TWI813952B - Composition for forming release layer and release layer - Google Patents

Abstract

A composition for forming a peeling layer containing, for example, a polyamide represented by the following formula (1) and an organic solvent is provided.

(In the formula, X is an aromatic group represented by the following formula (2) or formula (3), Y is a divalent aromatic group, and Z is an aromatic group represented by the following formula (2), Independently of each other, they are an aromatic group represented by the following formula (4) or formula (5). When X is an aromatic group represented by the following formula (3), they are independently of each other and are the following formula (6) or For the aromatic group represented by formula (7), m is a natural number.)

Description

Composition for forming peeling layer and peeling layer

The present invention relates to a composition for forming a release layer and a release layer.

In recent years, in addition to thinning and lightweighting, electronic devices have also been pursuing bendable functions. As a result, it is pursued to replace the conventional heavy, fragile and unbendable glass substrates with lightweight, flexible plastic substrates.

In particular, for next-generation displays, the development of active-matrix full-color TFT display panels using lightweight flexible plastic substrates (hereinafter referred to as resin substrates) is being pursued.

Therefore, research has begun on manufacturing methods for various electronic devices using resin films as substrates, and processes that can reuse existing TFT display panel manufacturing equipment for new-generation displays are being studied. Patent Documents 1, 2, and 3 disclose that an amorphous silicon thin film layer is formed on a glass substrate. After a plastic substrate is formed on the thin film layer, a laser is irradiated from the side of the glass substrate to crystallize the amorphous silicon. A method of peeling off a plastic substrate from a glass substrate using hydrogen gas generated along with the crystallization.

Furthermore, Patent Document 4 discloses the use of the technology disclosed in Patent Documents 1 to 3 to transfer the peeled layer (which is described in Patent Document 4 as "transferred"). "Layer") is bonded to a plastic film to complete a liquid crystal display device.

However, the methods disclosed in Patent Documents 1 to 4, especially the method disclosed in Patent Document 4, require the use of a highly translucent substrate in order to transmit laser light; in order to pass through the substrate, the laser light contained in the amorphous silicon The release of hydrogen requires laser light irradiation with sufficient and large energy; the problem of damage to the peeled layer due to laser light irradiation.

Moreover, when the peeled layer has a large area, laser processing requires a long time, making it difficult to improve the productivity of device manufacturing.

As a means to solve such a problem, Patent Document 5 uses an existing glass substrate as a base (hereinafter referred to as a glass base). A polymer such as a cyclic olefin copolymer is used on the glass base to form a peeling layer, and the peeling layer is After forming a heat-resistant resin film such as polyimide film on the film, ITO transparent electrodes or TFTs are formed on the film through a vacuum process. After sealing, the glass matrix is finally peeled off. Removed manufacturing steps.

Currently, low-temperature polysilicon TFTs that move twice as fast as amorphous silicon TFTs are used as TFTs. This low-temperature polysilicon TFT requires dehydrogenation annealing at 400°C or above after evaporation of amorphous silicon, and irradiation with pulse laser to crystallize the silicon (hereinafter, these are referred to as TFT steps). , but the temperature of the above-mentioned dehydrogenation annealing step is above the glass transition temperature (hereinafter Tg) of the existing polymer.

However, it is known that the adhesion of existing polymers increases when heated to a temperature higher than Tg (for example, refer to Patent Document 6). After the heat treatment, the adhesion between the peeling layer and the resin substrate increases, making it difficult to remove it. resin substrate The situation of body peeling.

[Prior technical literature]

[Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 10-125929

[Patent Document 2] Japanese Patent Application Publication No. 10-125931

[Patent Document 3] International Publication No. 2005/050754

[Patent Document 4] Japanese Patent Application Publication No. 10-125930

[Patent Document 5] Japanese Patent Application Publication No. 2010-111853

[Patent Document 6] Japanese Patent Application Publication No. 2008-188792

The present invention was completed in view of the above-mentioned circumstances to provide a resin substrate that can be peeled off without damaging the flexible electronic device formed thereon, and even after a relatively high-temperature heat treatment such as the above-mentioned TFT step. , the purpose is to form a composition for forming a peeling layer that does not change its peelability.

As a result of the inventors' efforts to solve the above-mentioned problems, they found that a composition containing a polyamide having specific aromatic groups at both ends of the molecular chain and an organic solvent can not only obtain an excellent substrate with a glass substrate, etc. Adhesion and resin substrate used in flexible electronic devices The present invention was completed by providing a release layer with moderate adhesion and moderate releasability, and the moderate adhesion and moderate releasability of the release layer did not change and were well maintained even after the heat treatment in the TFT step.

Therefore, the present invention provides the following composition for forming a release layer and a release layer.

[1] A composition for forming a release layer, characterized by containing a polyamide represented by the following formula (1) and an organic solvent.

(In the formula, X is an aromatic group represented by the following formula (2) or formula (3), Y is a divalent aromatic group, and Z is an aromatic group represented by the following formula (2), Independently of each other, they are an aromatic group represented by the following formula (4) or formula (5). When X is an aromatic group represented by the following formula (3), they are independently of each other and are the following formula (6) or For the aromatic group represented by formula (7), m is a natural number.)

[2] The composition for forming a release layer as described in [1], wherein X is an aromatic group represented by the following formulas (8) to (11), and Z is the following formula (8) or formula ( 9) When the aromatic groups represented are independent of each other, they are aromatic groups represented by the following formula (12) or formula (13), and X is an aromatic group represented by the following formula (10) or formula (11) When the groups are groups, they are independent of each other and are aromatic groups represented by the following formula (14) or formula (15).

[3] The composition for forming a release layer according to [1] or [2], wherein the above Y is A divalent aromatic group containing 1 to 5 benzene rings.

[4] The peeling layer forming composition according to [3], wherein Y is at least one selected from the following formulas (16) to (18).

(In the formula, R ¹ ~ R ²⁴ are independent of each other and are hydrogen atoms, halogen atoms, hydroxyl groups, nitro groups, cyano groups, or alkyl groups with 1 to 20 carbon atoms or alkenes with 2 to 20 carbon atoms that may be substituted by halogen atoms. group, an alkynyl group with 2 to 20 carbon atoms, an aryl group with 6 to 20 carbon atoms, or a heteroaryl group with 2 to 20 carbon atoms.)

[5] The composition for forming a peeling layer according to [4], wherein R ¹ to R ²⁴ are hydrogen.

[6] The composition for forming a release layer according to any one of [1] to [5], wherein m is a natural number of 100 or less.

[7] The composition for forming a release layer according to any one of [1] to [6], wherein the organic solvent includes amide represented by formula (S1), amide represented by formula (S2) and At least one selected amide represented by formula (S3).

(In the formula, R ²⁵ and R ²⁶ are independent of each other and are alkyl groups with 1 to 10 carbon atoms, R ²⁷ is a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, and b is a natural number.)

[8] A peeling layer formed from the composition for forming a peeling layer according to any one of [1] to [7].

[9] A method of manufacturing a flexible electronic device having a resin substrate, characterized by using the peeling layer described in [8].

[10] The manufacturing method according to [9], wherein the resin substrate is a substrate made of polyimide.

By using the peeling layer-forming composition of the present invention, a peeling layer having excellent adhesion to the base, moderate adhesion to the resin substrate, and moderate peelability can be obtained with good reproducibility. In particular, even after the heat treatment in the TFT step, the above-mentioned adhesion and peelability are still well maintained, so the resin substrate formed on the base can be not damaged during the manufacturing process of the flexible electronic device or further disposed thereon. circuits, etc., and the circuits, etc. and the resin substrate are separated from the base body. Therefore, the composition for forming a peeling layer of the present invention can simplify the manufacturing process of a flexible electronic device including a resin substrate or improve its yield.

[The best way to implement the invention]

The present invention will be described in more detail below.

The peeling layer forming composition of the present invention contains polyamide represented by the following formula (1) and an organic solvent.

In the above formula (1), X is an aromatic group represented by the following formula (2) or formula (3), Y is a divalent aromatic group, and Z is an aromatic group represented by the following formula (2). when X is an aromatic group represented by the following formula (3), they are independent of each other and are the following formula ( 6) or the aromatic group represented by formula (7), m is a natural number.

In the present invention, the release layer refers to a layer provided directly on the base (glass base, etc.) on which the resin substrate is formed. Typical examples include, for example, fixing in a specified process between the above-mentioned base and a resin substrate of a flexible electronic device composed of a resin such as polyimide during the manufacturing process of the flexible electronic device. The release layer is provided on the resin substrate, and is provided so that the resin substrate can be easily peeled off from the base after electronic circuits and the like are formed on the resin substrate.

The polyamic acid represented by the above formula (1) is obtained by reacting a specified tetracarboxylic dianhydride component and a diamine component.

As the tetracarboxylic dianhydride component, benzene tetracarboxylic dianhydride and biphenyltetracarboxylic dianhydride can be used. The diamine component may be any of aliphatic chain, alicyclic, aromatic, and aromatic alicyclic. However, in the present invention, from the viewpoint of improving the function of the obtained film as a release layer, the above-mentioned tetracarboxylic acid diamine component is A polyamic acid obtained by reacting an anhydride with a diamine component containing an aromatic diamine is preferred, and a fully aromatic polyamic acid obtained by reacting the above-mentioned tetracarboxylic dianhydride with an aromatic diamine is more preferred.

The above-mentioned X is preferably an aromatic group represented by the following formulas (8) to (11).

Moreover, the above-mentioned Z are independent of each other when X is an aromatic group represented by the above-mentioned formula (8) or formula (9), preferably an aromatic group represented by the following formula (12) or formula (13), and X is The aromatic groups represented by the above formula (10) or formula (11) are independent of each other, and the aromatic group represented by the following formula (14) or formula (15) is preferably

The above-mentioned Y is preferably an aromatic group containing 1 to 5 benzene rings, and more preferably an aromatic group represented by at least one selected from the following formulas (16) to (18).

In the above formulas (16) to (18), R ¹ to R ²⁴ are independent of each other and are a hydrogen atom, a hydroxyl group, a halogen atom, a nitro group, a cyano group, or an alkyl group having 1 to 20 carbon atoms that may be substituted by a halogen atom, Alkenyl group having 2 to 20 carbon atoms, alkynyl group having 2 to 20 carbon atoms, aryl group having 6 to 20 carbon atoms, or heteroaryl group having 2 to 20 carbon atoms.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

Specific examples of the alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and examples include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n -Butyl, isobutyl, s-butyl, t-butyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n- Butyl, 1,1-dimethyl-n-propyl, 1,2-dimethyl-n-propyl, 2,2-dimethyl-n-propyl, 1-ethyl-n-propyl base, cyclopentyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl-n-butyl, 2,2-dimethyl-n-butyl base, 2,3-dimethyl-n-butyl, 3,3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1, 1,2-Trimethyl-n-propyl, 1,2,2-trimethyl-n-propyl, 1-ethyl-1-methyl-n-propyl, 1-ethyl-2- Methyl-n-propyl, cyclohexan Base, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridedecanyl, n-tetradecanyl, n-pentadecanyl Base, n-hexadecyl base, n-seventeen base, n-octadecyl base, n-nineteen base, n-eicosyl base, etc.

Specific examples of the alkenyl group having 2 to 20 carbon atoms include vinyl, n-1-propenyl, n-2-propenyl, 1-methylvinyl, n-1-butene, and n-2- Butene, n-3-butene, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl, 1-methyl Base-2-propenyl, n-1-pentenyl, n-1-decenyl, n-1-eicosanyl, etc.

Specific examples of the alkynyl group having 2 to 20 carbon atoms include ethynyl, n-1-propynyl, n-2-propynyl, n-1-butynyl, n-2-butynyl, n-3-butynyl, 1-methyl-2-propynyl, n-1-pentynyl, n-2-pentynyl, n-3-pentynyl, n-4-pentynyl , 1-methyl-n-butynyl, 2-methyl-n-butynyl, 3-methyl-n-butynyl, 1,1-dimethyl-n-propynyl, n- 1-hexynyl, n-1-decynyl, n-1-pentadenyl, n-1-eicosynyl, etc.

Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, 1-anthracenyl, 2-anthracenyl, 9-anthracenyl, 1-phenanthrenyl, 2- Phenyl, 3-phenyl, 4-phenyl, 9-phenyl, etc.

Specific examples of the heteroaryl group having 2 to 20 carbon atoms include 2-thienyl, 3-thienyl, 2-furyl, 3-furyl, 2-oxazolyl, 4-oxazolyl, 5- Oxazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl and other oxygen-containing heteroaryl groups; 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isoxazolyl, etc. Sulfur-containing heteroaryl groups such as thiazolyl, 4-isothiazolyl, 5-isothiazolyl, etc.; 2-imidazolyl, 4-imidazolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyridyl Azinyl, 3-pyrazinyl, 5-pyrazinyl, 6-pyrazinyl, 2-pyrimidinyl, 4-pyrimidinyl Aldyl, 5-pyrimidinyl, 6-pyrimidinyl, 3-pyridazinyl, 4-pyridazinyl, 5-pyridazinyl, 6-pyridazinyl, 1,2,3-triazin-4-yl, 1,2,3-triazine-5-yl, 1,2,4-triazine-3-yl, 1,2,4-triazine-5-yl, 1,2,4-triazine-6-yl base, 1,3,5-triazin-2-yl, 1,2,4,5-tetrazin-3-yl, 1,2,3,4-tetrazin-5-yl, 2-quinolinyl , 3-quinolyl, 4-quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl, 1-isoquinolyl, 3-isoquinolyl , 4-isoquinolyl, 5-isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, 8-isoquinolyl, 2-quinoxalinyl, 5-quinoxalinyl, 6-quinoxalinyl, 2-quinazolinyl, 4-quinazolinyl, 5-quinazolinyl, 6-quinazolinyl, 7-quinazolinyl, 8-quinazolinyl, 3 -Nitrogen-containing heteroaryl groups such as ninozinyl, 4-nozinyl, 5-nozinyl, 6-nozinyl, 7-nozinyl, 8-nozinyl, etc.

Among these, R ¹ to R ²⁴ are represented by a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 20 carbon atoms which may be substituted by a halogen atom, an aryl group having 6 to 20 carbon atoms which may be substituted by a halogen atom, A heteroaryl group having 2 to 20 carbon atoms which may be substituted by a halogen atom is preferred, a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 10 carbon atoms which may be substituted by a halogen atom, benzene which may be substituted by a halogen atom. More preferably, the base is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and a hydrogen atom is the most preferred.

The above m can be a natural number, but a natural number of 100 or less is preferred, and a natural number of 2 to 100 is more preferred.

The tetracarboxylic dianhydride component, the diamine component and the aromatic carboxylic acid component that can be used for the synthesis of the polyamic acid having the structure represented by the above formula (1) will be described in detail below.

As the above-mentioned tetracarboxylic dianhydride component, benzene tetracarboxylic acid can be used dianhydride and biphenyltetracarboxylic dianhydride.

Specific examples thereof include pyromellitic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, biphenyl-2,2',3,3'-tetracarboxylic dianhydride, Biphenyl-2,3,3',4'-tetracarboxylic dianhydride, biphenyl-3,3',4,4'-tetracarboxylic dianhydride, etc., these can be used alone or in two kinds Use a combination of the above. In the present invention, from the viewpoint of improving the function of the resulting film as a release layer, it is preferable to use pyromellitic dianhydride and biphenyl-3,3',4,4'-tetracarboxylic dianhydride.

On the other hand, the aromatic diamine is not particularly limited if it has two amine groups directly bonded to an aromatic ring in the molecule, but an aromatic diamine containing 1 to 5 benzene rings is preferred.

Specific examples of the aromatic diamine having the above structure include 1,4-diaminobenzene (p-phenylenediamine), 1,3-diaminobenzene (m-phenylenediamine), 1,2 -Diaminobenzene (o-phenylenediamine), 2,4-diaminotoluene, 2,5-diaminotoluene, 2,6-diaminotoluene, 4,6-dimethyl-m- Phenylenediamine, 2,5-dimethyl-p-phenylenediamine, 2,6-dimethyl-p-phenylenediamine, 2,4,6-trimethyl-1,3-phenylenediamine, 2,3,5,6-Tetramethyl-p-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 5-trifluoromethylbenzene-1,3-diamine , 5-trifluoromethylbenzene-1,2-diamine, 3,5-bis(trifluoromethyl)benzene-1,2-diamine and other diamines with one benzene ring; 1,2- Naphthalene diamine, 1,3-naphthalene diamine, 1,4-naphthalene diamine, 1,5-naphthalene diamine, 1,6-naphthalene diamine, 1,7-naphthalene diamine, 1,8-naphthalene diamine Amine, 2,3-naphthylenediamine, 2,6-naphthylenediamine, 4,4'-biphenyldiamine, 2,2'-bis(trifluoromethyl)-4,4'-diamine Biphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 3,3' ,5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 4,4'-diaminobenzoaniline, 3,3'-dichlorobenzidine, 3,3'-Dimethylbenzidine, 2,2'-Dimethylbenzidine, 3,3'-Diaminodiphenylmethane, 3,4'-Diaminodiphenylmethane, 4, 4'-Diaminodiphenylmethane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-amine phenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane , 3,3'-Diaminodiphenylsterene, 3,4'-Diaminodiphenylsterene, 4,4'-Diaminodiphenylsterene, 3,3'-bis( Trifluoromethyl)biphenyl-4,4'-diamine, 3,3',5,5'-tetrafluorobiphenyl-4,4'-diamine, 4,4'-diaminoocta Fluorobiphenyl, 2-(3-aminophenyl)-5-aminobenzimidazole, 2-(4-aminophenyl)-5-aminobenzoxazole, etc. have two benzene rings. Diamine; 1,5-diaminoanthracene, 2,6-diaminoanthracene, 9,10-diaminoanthracene, 1,8-diaminophenanthrene, 2,7-diaminophenanthrene, 3, 6-diaminophenanthrene, 9,10-diaminophenanthrene, 1,3-bis(3-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4- Bis(3-aminophenyl)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(3-aminophenyl sulfide)benzene, 1,3-bis(4 -Aminophenyl sulfide) benzene, 1,4-bis (4-aminophenyl sulfide) benzene, 1,3-bis (3-aminophenyl sulfide) benzene, 1,3-bis (4 -Aminophenylsteine)benzene, 1,4-bis(4-aminophenylsteine)benzene, 1,3-bis[2-(4-aminophenyl)isopropyl]benzene, 1,4 -Bis[2-(3-aminophenyl)isopropyl]benzene, 1,4-bis[2-(4-aminophenyl)isopropyl]benzene, 4,4”-diamino- Diamines having three benzene rings, such as p-terphenyl and 4,4″-diamino-m-terphenyl, etc., but are not limited to these. These can be used individually by 1 type or in combination of 2 or more types.

Among these, aromatic diamines that do not have a substituent such as a methyl group on an aromatic ring or on an aromatic ring and a heterocyclic ring condensed with it are preferred from the viewpoint of improving the function of the resulting film as a release layer. Specifically, p-benzene di Amine, m-phenylenediamine, 2-(3-aminophenyl)-5-aminobenzimidazole, 2-(4-aminophenyl)-5-aminobenzoxazole, 4,4 "-Diamino-p-terphenyl, etc. are preferred.

In addition, from the viewpoint of improving the flexibility, heat resistance, etc. of the release layer obtained, the diamine component of the present invention may contain diamines other than aromatic diamines. A preferred example thereof is represented by formula (S). Diamine.

In the formula (S), each L is independent of each other and is an alkanediyl group with 1 to 20 carbon atoms, an alkenediyl group with 2 to 20 carbon atoms, or an alkyne diyl group with 2 to 20 carbon atoms. Each R' is independent of each other and is a carbon group. Alkyl group with 1 to 20 carbon atoms, alkenyl group with 2 to 20 carbon atoms, or alkynyl group with 2 to 20 carbon atoms.

The number of carbon atoms in the alkanediyl, alkenediyl and alkynediyl groups is preferably 10 or less, more preferably 5 or less.

Among them, in terms of L, considering the balance between the solubility of the obtained polyamide acid in organic solvents and the heat resistance of the obtained film, the alkane diyl group and -(CH ₂ ) _n - group (n=1~10) are preferred. Even better, -(CH ₂ ) _n -group (n=1~5) is even better, and then considering the ease of acquisition, trimethylene is even better.

Specific examples of other alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, and alkynyl groups having 2 to 20 carbon atoms are as mentioned above.

Among them, in terms of R’, considering the balance between the solubility of the obtained polyamide acid in organic solvents and the heat resistance of the obtained film, an alkyl group with a carbon number of 1 to 20 is used. Preferred, methyl and ethyl are more preferred.

Taking into account the ease of acquisition, the function of the obtained film as a release layer, etc., the diamine represented by formula (S) is 1,3-bis(3-aminopropyl)tetramethyldisiloxane. . In addition, the diamine represented by the formula (S) can be obtained as a commercial product or can be synthesized by a conventional method (for example, the method described in International Publication No. 2010/108785).

Furthermore, the above-mentioned aromatic diamine and other diamines may be used together as long as the peeling layer obtained is not adversely affected.

Specific examples of other diamines include 1,4-diaminocyclohexane, 1,4-cyclohexanebis(methylamine), 4,4'-diaminodicyclohexylmethane, bis( 4-Amino-3-methylcyclohexyl)methane, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0 ^2,6 ]decane, 2,5(6) -Bis(aminomethyl)bicyclo[2.2.1]heptane, 1,3-diaminoadamantane, 3,3'-diamino-1,1'-bisadamantyl, 1,6- Diaminodiadamantane (1,6-aminopentacyclo[7.3.1.1 ^{4,12,0 2,7} .0 ^6,11 ]tetradecane) and other alicyclic diamines; tetramethylene diamine Aliphatic diamines such as amines, hexamethylenediamine, etc.

In the present invention, the amount of the aromatic diamine in the total diamine component is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and more preferably 95 mol%. %above. Moreover, in particular, when using an aromatic diamine and a diamine represented by the formula (S), the amount of the aromatic diamine in the total amount of the aromatic diamine and the diamine represented by the formula (S) is preferably 80 Mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, more preferably 97 mol% or more. By using such a usage amount, excellent adhesion to the base and moderate adhesion to the resin substrate can be obtained with good reproducibility. Film with moderate peelability.

The addition ratio of the diamine component and the tetracarboxylic dianhydride component is appropriately determined by taking into account the target molecular weight or molecular weight distribution, the type of diamine or tetracarboxylic dianhydride, etc. and cannot be uniformly specified. However, in order to obtain the polyamide of (1) above As for the acid, it is preferable that the molar number of the tetracarboxylic dianhydride component is larger relative to the molar number of the diamine component. The specific molar ratio is preferably 1.05~2.5 moles for the tetracarboxylic dianhydride component relative to 1 mole of the diamine component, more preferably 1.07~1.5 moles, and even more preferably 1.1~1.3 moles.

By reacting the diamine component and the tetracarboxylic dianhydride component as described above, the polyamic acid of the above formula (1) contained in the composition for forming a release layer of the present invention can be obtained.

The organic solvent used in the synthesis of polyamic acid is not particularly limited as long as it does not have a negative impact on the reaction. However, specific examples thereof include m-cresol, 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl. Base-2-pyrrolidone, N-vinyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethyl Propylamide, 3-ethoxy-N,N-dimethylpropylamide, 3-propoxy-N,N-dimethylpropylamide, 3-isopropoxy-N, N-dimethylpropylamide, 3-butoxy-N,N-dimethylpropylamide, 3-sec-butoxy-N,N-dimethylpropylamide, 3- tert-butoxy-N,N-dimethylpropylamide, γ-butyrolactone, etc. Moreover, the organic solvent can be used individually by 1 type or in combination of 2 or more types.

The reaction temperature during the synthesis of polyamic acid can be appropriately set within the range from the melting point to the boiling point of the solvent used, usually about 0 to 100°C, in order to prevent the presence of imine in the resulting polyamic acid solution. Hua and Dimension From the viewpoint of a high polyamide unit content, it is preferably about 0 to 70°C, more preferably about 0 to 60°C, and even more preferably about 0 to 50°C. The reaction time cannot be uniformly specified because it depends on the reaction temperature or the reactivity of the raw material, but it is usually about 1 to 100 hours.

The weight average molecular weight of the polyamide of the above formula (1) thus obtained is usually about 5,000 to 500,000, but from the viewpoint of improving the function of the obtained film as a release layer, it is preferably about 10,000 to 200,000, more preferably It is about 30,000~150,000. In addition, in the present invention, the weight average molecular weight is a polystyrene-converted value measured by colloidal permeation chromatography (GPC).

Specific examples of polyamides suitable for use in the present invention include those represented by the following formulas, but are not limited thereto.

(式中，m同上述。)

(In the formula, m is the same as above.)

The peeling layer forming composition of the present invention contains an organic solvent. As the organic solvent, the same specific examples as the reaction solvent for the above reaction can be used, but by fully dissolving the polyamide of the above formula (1), And it is easy to prepare a composition with high uniformity, especially a composition containing amide represented by the following formula (S1), amide represented by the formula (S2) and amide represented by the formula (S3). At least 1 type is preferred.

In the above formula, R ²⁵ and R ²⁶ are independent of each other and are alkyl groups having 1 to 10 carbon atoms. R ²⁷ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. b is a natural number, but a natural number from 1 to 5 is preferred, and a natural number from 1 to 3 is even more preferred.

Specific examples of the alkyl group having 1 to 10 carbon atoms include those mentioned above.

Specific examples of the organic solvent represented by the above formulas (S1) to (S3) include 3-methoxy-N,N-dimethylpropamide, N,N-dimethylformamide, N ,N-dimethylacetamide, N,N-dimethylpropionamide, N,N-dimethylbutanamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone etc. Among them, N-methyl-2-pyrrolidone is preferred. These organic solvents can be used individually by 1 type or in combination of 2 or more types.

In addition, even if it is a solvent that does not dissolve polyamic acid alone, it can be used to prepare the composition as long as the polyamic acid does not precipitate. In particular, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, and 1-methoxy-2-propanol may be appropriately mixed. Alcohol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, Propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2- Solvents with low surface tension such as ethoxypropoxy) propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isopentyl lactate, etc. It is known that this improves the uniformity of the coating film when applied to a substrate, and it is also suitable for use in the present invention.

The peeling layer-forming composition of the present invention can be prepared by a general method. A preferred example of the preparation method is to filter the reaction solution containing the target polyamide obtained by the above-described method, and adjust the concentration of the obtained filtrate to a specified concentration using the above-mentioned organic solvent. By adopting such a method, not only can the contamination of impurities that cause deterioration of the adhesion, peelability, etc. of the peeling layer produced from the obtained composition be reduced, but also the composition for forming a peeling layer can be obtained efficiently.

The concentration of the polyamide of formula (1) in the composition for forming a release layer of the present invention is appropriately set taking into consideration the thickness of the release layer to be produced, the viscosity of the composition, etc., but is usually 1 to 30% by mass. About 1 to 20% by mass is preferred. By setting such a concentration, a peeling layer with a thickness of about 0.05 to 5 μm can be obtained with good reproducibility. The concentration of the polyamide of the above formula (1) can be adjusted by adjusting the usage amounts of the diamine component and the tetracarboxylic dianhydride component of the polyamide acid raw materials, and dividing the separated polyamide of the above formula (1). The acid is adjusted by adjusting the amount when it dissolves in the solvent, etc.

In addition, the viscosity of the peeling layer forming composition of the present invention is appropriately set taking into consideration the thickness of the peeling layer to be produced, etc., but especially when the purpose is to obtain a film with a thickness of about 0.05 to 5 μm with good reproducibility, it is usually 10~10,000mPa at 25℃. s, preferably 20~5,000mPa. around s.

Here, the viscosity can be measured using a viscometer for measuring the viscosity of a commercially available liquid, with reference to the procedure described in JIS K7117-2, for example, and the temperature of the composition is 25°C. It is better to use a cone-plate type (cone-plate type) rotational viscometer as the viscometer. It is better to use the same type of viscometer, using 1°34'×R24 as the standard conical rotor, and the temperature of the composition is 25°C. Make a determination. An example of such a rotational viscometer is TVE-25L manufactured by Toki Industrial Co., Ltd.

In addition, the peeling layer forming composition of the present invention may contain, in addition to the polyamide of formula (1) and the organic solvent, a crosslinking agent or the like in order to improve the film strength.

By applying the peeling layer forming composition of the present invention described above to a substrate and heating the resulting coating film to thermally imidize the polyamide of the above formula (1), a polyamide having the properties of A peeling layer composed of a polyimide film that has excellent adhesion to the base, moderate adhesion to the resin substrate, and moderate peelability.

When forming the peeling layer of the present invention on a base, the peeling layer may be formed on a part of the surface of the base or on the entire surface. Examples of methods for forming a peeling layer on a part of the base surface include forming the peeling layer only in a specified range of the base surface, and forming pattern patterns such as dot patterns, line/space patterns, etc. on the entire base surface. The shape of the peeling layer, etc. In addition, in the present invention, the substrate refers to one whose surface is coated with the release layer-forming composition of the present invention and which is used in the production of flexible electronic devices and the like.

As the matrix (base material), for example, glass, plastic (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy resin, melamine, triacetyl cellulose, ABS, AS, Bornene-based resin, etc.), metal (silicon wafer, etc.), wood, paper, slate, etc. In the present invention, a glass substrate is preferably used because the peeling layer has sufficient adhesion. In addition, the surface of the base may be made of a single material, or may be made of two or more materials. In the case where the surface of the base is made of two or more materials, there are those in which a certain range of the base surface is made of one material and the remaining areas are made of another material, or the entire surface of the base is made of a certain material in the form of dot patterns or lines. /Spacing patterns, etc. Patterns that exist in other materials.

The method of applying the peeling layer forming composition of the present invention to the substrate is not particularly limited, and may include cast coating, spin coating, knife coating, dip coating, roller coating, and rod coating. , die coating method, inkjet method, printing method (letterpressure, gravure, lithography, screen printing, etc.), etc.

The heating temperature for imidization is usually appropriately determined within the range of 50 to 550°C, but is preferably over 150°C to 510°C. By setting the heating temperature to such a temperature, it is possible to prevent the obtained film from becoming fragile and to allow the imidization reaction to fully proceed. The heating time varies depending on the heating temperature, so it cannot be uniformly specified, but it is usually 5 minutes to 5 hours. In addition, the imidization rate may be in the range of 50 to 100%.

A preferred example of the heating method in the present invention is, for example, heating at 50 to 150°C for 5 minutes to 2 hours, then directly increasing the heating temperature in stages, and finally heating to a temperature exceeding 150°C to 510°C for 30 minutes to 4 hours. Hourly heating method. In particular, conduct it at 50~150℃ for 5 minutes to 2 hours. After heating, it is better to conduct heating at a temperature exceeding 150°C to 350°C for 5 minutes to 2 hours, and finally to heat at a temperature exceeding 350°C to 450°C for 30 minutes to 4 hours.

Examples of the appliance used for heating include a hot plate, an oven, and the like. The heating environment can be under air or under inert gas; and it can also be under normal pressure or reduced pressure.

The thickness of the peeling layer is usually about 0.01 to 50 μm, and preferably about 0.05 to 20 μm from the viewpoint of productivity. In addition, the desired thickness can be achieved by adjusting the thickness of the coating film before heating.

The peeling layer described above has excellent adhesion to the substrate, especially the glass substrate, moderate adhesion to the resin substrate, and moderate peelability, and further, especially before and after heat treatment in the TFT step. The characteristics do not change and the performance is stable. Therefore, the release layer of the present invention can be used in the manufacturing process of a flexible electronic device to simultaneously peel off the resin substrate and the circuit formed on the resin substrate from the base without causing damage to the resin substrate of the device.

Hereinafter, an example of a method for manufacturing a flexible electronic device using the release layer of the present invention will be described.

Using the composition for forming a peeling layer of the present invention, a peeling layer is formed on a glass substrate according to the method described above. A resin solution for forming a resin substrate is coated on the release layer, and the coating film is heated to form a resin substrate fixed to the glass substrate via the release layer of the present invention. At this time, in order to cover the entire peeling layer, the substrate is formed with an area larger than the area of the peeling layer. Examples of the resin substrate include a resin substrate composed of polyimide, which is a representative resin substrate of a flexible electronic device; Examples of the resin solution include polyimide solution or polyamide acid solution. The formation method of the resin substrate only needs to follow a common method.

Next, a desired circuit is formed on the resin substrate fixed to the base body via the peeling layer of the present invention, and then, for example, the resin substrate is cut along the peeling layer, and the resin substrate is peeled off from the peeling layer together with the circuit, and the resin is removed. The substrate is separated from the matrix. At this time, a part of the base body may be cut along with the peeling layer.

In addition, Japanese Patent Application Publication No. 2013-147599 reports that the laser lift-off method (LLO method), which has been widely used in the production of high-brightness LEDs, three-dimensional semiconductor packages, etc., is applied to the production of flexible displays. The above-described LLO method is characterized by irradiating light with a specific wavelength, for example, light with a wavelength of 308 nm, from the side of the glass substrate from a surface opposite to the surface on which circuits and the like are formed. The irradiated light can penetrate the glass matrix, and only the polymer (polyimide) near the glass matrix absorbs the light and evaporates (sublimes). As a result, the resin substrate can be selectively peeled off from the glass base without affecting the circuits and the like provided on the resin substrate that determine the performance of the display.

The composition for forming a peeling layer of the present invention has the characteristic of fully absorbing light of a specific wavelength (for example, 308 nm) to which the above-mentioned LLO method can be applied. Therefore, it can be used as a sacrificial layer for the LLO method. Therefore, if a desired circuit is formed on a resin substrate fixed to a glass base through a peeling layer formed using the composition of the present invention, and then the LLO method is performed and 308 nm light is irradiated, only the peeling layer will absorb the light. evaporates (sublimates) due to light. Thereby, the peeling layer becomes sacrificial (functions as a sacrificial layer), and the resin substrate can be selectively peeled off from the glass substrate.

[Example]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[1]Abbreviation of compound

p-PDA: p-phenylenediamine

BPDA: 3,3’,4,4’-biphenyltetracarboxylic dianhydride

PMDA: Pyromellitic dianhydride

NMP: N-methyl-2-pyrrolidone

BCS: butyl cellosolve

[2]Measurement method of weight average molecular weight and molecular weight distribution

The weight average molecular weight (hereinafter referred to as Mw) and molecular weight distribution of the polymer were measured using a GPC device manufactured by JASCO Corporation (column: KD801 and KD805 manufactured by Shodex; eluent: dimethylformamide/ _LiBr.H2 O (29.6mM)/H ₃ PO ₄ (29.6mM)/THF (0.1wt%); flow rate: 1.0mL/min; column temperature: 40°C; Mw: standard polystyrene conversion value).

[3]Synthesis of polymers

Polyamide was synthesized using the following method.

Furthermore, instead of isolating the polymer from the reaction liquid containing the obtained polymer, the reaction liquid is diluted as described below to prepare a resin substrate forming composition or Composition for forming a peeling layer.

<Synthesis Example S1 Synthesis of polyamide (S1)>

Dissolve p-PDA3.218g (30mmol) in NMP88.2g. 8.581g (29mmol) of BPDA was added to the obtained solution, and the reaction was carried out at 23°C for 24 hours under a nitrogen environment. The obtained polymer had an Mw of 107,300 and a molecular weight distribution of 4.6.

<Synthesis Example L1 Synthesis of Polyamide (L1)>

Dissolve p-PDA4.47g (41.4mmol) in NMP132g. To the obtained solution, 13.53 g (46.0 mmol) of BPDA was added, and the reaction was carried out at 23° C. for 24 hours under a nitrogen atmosphere. The obtained polymer had an Mw of 75,400 and a molecular weight distribution of 3.3.

<Synthesis Example L2 Synthesis of polyamide (L2)>

Dissolve p-PDA5.55g (51.4mmol) in NMP132g. To the obtained solution, 12.45 g (57.1 mmol) of PMDA was added, and the reaction was carried out at 23° C. for 24 hours under a nitrogen atmosphere. The obtained polymer had an Mw of 76,400 and a molecular weight distribution of 2.2.

<Synthesis Example L3 Synthesis of Polyamide (L3)>

Dissolve p-PDA2.73g (25.2mmol) in NMP88g. To the obtained solution, 9.27g (31.5 mmol) of BPDA was added, and the reaction was carried out at 23°C for 24 hours under a nitrogen environment. The obtained polymer had an Mw of 45,000 and a molecular weight of Cloth is 3.9.

<Comparative Synthesis Example B1 Synthesis of Polyamide (B1)>

Dissolve p-PDA20.8g (192mmol) in NMP425g. To the obtained solution, 54.2 g (184 mmol) of BPDA was added, and the reaction was carried out at 23° C. for 24 hours under a nitrogen atmosphere. The obtained polymer had an Mw of 69,200 and a molecular weight distribution of 2.2.

[4] Preparation of composition for forming resin substrate

[Preparation example 1]

The reaction liquid obtained in Synthesis Example S1 was used as it was as a composition for forming a resin substrate.

[5] Preparation of composition for forming peeling layer

[Example 1-1]

BCS and NMP were added to the reaction liquid obtained in Synthesis Example L1, and the mixture was diluted so that the polymer concentration became 5% by mass and BCS became 20% by mass, thereby obtaining a composition for forming a peeling layer.

[Examples 1-2~1-3]

A composition for forming a peeling layer was obtained in the same manner as in Example 1-1, except that the reaction liquid obtained in Synthesis Examples L2 to L3 was used instead of the reaction liquid obtained in Synthesis Example L1.

[Comparative Example 1-1]

A composition for forming a peeling layer was obtained in the same manner as in Example 1-1, except that the reaction liquid obtained in Comparative Synthesis Example B1 was used instead of the reaction liquid obtained in Synthesis Example L1.

[6] Production of peeling layer and resin substrate

[Example 2-1]

The peeling layer forming composition obtained in Example 1-1 was coated on a 100 mm × 100 mm glass substrate (the same below) as a glass base using a spin coater (conditions: rotation number: 3,000 rpm, about 30 seconds). .

Next, the obtained coating film was heated at 80°C for 10 minutes using a hot plate, and then heated at 300°C for 30 minutes using an oven to raise the heating temperature (10°C/min) to 400°C, and then heated it at 400°C. Heating was performed for 30 minutes to form a peeling layer with a thickness of approximately 0.1 μm on the glass substrate, thereby obtaining a glass substrate with a peeling layer. In addition, during the heating period, the substrate with the film is heated in the oven without taking it out from the oven.

The resin substrate forming composition was applied to the release layer (resin film) on the glass substrate obtained above using a bar coater (gap: 250 μm). Next, the obtained coating film was heated at 80°C for 30 minutes using a hot plate, and then heated at 140°C for 30 minutes using an oven to raise the heating temperature (2°C/min, the same below) to 210°C. 210°C for 30 minutes, raise the heating temperature to 300°C, 300°C for 30 minutes, raise the heating temperature to 400°C, and heat at 400°C for 60 minutes to form a polyimide with a thickness of about 20 μm on the peeling layer. substrate, get Comes with resin substrate. Peel off the layers from the glass substrate. During the heating period, the film-coated substrate is heated in the oven without taking it out from the oven.

[Example 2-2~2-3]

In the same manner as in Example 2-1, except that the composition for forming a peeling layer obtained in Examples 1-2 to 1-3 was used instead of the composition for forming a peeling layer obtained in Example 1-1. Make a peeling layer and a polyimide substrate to obtain a glass substrate with a peeling layer and a resin substrate. Peel off the layers from the glass substrate.

[Comparative Example 2-1]

Except using the composition for forming a peeling layer obtained in Comparative Example 1-1 instead of the composition for forming a peeling layer obtained in Example 1-1, a peeling layer and a polyethylene were produced in the same manner as in Example 2-1. The imide substrate is used to obtain a glass substrate with a peeling layer and a resin substrate. Peel off the layers from the glass substrate.

[7] Evaluation of peelability

Regarding the glass substrate with a peeling layer obtained in Examples 2-1 to 2-3 and Comparative Example 2-1, the peelability of the peeling layer and the glass substrate was confirmed by the following method. In addition, the following tests were performed using the same glass substrate.

<Evaluation of peelability of resin film by cross-cutting test>

The peeling layers on the glass substrates with peeling layers obtained in Examples 2-1 to 2-3 and Comparative Example 2-1 were cross-cut (1 mm vertical and horizontal intervals, the following Same as), cut into 100 squares. That is, 100 1mm square grids are formed by this cross cutting.

Next, apply adhesive tape to the 100-square section, peel off the tape, and evaluate the degree of peeling based on the following standards (5B~0B, B, A, AA). The results are shown in Table 1.

<Judgment criteria>

5B: 0% peeling (no peeling)

4B: Less than 5% peeling

3B: 5~15% peeling

2B: 15~ less than 35% peeling

1B: 35~less than 65% peeling

0B: 65%~less than 80% peeling

B: 80%~less than 95% peeling

A: 95% ~ less than 100% peeling

AA: 100% peeling (all peeling off)

<Evaluation of initial peeling force of resin substrate>

The resin substrates obtained in Examples 2-1 to 2-3 and Comparative Example 2-1 were used. The resin substrate of the glass substrate of the peeling layer was cut into strips with a width of 25 mm using a cutting machine. Next, a cellophane tape was stuck to the front end of the cut resin substrate, and this was used as a test piece. This test piece was subjected to a peeling test using a push-pull tester manufactured by Attonic Co., Ltd. so that the peeling angle was 90°, and the peeling force was evaluated based on the following criteria. The results are shown in Table 1.

<Judgment criteria>

4b: No peeling

3b: Peeling force above 1.00 (N/25mm)

2b: Peeling force from 0.80 to less than 1.00 (N/25mm)

1b: Peeling force from 0.60 to less than 0.80 (N/25mm)

0b: Peeling force from 0.40 to less than 0.60 (N/25mm)

b: Peeling force from 0.30 to less than 0.40 (N/25mm)

a: Peeling force from 0.20 to less than 0.30 (N/25mm)

aa: Peeling force less than 0.20 (N/25mm)

<Evaluation of peeling force of resin substrates subjected to high temperature treatment>

The initial peeling force of Examples 2-1~2-3 and Comparative Example 2-1 were attached to the resin substrate. The resin substrate of the peeled-off layer glass substrate was heated at 400° C. for 6 hours using an oven, and the same high-temperature treatment as the TFT step was performed. Next, a 90° peel test of the resin substrate was performed in the same manner as the initial peel force evaluation. The obtained peeling force was evaluated on the same basis as the initial peeling force.

<Evaluation of variation in peeling force>

The change amount of the peeling force before the high temperature treatment and the peeling force after the high temperature treatment was calculated using the following formula. Next, the degree of change in peeling force was evaluated based on the following criteria. The results are reported in Table 1.

Change amount (%) = {(peeling force after high temperature treatment) - (peeling force before high temperature treatment)}/(peeling force before high temperature treatment) × 100

○: Peeling force change less than 40% (good peeling)

△: 40~less than 70% change in peeling force

×: 70~less than 100% change in peeling force

××: Change in peeling force of more than 100% (deterioration of peeling force)

As shown in Table 1, it can be seen that the peeling force of the peeling layer of the Example does not change even after high-temperature treatment.

On the other hand, it was found that the peeling layer of Comparative Example 2-1 had excellent adhesion to the glass substrate and excellent peelability to the resin substrate, but the peeling force deteriorated after high-temperature treatment.

Claims (5)

A composition for forming a release layer, characterized by containing polyamide represented by any of the following formulas and an organic solvent,

(In the formula, m is a natural number below 100). The composition for forming a release layer according to claim 1, wherein the organic solvent includes amide represented by formula (S1), amide represented by formula (S2) and amide represented by formula (S3). At least 1 type selected from amines,

(In the formula, R ²⁵ and R ²⁶ are independent of each other and are alkyl groups with 1 to 10 carbon atoms, R ²⁷ is a hydrogen atom or an alkyl group with 1 to 10 carbon atoms, and b is a natural number). A peeling layer characterized by being formed from the composition for forming a peeling layer according to claim 1 or 2. A method of manufacturing a flexible electronic device having a resin substrate, characterized by using the peeling layer described in claim 3. The manufacturing method as described in claim 4, wherein the above-mentioned The resin substrate is a substrate made of polyimide.