can cross-link the heat-resistant resin or its precursor and other additive components, and can increase the chemical resistance and hardness of the resulting heat-resistant resin film.

In the chemical formula (31), R ³¹ represents a divalent to tetravalent linking group. R ³² represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, Cl, Br, I or F. R ³³ and R ³⁴ each independently represents CH ₂ OR ³⁶ (R ³⁶ is hydrogen or a monovalent hydrocarbon group having 1 to 6 carbon atoms). R ³⁵ represents hydrogen, a methyl group or an ethyl group. s represents an integer of 0 to 2, and t represents an integer of 2 to 4. The plurality of R ³² may be the same or different. The plurality of R ³³ and R ³⁴ may be the same or different. The plurality of R ³⁵ may be the same or different. Examples of the linking group ^{R 31} shown below.

In the above chemical formula, R ⁴¹ to R ⁶⁰ are hydrogen, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a hydrocarbon group in which part of hydrogen of these hydrocarbon groups is substituted with Cl, Br, I or F. Indicates.

In the chemical formula (32), R ³⁷ represents hydrogen or a monovalent hydrocarbon group having 1 to 6 carbon atoms. u represents 1 or 2, and v represents 0 or 1. However, u + v is 1 or 2.

In the chemical formula (31), R ³³ and R ³⁴ represent CH ₂ OR ³⁶ which is a thermally crosslinkable group. R ³⁶ is preferably a monovalent hydrocarbon group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, because the thermal crosslinking agent represented by the chemical formula (31) leaves moderate reactivity and is excellent in storage stability. preferable.

Preferred examples of the thermal crosslinking agent including the structure represented by the chemical formula (31) are shown below.

In the chemical formula (32), R ³⁷ is preferably a monovalent hydrocarbon group having 1 to 4 carbon atoms. From the viewpoint of stability of the compound and storage stability in the photosensitive resin composition, R ³⁷ is preferably a methyl group or an ethyl group, and the number of (CH ₂ OR ³⁷ ) groups contained in the compound is 8 or less. It is preferable.

Preferred examples of the thermal crosslinking agent containing a group represented by the chemical formula (32) are shown below.

The content of the thermal crosslinking agent is preferably 10 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the heat-resistant resin precursor. If content of a thermal crosslinking agent is 10 mass parts or more and 100 mass parts or less, the intensity | strength of the obtained heat resistant resin film is high, and it is excellent also in the storage stability of the photosensitive resin composition.

The varnish in the present invention may further contain a thermal acid generator. The thermal acid generator generates an acid by heating after development, which will be described later, and promotes a crosslinking reaction between the precursor of the heat resistant resin and the thermal crosslinking agent, and also promotes a curing reaction of the precursor of the heat resistant resin. For this reason, the chemical resistance of the resulting heat-resistant resin film is improved, and film loss can be reduced. The acid generated from the thermal acid generator is preferably a strong acid. For example, arylsulfonic acids such as p-toluenesulfonic acid and benzenesulfonic acid, and alkylsulfonic acids such as methanesulfonic acid, ethanesulfonic acid, and butanesulfonic acid are preferable. In the present invention, the thermal acid generator is preferably an aliphatic sulfonic acid compound represented by the chemical formula (33) or (34), and may contain two or more of these.

In the above chemical formulas (33) and (34), R ⁶¹ to R ⁶³ may be the same or different and each represents an organic group having 1 to 20 carbon atoms, preferably a hydrocarbon group having 1 to 20 carbon atoms. . Further, it may be an organic group having 1 to 20 carbon atoms containing hydrogen and carbon as essential components and containing one or more atoms selected from boron, oxygen, sulfur, nitrogen, phosphorus, silicon and halogen.

Specific examples of the compound represented by the chemical formula (33) include the following compounds.

Specific examples of the compound represented by the chemical formula (34) include the following compounds.

The content of the thermal acid generator is preferably 0.5 parts by mass or more and preferably 10 parts by mass or less with respect to 100 parts by mass of the heat-resistant resin precursor from the viewpoint of further promoting the crosslinking reaction.

If necessary, (b) a compound containing a phenolic hydroxyl group may be contained for the purpose of supplementing the alkali developability of the photosensitive resin composition. Examples of the compound containing a phenolic hydroxyl group include those having the following trade names (Bis-Z, BisOC-Z, BisOPP-Z, BisP-CP, Bis26X-Z, BisOTBP-Z, manufactured by Honshu Chemical Industry Co., Ltd.) BisOCHP-Z, BisOCR-CP, BisP-MZ, BisP-EZ, Bis26X-CP, BisP-PZ, BisP-IPZ, BisCR-IPZ, BisOCP-IPZ, BisOIPP-CP, Bis26X-IPZ, BisOTBP-CP, TekP- 4HBPA (Tetrakis P-DO-BPA), TrisP-HAP, TrisP-PA, TrisP-PHBA, TrisP-SA, TrisOCR-PA, BisOFP-Z, BisRS-2P, BisPG-26X, BisRS-3P, BisOC-OC P, BisPC-OCHP, Bis25X-OCHP, Bis26X-OCHP, BisOCHP-OC, Bis236T-OCHP, Methylenetris-FR-CR, BisRS-26X, BisRS-OCHP), manufactured by Asahi Organic Materials Co., Ltd. Names (BIR-OC, BIP-PC, BIR-PC, BIR-PTBP, BIR-PCHP, BIP-BIOC-F, 4PC, BIR-BIPC-F, TEP-BIP-A), 1,4-dihydroxy Naphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,4-dihydroxyquinoline 2,6-dihydroxy Phosphorus, 2,3-dihydroxy quinoxaline, anthracene -1,2,10- triol, anthracene -1,8,9- triols, such as 8-quinolinol, and the like. By containing these phenolic hydroxyl group-containing compounds, the resulting photosensitive resin composition hardly dissolves in an alkali developer before exposure, and easily dissolves in an alkali developer upon exposure. There is little film loss and development can be easily performed in a short time. Therefore, the sensitivity is easily improved.

The content of such a compound containing a phenolic hydroxyl group is preferably 3 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the precursor of the heat resistant resin.

The varnish in the present invention may contain an adhesion improving agent. As adhesion improvers, vinyltrimethoxysilane, vinyltriethoxysilane, epoxycyclohexylethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, Examples include silane coupling agents such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane, titanium chelating agents, and aluminum chelating agents. In addition to these, alkoxysilane-containing aromatic amine compounds, alkoxysilane-containing aromatic amide compounds and the like as shown below can be mentioned.

A compound obtained by reacting an aromatic amine compound and an alkoxy group-containing silicon compound can also be used. Examples of such compounds include compounds obtained by reacting an aromatic amine compound with an alkoxysilane compound containing a group that reacts with an amino group such as an epoxy group or a chloromethyl group. You may contain 2 or more types of the adhesion improving agent mentioned above. By containing these adhesion improving agents, adhesion to an underlying substrate such as a silicon wafer, ITO, SiO ₂ or silicon nitride can be improved when developing a photosensitive resin film. In addition, by improving the adhesion between the heat-resistant resin film and the underlying base material, resistance to oxygen plasma and UV ozone treatment used for cleaning can be increased. The content of the adhesion improving agent is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the heat-resistant resin precursor.

The varnish in the present invention can contain inorganic particles for the purpose of improving heat resistance. Inorganic particles used for such purposes include inorganic metal particles such as platinum, gold, palladium, silver, copper, nickel, zinc, aluminum, iron, cobalt, rhodium, ruthenium, tin, lead, bismuth, tungsten, and silicon oxide. (Silica), titanium oxide, aluminum oxide, zinc oxide, tin oxide, tungsten oxide, zirconium oxide, calcium carbonate, barium sulfate, and other metal oxide inorganic particles. The shape of the inorganic particles is not particularly limited, and examples thereof include a spherical shape, an elliptical shape, a flat shape, a lot shape, and a fiber shape. In order to suppress an increase in the surface roughness of the heat resistant resin film containing inorganic particles, the average particle size of the inorganic particles is preferably 1 nm to 100 nm, and more preferably 1 nm to 50 nm. More preferably, it is 1 nm or more and 30 nm or less.

The content of the inorganic particles is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, and preferably 100 parts by mass or less, with respect to 100 parts by mass of the precursor of the heat resistant resin. More preferably, it is 80 mass parts or less, More preferably, it is 50 mass parts or less. When the content of the inorganic particles is 3 parts by mass or more, the heat resistance is sufficiently improved, and when the content is 100 parts by mass or less, the toughness of the fired film is hardly lowered.

The varnish in the present invention preferably contains (c) a surfactant in order to improve applicability. As surfactants, “Florard” (registered trademark) manufactured by Sumitomo 3M Co., Ltd., “Megafac” (registered trademark) manufactured by DIC Corporation, “sulfuron” (registered trademark) manufactured by Asahi Glass Co., Ltd., etc. Fluorosurfactant, Shin-Etsu Chemical Co., Ltd. KP341, Chisso Co., Ltd. DBE, Kyoeisha Chemical Co., Ltd. “Polyflow” (registered trademark), “Granol” (registered trademark), Examples thereof include organic siloxane surfactants such as BYK manufactured by Chemie Corp. and acrylic polymer surfactants such as polyflow manufactured by Kyoeisha Chemical Co., Ltd. The surfactant is preferably contained in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the heat-resistant resin precursor.

Generally, (a) a photoacid generator, (b) a compound containing a phenolic hydroxyl group, and (c) a surfactant are likely to cause outgassing by remaining in a small amount after heating as described later. However, according to the method for producing a heat-resistant resin film of the present invention, even when the solution containing the precursor of the heat-resistant resin contains a surfactant, the heat resistance has little outgas and has excellent mechanical properties. A resin film can be obtained.

The precursor of the heat resistant resin can be polymerized by a known method. For example, in the case of a polyimide preferably used in the present invention, tetracarboxylic acid or a corresponding acid dianhydride, active ester, active amide or the like as an acid component, and diamine or a corresponding trimethylsilylated diamine or the like as a diamine component in a reaction solvent. By polymerizing, a precursor polyamic acid can be obtained. The polyamic acid may be one in which a carboxyl group is esterified with a hydrocarbon group having 1 to 10 carbon atoms or an alkylsilyl group having 1 to 10 carbon atoms.

Reaction solvents include aprotic polar solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, propylene glycol monomethyl ether, propylene Glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol ethyl methyl ether, ethers such as diethylene glycol dimethyl ether, ketones such as acetone, methyl ethyl ketone, diisobutyl ketone, diacetone alcohol, cyclohexanone, ethyl acetate, propylene glycol monomethyl ether acetate , Esters such as ethyl lactate, toluene, Can be used alone, or two or more such aromatic hydrocarbons such as Ren. Furthermore, by using the same solvent as the varnish, the target varnish can be obtained without isolating the resin after production.

Next, a method for producing a solution containing the precursor of the heat resistant resin film in the present invention (hereinafter referred to as varnish) will be described. For example, a varnish can be obtained by dissolving a precursor of a heat resistant resin, and if necessary, a photoacid generator, a dissolution regulator, an adhesion improver, inorganic particles or a surfactant in a solvent. Examples of the dissolution method include stirring and heating. When the photoacid generator is included, the heating temperature is preferably set in a range that does not impair the performance as the photosensitive resin composition, and is usually room temperature to 80 ° C. In addition, the dissolution order of each component is not particularly limited, and for example, there is a method of sequentially dissolving compounds having low solubility. In addition, for components that tend to generate bubbles when stirring and dissolving, such as surfactants and some adhesion improvers, by dissolving other components and adding them last, poor dissolution of other components due to the generation of bubbles Can be prevented.

The obtained varnish is preferably filtered using a filter to remove foreign matters such as dust. Examples of the filter pore diameter include, but are not limited to, 10 μm, 3 μm, 1 μm, 0.5 μm, 0.2 μm, 0.1 μm, 0.07 μm, and 0.05 μm. Examples of the material for the filter include polypropylene (PP), polyethylene (PE), nylon (NY), polytetrafluoroethylene (PTFE), and polyethylene and nylon are preferable.

<Method for producing heat-resistant resin film>
Next, the manufacturing method of the heat resistant resin film of this invention is demonstrated. A method for producing a heat-resistant resin film, which is one of the features of the present invention, includes a step of applying a solution containing a precursor of a heat-resistant resin on a support and a step of heating in multiple stages. And (B) oxygen in which the step of heating in the multi-stage is at least (A) heating at a temperature higher than 200 ° C. in an atmosphere having an oxygen concentration of 10% by volume or more. A method for producing a heat-resistant resin film, comprising a second heating step of heating at a temperature higher than that of the first heating step in an atmosphere having a concentration of 3% by volume or less in the above order.

First, a varnish containing a precursor of a heat resistant resin is applied on a support. Examples of the support include a wafer substrate such as silicon and gallium arsenide, a glass substrate such as sapphire glass, soda-lime glass, and non-alkali glass, a metal substrate such as stainless steel and copper, a metal foil, and a ceramic substrate. Not.

Examples of varnish coating methods include spin coating, slit coating, dip coating, spray coating, and printing, and these may be combined. Prior to application, the support may be pretreated with the adhesion improving agent described above in advance. For example, a solution obtained by dissolving 0.5-20% by mass of an adhesion improver in a solvent such as isopropanol, ethanol, methanol, water, tetrahydrofuran, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, diethyl adipate, etc. Examples thereof include a method of treating the surface of the support by a method such as spin coating, slit die coating, bar coating, dip coating, spray coating, or steam treatment. If necessary, a drying treatment under reduced pressure is performed, and then the reaction between the support and the adhesion improving agent can be advanced by heating at 50 ° C. to 300 ° C.

After coating, it is common to dry the coating film of varnish. As a drying method, vacuum drying, heat drying, or a combination thereof can be used. As a method for drying under reduced pressure, for example, a support body on which a coating film is formed is placed in a vacuum chamber, and the inside of the vacuum chamber is decompressed. Heat drying is performed by using an apparatus such as a hot plate or an oven and treating with infrared rays or hot air. When a hot plate is used, the coating film is held directly on the plate or on a jig such as a proxy pin installed on the plate and dried by heating.

As the material of the proxy pin, there is a metal material such as aluminum or stainless steel, or a synthetic resin such as polyimide resin or “Teflon” (registered trademark). Any material can be used as long as it has heat resistance. . The height of the proxy pin can be selected variously depending on the size of the support, the type of solvent used in the varnish, the drying method, etc., but is preferably about 0.1 to 10 mm. The heating temperature varies depending on the type and purpose of the solvent used in the varnish, and it is preferably performed in the range of room temperature to 180 ° C. for 1 minute to several hours.

When the varnish in the present invention contains a photoacid generator, a pattern can be formed from the dried coating film by the method described below. The coating film is exposed to actinic radiation through a mask having a desired pattern. As the actinic radiation used for exposure, there are ultraviolet rays, visible rays, electron beams, X-rays and the like. In the present invention, it is preferable to use i rays (365 nm), h rays (405 nm), and g rays (436 nm) of a mercury lamp. . When it has positive photosensitivity, the exposed portion is dissolved in the developer. When it has negative photosensitivity, the exposed area is cured and insolubilized in the developer.

After exposure, a desired pattern is formed by removing an exposed portion in the case of a positive type and a non-exposed portion in the case of a negative type using a developer. As a developer, in both positive and negative types, tetramethylammonium, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine, dimethylamino acetate An aqueous solution of an alkaline compound such as ethyl, dimethylaminoethanol, dimethylaminoethyl methacrylate, cyclohexylamine, ethylenediamine, and hexamethylenediamine is preferred. In some cases, these alkaline aqueous solutions may contain polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, dimethylacrylamide, methanol, ethanol, Alcohols such as isopropanol, esters such as ethyl lactate and propylene glycol monomethyl ether acetate, ketones such as cyclopentanone, cyclohexanone, isobutyl ketone, and methyl isobutyl ketone may be added singly or in combination. Good.

In the negative type, the above polar solvent not containing an alkaline aqueous solution, alcohols, esters, ketones or the like can be used alone or in combination. After development, it is common to rinse with water. Here, alcohols such as ethanol and isopropyl alcohol, and esters such as ethyl lactate and propylene glycol monomethyl ether acetate may be added to water for rinsing treatment.

Next, multistage heating, which is a feature of the method for producing a heat resistant resin film of the present invention, is performed. In the step of performing the multi-stage heating, heating is performed in a range of 180 ° C. or more, and the coating film is made into a heat resistant resin film. The heating process in the present invention requires heating in multiple stages, and at least (A) a first heating process for heating at a temperature higher than 200 ° C. in an atmosphere having an oxygen concentration of 10% by volume or more and (B) It is necessary to include, in the above order, the second heating step of heating at a temperature higher than that of the first heating step in an atmosphere having an oxygen concentration of 3% or less. The reason is as follows.

When the varnish in the present invention contains a precursor other than a heat-resistant resin and a solvent, or when an unreacted monomer component is present, the component or its decomposition product remains in the heat-resistant resin film, Outgas characteristics may be degraded. A compound containing a photoacid generator and a phenolic hydroxyl group is unlikely to cause outgassing because it does not have a bonding point with a heat resistant resin or a substrate, unlike a thermal crosslinking agent or an adhesion improver. Further, as described above, the surfactant is often a resin such as an acrylic polymer or polyoxyethylene alkyl ether. These leave the oligomer component and monomer component decomposed in the heat resistant resin film, and cause the outgas characteristics of the heat resistant resin film to deteriorate. Therefore, it is preferable to oxidize components that cause outgas and promote decomposition and vaporization by heating in an atmosphere in which oxygen molecules are present in the first heating step.

The range of oxygen concentration in the first heating step is 10% by volume or more, more preferably 15% by volume or more. If the oxygen concentration range is 10% by volume or more, the components that cause outgassing can be oxidized by the oxidation reaction to promote decomposition and vaporization. The oxygen concentration range in the first heating step is preferably 22% by volume or less. If the oxygen concentration range is 22% by volume or less, the first heating step can be performed in the atmosphere, and there is almost no need to introduce oxygen gas into the heating atmosphere.

The heating temperature in the first step needs to be equal to or higher than the temperature necessary to cure the precursor of the heat resistant resin. Specifically, a temperature higher than 200 ° C. is necessary. Moreover, it is preferable that the heating temperature in a 1st heating process is lower than the temperature which the heat resistant resin oxidizes. Specifically, it is preferably 420 ° C. or lower, more preferably 370 ° C. or lower, and further preferably 320 ° C. or lower.

On the other hand, in order to improve the mechanical properties of the heat resistant resin film, it is preferable to increase the heating temperature. However, when the heating temperature is increased in an atmosphere where oxygen molecules are present, oxidation of the heat resistant resin and decomposition due to the oxidation occur, and it becomes difficult to obtain good physical properties. Therefore, by heating in an atmosphere having a low oxygen concentration in the second heating step, the mechanical characteristics can be improved while suppressing oxidation and decomposition of the heat resistant resin.

The range of the oxygen concentration in the second heating step is 3% by volume or less, more preferably 1% by volume or less, and still more preferably 0.1% by volume or less. If the oxygen concentration range is 3% by volume or less, the resin can be prevented from deteriorating even if the heating temperature in the second step is 300 ° C. or higher. Further, the oxygen concentration range in the second heating step is preferably 0.000001% by volume or more, more preferably 0.00001% by volume or more, and further preferably 0.0001% by volume or more. If the range of oxygen concentration is 0.000001 volume% or more, it can prevent that the usage-amount of inert gas increases extremely and a burden is applied to a vacuum pump.

The heating temperature in the second step needs to be higher than the maximum temperature of the first heating step, specifically 300 ° C or higher, more preferably 350 ° C or higher, more preferably 400 ° C or higher. is there. On the other hand, it is preferable that the heating temperature in a 2nd heating process does not exceed the decomposition temperature of resin, specifically 600 degreeC or less is preferable and 550 degreeC or less is more preferable.

The step of heating in multiple steps in the method for producing a heat resistant resin film of the present invention may include three or more heating steps. When an additional heating step is provided before the first heating step, the heating is preferably performed at a temperature lower than that of the first heating step in an atmosphere having an oxygen concentration higher than that of the first heating step. . When an additional step is provided after the second heating step, it is preferable that heating is performed at a temperature higher than that of the second heating step in an atmosphere having an oxygen concentration equal to or lower than that of the second heating step.

As the heating method, any of the methods described in the above-mentioned heat drying can be suitably used. That is, it is preferable to use an apparatus such as a hot plate or an oven and treat with hot air or infrared rays.

After the completion of all heating steps, cooling is performed and the heat-resistant resin film is taken out from the apparatus. Cooling includes a method in which heating by the apparatus is stopped and natural cooling is performed, or a cooling unit provided in the apparatus is forcibly cooled. When taking out manually after cooling, it is preferable to cool to room temperature. However, if it is not limited to this, it may be taken out at a temperature higher than room temperature. However, it is preferable to carry out within a range in which the physical properties of the heat resistant resin film are not greatly reduced. Further, the atmosphere in the apparatus at the time of cooling is preferably a state in which the atmosphere immediately after the end of the heating process is maintained. However, the atmosphere in the apparatus may be replaced with air when the temperature in the apparatus is cooled to a predetermined temperature or lower. Also in this case, it is preferable to determine the temperature to be substituted with the atmosphere within a range in which the physical properties of the heat resistant resin film are not greatly reduced.

<Heating furnace>
Next, the heating furnace which is one of the features of the present invention will be described. This furnace is
A temperature measurement unit for measuring the temperature in the furnace;
A temperature adjusting unit for adjusting the temperature in the furnace;
An oxygen concentration measuring unit for measuring the oxygen concentration in the furnace;
A gas flow rate adjusting unit for adjusting the flow rate of the heating atmosphere gas into the furnace;
A control unit for controlling the temperature adjusting unit and the gas flow rate adjusting unit;
A heating furnace comprising:
The controller is
While controlling the gas flow rate adjustment unit according to the oxygen concentration in the furnace measured by the oxygen concentration measurement unit,
The temperature adjusting unit is controlled so that the temperature in the furnace measured by the temperature measuring unit after the oxygen concentration reaches a predetermined oxygen concentration becomes a predetermined temperature.

An embodiment of the heating furnace of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a heating furnace 10 which is an embodiment of the heating of the present invention.

Gas supply pipes 41 and 51 and an exhaust pipe 61 are connected to the furnace body 11 for arranging the heated body. The gas supply pipes 41 and 51 are provided with gas flow rate adjusting units, respectively, and a purge on / off valve 42 and 52, a purge flow rate adjusting valve 43 and 53, a running on / off valve 44 and 54, and a running flow rate adjusting valve, respectively. 45 and 55. The exhaust pipe 61 is also provided with an exhaust opening / closing valve 62 and an exhaust flow rate adjusting valve 63.

The purge on-off valve is opened particularly when the atmosphere in the furnace 12 filled with a gas different from the supply gas is rapidly replaced with the supply gas. For this reason, it is necessary that a sufficiently large gas flow rate is set by the purge flow rate adjusting valve so that the inside of the furnace 12 can be replaced with the supply gas. On the other hand, the running on-off valve is opened particularly when supplying gas in order to maintain the atmosphere in the furnace 12. For this reason, it is sufficient that the gas flow rate capable of maintaining the atmosphere in the furnace 12 is set by the running flow rate adjustment valve, and usually a gas flow rate lower than the flow rate set by the purge flow rate control valve is set.

The furnace body 11 is provided with a temperature measuring unit 22 and a heating unit 23. The temperature measuring unit 22 and the heating unit 23 are connected to the temperature adjusting unit 21 through an electrical connection indicated by a broken line. Further, the temperature adjustment unit 21 is electrically connected to the control unit 71.

In addition, the heating furnace 10 is provided with an oxygen concentration measuring unit for measuring the oxygen concentration, and includes an oxygen concentration meter 31 and a gas sampling port 32 for collecting the gas in the furnace 12. The oxygen concentration meter 31 is also connected to the control unit 71 via an electrical connection indicated by a broken line. Further, a user interface 81 that can set a program in advance for automatically executing the heating process under a predetermined condition is provided, which is also electrically connected to the control unit 71.

Although not shown, the gas flow rate adjusting unit is also connected to the control unit 71 via an electrical connection, and the on / off valves 42, 44, 52, 54, and 62 are opened and closed electrically from the control unit 71. Controlled by signal. Although not shown, the furnace body 11 is provided with an opening / closing door for taking in and out the heated body.

The control unit 71 controls at least the temperature adjustment unit 21 and the gas flow rate adjustment unit. Specifically, the gas flow rate adjusting unit is controlled in accordance with the oxygen concentration in the furnace 12 measured by the oxygen concentration measuring unit, and the temperature measuring unit after the oxygen concentration in the furnace 12 reaches a predetermined oxygen concentration. The temperature adjusting unit 21 is controlled so that the temperature in the furnace 12 measured in step 1 becomes a predetermined temperature.

At this time, it is preferable that the control unit 71 can control the temperature adjusting unit 21 and the gas flow rate adjusting unit so as to continuously perform the multi-step heating process. For example, at least a first heating step in which heating is performed at a first temperature in a first oxygen concentration atmosphere and a second heating step in which heating is performed at a second temperature in a second oxygen concentration atmosphere. In the multi-stage heating process including the above order, it is preferable that the control unit 71 can control the gas flow rate adjusting unit and the temperature adjusting unit 21 so as to continuously perform the first heating process and the second heating process.

Hereinafter, the case where the heat-resistant resin film of the present invention is manufactured using the heating furnace 10 will be described, and the function of each part will also be described. As an example, a two-step heating process is performed, and the first heating process and the second heating process are performed in the atmosphere (oxygen concentration 21 vol%) and nitrogen (oxygen concentration 0.01 vol% or less), respectively. I will do it.

First, the gas supply pipes 41 and 51 are connected to nitrogen and air supply lines, respectively. Subsequently, a coating film obtained by applying and drying a solution containing the above-described precursor of the heat-resistant resin film on the substrate is placed in the furnace body 11. A heating process program is set via the user interface 81.

After completing the above preparations, start the heating process. Since the furnace 12 is filled with air at the start time, the first heating step is started. If the inside of the furnace 12 does not have the same oxygen concentration as the atmosphere, it is detected by the oximeter 31 and a signal is sent from the control unit 71 to the purge opening / closing valve 52 to open the valve and purge the atmosphere into the furnace 12. To do. When the inside of the furnace 12 is filled with the atmosphere and the oximeter 31 detects this, the purge on-off valve 52 is closed by the signal from the control unit 71 and the supply of the atmosphere is stopped. During the first heating step, the purge on-off valve 42 and the running on-off valve 44 provided in the gas supply pipe 41 for supplying nitrogen are both closed.

In a state where the furnace 12 is filled with the atmosphere, a signal is sent from the control unit 71 to the temperature adjustment unit 21, and the temperature rise is started according to a preset program. During heating, the temperature measuring unit 22 always monitors the temperature in the furnace 12 and the temperature adjusting unit 21 controls the heating unit 23 so that heating can be performed as programmed. Since outgas is generated from the coating film during the first heating step, the atmosphere is always supplied from the gas supply pipe 51 for supplying air to the furnace 12, and the outgas from the coating film is exhausted together with the atmosphere in the furnace 12. It is preferable to discharge from 61. Therefore, it is preferable that the running on-off valve 54 of the gas supply pipe 51 is open during heating.

It is more preferable that the running flow rate adjustment valve 55 and the exhaust flow rate adjustment valve 63 are adjusted so that the atmosphere in the furnace 12 is always positive. When the pressure in the furnace 12 is negative, outside air may enter the furnace 12 through a gap between the doors.

During the first heating step, the oxygen concentration meter 31 can always monitor the oxygen concentration in the furnace 12. If a decrease in oxygen concentration is detected, a signal is sent from the control unit 71 to the gas flow rate adjustment unit, and the purge on-off valve 52 is opened to purge the atmosphere. If the oxygen concentration in the furnace 12 returns to a predetermined concentration and the oximeter 31 can detect it, a signal is sent from the control unit 71 to the gas flow rate adjustment unit, and the purge on-off valve 52 is closed to stop the purge of the atmosphere. .

The running on / off valve 54 may be closed while the purge on / off valve 52 is opened to purge the atmosphere. However, when the purge on-off valve 52 is closed to stop the purge of the atmosphere, it is preferable that the running on-off valve 54 is opened to continuously supply air.

After the completion of the first heating step, before the second heating step is started, a signal is sent from the control unit 71 to the gas flow rate adjustment unit in order to reduce the oxygen concentration in the furnace 12 to a predetermined concentration. . By this signal, both the purge on-off valve 52 and the running on-off valve 54 of the gas supply pipe 51 are closed, and the supply of air is stopped. On the other hand, the purge opening / closing valve 42 of the gas supply pipe 41 is opened to supply nitrogen into the furnace 12. The supply of nitrogen is continued until the inside of the furnace 12 becomes a predetermined oxygen concentration or less, and the start of the second heating step is often in a standby state.

When the oxygen concentration meter 31 detects that the oxygen concentration in the furnace 12 has become equal to or lower than a predetermined oxygen concentration, the signal is sent to the control unit 71, and the purge opening / closing valve 42 of the gas supply pipe 41 is sent from the control unit 71. Closed. At the same time, a signal for starting the second heating step is sent from the control unit 71 to the temperature adjusting unit 21 to start heating.

In this second heating step, outgas is generated from the coating film during heating. Therefore, nitrogen is always supplied from the gas supply pipe 41 to the furnace interior 12, and the outgas from the coating film is discharged from the exhaust pipe 61 together with the atmosphere in the furnace 12. It is preferable to discharge. Therefore, it is preferable that the running on-off valve 44 of the gas supply pipe 41 is open during heating. It is more preferable that the running flow rate adjustment valve 45 and the exhaust flow rate adjustment valve 63 are adjusted so that the atmosphere in the furnace 12 always has a positive pressure. When the pressure in the furnace 12 is negative, outside air may enter the furnace 12 through a gap between the doors.

Even during the second heating step, the oxygen concentration in the furnace 12 can always be monitored by the oxygen concentration meter 31. If an increase in oxygen concentration is detected, a signal is sent from the control unit 71 to the gas flow rate adjustment unit, and the purge on-off valve 42 is opened to purge nitrogen. When the oxygen concentration in the furnace 12 returns to a predetermined concentration or less and the oximeter 31 detects this, a signal is sent from the control unit 71 to the gas flow rate adjustment unit, and the purge on-off valve 42 is closed to purge nitrogen. Stop.

After the second heating process is completed, cooling of the furnace 12 begins. When a signal is sent from the control unit 71 to the temperature adjustment unit 21 and heating in the heating unit 23 is stopped according to the signal, cooling starts naturally. Depending on the case, a heating furnace in which a cooling unit (not shown) electrically connected to the temperature adjusting unit 21 is provided in the furnace body 11 may be used. Due to the action of the cooling section, the temperature in the furnace 12 can be forcibly lowered.

When the temperature in the furnace 12 falls below a predetermined temperature, an operation of replacing the atmosphere in the furnace 12 with the atmosphere is started. The work is performed as follows, for example. The temperature measuring unit 22 detects that the temperature in the furnace 12 has become equal to or lower than a predetermined temperature according to the program set in the user interface 81. The signal is transmitted to the control unit 71 via the temperature adjustment unit 21. Subsequently, a signal is sent from the control unit 71 to the gas flow rate adjusting unit, the purge on-off valve 42 and the running on-off valve 44 provided in the gas supply pipe 41 are closed, and the supply of nitrogen to the furnace 12 is stopped. . At the same time, the purge opening / closing valve 52 provided in the gas supply pipe 51 is opened, and the supply of air to the furnace 12 is started.

During cooling, the temperature and oxygen concentration in the furnace 12 are monitored by the temperature measuring unit 22 and the oxygen concentration meter 31, and the temperature in the furnace 12 has dropped below a predetermined temperature set by the program. All of the steps are completed when the atmosphere of 12 reaches almost the same oxygen concentration as the atmosphere. After that, the coating film is taken out from the open / close door provided in the furnace body 11. During the heating process, it is preferable that the open / close door is in a locked state, and a mechanism in which the lock is released when all the processes are completed and the heated object can be taken out is preferable.

Although an example of a heating furnace which is one of the features of the present invention has been described above, the present invention is not limited only by this example. In the above example, the gas flow rate adjustment unit is controlled by the control unit 71 and automatically opens and closes the on-off valves 42, 44, 52, 54 and 62 according to a program set in advance via the user interface 81. It is a mechanism to do. The flow rate adjusting valves 43, 45, 53, 55 and 63 may be adjusted in advance and not changed during the heating process, or may be automatically adjusted.

Also, it is necessary to keep the oxygen concentration meter 31 in operation in order to monitor the oxygen concentration during heating. However, there is a possibility that it is difficult to measure an accurate oxygen concentration or the oxygen concentration meter 31 is contaminated by outgas from the heated object. In order to prevent this, it is preferable to provide a cold trap between the gas sampling port 32 and the oximeter 31. By providing the cold trap, the outgas from the object to be heated can be trapped and an accurate oxygen concentration can be measured. Further, the possibility that the oximeter 31 is contaminated is reduced.

The heat-resistant resin film obtained by the present invention includes a surface protective film and an interlayer insulating film of a semiconductor element, an insulating layer and a spacer layer of an organic electroluminescence element (organic EL element), a planarization film of a thin film transistor substrate, and an insulating film of an organic transistor. It is suitably used for a layer, a flexible printed circuit board, a flexible display substrate, a flexible electronic paper substrate, a flexible solar cell substrate, a flexible color filter substrate, and the like. Especially for image display devices such as organic EL, electronic paper, and color filters, heat resistance (outgas characteristics, glass transition temperature, etc.) to the temperature of the manufacturing process and toughness are imparted to the image display device after manufacture. Since the heat-resistant resin film has mechanical properties suitable for the above, it can be preferably used as those substrates.

A method of using the heat resistant resin film obtained by the production method of the present invention as a substrate of an image display device will be described. First, a heat resistant resin film is produced on a support such as a glass substrate by the production method of the present invention.

Subsequently, pixel driving elements or colored pixels are formed on the heat resistant resin film. For example, in the case of an organic EL display, a TFT, which is an image driving element, a first electrode, an organic EL light emitting element, a second electrode, and a sealing film are sequentially formed. In the case of a color filter, after forming a black matrix as necessary, colored pixels such as red, green, and blue are formed.

If necessary, a gas barrier film may be provided between the heat resistant resin film and the pixel driving element or the colored pixel. By providing the gas barrier film, it is possible to prevent moisture and oxygen from passing through the heat resistant resin film from the outside of the image display device and causing deterioration of the pixel driving element and the colored pixel. As the gas barrier film, a single film of inorganic films such as a silicon oxide film (SiOx), a silicon nitrogen film (SiNy), a silicon oxynitride film (SiOxNy), or a laminate of a plurality of types of inorganic films is used. The gas barrier film is formed by using a method such as chemical vapor deposition (CVD) or physical vapor deposition (PVD). Furthermore, as the gas barrier film, a film in which these inorganic films and organic films such as polyvinyl alcohol are alternately laminated can be used.

Finally, peeling is performed at the interface between the support and the heat resistant resin film to obtain an image display device including the heat resistant resin film. Examples of the method of peeling at the interface between the support and the heat-resistant resin film include a method using a laser, a mechanical peeling method, and a method of etching the support. In the method using a laser, peeling can be performed without damaging the image display element by irradiating the support such as a glass substrate from the side where the image display element is not formed. Moreover, you may provide the primer layer for making it easy to peel between a support body and a heat resistant resin film.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In addition, when the number of measurements was not particularly mentioned, the measurement was performed only once.

(1) Measurement of maximum tensile elongation and maximum tensile stress The glass substrate on which the heat-resistant resin film obtained in each Example and Comparative Example was laminated was immersed in hydrofluoric acid for 4 minutes to remove the heat-resistant resin film from the glass substrate. It peeled and air-dried at 50 degreeC in air | atmosphere for 1 hour. Subsequently, the maximum tensile elongation and the maximum tensile stress were determined by measuring with the following apparatus and conditions.

Measuring device: Tensilon Universal Material Testing Machine “RTM-100” (Orientec Co., Ltd.)
Measurement sample shape: Ribbon shape Measurement sample size: Length> 70 mm, width 10 mm
Pulling speed: 50mm / min
Distance between chucks at the start of the test: 50 mm
Experimental temperature: 0 to 35 ° C
Number of samples: 10
Calculation method of measurement results: An arithmetic average value of measured values of 10 samples was obtained.

(2) Measurement of outgas generated during heating for 30 minutes at 450 ° C. in a helium stream About the heat-resistant resin film obtained in each Example and Comparative Example, after reaching 450 ° C. by the following apparatus and conditions, 30 The outgas measured while holding for minutes was measured.

Measuring device: heating section “Small-4” (manufactured by Toray Research Center), GC / MS “QP5050A (7)” (manufactured by Shimadzu Corporation)
Heating condition: Temperature is raised from room temperature at 10 ° C./min and held for 30 minutes after reaching 450 ° C. Measurement atmosphere: under a helium stream (50 mL / min).

Hereinafter, abbreviations of compounds used in Synthesis Examples and Examples are described.
p-PDA: p-phenylenediamine DAE: 4,4′-diaminodiphenyl ether HAB: 3,3′-dihydroxybenzidine BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PMDA: pyromellitic acid Dianhydride ODPA: 4,4′-oxydiphthalic dianhydride TPC: terephthalic acid dichloride NMP: N-methyl-2-pyrrolidone THPE: 1,1,1-tris (4-hydroxyphenyl) ethane surfactant b: BYK-350 (manufactured by BYK-Chemie GmbH)
Surfactant c: Megafax F-444 (DIC Corporation)
Surfactant d: Polyflow 77 (manufactured by Kyoeisha Chemical Co., Ltd.).

A thermometer and a stirring rod with stirring blades were set in a 200 mL four-necked flask. Next, 90 g of NMP was added under a dry nitrogen stream, and the temperature was raised to 60 ° C. After the temperature was raised, 5.407 g (50.00 mmol) of p-PDA was added with stirring, and washed with 15 g of NMP. After confirming that p-PDA was dissolved, 14.49 g (49.25 mmol) of BPDA was added and washed with 15 g of NMP.

Synthesis example 2:
A thermometer and a stirring rod with stirring blades were set in a 200 mL four-necked flask. Next, 90 g of NMP was added under a dry nitrogen stream, and the temperature was raised to 40 ° C. After raising the temperature, 10.01 g (50.00 mmol) of DAE was added while stirring and washed with 15 g of NMP. After confirming that DAE was dissolved, 10.74 g (49.25 mmol) of PMDA was added and washed with 15 g of NMP. Cooled after 4 hours.

Synthesis Example 3:
A thermometer and a stirring rod with stirring blades were set in a 200 mL four-necked flask. Next, 90 g of NMP was added under a dry nitrogen stream, and the temperature was raised to 60 ° C. After the temperature was raised, 5.407 g (50.00 mmol) of p-PDA was added with stirring, and washed with 15 g of NMP. After confirming that p-PDA was dissolved, 15.28 g (49.25 mmol) of ODPA was added and washed with 15 g of NMP.

Synthesis Example 4:
A thermometer and a stirring rod with stirring blades were set in a 200 mL four-necked flask. Next, 90 g of NMP was charged under a dry nitrogen stream and cooled to 10 ° C. or lower. After cooling, 10.81 g (50.00 mmol) of HAB and 13.22 g (150.0 mmol) of glycidyl methyl ether were added with stirring, and washed with 15 g of NMP. Subsequently, 10.15 g (50.00 mmol) of TPC diluted with 15 g of NMP was added dropwise. After completion of dropping, the mixture was stirred overnight at room temperature.

Synthesis Example 5:
A thermometer and a stirring rod with stirring blades were set in a 200 mL four-necked flask. Next, 90 g of NMP was added under a dry nitrogen stream, and the temperature was raised to 60 ° C. After the temperature was raised, 6.488 g (60.00 mmol) of p-PDA was added with stirring and washed with 15 g of NMP. After confirming that p-PDA was dissolved, 7.061 g (24.00 mmol) of BPDA and 7.525 g (34.50 mmol) of PMDA were added and washed with 15 g of NMP. Cooled after 4 hours. After cooling, 0.100 g of a surfactant d was added to make a varnish.

Synthesis Example 6: Synthesis of photoacid generator a A 1000 mL four-necked flask was equipped with a thermometer and a stirring rod with stirring blades. Next, in a dry nitrogen stream, 15.31 g (50.00 mmol) of 1,1,1-tris (4-hydroxyphenyl) ethane and 20.15 g (75.00 mmol) of 5-naphthoquinone diazide sulfonyl chloride were added to 1,4 -Dissolved in 450 g dioxane and brought to room temperature. To this, 7.59 g (75.00 mol) of triethylamine mixed with 50 g of 1,4-dioxane was added dropwise so that the temperature in the reaction system did not exceed 35 ° C. It stirred at 30 degreeC after dripping for 2 hours. The triethylamine salt was filtered and the filtrate was poured into water. Thereafter, the deposited precipitate was collected by filtration. This precipitate was dried with a vacuum dryer to obtain a photoacid generator a. The esterification rate of this naphthoquinonediazide compound was 50%.

Example 1:
The resin solution obtained in Synthesis Example 1 was subjected to pressure filtration using a 1 μm filter to remove foreign matters. Spin coating was performed on a 6-inch glass substrate using a coating and developing apparatus Mark-7 (manufactured by Tokyo Electron Ltd.) so that the film thickness after pre-baking was 15 μm, and then pre-baking was performed at 140 ° C. for 5 minutes. . The pre-baked film was heated using a gas oven (INH-21CD manufactured by Koyo Thermo Systems Co., Ltd.) according to the following first condition, and then heated according to the following second condition to produce a heat resistant resin film on the glass substrate. . The heating under the first condition and the heating under the second condition were performed continuously.

1st process: 350 degreeC under air | atmosphere atmosphere (oxygen concentration about 21 volume%)
For 30 minutes.

Second step: Heated at 400 ° C. for 30 minutes in a nitrogen atmosphere with an oxygen concentration of less than 20 ppm.

However, in the first step, the temperature was raised from room temperature, and the rate of temperature rise was 5 ° C./min. In the second step, the temperature was raised from the maximum heating temperature of the first step, and the rate of temperature rise was 5 ° C./min.

Examples 2 to 10c, Comparative Examples 1 to 12:
As shown in Table 1, a pre-baked film was prepared in the same manner as in Example 1 using the resin solutions obtained in Synthesis Examples 1 to 5. However, Examples 6 to 9 and Comparative Examples 6 to 9 were used with the additives shown in Table 1 added. Subsequently, a heat resistant resin film was produced in the same manner as in Example 1 except that the maximum heating temperature and the heating atmosphere in the first step and the second step were changed to the conditions shown in Table 1. However, for Comparative Example 12, the following third step was added.

Third step: Heated at 450 ° C. for 30 minutes in an air atmosphere.
However, in the third step, the temperature was raised from room temperature, and the rate of temperature rise was 5 ° C./min.

Tables 1 and 2 show the measurement results of the maximum tensile elongation, maximum tensile stress, and outgas of the heat resistant resin films obtained in Examples 1 to 10c and Comparative Examples 1 to 12.

Example 11
A gas barrier film made of a laminate of SiO ₂ and Si ₃ N ₄ was formed on the heat resistant resin film obtained in Example 10a by CVD. Subsequently, a TFT was formed, and an insulating film made of Si ₃ N ₄ was formed so as to cover the TFT. Next, after forming a contact hole in the insulating film, a wiring connected to the TFT through the contact hole was formed.

Furthermore, in order to flatten the unevenness due to the formation of the wiring, a flattening film was formed. Next, a first electrode made of ITO was formed on the obtained flattened film by being connected to the wiring. Thereafter, a resist was applied, prebaked, exposed through a mask having a desired pattern, and developed. Using this resist pattern as a mask, pattern processing was performed by wet etching using an ITO etchant. Thereafter, the resist pattern was stripped using a resist stripping solution (mixed solution of monoethanolamine and diethylene glycol monobutyl ether). The substrate after peeling was washed with water and dehydrated by heating to obtain an electrode substrate with a planarizing film. Next, an insulating film having a shape covering the periphery of the first electrode was formed.

Furthermore, a hole transport layer, an organic light emitting layer, and an electron transport layer were sequentially deposited through a desired pattern mask in a vacuum deposition apparatus. Next, a second electrode made of Al / Mg was formed on the entire surface above the substrate. Further, a sealing film made of a laminate of SiO ₂ and Si ₃ N ₄ was formed by CVD. Finally, the glass substrate was irradiated with a laser (wavelength: 308 nm) from the side where the heat resistant resin film was not formed, and peeling was performed at the interface with the heat resistant resin film.

Thus, an organic EL display device formed on the heat resistant resin film was obtained. When voltage was applied through the drive circuit, good light emission was exhibited.

Comparative Example 13
On the heat-resistant resin film obtained in Comparative Example 10, a gas barrier film was formed by CVD in the same manner as in Example 11. Continued to form the TFT, but due to the cause of outgassing of the heat-resistant resin film, the adhesion between the heat-resistant resin film and the gas barrier film was reduced and peeling occurred. could not.

According to the present invention, it is possible to provide a method for producing a heat-resistant resin film that does not impair the mechanical characteristics of the heat-resistant resin film and has good outgas characteristics. The obtained heat-resistant resin film includes a surface protective film and an interlayer insulating film of a semiconductor element, an insulating layer and a spacer layer of an organic electroluminescence element (organic EL element), a flattening film of a thin film transistor substrate, an insulating layer of an organic transistor, a flexible It can be suitably used for printed circuit boards, flexible display substrates, flexible electronic paper substrates, flexible solar cell substrates, flexible color filter substrates, and the like.

DESCRIPTION OF SYMBOLS 10 Heating furnace 11 Furnace body 12 Furnace 21 Temperature adjustment part 22 Temperature measurement part 23 Heating part 31 Oxygen meter 32 Gas sampling port 41 * 51 Gas supply pipe 42 * 52 Purge on-off valve 43 * 53 Purge flow control valve 44・ 54 Running open / close valve 45/55 Running flow control valve 61 Exhaust pipe 62 Exhaust open / close valve 63 Exhaust flow control valve 71 Control unit 81 User interface

Claims (17)

A heat-resistant resin film in which an outgas generated during heating at 450 ° C. for 30 minutes in a helium stream is 0.01 to 4 μg / cm ² . The heat resistant resin film according to claim 1, wherein the maximum tensile stress is 200 MPa or more. The heat resistant resin film of Claim 1 or 2 which has a structure represented by Chemical formula (1).

(In the chemical formula (1), X represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms, Y represents a divalent diamine residue having 2 or more carbon atoms, and m represents a positive integer.) In the chemical formula (1), X is a divalent diamine residue whose main component is a tetravalent tetracarboxylic acid residue represented by the chemical formula (2) or (3), and Y is represented by the chemical formula (4). The heat-resistant resin film according to any one of claims 1 to 3, comprising as a main component.

A method for producing a heat-resistant resin film comprising a step of applying a solution containing a precursor of a heat-resistant resin on a support and a step of heating in multiple steps, wherein the step of heating in the multiple steps comprises at least ( A) a first heating step in which heating is performed at a temperature higher than 200 ° C. in an atmosphere having an oxygen concentration of 10% by volume or higher; and (B) a temperature higher than that in the first heating step in an atmosphere having an oxygen concentration of 3% by volume or lower. A method for producing a heat resistant resin film, comprising: a second heating step for heating at a temperature in the above order. The method for producing a heat resistant resin film according to claim 5, wherein the first heating step is performed at 420 ° C or lower. The method for producing a heat resistant resin film according to claim 5 or 6, wherein the heat resistant resin is a resin having a structure represented by the chemical formula (1).

(In the chemical formula (1), X represents a tetravalent tetracarboxylic acid residue having 2 or more carbon atoms, Y represents a divalent diamine residue having 2 or more carbon atoms, and m represents a positive integer.) In the chemical formula (1), X is a divalent diamine residue whose main component is a tetravalent tetracarboxylic acid residue represented by the chemical formula (2) or (3), and Y is represented by the chemical formula (4). The method for producing a heat-resistant resin film according to any one of claims 5 to 7, comprising:

The solution containing the precursor of the heat resistant resin contains at least one of (a) a photoacid generator, (b) a compound containing a phenolic hydroxyl group, and (c) a surfactant. The method for producing a heat-resistant resin film according to any one of 1 to 8. A temperature measurement unit for measuring the temperature in the furnace;
A temperature adjusting unit for adjusting the temperature in the furnace;
An oxygen concentration measuring unit for measuring the oxygen concentration in the furnace;
A gas flow rate adjusting unit for adjusting the flow rate of the heating atmosphere gas into the furnace;
A control unit for controlling the temperature adjusting unit and the gas flow rate adjusting unit;
A heating furnace comprising:
The controller is
While controlling the gas flow rate adjustment unit according to the oxygen concentration in the furnace measured by the oxygen concentration measurement unit,
A heating furnace that controls the temperature adjusting unit so that a temperature in the furnace measured by the temperature measuring unit becomes a predetermined temperature after the oxygen concentration reaches a predetermined oxygen concentration. The controller is
At least a first heating step of heating at a first temperature in a first oxygen concentration atmosphere;
A second heating step of heating at a second temperature in a second oxygen concentration atmosphere;
In a multi-stage heating process comprising
The heating furnace according to claim 10, wherein the gas flow rate adjusting unit and the temperature adjusting unit are controlled so that the first heating step and the second heating step are continuously performed. The oxygen concentration measuring unit is
A gas sampling port for collecting the gas in the furnace;
An oxygen concentration meter for measuring the oxygen concentration at the gas sampling port;
A cold trap located between the oximeter and the gas sampling port;
The heating furnace according to claim 10 or 11, further comprising: The method for producing a heat resistant resin film according to any one of claims 5 to 9, wherein the multi-step heating step is performed using the heating furnace according to any one of claims 10 to 12. An image display device comprising the heat-resistant resin film according to any one of claims 1 to 4. An image comprising a step of producing a heat resistant resin film by the method of producing a heat resistant resin film according to any one of claims 5 to 9 and forming a pixel driving element or a colored pixel on the heat resistant resin film. Manufacturing method of display device. The method for manufacturing an image display device according to claim 15, further comprising a step of peeling the heat resistant resin film from the support. The method for manufacturing an image display device according to claim 15 or 16, wherein the image display device is an organic EL display.

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