JP6939862B2 - Composition for forming a release layer - Google Patents

Description

The present invention relates to a composition for forming a release layer, and more specifically, to a composition for forming a release layer for forming a release layer provided on a substrate.

In recent years, electronic devices are required to have a function of bending, thinning, and weight reduction. For this reason, it is required to use a lightweight flexible plastic substrate instead of the conventional heavy, fragile and inflexible glass substrate. Further, in the new generation display, development of an active full-color TFT display panel using a lightweight flexible plastic substrate is required. Therefore, various methods for manufacturing electronic devices using a resin film as a substrate have begun to be studied, and for new-generation displays, manufacturing studies are being carried out by a process in which existing TFT equipment can be diverted.

In Patent Documents 1, 2 and 3, an amorphous silicon thin film layer is formed on a glass substrate, a plastic substrate is formed on the thin film layer, and then a laser is irradiated from the glass surface side to accompany the crystallization of amorphous silicon. A method of peeling a plastic substrate from a glass substrate by the generated hydrogen gas is disclosed. Further, in Patent Document 4, a peelable layer (described as “transfer layer” in Patent Document 4) is attached to a plastic film by using the techniques disclosed in Patent Documents 1 to 3 to complete a liquid crystal display device. Disclose the method.

However, in the methods disclosed in Patent Documents 1 to 4, particularly the method disclosed in Patent Document 4, it is essential to use a substrate having high translucency, and the substrate is passed through the substrate to be further subjected to amorphous silicon. In order to give sufficient energy to release the contained hydrogen, it is necessary to irradiate a relatively large laser beam, and there is a problem that the layer to be separated is damaged. Further, since the laser treatment requires a long time and it is difficult to peel off the layer to be peeled off having a large area, there is also a problem that it is difficult to increase the productivity of device fabrication.

Japanese Unexamined Patent Publication No. 10-125929 Japanese Unexamined Patent Publication No. 10-125931 International Publication No. 2005/050754 Japanese Unexamined Patent Publication No. 10-125930

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composition for forming a release layer that can be peeled off without damaging the resin substrate of a flexible electronic device.

As a result of diligent studies to solve the above problems, the present inventors have made a composition containing a polyamic acid obtained by reacting an aromatic diamine with an aromatic tetracarboxylic acid dianhydride and an organic solvent. The aromatic tetracarboxylic acid dianhydride contains an aromatic diamine containing at least one of an ester bond and an ether bond, and / or the aromatic tetracarboxylic acid dianhydride contains at least one of an ester bond and an ether bond. When an anhydride is contained, a composition capable of forming a release layer having excellent adhesion to a substrate, appropriate adhesion to a resin substrate used as a flexible electronic device, and appropriate peelability can be obtained. Find out and complete the present invention.

３．前記エーテル結合を含む芳香族ジアミンが、式（Ａ８）、（Ａ９）、（Ａ１１）、（Ａ２６）〜（Ａ３３）及び（Ａ４０）〜（Ａ４２）からなる群から選ばれる少なくとも１種である２の剥離層形成用組成物。
４．前記エーテル結合を含む芳香族テトラカルボン酸二無水物が、式（Ｂ３）、（Ｂ４）、（Ｂ８）〜（Ｂ１０）及び（Ｂ１２）〜（Ｂ１４）からなる群から選ばれる少なくとも１種である１〜３のいずれかの剥離層形成用組成物。

５．前記エーテル結合を含む芳香族テトラカルボン酸二無水物が、式（Ｂ３）、（Ｂ４）及び（Ｂ８）〜（Ｂ１０）からなる群から選ばれる少なくとも１種である４の剥離層形成用組成物。
６．前記芳香族テトラカルボン酸二無水物が、更にエステル結合及びエーテル結合のいずれも含まない芳香族テトラカルボン酸二無水物を含む１〜５のいずれかの剥離層形成用組成物。
７．前記エステル結合及びエーテル結合のいずれも含まない芳香族テトラカルボン酸二無水物が、ベンゼン骨格、ナフチル骨格又はビフェニル骨格を含むものである６の剥離層形成用組成物。
８．前記エステル結合及びエーテル結合のいずれも含まない芳香族テトラカルボン酸二無水物が、式（Ｃ１）〜（Ｃ１２）からなる群から選ばれる少なくとも１種である７の剥離層形成用組成物。

９．前記有機溶媒が、式（Ｓ１）で表されるアミド類、式（Ｓ２）で表されるアミド類及び式（Ｓ３）で表されるアミド類から選ばれる少なくとも１つを含む１〜８のいずれかの剥離層形成用組成物。

（式中、Ｒ¹及びＲ²は、互いに独立して、炭素数１〜１０のアルキル基を表す。Ｒ³は、水素原子、又は炭素数１〜１０のアルキル基を表す。ｈは、自然数を表す。）
１０．１〜９のいずれかの剥離層形成用組成物を用いて形成される剥離層。
１１．１０の剥離層を用いることを特徴とする、樹脂基板を備えるフレキシブル電子デバイスの製造方法。
１２．１０の剥離層を用いることを特徴とする、樹脂基板を備えるタッチパネルセンサーの製造方法。
１３．前記樹脂基板が、ポリイミドからなる基板である１１又は１２の製造方法。 That is, the present invention provides the following composition for forming a release layer.
1. 1. It contains a polyamic acid having a weight average molecular weight of 15,000 to 200,000 obtained by reacting an aromatic diamine with an aromatic tetracarboxylic dianhydride, and an organic solvent.
Peeling characterized in that the aromatic diamine comprises an aromatic diamine comprising an ether bond and / or the aromatic tetracarboxylic acid dianhydride comprises an aromatic tetracarboxylic acid dianhydride comprising an ether bond. Layer-forming composition (where the polyamic acid is 2,2'-dimethylbenzidine, 1,3-bis (4-aminophenoxy) benzene, pyromellitic acid dianhydride, 3,3', 4 , 4'-Does not include those obtained by reacting with biphenyltetracarboxylic acid dianhydride.)
2. The aromatic diamine containing the ether bond is at least one selected from the group consisting of the formulas (A1) to (A3), (A7) to (A12), (A25) to (A33) and (A40) to (A42). The composition for forming a release layer of 1 which is a seed.

3. 3. The aromatic diamine containing an ether bond is at least one selected from the group consisting of formulas (A8), (A9), (A11), (A26) to (A33) and (A40) to (A42) 2 Composition for forming a release layer.
4 . The aromatic tetracarboxylic dianhydride containing the ether bond is at least one selected from the group consisting of the formulas (B3), (B4), (B8) to (B10) and (B12) to (B14). The composition for forming a release layer according to any one of 1 to 3.

5. The composition for forming a release layer of 4 in which the aromatic tetracarboxylic dianhydride containing the ether bond is at least one selected from the group consisting of the formulas (B3), (B4) and (B8) to (B10). ..
6 . The composition for forming a release layer according to any one of 1 to 5 , wherein the aromatic tetracarboxylic acid dianhydride further contains an aromatic tetracarboxylic acid dianhydride containing neither an ester bond nor an ether bond.
7 . 6. The composition for forming an exfoliation layer of 6 , wherein the aromatic tetracarboxylic acid dianhydride containing neither an ester bond nor an ether bond contains a benzene skeleton, a naphthyl skeleton or a biphenyl skeleton.
8 . The composition for forming a release layer of 7 , wherein the aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond is at least one selected from the group consisting of the formulas (C1) to (C12).

9 . Any of 1 to 8 in which the organic solvent contains at least one selected from amides represented by the formula (S1), amides represented by the formula (S2) and amides represented by the formula (S3). Composition for forming a release layer.

(In the formula, R ¹ and R ² represent an alkyl group having 1 to 10 carbon atoms independently of each other. R ³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. H is a natural number. Represents.)
10 . A release layer formed by using the composition for forming a release layer according to any one of 1 to 9.
11 . A method for manufacturing a flexible electronic device including a resin substrate, which comprises using 10 release layers.
1 2 . A method for manufacturing a touch panel sensor including a resin substrate, which comprises using 10 release layers.
1 3 . It said resin substrate, 11 or 1 second manufacturing method is a substrate made of polyimide.

By using the composition for forming a release layer of the present invention, it is possible to obtain a film having excellent adhesion to a substrate, appropriate adhesion to a resin substrate, and appropriate peelability with good reproducibility. By using the composition of the present invention, in the manufacturing process of the flexible electronic device, the resin substrate formed on the substrate and the circuit and the like provided on the substrate are not damaged, and the resin substrate is combined with the circuit and the like. Can be separated from the substrate. Therefore, the composition for forming a release layer of the present invention can contribute to the simplification of the manufacturing process of the flexible electronic device including the resin substrate and the improvement of the yield thereof.

It is a graph which shows the transmittance measured in Example 4.

Hereinafter, the present invention will be described in more detail.
The composition for forming a release layer of the present invention contains a polyamic acid obtained by reacting an aromatic diamine with an aromatic tetracarboxylic acid dianhydride, and an organic solvent, and the aromatic diamine is an ester. An aromatic tetracarboxylic acid dianhydride comprising at least one of a bond and an ether bond and / or said aromatic tetracarboxylic acid dianhydride comprising at least one of an ester bond and an ether bond. .. Here, the release layer in the present invention is a layer provided directly above the glass substrate for a predetermined purpose, and as a typical example thereof, in the manufacturing process of a flexible electronic device, a flexible electron composed of a substrate and a resin such as polyimide is used. The resin substrate is provided between the device and the resin substrate in order to fix the resin substrate in a predetermined process, and the resin substrate is easily peeled off from the substrate after an electronic circuit or the like is formed on the resin substrate. Some are provided to enable this.

The aromatic diamine containing at least one of the ester bond and the ether bond contains one of the ester bond and the ether bond in the molecule, or contains both of them.

Examples of such an aromatic diamine include diamines having a structure in which a plurality of aromatic rings having 6 to 20 carbon atoms are linked by an ester bond or an ether bond. Specific examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and the like. Among them, a diamine having a structure in which two or three aromatic rings are linked by an ester bond or an ether bond is preferable from the viewpoint of ensuring the solubility of the polyamic acid in an organic solvent.

In the present invention, preferred specific examples of the aromatic diamine containing at least one of an ester bond and an ether bond include those shown below.

The aromatic tetracarboxylic dianhydride containing at least one of the ester bond and the ether bond contains one or both of the ester bond and the ether bond in the molecule.

Examples of such aromatic tetracarboxylic acid dianhydride include tetracarboxylic acid dianhydride having a structure in which a plurality of aromatic rings having 6 to 20 carbon atoms are linked by an ester bond or an ether bond. Specific examples of the aromatic ring include the same as described above. Among them, those having a structure in which 3 or 4 aromatic rings are linked by an ester bond or an ether bond are preferable from the viewpoint of ensuring the solubility of the polyamic acid in an organic solvent.

In the present invention, preferred specific examples of the aromatic tetracarboxylic dianhydride containing at least one of an ester bond and an ether bond include those shown below.

In the present invention, other diamines can be used together with the aromatic diamine containing at least one of the ester bond and the ether bond described above.

Such a diamine may be either an aliphatic diamine or an aromatic diamine, but from the viewpoint of ensuring the strength and heat resistance of the obtained thin film, an aromatic diamine containing neither an ester bond nor an ether bond is preferable.

Specific examples thereof include 1,4-diaminobenzene (p-phenylenediamine), 1,3-diaminobenzene (m-phenylenediamine), 1,2-diaminobenzene (o-phenylenediamine), and 2,4-diamino. Toluene, 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-xylylene diamine, p-xylylene diamine, 5-trifluoromethylbenzene-1 , 3-Diamine, 5-trifluoromethylbenzene-1,2-diamine, 3,5-bis (trifluoromethyl) benzene-1,2-diamine and other diamines containing one benzene nucleus; 1,2-naphthalene Diamine, 1,3-naphthalenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 1,6-naphthalenediamine, 1,7-naphthalenediamine, 1,8-naphthalenediamine, 2,3-naphthalenediamine 2,6-naphthalenediamine, 4,4'-biphenyldiamine, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane 3,3'-Dicarboxy-4,4'-diaminodiphenylmethane, 3,3', 5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 4,4'-diaminobenzanilide, 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-aminophenyl) -1,1,1,1,3,3,3-hexafluoropropane, 2 , 2-Bis (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4'- Diaminodiphenyl sulfoxide, 3,3'-bis (trifluoromethyl) biphenyl-4,4'-diamine, 3,3', 5,5'-tetrafluorobiphenyl-4,4' -Diamine, a diamine containing two benzene nuclei such as 4,4'-diaminooctafluorobiphenyl; 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-aminophenylsulfide) benzene, 1,3-bis (3-aminophenylsulfone) benzene, 1,3-bis (4-aminophenylsulfone) benzene, 1,4-bis (4) −Aminophenylsulfone) Benzene, 1,3-bis [2- (4-aminophenyl) isopropyl] benzene, 1,4-bis [2- (3-aminophenyl) isopropyl] benzene, 1,4-bis [2 -(4-Aminophenyl) isopropyl] Diamine containing three benzene nuclei such as benzene can be mentioned, but is not limited thereto. These can be used alone or in combination of two or more.

In the present invention, when other diamines are used together with the aromatic diamine containing at least one of the ester bond and the ether bond, the amount of the aromatic diamine containing at least one of the ester bond and the ether bond is preferably used in the total diamine. Is 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more. By adopting such a usage amount, it is possible to obtain a film having excellent adhesion to the substrate, appropriate adhesion to the resin substrate, and appropriate peelability with good reproducibility.

In the present invention, other tetracarboxylic acid dianhydrides can be used together with the aromatic tetracarboxylic acid dianhydride containing at least one of the ester bond and the ether bond described above.

Such a tetracarboxylic acid dianhydride may be either an aliphatic tetracarboxylic acid dianhydride or an aromatic tetracarboxylic acid dianhydride, but from the viewpoint of ensuring the strength and heat resistance of the obtained thin film, an ester bond is used. And aromatic tetracarboxylic acid dianhydride containing neither ether bond is preferable.

Specific examples thereof include pyromellitic acid dianhydride, benzene-1,2,3,4-tetracarboxylic acid dianhydride, naphthalene-1,2,3,4-tetracarboxylic acid dianhydride, and naphthalene-1. , 2,5,6-Tetracarboxylic acid dianhydride, naphthalene-1,2,6,7-tetracarboxylic acid dianhydride, naphthalene-1,2,7,8-tetracarboxylic acid dianhydride, naphthalene- 2,3,5,6-Tetracarboxylic acid dianhydride, naphthalene-2,3,6,7-tetracarboxylic acid dianhydride, naphthalene-1,4,5,8-tetracarboxylic acid dianhydride, biphenyl -2,2', 3,3'-tetracarboxylic acid dianhydride, biphenyl-2,3,3', 4'-tetracarboxylic acid dianhydride, biphenyl-3,3', 4,4'-tetra Carous acid dianhydride, anthracene-1,2,3,4-tetracarboxylic acid dianhydride, anthracene-1,2,5,6-tetracarboxylic acid dianhydride, anthracene-1,2,6,7- Tetracarboxylic acid dianhydride, anthracene-1,2,7,8-tetracarboxylic acid dianhydride, anthracene-2,3,6,7-tetracarboxylic acid dianhydride, phenanthrene-1,2,3,4 -Tetracarboxylic acid dianhydride, phenanthrene-1,2,5,6-tetracarboxylic acid dianhydride, phenanthrene-1,2,6,7-tetracarboxylic acid dianhydride, phenanthrene-1,2,7, 8-Tetracarboxylic acid dianhydride, phenanthrene-1,2,9,10-tetracarboxylic acid dianhydride, phenanthrene-2,3,5,6-tetracarboxylic acid dianhydride, phenanthrene-2,3,6 , 7-Tetracarboxylic acid dianhydride, phenanthrene-2,3,9,10-tetracarboxylic acid dianhydride, phenanthrene-3,4,5,6-tetracarboxylic acid dianhydride, phenanthrene-3,4, Examples include, but are not limited to, 9,10-tetracarboxylic acid dianhydride. These can be used alone or in combination of two or more.

In particular, as the aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond, at least one selected from the group consisting of the formulas (C1) to (C12) is preferable from the viewpoint of ensuring heat resistance. , At least one selected from the group consisting of the formula (C1) and the formula (C9) is more preferable.

In the present invention, when an aromatic tetracarboxylic acid dianhydride containing at least one of an ester bond and an ether bond is used together with another tetracarboxylic acid dianhydride, an aromatic tetracarbonate containing at least one of an ester bond and an ether bond is used. The amount of the carboxylic acid dianhydride used is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more, based on the total tetracarboxylic acid dianhydride. Is. By adopting such a usage amount, it is possible to obtain a film having sufficient adhesion to the substrate, appropriate adhesion to the resin substrate, and appropriate peelability with good reproducibility.

By reacting the diamine described above with the tetracarboxylic dianhydride, the polyamic acid contained in the composition for forming a release layer according to the present invention can be obtained.

The organic solvent used for such a reaction is not particularly limited as long as it does not adversely affect the reaction, and specific examples thereof include m-cresol, 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-. Pyrrolidone, N-vinyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, 3-methoxy-N, N-dimethylpropylamide, 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 -Tart-butoxy-N, N-dimethylpropylamide, γ-butyrolactone and the like can be mentioned. The organic solvent may be used alone or in combination of two or more.

In particular, since the organic solvent used in the reaction dissolves diamine, tetracarboxylic dianhydride and polyamic acid well, the amides represented by the formula (S1), the amides represented by the formula (S2) and the formula (S2). At least one selected from the amides represented by S3) is preferable.

In the formula, R ¹ and R ² represent alkyl groups having 1 to 10 carbon atoms independently of each other. R ³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. h represents a natural number, preferably 1 to 3, more preferably 1 or 2.

Alkyl groups having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group and n-. Examples thereof include a hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group and an n-decyl group. Of these, an alkyl group having 1 to 3 carbon atoms is preferable, and an alkyl group having 1 or 2 carbon atoms is more preferable.

The reaction temperature may be appropriately set in the range from the melting point to the boiling point of the solvent to be used, and is usually about 0 to 100 ° C., but imidization in the obtained polyamic acid solution is prevented and the polyamic acid unit is high. In order to maintain the amount, 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 unconditionally defined because it depends on the reaction temperature and the reactivity of the raw material, but it is usually about 1 to 100 hours.

By the method described above, a reaction solution containing the desired polyamic acid can be obtained.

The weight average molecular weight of the polyamic acid is preferably 5,000 to 1,000,000, more preferably 10,000 to 500,000, and even more preferably 15,000 to 200,000 from the viewpoint of handleability. In the present invention, the weight average molecular weight is the average molecular weight obtained in terms of standard polystyrene by gel permeation chromatography (GPC) analysis.

In the present invention, a solution obtained by filtering the reaction solution and then using the filtrate as it is or by diluting or concentrating the reaction solution can be used as the composition for forming a release layer of the present invention. By doing so, not only can the mixing of impurities that can cause deterioration of the adhesiveness and peelability of the obtained release layer be reduced, but also a composition for forming the release layer can be efficiently obtained. Further, after isolating the polyamic acid from the reaction solution, it may be dissolved in a solvent again to obtain a composition for forming a release layer. Examples of the solvent in this case include the organic solvent used in the above-mentioned reaction.

The solvent used for dilution is not particularly limited, and specific examples thereof include the same as the specific examples of the reaction solvent for the reaction. The solvent used for dilution may be used alone or in combination of two or more. Among them, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2 because it dissolves polyamic acid well. -Pyrrolidone and γ-butyrolactone are preferable, and N-methyl-2-pyrrolidone is more preferable.

Further, even if the solvent does not dissolve the polyamic acid by itself, it can be mixed with the composition for forming a release layer of the present invention as long as the polyamic acid does not precipitate. In particular, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 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-ethoxy Propoxy) Solvents having low surface tension such as propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, and isoamyl lactate can be appropriately mixed. It is known that this improves the uniformity of the coating film when it is applied to a substrate, and it is also preferably used in the composition for forming a release layer of the present invention.

The concentration of the polyamic acid in the composition for forming a release layer of the present invention is appropriately set in consideration of the thickness of the release layer to be produced, the viscosity of the composition, etc., but is usually about 1 to 30% by mass, preferably about 1 to 30% by mass. It is about 1 to 20% by mass. With such a concentration, a peeling layer having a thickness of about 0.05 to 5 μm can be obtained with good reproducibility. The concentration of the polyamic acid is adjusted by adjusting the amount of diamine and tetracarboxylic dianhydride used as raw materials of the polyamic acid, filtering the reaction solution and then diluting or concentrating the filtrate, and the isolated polyamic acid. Can be adjusted by adjusting the amount of the substance when it is dissolved in the solvent.

The viscosity of the composition for forming a release layer is appropriately set in consideration of the thickness of the release layer to be produced, etc., but the purpose is to obtain a film having a thickness of about 0.05 to 5 μm with good reproducibility. In this case, it is usually about 10 to 10,000 mPa · s at 25 ° C., preferably about 20 to 5,000 mPa · s. Here, the viscosity can be measured using a commercially available viscometer for measuring the viscosity of a liquid, for example, with reference to the procedure described in JIS K7117-2, under the condition that the temperature of the composition is 25 ° C. .. Preferably, a conical plate type (cone plate type) rotational viscometer is used as the viscometer, and 1 ° 34'x R24 is preferably used as the standard cone rotor with the same type viscometer, and the temperature of the composition is 25. It can be measured under the condition of ° C. Examples of such a rotational viscometer include TVE-25L manufactured by Toki Sangyo Co., Ltd.

In addition to the polyamic acid and the organic solvent, the composition for forming a release layer according to the present invention may contain components such as a cross-linking agent in order to improve the film strength, for example.

By applying the release layer forming composition of the present invention described above to a substrate and heating the obtained coating film to thermally imidize the polyamic acid, excellent adhesion to the substrate and appropriate adhesion to the resin substrate are obtained. It is possible to obtain a peeling layer made of a polyimide film having excellent adhesion and appropriate peeling property.

When the release layer of the present invention is formed on a substrate, the release layer may be formed on a partial surface of the substrate or may be formed on the entire surface of the substrate. Examples of forming the release layer on a part of the surface of the substrate include forming the release layer only in a predetermined range on the surface of the substrate, and forming the release layer in a pattern such as a dot pattern or a line and space pattern on the entire surface of the substrate. There are modes of formation and the like. In the present invention, the substrate means a substrate on which the composition for forming a release layer according to the present invention is coated, and is used for manufacturing a flexible electronic device or the like.

Examples of the substrate (base material) include glass, plastic (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy, melamine, triacetyl cellulose, ABS, AS, norbornene resin, etc.), metal (silicon wafer, etc.), and the like. Examples thereof include wood, paper, and slate. In particular, glass is preferable because the release layer obtained from the release layer forming composition according to the present invention has sufficient adhesion to the release layer. The surface of the substrate may be made of a single material or may be made of two or more materials. A mode in which the surface of the substrate is composed of two or more materials is a mode in which a certain range of the surface of the substrate is composed of a certain material and the remaining surface is composed of other materials, and a dot pattern is formed on the entire surface of the substrate. , A pattern in which a patterned material such as a line-and-space pattern is present in other materials, and the like.

The coating method is not particularly limited, but for example, a cast coating method, a spin coating method, a blade coating method, a dip coating method, a roll coating method, a bar coating method, a die coating method, an inkjet method, and a printing method (letter plate, intaglio plate, planographic plate). , Screen printing, etc.).

The heating temperature for imidization is usually appropriately determined in the range of 50 to 550 ° C, but is preferably 200 ° C or higher, and preferably 500 ° C or lower. By setting the heating temperature in this way, it is possible to sufficiently proceed the imidization reaction while preventing the resulting film from becoming fragile. The heating time cannot be unconditionally specified because it varies depending on the heating temperature, but is usually 5 minutes to 5 hours. The imidization rate may be in the range of 50 to 100%.

As a preferable example of the heating mode in the present invention, after heating at 50 to 100 ° C. for 5 minutes to 2 hours, the heating temperature is gradually increased as it is, and finally, the heating temperature is increased over 375 ° C. to 450 ° C. for 30 minutes to 4 hours. A method of heating can be mentioned. In particular, it is preferable to heat at 50 to 100 ° C. for 5 minutes to 2 hours, then at 100 ° C. to 375 ° C. for 5 minutes to 2 hours, and finally at 375 ° 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 atmosphere may be under air or under an inert gas, and may be under normal pressure or reduced pressure.

The thickness of the release layer is usually about 0.01 to 50 μm, preferably about 0.05 to 20 μm, more preferably about 0.05 to 5 μm from the viewpoint of productivity, and the thickness of the coating film before heating. To achieve the desired thickness.

The release layer described above has excellent adhesion to a substrate, particularly a glass substrate, appropriate adhesion to a resin substrate, and appropriate peelability. Therefore, in the process of manufacturing a flexible electronic device, the release layer according to the present invention can be used to remove the resin substrate from the substrate together with a circuit or the like formed on the resin substrate without damaging the resin substrate of the device. It can be suitably used for peeling.

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 release layer forming composition according to the present invention, a release layer is formed on the glass substrate by the above-mentioned method. A resin solution for forming a resin substrate is applied onto the release layer, and the coating film is heated to form a resin substrate fixed to the glass substrate via the release layer according to the present invention. .. At this time, the resin substrate is formed with an area larger than the area of the release layer so as to cover the entire release layer. Examples of the resin substrate include a resin substrate made of polyimide, which is a typical resin substrate for flexible electronic devices, and examples of the resin solution for forming the resin substrate include a polyimide solution and a polyamic acid solution. The method for forming the resin substrate may be a conventional method.

Next, a desired circuit is formed on the resin substrate fixed to the substrate via the release layer according to the present invention, and then, for example, the resin substrate is cut along the release layer, and the resin substrate is cut together with this circuit. Is peeled off from the peeling layer to separate the resin substrate and the substrate. At this time, a part of the substrate may be cut together with the release layer.

On the other hand, in the manufacture of flexible displays, it has been reported that the polymer substrate can be suitably peeled from the glass carrier by using the laser lift-off method (LLO method) which has been used in the manufacture of high-brightness LEDs and three-dimensional semiconductor packages. (Japanese Patent Laid-Open No. 2013-147599). In the manufacture of flexible displays, a polymer substrate made of polyimide or the like is provided on a glass carrier, then a circuit or the like including electrodes or the like is formed on the substrate, and finally the substrate is peeled off from the glass carrier together with this circuit or the like. There is a need. When the LLO method is adopted in this peeling step, that is, when a light beam having a wavelength of 308 nm is applied to the glass carrier from a surface opposite to the surface on which the circuit or the like is formed, the light ray having the wavelength is transmitted through the glass carrier and the glass carrier. Only the nearby polymer (polyimide) absorbs this light beam and evaporates (sublimates). As a result, it has been reported that the substrate can be selectively peeled from the glass carrier without affecting the circuits provided on the substrate, which determines the performance of the display.

When a desired circuit is formed on the resin substrate fixed to the substrate via the release layer according to the present invention and then the LLO method is adopted, only the release layer absorbs this light beam and evaporates (sublimates). )do. That is, the peeling layer is sacrificed (acts as a sacrificial layer), and the substrate can be selectively peeled from the glass carrier. The composition for forming a release layer of the present invention has a feature of sufficiently absorbing light rays having a specific wavelength (for example, 308 nm) to which the LLO method can be applied, and therefore can be used as a sacrificial layer of the LLO method.

Hereinafter, the present invention will be described in more detail with reference to Synthesis Examples, Comparative Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to these Examples. The abbreviations of the compounds used in the following examples and the methods for measuring the number average molecular weight and the weight average molecular weight are as follows.

<Abbreviation of compound>
p-PDA: p-phenylenediamine m-PDA: m-phenylenediamine DATP: 4,4 '' -diamino-p-terphenyl DBA: 3,5-diaminobenzoate HAB: 3,3'-dihydroxybenzidine DDE: 4,4'-Oxydianiline BABP: 4,4'-bis (4-aminophenoxy) biphenyl FABP: 4,4'-bis (4-amino-2-trifluoromethylphenoxy) biphenyl APAB: 5-amino- 2- (4-Aminophenyl) -1H-benzoimidazole APAB-E: 4-aminophenyl-4'-aminobenzoate 6FAP: 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane TFMB: 2 , 2'-bis (trifluoromethyl) biphenyl-4,4'-diamine BPDA: 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride TAHQ: p-phenylenebis (trimeritic acid monoesteric acid) (Anhydrous)
PMDA: pyromellitic acid dianhydride BPTME: p-biphenylene bis (trimellitic acid monoesteric anhydride)
BPODA: 4,4'-(biphenyl-4,4'-diylbisoxy) bisphthalic dianhydride CF3-BP-TMA: N, N'-[2,2'-bis (trifluoromethyl) biphenyl-4 , 4'-Diyl] bis (1,3-dioxo-1,3-dihydroisobenzofuran-5-carbamide)
6FDA: 4,4'-(hexafluoroisopropyridene) diphthalic acid anhydride CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride IPBBT: N, N'-isophthalic acid (benzoxazoline-2-thione) )
NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve

<Measurement of weight average molecular weight and molecular weight distribution>
The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the polymer are measured by GPC equipment manufactured by JASCO Corporation (column: OHpak SB803-HQ and OHpak SB804-HQ manufactured by Showa Denko Corporation; eluent. : Dimethylformamide / LiBr · H ₂ O (29.6 mM) / H ₃ PO ₄ (29.6 mM) / THF (0.1% by mass); Flow rate: 1.0 mL / min; Column temperature: 40 ° C; Mw: (Standard polystyrene conversion value) was used (the same applies to the following examples and comparative examples).

[1] Polymer synthesis A polyamic acid and a polybenzoxazole precursor were synthesized by the following method.
The polymer was not isolated from the obtained polymer-containing reaction solution, and the reaction solution was diluted to prepare a resin substrate forming composition or a release layer forming composition as described later.

[Synthesis Example S1] Synthesis of polyamic acid S1 20.261 g (187 mmol) of p-PDA and 12.206 g (47 mmol) of DATP were dissolved in NMP 617.4 g. The obtained solution was cooled to 15 ° C., PMDA 50.112 g (230 mmol) was added thereto, the temperature was raised to 50 ° C. under a nitrogen atmosphere, and the mixture was reacted for 48 hours to obtain polyamic acid S1. The Mw of the polyamic acid S1 was 82,100, and the Mw / Mn was 2.7.

[Synthesis Example S2] Synthesis of polyamic acid S2 3.218 g (30 mmol) of p-PDA was dissolved in 88.2 g of NMP. 8.581 g (29 mmol) of BPDA was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid S2. The Mw of the polyamic acid S2 was 107,300, and the Mw / Mn was 4.6.

[Synthesis Example S3] Synthesis of polyamic acid S3 17.8 g (56 mmol) of TFMB, 0.4 g (1 mmol) of BABP and 2.5 g (23 mmol) of p-PDA were dissolved in 430 g of NMP. To the obtained solution, 6.3 g (14 mmol) of 6FDA and 42.8 g (64 mmol) of CF3-BP-TMA were added and reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid S3. The Mw of the polyamic acid S3 was 38,700, and the Mw / Mn was 2.1.

[Synthesis Example S4] Synthesis of polyamic acid S4 30.6 g (153 mmol) of DDE was dissolved in 440 g of NMP. 29.4 g (150 mmol) of CBDA was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid S4. The Mw of the polyamic acid S4 was 29,800, and the Mw / Mn was 2.2.

[Synthesis Example L1] Synthesis of polyamic acid L1 2.054 g (19 mmol) of p-PDA was dissolved in 88 g of NMP. 9.946 g (19 mmol) of BPTME was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L1. The Mw of the polyamic acid L1 was 57,500, and the Mw / Mn was 3.0.

[Synthesis Example L2] Synthesis of polyamic acid L2 1.836 g (17 mmol) of p-PDA and 0.287 g (1.9 mmol) of DBA were dissolved in 88 g of NMP. 9.878 g (18 mmol) of BPTME was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L2. The Mw of the polyamic acid L2 was 65,100, and the Mw / Mn was 3.0.

[Synthesis Example L3] Synthesis of polyamic acid L3 1.367 g (13 mmol) of p-PDA and 1.172 g (5.4 mmol) of HAB were dissolved in 88 g of NMP. 9.461 g (18 mmol) of BPTME was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L3. The Mw of the polyamic acid L3 was 43,600 and Mw / Mn2.6.

[Synthesis Example L4] Synthesis of polyamic acid L4 3.984 g (15 mmol) of DATP was dissolved in 88 g of NMP. 8.016 g (15 mmol) of BPTME was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L4. The Mw of the polyamic acid L4 was 42,600, and the Mw / Mn was 3.9.

[Synthesis Example L5] Synthesis of polyamic acid L5 5.17 g (14 mmol) of BAPB was dissolved in 88 g of NMP. 6.83 g (13 mmol) of BPTME was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L5. The Mw of the polyamic acid L5 was 52,100, and the Mw / Mn was 2.7.

[Synthesis Example L6] Synthesis of polyamic acid L6 5.89 g (12 mmol) of FAPB was dissolved in 88 g of NMP. 6.11 g (11 mmol) of BPTME was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L6. The Mw of the polyamic acid L6 was 87,700, and the Mw / Mn was 3.3.

[Synthesis Example L7] Synthesis of polyamic acid L7 3.60 g (16 mmol) of APAB was dissolved in 88 g of NMP. 8.40 g (16 mmol) of BPTME was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L7. The Mw of the polyamic acid L7 was 58,300, and the Mw / Mn was 2.8.

[Synthesis Example L8] Synthesis of polyamic acid L8 2.322 g (12 mmol) of DDE was dissolved in 35.2 g of NMP. 2.478 g (11 mmol) of PMDA was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L8. The Mw of the polyamic acid L8 was 22,600, and the Mw / Mn was 2.1.

[Synthesis Example L9] Synthesis of polyamic acid L9 1.762 g (7 mmol) of DATP was dissolved in 35.2 g of NMP. 3.038 g (7 mmol) of TAHQ was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L9. The Mw of the polyamic acid L9 was 61,300, and the Mw / Mn was 3.3.

[Synthesis Example L10] Synthesis of polyamic acid L10 0.899 g (8 mmol) of p-PDA was dissolved in 35.2 g of NMP. 3.900 g (8 mmol) of BPODA was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L10. The Mw of the polyamic acid L10 was 17,300, and the Mw / Mn was 2.4.

[Synthesis Example L11] Synthesis of polyamic acid L11 1.713 g (7 mmol) of DATP was dissolved in 35.2 g of NMP. 3.086 g (6 mmol) of BPODA was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L11. The Mw of the polyamic acid L11 was 27,000, and the Mw / Mn was 2.4.

[Synthesis Example L12] Synthesis of polyamic acid L12 0.931 g (9 mmol) of p-PDA was dissolved in 35.2 g of NMP. 3.868 g (8 mmol) of TAHQ was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L12. The Mw of the polyamic acid L12 was 45,000, and the Mw / Mn was 2.7.

[Synthesis Example L13] Synthesis of polyamic acid L13 0.839 g (8 mmol) of p-PDA and 0.093 g (1 mmol) of m-PDA were dissolved in 35.2 g of NMP. 3.868 g (8 mmol) of TAHQ was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L13. The Mw of the polyamic acid L13 was 39,100, and the Mw / Mn was 2.6.

[Synthesis Example L14] Synthesis of polyamic acid L14 0.652 g (6 mmol) of p-PDA and 0.280 g (3 mmol) of m-PDA were dissolved in 35.2 g of NMP. 3.868 g (8 mmol) of TAHQ was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L14. The Mw of the polyamic acid L14 was 42,700, and the Mw / Mn was 2.6.

[Synthesis Example L15] Synthesis of polyamic acid L15 0.931 g (9 mmol) of m-PDA was dissolved in 35.2 g of NMP. 3.868 g (8 mmol) of TAHQ was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L15. The Mw of the polyamic acid L15 was 36,100, and the Mw / Mn was 2.5.

<Synthesis Example L16] Synthesis of polyamic acid L16 0.816 g (8 mmol) of p-PDA and 0.218 g (1 mmol) of DATP were dissolved in 35.2 g of NMP. 3.765 g (8 mmol) of TAHQ was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L16. The Mw of the polyamic acid L16 was 43,800, and the Mw / Mn was 2.5.

[Synthesis Example L17] Synthesis of polyamic acid L17 p-PDA 0.603 g (6 mmol) and DATP 0.622 g (2 mmol) were dissolved in NMP 35.2 g. 3.575 g (8 mmol) of TAHQ was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L17. The Mw of the polyamic acid L17 was 46,000, and the Mw / Mn was 2.6.

[Synthesis Example L18] Synthesis of polyamic acid L18 0.832 g (8 mmol) of p-PDA and 0.130 g (1 mmol) of DBA were dissolved in 35.2 g of NMP. 3.838 g (8 mmol) of TAHQ was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L18. The Mw of the polyamic acid L18 was 57,000, and the Mw / Mn was 3.0.

[Synthesis Example L19] Synthesis of polyamic acid L19 0.822 g (8 mmol) of p-PDA and 0.183 g (1 mmol) of HAB were dissolved in 35.2 g of NMP. 3.794 g (8 mmol) of TAHQ was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L19. The Mw of the polyamic acid L19 was 54,200, and the Mw / Mn was 2.7.

[Synthesis Example L20] Synthesis of polyamic acid L20 0.616 g (6 mmol) of p-PDA and 0.528 g (2 mmol) of HAB were dissolved in 35.2 g of NMP. 3.655 g (8 mmol) of TAHQ was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain a polyamic acid L20. The Mw of the polyamic acid L20 was 55,900, and the Mw / Mn was 2.6.

[Synthesis Example L21] Synthesis of polyamic acid L21 1.239 g (5 mmol) of APAB-E was dissolved in 17.6 g of NMP. 1.160 g (5 mmol) of PMDA was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L21. The Mw of the polyamic acid L21 was 20,900, and the Mw / Mn was 2.1.

[Synthesis Example L22] Synthesis of polyamic acid L22 1.060 g (5 mmol) of APAB-E was dissolved in 17.6 g of NMP. 1.339 g (5 mmol) of BPDA was added to the obtained solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L22. The Mw of the polyamic acid L22 was 26,600, and the Mw / Mn was 2.3.

[Comparative Synthesis Example 1] Synthesis of polybenzoxazole precursor B1 5.49 g (0.015 mol) of 6FAP was dissolved in 27 g of NMP. 6.48 g (0.015 mol) of IPBBT was added to the obtained solution, and the mixture was reacted at 23 ° C. for 3 hours under a nitrogen atmosphere. Then, this solution was put into 300 g of pure water, stirred for 24 hours, and then the precipitate was filtered. Then, it was dried under reduced pressure to obtain a polybenzoxazole precursor B1. The Mw of the polybenzoxazole precursor B1 was 21,000 , and the Mw / Mn was 3.9.

[2] Preparation of Resin Substrate Forming Composition The reaction solutions obtained in Synthesis Examples S1 to S4 were used as they were as the resin substrate forming compositions W, X, Y and Z, respectively.

[3] Preparation of composition for forming a release layer [Example 1-1]
BCS was added to the reaction solution obtained in Synthesis Example L1 and diluted with NMP so that the polymer concentration was 5% by mass and the BCS was 20% by mass to obtain a composition for forming a release layer.

[Examples 1-2 to 1-22]
A composition for forming a release layer was obtained in the same manner as in Example 1-1, except that the reaction solutions obtained in Synthesis Examples L2 to L22 were used instead of the reaction solutions obtained in Synthesis Example L1. rice field.

[Comparative Example 1]
The reaction solution obtained in Comparative Synthesis Example 1 was diluted with NMP so that the polymer concentration was 5% by mass to obtain a composition.

[4] Formation of release layer and evaluation thereof [Example 2-1]
Using a spin coater (condition: about 30 seconds at a rotation speed of 3000 rpm), the composition for forming a release layer obtained in Example 1-1 was applied as a glass substrate on a 100 mm × 100 mm glass substrate (the same applies hereinafter). ..
Then, the obtained coating film is 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 to 400 ° C. (10 ° C./min). ), And further heated at 400 ° C. for 30 minutes to form a release layer having a thickness of about 0.1 μm on the glass substrate. During the temperature rise, the substrate with the film was not taken out of the oven, but was heated in the oven.

[Examples 2-2-2-22]
Example 2-1 except that the composition for forming a release layer obtained in Examples 1-2 to 1-22 was used instead of the composition for forming a release layer obtained in Example 1-1. The release layer was formed in the same manner as in the above.

[Example 2-23]
Using a spin coater (condition: rotation speed 3000 rpm for about 30 seconds), the composition for forming a release layer obtained in Example 1-12 was applied onto a 100 mm × 100 mm glass substrate.
Then, the obtained coating film is heated at 80 ° C. for 10 minutes using a hot plate, and then heated at 140 ° C. for 30 minutes using an oven to raise the heating temperature to 250 ° C. (2 ° C./min). ), And further heated at 250 ° C. for 60 minutes to form a release layer having a thickness of about 0.1 μm on the glass substrate. During the temperature rise, the substrate with the film was not taken out of the oven, but was heated in the oven.

[Example 2-24]
Using a spin coater (condition: rotation speed 3000 rpm for about 30 seconds), the composition for forming a release layer obtained in Example 1-8 was applied onto a 100 mm × 100 mm glass substrate as a glass substrate.
Then, the obtained coating film is heated at 80 ° C. for 10 minutes using a hot plate, and then heated at 300 ° C. for 30 minutes in a nitrogen atmosphere using an oven to raise the heating temperature to 400 ° C. (10). (° C./min), further heated at 400 ° C. for 60 minutes, and finally heated at 500 ° C. for 10 minutes to form a release layer having a thickness of about 0.1 μm on the glass substrate. During the temperature rise, the substrate with the film was not taken out of the oven, but was heated in the oven.

[Example 2-25]
A resin thin film was prepared in the same manner as in Examples 2-24, except that the composition obtained in Example 1-12 was used instead of the composition for forming a release layer obtained in Example 1-8. Formed.

[Comparative Example 2]
A resin thin film was formed in the same manner as in Example 2-1 except that the composition obtained in Comparative Example 1 was used instead of the composition for forming a release layer obtained in Example 1-1. ..

[5] Evaluation of peelability [Examples 3-1 to 3-47, Comparative Example 3]
The peelability between the release layer and the glass substrate obtained in Examples 2-1 to 2-25 and the peelability between the release layer (resin thin film) and the resin substrate were confirmed. As the resin substrate, a resin substrate made of polyimide was used.
First, the cross-cut of the release layer on the glass substrate with the release layer obtained in Examples 2-1 to 2-25 (1 mm intervals in length and width, the same applies hereinafter), and the resin substrate / resin substrate on the glass substrate with the release layer. -100 muscats were performed by cross-cutting the release layer. That is, by this cross cut, 100 squares of 1 mm square were formed.
Then, an adhesive tape was attached to the 100 muscat portion, the tape was peeled off, and the degree of peeling was evaluated based on the following criteria (5B to 0B, B, A, AA) (Examples 3 to 1-3-). 47). Further, according to the above method, the same test was conducted using the glass substrate with the resin thin film obtained in Comparative Example 2 (Comparative Example 3). The results are shown in Table 1. The evaluation criteria for peelability in Table 1 are as follows.

5B: 0% peeling (no peeling)
4B: Peeling less than 5% 3B: Peeling 5 to 15% 2B: Peeling less than 15-35% 1B: Peeling less than 35-65% 0B: Peeling less than 65% to 80% B: 80% to 95% Less than peeling A: 95% to less than 100% peeling AA: 100% peeling (all peeling)

The resin substrates of Examples 3-1 to 3-41, 3-44 to 3-47 and Comparative Example 3 were formed by the following methods.
Using a bar coater (gap: 250 μm), either the resin substrate forming composition W or X was applied onto the release layer (resin thin film) on the glass substrate. Then, the obtained coating film is heated at 80 ° C. for 10 minutes using a hot plate, and then heated at 140 ° C. for 30 minutes using an oven to raise the heating temperature to 210 ° C. (10 ° C./min). , And so on), raise the heating temperature to 300 ° C for 30 minutes at 210 ° C, raise the heating temperature to 400 ° C for 30 minutes at 300 ° C, heat at 400 ° C for 60 minutes, and put it on the release layer. A polyimide substrate having a thickness of about 20 μm was formed. During the temperature rise, the substrate with the membrane was not removed from the oven, but was heated in the oven.

The resin substrates of Examples 3-42 to 3-43 were formed by the following methods.
Using a bar coater (gap: 50 μm), either the resin substrate forming composition Y or Z was applied onto the release layer on the glass substrate. Then, the obtained coating film is heated at 80 ° C. for 10 minutes using a hot plate, and then heated at 140 ° C. for 30 minutes using an oven to raise the heating temperature to 250 ° C. (2 ° C./min). ), And heated at 250 ° C. for 60 minutes to form a polyimide substrate having a thickness of about 0.8 μm on the release layer. During the temperature rise, the substrate with the membrane was not removed from the oven, but was heated in the oven.

As shown in Tables 1 and 2, it was found that the release layer of the example was excellent in adhesion to the glass substrate and excellent in peelability to the resin substrate. On the other hand, the release layer of the comparative example did not separate from the resin substrate and the glass substrate and did not function as the release layer.

[6] Evaluation of transmittance [Example 4]
Using a spin coater (condition: about 30 seconds at a rotation speed of 800 rpm), the composition for forming a release layer obtained in Example 2-8 was applied as a glass substrate on a 100 mm × 100 mm glass substrate (the same applies hereinafter). ..
Then, the obtained coating film is 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 to 400 ° C. (10 ° C./min). ), And further heated at 400 ° C. for 30 minutes to form a release layer having a thickness of about 0.4 μm on the glass substrate. During the temperature rise, the substrate with the film was not taken out of the oven, but was heated in the oven. The transmittance of the obtained film was measured using an ultraviolet visible spectrophotometer (SIMADSU UV-2550 model number manufactured by Shimadzu Corporation).
The results are shown in FIG. The transmittance of the obtained film was 1% or less with respect to a wavelength of 308 nm, indicating a transmittance that could be used as a sacrificial layer.

Claims (9)

It contains a polyamic acid having a weight average molecular weight of 15,000 to 200,000 obtained by reacting an aromatic diamine with an aromatic tetracarboxylic dianhydride, and an organic solvent.
The aromatic diamine comprises an aromatic diamine containing at least one ether bond selected from the group consisting of formulas (A25) and (A40), and / or the aromatic tetracarboxylic acid dianhydride is of the formula ( A composition for forming a release layer, which comprises an aromatic tetracarboxylic acid dianhydride containing at least one ether bond of B8) (provided that the polyamic acid is 2,2'-dimethylbenzidine, and the like. Does not contain those obtained by reacting 1,3-bis (4-aminophenoxy) benzene, pyromellitic acid dianhydride, and 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride. .).

The composition for forming a release layer according to claim 1, wherein the aromatic tetracarboxylic acid dianhydride further contains an aromatic tetracarboxylic acid dianhydride containing neither an ester bond nor an ether bond. The composition for forming a release layer according to claim 2, wherein the aromatic tetracarboxylic acid dianhydride containing neither an ester bond nor an ether bond contains a benzene skeleton, a naphthyl skeleton or a biphenyl skeleton. The peeling layer formation according to claim 3, wherein the aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond is at least one selected from the group consisting of the formulas (C1) to (C12). Composition.

Claims 1 to 4 wherein the organic solvent contains at least one selected from amides represented by the formula (S1), amides represented by the formula (S2) and amides represented by the formula (S3). The composition for forming a release layer according to any one of the above items.

(In the formula, R ¹ and R ² represent an alkyl group having 1 to 10 carbon atoms independently of each other. R ³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. H is a natural number. Represents.) A release layer formed by using the release layer forming composition according to any one of claims 1 to 5. A method for manufacturing a flexible electronic device including a resin substrate, which comprises using the release layer according to claim 6. A method for manufacturing a touch panel sensor including a resin substrate, which comprises using the release layer according to claim 6. The manufacturing method according to claim 7 or 8, wherein the resin substrate is a substrate made of polyimide.

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