JP6954308B2 - Method of manufacturing the release layer - Google Patents

Description

The present invention relates to a method for producing a release layer.

In recent years, in addition to the characteristics of thinning and weight reduction, electronic devices are required to be provided with a function of being bendable. For this reason, it is required to use a lightweight flexible plastic substrate instead of the conventional heavy, fragile and inflexible glass substrate.
In particular, in the new generation display, development of an active matrix type full-color TFT display panel using a lightweight flexible plastic substrate (hereinafter referred to as a resin 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, studies are underway on a process in which existing equipment for manufacturing TFT display panels 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 substrate side to crystallize the amorphous silicon. A method of peeling a plastic substrate from a glass substrate by hydrogen gas generated by crystallization 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 form a liquid crystal display device. The method of completion is disclosed.

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 highly translucent substrate in order to transmit laser light, and the method passes through the substrate. In addition, it is necessary to irradiate a laser beam with a relatively large energy sufficient to release hydrogen contained in amorphous silicon, and the irradiation of the laser beam may damage the layer to be peeled off. There is a problem such as that.
Moreover, when the layer to be peeled has a large area, it takes a long time for laser processing, so that it is difficult to increase the productivity of device fabrication.

As a means for solving such a problem, in Patent Document 5, a current glass substrate is used as a substrate (hereinafter referred to as a glass substrate), and a release layer is formed on the glass substrate by using a polymer such as a cyclic olefin copolymer. A manufacturing process in which a heat-resistant resin film such as a polyimide film is formed on the peeling layer, an ITO transparent electrode, a TFT, or the like is formed and sealed on the film by a vacuum process, and then the glass substrate is finally peeled and removed. Has been adopted.

By the way, at present, as a TFT, a low-temperature polysilicon TFT whose mobility is twice as fast as that of an amorphous silicon TFT is used. This low-temperature polysilicon TFT needs to be dehydroanylated at 400 ° C. or higher after vapor deposition of amorphous silicon and irradiated with a pulse laser to crystallize the silicon (hereinafter, these are referred to as TFT steps). The temperature of the annealing step is higher than the glass transition (hereinafter Tg) of the existing polymer.
However, it is known that the existing polymer has increased adhesion when heated to a temperature of Tg or higher (see, for example, Patent Document 6), and the adhesion between the release layer and the resin substrate is enhanced after the heat treatment. , It may be difficult to peel off the resin substrate from the substrate.

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 Japanese Unexamined Patent Publication No. 2010-111853 Japanese Unexamined Patent Publication No. 2008-188792

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing 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 used a composition containing a polyamic acid having an alkali-soluble group in the molecule and an organic solvent, and determined the firing temperature at the time of forming the release layer. The present invention has been found that a release layer having excellent adhesion to a substrate, appropriate adhesion to a resin substrate used for a flexible electronic device, and appropriate peelability can be formed by setting the temperature to the maximum temperature reached or higher. Completed.

（式中、Ｘは、互いに独立して、２つのカルボン酸誘導体を有する４価の芳香族基であり、Ｙは、互いに独立して、２価の芳香族基であり、Ｚ¹及びＺ²は、互いに独立して、１価の有機基であり、式（１Ａ）において、Ｙ、Ｚ¹及びＺ²の少なくとも１つがアルカリ可溶性基を有し、式（１Ｂ）において、Ｙ及び２つのＺ¹の少なくとも１つがアルカリ可溶性基を有し、式（１Ｃ）において、Ｙ及び２つのＺ²の少なくとも１つがアルカリ可溶性基を有し、ｍは、互いに独立して自然数を表す。）
２． 上記アルカリ可溶性基が、カルボキシ基又はフェノール性水酸基である１の剥離層の製造方法、
３． 上記Ｙが、下記式（２）〜（５）で表される芳香族基を含む１又は２の剥離層の製造方法、

（式中、Ｗは、互いに独立して、カルボキシ基又は水酸基を表し、Ｒ¹〜Ｒ³は、互いに独立して、ハロゲン原子で置換されていてもよい、炭素数１〜２０のアルキレン基、炭素数２〜２０のアルケニレン基、炭素数２〜２０のアルキニレン基、炭素数６〜２０のアリーレン基もしくは炭素数２〜２０のヘテロアリーレン基、エーテル基、エステル基又はアミド基を表し、○は結合手を表す。）
４． 上記Ｙが、下記式（６）〜（９）で表される芳香族基を含む３の剥離層の製造方法、

（式中、表し、○は結合手を表す。）
５． 上記Ｚ¹が、下記式（１０）で表される１価の有機基である１〜４のいずれかの剥離層の製造方法、

（式中、Ｚ³は、カルボキシ基又は水酸基を表し、○は結合手を表す。）
６． 上記Ｚ²が、下記式（１１）で表される１価の有機基である１〜５のいずれかの剥離層の製造方法、

（式中、Ｚ³は、カルボキシ基又は水酸基を表し、○は結合手を表す。）
７． 上記Ｙが、さらにアルカリ可溶性基を有しない芳香族基を含む３〜６のいずれかの剥離層の製造方法、
８． 上記アルカリ可溶性基を有しない芳香族基が、フェニレン基、ビフェニレン基又はターフェニレン基である７の剥離層の製造方法、
９． １〜８のいずれかの製造方法を用いて形成される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、
１０． １〜８のいずれかの製造方法を用いて形成した剥離層上に、樹脂基板形成用組成物を塗布した後、最高温度４５０℃以上で焼成して樹脂基板を形成する工程を含むフレキシブル電子デバイスの製造方法、
１１． 前記樹脂基板が、ポリイミド樹脂基板である９又は１０のフレキシブル電子デバイスの製造方法
を提供する。Therefore, the present invention
1. 1. A step of applying a composition for forming a release layer containing at least one of the polyamic acids represented by the following formulas (1A) to (1C) and an organic solvent on a substrate and firing at a maximum temperature of 450 to 550 ° C. is included. Method of manufacturing the release layer,

(In the formula, X is a tetravalent aromatic group having two carboxylic acid derivatives independent of each other, and Y is a divalent aromatic group independently of each other, Z ¹ and Z ² Are monovalent organic groups independently of each other, in formula (1A) ^{at least one of Y, Z 1} and Z ² has an alkali-soluble group, and in formula (1B) Y and two Z. ^At least one of 1 has an alkali-soluble group, and in formula (1C), ^{at least one of Y and two Z 2} has an alkali-soluble group, and m represents a natural number independently of each other.)
2. A method for producing a release layer of 1 in which the alkali-soluble group is a carboxy group or a phenolic hydroxyl group.
3. 3. A method for producing a release layer of 1 or 2 containing an aromatic group represented by the following formulas (2) to (5).

(In the formula, W represents a carboxy group or a hydroxyl group independently of each other, and R ^{1 to} R ³ are independent of each other and may be substituted with a halogen atom. It represents an alkenylene group having 2 to 20 carbon atoms, an alkynylene group having 2 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms or a heteroarylene group having 2 to 20 carbon atoms, an ether group, an ester group or an amide group. Represents a bond.)
4. The method for producing a release layer of 3 containing an aromatic group represented by the following formulas (6) to (9), wherein Y is the method for producing the release layer.

(In the formula, it is represented, and ○ represents the bond.)
5. A method for producing a release layer according to any one of 1 to 4, wherein ^{Z 1 is a monovalent organic group represented by the following formula (10).}

(In the formula, Z ³ represents a carboxy group or a hydroxyl group, and ◯ represents a bond.)
6. A method for producing a release layer according to any one of 1 to 5, wherein ^{Z 2 is a monovalent organic group represented by the following formula (11).}

(In the formula, Z ³ represents a carboxy group or a hydroxyl group, and ◯ represents a bond.)
7. The method for producing a release layer according to any one of 3 to 6, wherein Y further contains an aromatic group having no alkali-soluble group.
8. The method for producing an exfoliated layer of 7, wherein the aromatic group having no alkali-soluble group is a phenylene group, a biphenylene group or a terphenylene group.
9. A method for manufacturing a flexible electronic device including a resin substrate, which comprises using a release layer formed by using any of the manufacturing methods 1 to 8.
10. A flexible electronic device including a step of applying a resin substrate forming composition onto a release layer formed by any of the production methods 1 to 8 and then firing at a maximum temperature of 450 ° C. or higher to form a resin substrate. Manufacturing method,
11. The resin substrate provides a method for manufacturing 9 or 10 flexible electronic devices in which the resin substrate is a polyimide resin substrate.

By adopting the method for producing a release layer of the present invention, it is possible to obtain a release layer having excellent adhesion to a substrate, appropriate adhesion to a resin substrate, and appropriate release property with good reproducibility. Therefore, by implementing the manufacturing method of the present invention, in the manufacturing process of the flexible electronic device, the circuit, etc., without damaging the resin substrate formed on the substrate and the circuit, etc. provided on the substrate, etc. At the same time, the resin substrate can be separated from the substrate. Therefore, the manufacturing method of the present invention can contribute to the simplification of the manufacturing process of the flexible electronic device provided with the resin substrate and the improvement of the yield thereof.

Hereinafter, the present invention will be described in more detail.
In the method for producing a release layer according to the present invention, a composition for forming a release layer containing at least one of the polyamic acids represented by the following formulas (1A) to (1C) and an organic solvent is applied onto a substrate. It is characterized by including a step of firing at a maximum temperature of 450 to 550 ° C.
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 a predetermined process, and the resin substrate can be easily peeled off from the substrate after an electronic circuit or the like is formed on the resin substrate. Examples thereof include a release layer provided for such a purpose.

In each of the above formulas, X is a tetravalent aromatic group having two carboxylic acid derivatives independently of each other, Y is a divalent aromatic group independently of each other, and Z ¹ and Z ² are. , Independent of each other, monovalent organic groups, but in formula (1A) ^{at least one of Y, Z 1} and Z ² has an alkali-soluble group, and in formula (1B) Y and two Z1 At least one of them has an alkali-soluble group, and in the formula (1C), at least one of Y and two Z2 has an alkali-soluble group.
m represents a natural number independently of each other, but an integer of 2 or more is preferable.

The above X is preferably a tetravalent aromatic ring containing 1 to 5 benzene rings, more preferably a tetravalent benzene ring, a tetravalent naphthalene ring, and a tetravalent biphenyl ring, and more preferably a tetravalent benzene ring or a tetravalent ring. The biphenyl ring is even more preferred.

As the divalent aromatic group of Y, an aromatic group containing 1 to 5 benzene rings is preferable, and those represented by the following formulas (2') to (5') are more preferable.

In the above formulas (2') to (5'), R ^{1 to} R ³ are alkylene groups having 1 to 20 carbon atoms and 2 to 20 carbon atoms which may be substituted with halogen atoms independently of each other. It represents an alkenylene group, an alkynylene group having 2 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms or a heteroarylene group having 2 to 20 carbon atoms, an ether group, an ester group or an amide group, and ◯ represents a bond.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.
The alkylene group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms may be linear, branched, or cyclic, and may be, for example, methylene, methylmethylene, dimethylmethylene, ethylene, trimethylene, propylene, tetramethylene, or penta. Examples thereof include methylene and hexamethylene groups.
The alkenylene group having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms may be linear, branched or cyclic, and may be, for example, ethenylene, propenylene, butenylene, pentenylene, hexenylene, heptenylene, octenylene, nonenylene group or the like. Can be mentioned.
The alkynylene group having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms may be linear, branched or cyclic, and may be, for example, ethynylene, propynylene, butynylene, pentinylene, hexynylene, heptinylene, octinilen, noninylene group or the like. Can be mentioned.

When Y is a divalent aromatic group having at least one alkali-soluble group, it is preferably an organic group containing a benzene ring substituted with at least one alkali-soluble group, and in particular, at least one alkali. It is more preferable that the organic group contains two or more benzene rings substituted with soluble groups, and the aromatic groups represented by the following formulas (2) to (5) are even more preferable, and in particular, the following formula (6). The structures represented by (9) are more preferable, and the structures represented by the formulas (6), (7) and (9) having a phenolic hydroxyl group at the ortho position with respect to the adjacent bond are most suitable.

（式中、Ｗは、アルカリ可溶性基、好ましくはカルボキシ基又はフェノール性水酸基を表し、Ｒ¹〜Ｒ³および○は上記と同じ意味を表す。）

(In the formula, W represents an alkali-soluble group, preferably a carboxy group or a phenolic hydroxyl group, and R ^{1 to} R ³ and ◯ have the same meanings as described above.)

（式中、○は結合手を表す。）

(In the formula, ○ represents a bond.)

In the polyamic acid used in the present invention, the Y may contain both a divalent aromatic group having an alkali-soluble group and a divalent aromatic group having no alkali-soluble group.
In this case, the proportion of the divalent aromatic group having an alkali-soluble group in all Y can be about 0.1 to 99.9 mol%, preferably 1 to 50 mol%, and 1 to 10 mol%. % Is more preferable.

Further, in the above formulas (1A) to (1C), Z ¹ and Z ² are monovalent organic groups, but a monovalent organic group containing a benzene ring is preferable, and a monovalent organic group containing one benzene ring is preferable. ^{The group is preferable, Z 1} bonded to the tetracarboxylic acid terminal side is preferably a monovalent organic group represented by the following formula (10A), and Z ² bonded to the diamine terminal side is represented by the following formula (11A). A monovalent organic group is preferred.

（式中、○は結合手を表す。）

(In the formula, ○ represents a bond.)

When Z ¹ and Z ² are divalent aromatic groups having an alkali-soluble group, the alkali-soluble group is preferably directly linked to the aromatic ring, and the number of alkali-soluble groups is one. Is preferable.
^{More specifically, Z 1} bonded to the terminal side of the tetracarboxylic acid is preferably a monovalent organic group represented by the following formula (10B), and the alkali-soluble group is present at the ortho position with respect to NH (the following formula). ^{The monovalent organic group represented by 10) is more preferable, and Z 2} bonded to the diamine terminal side is preferably a monovalent organic group represented by the following formula (11B), and the alkali-soluble group is in the ortho position with respect to CO. The monovalent organic group represented by the following formula (11) present in is more preferable.
In particular, since the polymer terminal has a hydroxyl group, the skeleton can be different from that of the flexible substrate used for the upper layer, so that the function of the obtained film as a release layer can be improved.

（式中、Ｚ³は、カルボキシ基又は水酸基を表し、○は結合手を表す。）

(In the formula, Z ³ represents a carboxy group or a hydroxyl group, and ◯ represents a bond.)

（式中、Ｚ³は、カルボキシ基又は水酸基を表し、○は結合手を表す。）

(In the formula, Z ³ represents a carboxy group or a hydroxyl group, and ◯ represents a bond.)

The polyamic acid represented by the above formulas (1A) to (1C) can be obtained by reacting a predetermined aromatic tetracarboxylic dianhydride component and an aromatic diamine component at a predetermined ratio.
Hereinafter, the aromatic tetracarboxylic acid dianhydride component and the aromatic diamine component used for the synthesis of the polyamic acid used in the production method of the present invention will be described.

The aromatic tetracarboxylic acid dianhydride used for the synthesis of the polyamic acid represented by the above formulas (1A) to (1C) has two dicarboxylic acid anhydride moieties in the molecule and has an aromatic ring. As long as it has, it is not particularly limited, but an aromatic tetracarboxylic acid dianhydride containing 1 to 5 benzene nuclei is preferable.

Specific examples of the aromatic tetracarboxylic acid dianhydride include pyromellitic acid dianhydride, benzene-1,2,3,4-tetracarboxylic acid dianhydride, and naphthalene-1,2,3,4-tetra. Carous acid dianhydride, 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'-tetracarboxylic 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, Phenantren-1,2,3,4-tetracarboxylic acid dianhydride, phenanthrene-1,2,5,6-tetracarboxylic acid dianhydride, phenanthrene-1,2,6,7-tetracarboxylic acid dianhydride , Phenantren-1,2,7,8-tetracarboxylic acid dianhydride, Phenantren-1,2,9,10-tetracarboxylic acid dianhydride, Phenantren-2,3,5,6-tetracarboxylic acid dianhydride Phenantren-2,3,6,7-tetracarboxylic acid dianhydride, phenanthrene-2,3,9,10-tetracarboxylic acid dianhydride, phenanthrene-3,4,5,6-tetracarboxylic acid dianhydride Anhydrous, phenanthrene-3,4,9,10-tetracarboxylic acid dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic acid, 3,3', 4,4'-diphenyl ether tetracarboxylic acid, 3,3', 4,4'-diphenylsulfone tetracarboxylic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid, 2,2-bis (3,4-di) Carboxyphenyl) hexafluoroisopropyridene, 4,4'-hexafluoroisopropyridene diphthalic acid and the like can be mentioned, and these may be used alone or in combination of two or more.

On the other hand, the diamine component is preferably an aromatic diamine containing 1 to 5 benzene nuclei, more preferably an aromatic diamine substituted with at least one alkali-soluble group, and an aromatic having an aromatic ring having a carboxy group or a phenolic hydroxyl group. Group diamines are even more preferred, and aromatic diamines containing aromatic groups substituted with phenolic hydroxyl groups are even more preferred.

Examples of the aromatic diamine having a phenolic hydroxyl group include 3,3'-diamino-4,4'-dihydroxybiphenyl (4BP), 3,3'-diamino-2,2'-dihydroxybiphenyl (2BP), and 2 , 2'-bis (3-amino-4-hydroxyphenyl) hexafluoropropane (BAHF), 2,2-bis (4-amino-3,5-dihydroxyphenyl) hexafluoropropane, 2,2-bis [4 -(3-Amino-4-hydroxyphenoxy) phenyl] Hexafluoropropane, bis (3-amino-4-hydroxyphenyl) methane (BAPF), 3,3'-diamino-4,4'-dihydroxybenzophenone (AHPK) , 3,3'-diamino-4,4'-dihydroxy-phenyl ether (AHPE), 3,3'-diamino-4,4'-dihydroxy-thiophenyl ether, 2,2'-bis (3-amino-) 4-Hydroxyphenyl) propane (BAPA), (3-amino-4-hydroxy) phenyl (3-amino4-hydroxy) anilide (AHPA), bis (3-amino-4-hydroxyphenyl) sulfone (BSDA), bis -N, N'-(p-aminobenzoyl) -hexafluoro-2,2'-bis (4-hydroxyphenyl) propane (BABHBPA), [4- (4-aminophenoxy) phenyl] sulfone, 2,4- Diaminophenol, 3,5-diaminophenol, 2,5-diaminophenol, 4,6-diaminoresorcinol, 2,5-diaminohydroquinone, bis (3-amino-4-hydroxyphenyl) thioether, bis (4-amino- 3,5-Dihydroxyphenyl) thioether, bis (3-amino-4-hydroxyphenyl) ether, bis (4-amino-3,5-dihydroxyphenyl) ether, bis (3-amino-4-hydroxyphenyl) methane, Bis (4-amino-3,5-dihydroxyphenyl) methane, bis (3-amino-4-hydroxyphenyl) sulfone, bis (4-amino-3,5-dihydroxyphenyl) sulfone, 4,4'-diamino- 3,3'-Dihydroxybiphenyl (3BP), 4,4'-diamino-3,3'-dihydroxy-5,5'-dimethylbiphenyl, 4,4'-diamino-3,3'-dihydroxy-5,5 '-Dimethoxybiphenyl, 1,4-bis (3-amino-4-hydroxyphenoxy) benzene, 1,3-bis (3-Amino-4-hydroxyphenoxy) benzene, 1,4-bis (4-amino-3-hydroxyphenoxy) benzene, 1,3-bis (4-amino-3-hydroxyphenoxy) benzene, bis [4-amino-3-hydroxyphenoxy) Examples thereof include (3-amino-4-hydroxyphenoxy) phenyl] sulfone, bis [4- (3-amino-4-hydroxyphenoxy) phenyl] propane, and 1,4-bis (4-aminophenoxy) benzene. , Not limited to this.

Of the above diamine components, preferably 3,3'-diamino-4,4'-dihydroxybiphenyl (4BP), 3,3'-diamino-2,2'-dihydroxybiphenyl (2BP), 2,2'-bis (3-Amino-4-hydroxyphenyl) Hexafluoropropane (BAHF), 2,2-bis (4-amino-3,5-dihydroxyphenyl) Hexafluoropropane, 2,2-bis [4- (3-amino) -4-Hydroxyphenoxy) phenyl] Hexafluoropropane, bis (3-amino-4-hydroxyphenyl) methane (BAPF), 3,3'-diamino-4,4'-dihydroxybenzophenone (AHPK), 3,3' -Diamino-4,4'-dihydroxy-phenyl ether (AHPE), 3,3'-diamino-4,4'-dihydroxy-thiophenyl ether, 2,2'-bis (3-amino-4-hydroxyphenyl) Propane (BAPA), (3-amino-4-hydroxy) phenyl (3-amino4-hydroxy) anilide (AHPA), bis (3-amino-4-hydroxyphenyl) sulfone (BSDA), bis-N, N' -(P-Aminobenzoyl) -hexafluoro-2,2'-bis (4-hydroxyphenyl) propane (BABHBPA), [4- (4-aminophenoxy) phenyl] sulfone, 2,4-diaminophenol, 2, 5-Diaminophenol, 4,6-diaminoresorcinol, 2,5-diaminohydroquinone, bis (3-amino-4-hydroxyphenyl) thioether, bis (4-amino-3,5-dihydroxyphenyl) thioether, bis (3) -Amino-4-hydroxyphenyl) ether, bis (3-amino-4-hydroxyphenyl) methane, bis (3-amino-4-hydroxyphenyl) sulfone, 4,4'-diamino-3,3'-dihydroxybiphenyl (3BP), 4,4'-diamino-3,3'-dihydroxy-5,5'-dimethylbiphenyl, 4,4'-diamino-3,3'-dihydroxy-5,5'-dimethoxybiphenyl, 1, 4-Bis (3-amino-4-hydroxyphenoxy) benzene, 1,3-bis (3-amino-4-hydroxyphenoxy) benzene, 1,4-bis (4-amino-3-hydroxyphenoxy) benzene, 1 , 3-Bis (4-amino-3-hydroxyphenoxy) benzene, Bis [4- (3-Amino-4-hydroxyphenoxy) Examples thereof include phenyl] sulfone, bis [4- (3-amino-4-hydroxyphenoxy) phenyl] propane, and 1,4-bis (4-aminophenoxy) benzene.

Particularly suitable are bis (3-amino-4-hydroxyphenyl) methane (BAPF), 2,2'-bis (3-amino-4-hydroxyphenyl) propane (BAPA), 2,2'-bis (2,2'-bis (BAPA). 3-Amino-4-hydroxyphenyl) Hexafluoropropane (BAHF), 3,3'-diamino-4,4'-dihydroxy-phenyl ether (AHPE), 3,3'-diamino-4,4'-dihydroxybenzophenone (AHPK), bis (3-amino-4-hydroxyphenyl) sulfide (BSDA), (3-amino-4-hydroxy) phenyl (3-amino-4-hydroxy) anilides (AHPA), bis-N, N' -(P-Aminobenzoyl) -hexafluoro-2,2'-bis (4-hydroxyphenyl) propane (BABHBPA) and the like can be mentioned.

Examples of the aromatic diamine having a carboxy group include 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,6-diamino-1,3-benzenedicarboxylic acid, 2, 5-Diamino-1,4-benzenedicarboxylic acid, bis (4-amino-3-carboxyphenyl) ether, bis (4-amino-3,5-dicarboxyphenyl) ether, bis (4-amino-3-carboxyphenyl) Phenyl) sulfone, bis (4-amino-3,5-dicarboxyphenyl) sulfone, 4,4'-diamino-3,3'-dicarboxybiphenyl, 4,4'-diamino-3,3'-dicarboxy -5,5'-Dimethylbiphenyl, 4,4'-diamino-3,3'-dicarboxy-5,5'-dimethoxybiphenyl, 1,4-bis (4-amino-3-carboxyphenoxy) benzene, 1 , 3-bis (4-amino-3-carboxyphenoxy) benzene, bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone, bis [4- (4-amino-3-carboxyphenoxy) phenyl] Examples thereof include propane, 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] hexafluoropropane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane and the like.

Further, as described above, as the diamine component used for the synthesis of the polyamic acid, an aromatic diamine having no alkali-soluble group can also be used.
Specific examples of aromatic diamines having no alkali-soluble group include p-phenylenediamine, m-phenylenediamine, 2,4,6-trimethyl-1,3-phenylenediamine, 2,3,5,6-tetramethyl. -1,4-phenylenediamine, 4,4'-diaminodiphenyl ether (ODA), 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'-diamino Diphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4-methylene-bis (2-methylaniline), 4,4'-methylene-bis (2,6-dimethylaniline), 4 , 4-Methylene-bis (2,6-diethylaniline), 4,4'-methylene-bis (2-isopropyl-6-methylaniline), 4,4'-methylene-bis (2,6-diisopropylaniline) , 4,4'-Diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, benzidine, o-trizine, m-trizine, 3,3', 5,5'-tetramethylbenzidine, 1,4-bis (4) −Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- Examples thereof include (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, and 2,2-bis [4- (3-aminophenoxy) phenyl] propane.

The charging ratio of the diamine component and the tetracarboxylic acid dianhydride component cannot be unconditionally specified because it is appropriately determined in consideration of the target molecular weight and molecular weight distribution, the type of diamine, the type of tetracarboxylic acid dianhydride, and the like. The ratio may be set according to the desired molecular chain end based on 1: 1 (molar ratio), and when both ends of the molecular chain derived from tetracarboxylic acid are used (formula (1B)), the ratio is based on 1 mol of the diamine component. The tetracarboxylic acid dianhydride component is preferably 1.05 to 3.0 mol, more preferably 1.07 to 2.5 mol, further preferably 1.1 to 2.0 mol, and a molecular chain derived from diamine. In the case of both ends (formula (1C)), 1.00 to 2.5 mol of the diamine component is preferable, and 1.01 to 1.5 mol is more preferable with respect to 1 mol of the tetracarboxylic acid dianhydride component. 1.02 to 1.3 mol is even more preferable.

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.

A terminal-sealing compound having an alkali-soluble group or an alkali-soluble group that ^{further imparts Z 1} and / or Z ² to the polyamic acid obtained by reacting the tetracarboxylic acid dianhydride component and the diamine component described above. The polyamic acid represented by the formulas (1A) to (1C) can be obtained by reacting the terminal-sealing compound having the above.
More specifically, an aromatic monoamine can be preferably used as the terminal-sealing compound that gives ^{Z 1} that binds to the terminal side of the tetracarboxylic acid.
The aromatic monoamine preferably has an aromatic ring having 6 to 30 carbon atoms, preferably has an aromatic ring having 6 to 15 carbon atoms, and more preferably has an aromatic ring having 6 to 10 carbon atoms. As described above, those containing one benzene ring are preferable.

Specific examples of aromatic monoamines having no alkali-soluble group include aniline, 1-naphthylamine, 2-naphthylamine, 1-aminoanthracene, 2-aminoanthracene, 9-aminoanthracene, 9-aminophenanthracene and 2-amino. Biphenyl, 3-aminobiphenyl, 4-aminobiphenyl and the like can be mentioned.
Specific examples of aromatic monoamines having an alkali-soluble group include aromatic monoamines having phenolic hydroxyl groups such as 2-aminophenol, 3-aminophenol, and 4-aminophenol; 2-aminobenzoic acid and 3-aminobenzoic acid. , 4-Aminobenzoic acid and the like, which include aromatic monoamines having a carboxy group.
Among these, ^{as the terminal-sealing compound that gives Z 1} , an aromatic monoamine having an alkali-soluble group is preferable, an aromatic monoamine having a phenolic hydroxyl group is more preferable, and 2-aminophenol is even more preferable.

On the other hand, an aromatic carboxylic acid can be preferably used as the terminal-sealing compound that gives ^{Z 2} to be bonded to the diamine terminal side.
The aromatic carboxylic acid preferably has an aromatic ring having 6 to 30 carbon atoms, preferably has an aromatic ring having 6 to 15 carbon atoms, and even more preferably has an aromatic ring having 6 to 10 carbon atoms. As described above, those containing one benzene ring are preferable.

Specific examples of aromatic carboxylic acids that do not have an alkali-soluble group after terminal sealing include benzoic acid, 1-naphthalenecarboxylic acid, 2-naphthalenecarboxylic acid, 1-anthracenecarboxylic acid, 2-anthracenecarboxylic acid, and 9-anthracene. Examples thereof include aromatic monocarboxylic acids such as carboxylic acid, 2-phenylbenzoic acid, 3-phenylbenzoic acid and 4-phenylbenzoic acid.
Specific examples of aromatic carboxylic acids having an alkali-soluble group after terminal encapsulation include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid; phenols such as salicylic acid, 3-hydroxybenzoic acid and 4-hydroxybenzoic acid. Examples thereof include aromatic monocarboxylic acids having a sex hydroxylation.
The carboxylic acid may be in the form of an acid halide or an acid anhydride.
Among these, ^{as the terminal-sealing compound that gives Z 2} , an aromatic carboxylic acid having an alkali-soluble group after terminal-sealing is preferable, an aromatic dicarboxylic acid is preferable, and a phthalic acid is even more preferable.

When the polyamic acid represented by the formulas (1A) to (1C) of the present invention uses only a diamine component having no alkali-soluble group as the diamine component (that is, when all Ys do not have an alkali-soluble group) , Z ¹ and / or Z ² must have an alkali-soluble group, in which case either or both of the molecular chain ends of the synthesized polyamic acid may be monoamines or the above-mentioned monoamines having an alkali-soluble group. It may be sealed with a carboxylic acid.

The amount of the end-sealing compound charged may be 1 mol or more, preferably 2 mol or more, more preferably 2 to 4 mol, still more preferably 2 to 3 mol, based on 1 mol of the polyamic acid. When an aromatic monoamine is used, the amount added is preferably 0.1 mol or more, more preferably 0.2 to 4 mol, based on 1 mol of the tetracarboxylic acid dianhydride used for the synthesis of the polyamic acid. A mole, more preferably 0.2 to 3 mol, may be used as a guide. The amount of the aromatic carboxylic acid added is preferably 0.1 mol or more, more preferably 0.2 to 4 mol, still more preferably 0, with respect to 1 mol of the diamine component used in the synthesis of the polyamic acid. A few moles may be used as a guide.

The organic solvent used for sealing the end of the molecular chain of the polyamic acid is not particularly limited as long as it does not adversely affect the reaction, and the same solvent as that exemplified in the above-mentioned polyamic acid synthesis can be used.
The reaction temperature at the time of sealing the molecular chain ends of the polyamic acid may be appropriately set in the range from the melting point to the boiling point of the solvent to be used, as in the case of synthesizing the polyamic acid, and is usually about 0 to 100 ° C. From the viewpoint of reliably sealing the molecular chain ends of the synthesized polyamic acid, the temperature can be 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.

The weight average molecular weight of the polyamic acid obtained in this manner, in which either one or both of the ends of the molecular chain is sealed, is usually about 5,000 to 500,000, but as a release layer of the obtained film. From the viewpoint of improving the function of the above, it is preferably about 6,000 to 200,000, more preferably about 7,000 to 150,000. In the present invention, the weight average molecular weight is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

In the present invention, a solution obtained by diluting or concentrating the reaction solution after end-sealing as it is can be used as the composition for forming a release layer of the present invention. The reaction solution may be filtered if necessary. By filtering, not only can the mixing of impurities that can cause deterioration of the adhesion 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 release 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 acid dianhydride which are the raw materials of the polyamic acid, filtering the reaction solution and then diluting or concentrating the filtrate, and using the isolated polyamic acid as a solvent. It can be adjusted by adjusting the amount of the solution when it is dissolved in.

Further, 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 it is particularly necessary to obtain a film having a thickness of about 0.05 to 5 μm with good reproducibility. For the purpose, 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 composition for forming a release layer described above onto a substrate and then thermally imidizing the polyamic acid by a firing method including a step of firing at a maximum temperature of 450 to 550 ° C. or higher, the polyamic acid is excellently bonded to the substrate. It is possible to obtain a release layer made of a polyimide film, which has appropriate adhesion, appropriate adhesion to a resin substrate, and appropriate release property.
In the present invention, the maximum temperature at the time of firing is not particularly limited as long as it is in the range of 450 to 550 ° C. and the heat resistant temperature of polyimide or less, but it is not particularly limited as long as it has the above-mentioned adhesion to the substrate and the resin substrate. Considering that the appropriate adhesion and peelability are improved, 500 ° C. or higher is preferable. The upper limit is usually about 550 ° C, but preferably about 510 ° C. By setting the heating temperature in the above range, 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 1 minute to 5 hours. The imidization rate may be in the range of 50 to 100%.

Further, the firing temperature may include a step of firing at a temperature lower than that as long as the maximum temperature is within the above range.
As a preferable example of the heating mode in the present invention, there is a method of heating at 50 to 150 ° C., then gradually increasing the heating temperature as it is, and finally heating at 450 to 550 ° C. In particular, as a more preferable example of the heating mode, there is a method of heating at 50 to 100 ° C., heating at more than 100 ° C. to less than 450 ° C., and heating at 450 ° C. or higher. Further, as another more preferable example of the heating embodiment, after heating at 50 to 150 ° C., heating at more than 150 ° C. to 350 ° C., then heating at more than 350 ° C. to less than 450 ° C., and finally 450 to 550 ° C. There is a method of heating with.

Further, as a preferable example of the heating mode in consideration of the firing time, after heating at 50 to 150 ° C. for 1 minute to 2 hours, the heating temperature is gradually increased as it is, and finally at 400 ° C. or higher for 30 minutes. A method of heating for ~ 4 hours can be mentioned. In particular, as a more preferable example of the heating mode, heating is performed at 50 to 100 ° C. for 1 minute to 2 hours, above 100 ° C. to below 450 ° C. for 5 minutes to 2 hours, and at 450 ° C. or higher for 30 minutes to 4 hours. There is a method to do. Further, as another more preferable example of the heating embodiment, after heating at 50 to 150 ° C. for 1 minute to 2 hours, the temperature exceeds 150 ° C. to 350 ° C. for 5 minutes to 2 hours, and then the temperature exceeds 350 ° C. to less than 450 ° C. 30. A method of heating for 30 minutes to 4 hours at 450 to 510 ° C. for 1 minute to 4 hours and finally at 450 to 510 ° C. can be mentioned.

When the release layer of the present invention is formed on the substrate, the release layer may be formed on a part of the 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 of the present invention is coated, which is used for manufacturing a flexible electronic device or the like.

Examples of the substrate (base material) include glass, metal (silicon wafer, etc.), slate, and the like. In particular, the release layer obtained from the release layer forming composition according to the present invention has sufficient adhesion to it. Therefore, glass is preferable. 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 method of coating 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.).

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, the release layer of the present invention detaches the resin substrate from the substrate together with the circuit and the like formed on the resin substrate without damaging the resin substrate of the device in the manufacturing process of the flexible electronic device. It can be preferably used to make it.

Hereinafter, an example of a method for manufacturing a flexible electronic device using the release layer of the present invention will be described.
The release layer forming composition of the present invention is used to form a release layer on a glass substrate by the above-mentioned method. A solution for forming a resin substrate for forming a resin substrate is applied onto the release layer, and the coating film is fired to obtain a resin substrate fixed to the glass substrate via the release layer of the present invention. Form.
The firing temperature of the coating film is appropriately set according to the type of resin and the like, but in the present invention, the maximum temperature at the time of firing is preferably 450 to 550 ° C or higher, and is preferably 480 ° C or higher. It is more preferably 490 ° C. or higher, and even more preferably 500 ° C. or higher. By setting the maximum temperature at the time of firing during the production of the resin substrate within this range, the adhesion between the release layer as a base and the substrate, and the appropriate adhesion and peelability between the release layer and the resin substrate are further improved. be able to.
In this case as well, as long as the maximum temperature is within the above range, the step of firing at a temperature lower than that may be included.

As a preferable example of the heating mode at the time of producing the resin substrate, there is a method of heating at 50 to 150 ° C., then gradually increasing the heating temperature as it is, and finally heating at 450 to 550 ° C. In particular, as a more preferable example of the heating mode, there is a method of heating at 50 to 100 ° C., heating at more than 100 ° C. to less than 450 ° C., and heating at 450 ° C. or higher. Further, as another more preferable example of the heating mode, after heating at 50 to 100 ° C., heating at more than 100 ° C. to 200 ° C., then above 200 ° C. to less than 300 ° C., and then heating at 300 ° C. to less than 400 ° C. Then, a method of heating at 400 ° C. to less than 450 ° C. and finally heating at 450 to 550 ° C. can be mentioned.

Further, as a preferable example of the heating mode in consideration of the firing time, after heating at 50 to 150 ° C. for 5 minutes to 2 hours, the heating temperature is gradually increased as it is, and finally 30 at 450 to 550 ° C. A method of heating for minutes to 4 hours can be mentioned. In particular, as a more preferable example of the heating mode, heating is performed at 50 to 100 ° C. for 5 minutes to 2 hours, above 100 ° C. to below 450 ° C. for 5 minutes to 2 hours, and at 450 ° C. or higher for 30 minutes to 4 hours. There is a method to do. Further, as another more preferable example of the heating embodiment, after heating at 50 to 100 ° C. for 5 minutes to 2 hours, the temperature exceeds 100 ° C. to 200 ° C. for 5 minutes to 2 hours, and then the temperature exceeds 200 ° C. to less than 300 ° C. 30. Examples include a method of heating for minutes to 4 hours, 30 minutes to 4 hours at 300 ° C. to less than 400 ° C., 30 minutes to 4 hours at 400 ° C. to less than 450 ° C., and finally 30 minutes to 4 hours at 450 to 550 ° C.

The resin substrate covers the entire release layer, and forms the resin substrate in an area larger than the area of the 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 of the present invention, and then, for example, the resin substrate is cut along the release layer, and the resin substrate is formed together with this circuit. The resin substrate and the substrate are separated by peeling from the peeling layer. At this time, a part of the substrate may be cut together with the release layer.

Japanese Patent Application Laid-Open No. 2013-147599 reports that the laser lift-off method (LLO method), which has been used in the manufacture of high-brightness LEDs and three-dimensional semiconductor packages, is applied to the manufacture of flexible displays. .. The LLO method is characterized in that a ray having a specific wavelength, for example, a ray having a wavelength of 308 nm is emitted from the glass substrate side from a surface opposite to the surface on which a circuit or the like is formed. The irradiated light rays pass through the glass substrate, and only the polymer (polyimide) in the vicinity of the glass base absorbs the light rays and evaporates (sublimates). As a result, the resin substrate can be selectively peeled from the glass substrate without affecting the circuit or the like provided on the resin substrate, which determines the performance of the display.

Since the 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, it can be used as a sacrificial layer of the LLO method. Therefore, when a desired circuit is formed on a resin substrate fixed to a glass substrate via a release layer formed by using the composition in the present invention, and then an LLO method is carried out to irradiate a light beam of 308 nm. Only the release layer absorbs this light beam and evaporates (sublimates). As a result, the release layer is sacrificed (acts as a sacrifice layer), and the resin substrate can be selectively peeled from the glass substrate.

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

[1] Abbreviation of compound NMP: N-methylpyrrolidone BCS: Butyl cellosolve p-PDA: p-phenylenediamine 6FAP: 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane 2AP: 2-aminophenol BPDA : 3,3-4,4-biphenyltetracarboxylic dianhydride TFMB: 2,2'-bis (trifluoromethyl) benzidine PMDA: pyromellitic acid dianhydride PA: phthalic anhydride CBDA: 1,2, 3,4-Cyclobutanetetracarboxylic acid-1,2: 3,4-dianhydride

[2] Measurement of weight average molecular weight and molecular weight distribution The weight average molecular weight (hereinafter abbreviated as Mw) and molecular weight distribution of the polymer are determined by using a GPC apparatus (Shodex® columns KF803L and KF805L) manufactured by JASCO Corporation and an elution solvent. Dimethylformamide was measured under the conditions of a flow rate of 1 ml / min and a column temperature of 50 ° C. In addition, Mw was a polystyrene conversion value.

[3] Polymer synthesis A polyamic acid was 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 polyamic acid (synthesis of S1)>
3.176 g (0.02937 mol) of p-PDA was dissolved in 88.2 g of NMP, 8.624 g (0.02931 mol) of BPDA was added, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 107,300 and the molecular weight distribution was 4.6.

<Synthesis example L1 Synthesis of polyamic acid (L1)>
1.507 g (0.0139 mol) of p-PDA was dissolved in 43.2 g of NMP, 3.166 g (0.01452 mol) of PMDA was added, and then the reaction was carried out at 23 ° C. for 2 hours under a nitrogen atmosphere. Then, 0.127 g (0.0012 mol) of 2AP was further added, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 48,500 and the molecular weight distribution was 2.08.

<Synthesis example L2 Synthesis of polyamic acid (L2)>
1.119 g (0.01103 mol) of p-PDA was dissolved in 35.2 g of NMP, 3.006 g (0.01378 mol) of PMDA was added, and then the mixture was reacted at 23 ° C. for 2 hours under a nitrogen atmosphere. Then, 0.602 g (0.00551 mol) of 2AP was further added, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 11,700 and the molecular weight distribution was 1.76.

<Synthesis example L3 Synthesis of polyamic acid (L3)>
0.681 g (0.00629 mol) of p-PDA was dissolved in 35.2 g of NMP, 2.746 g (0.01259 mol) of PMDA was added, and the mixture was reacted at 23 ° C. for 2 hours under a nitrogen atmosphere. Then, 1.373 g (0.012588 mol) of 2AP was further added, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 8,000 and the molecular weight distribution was 1.57.

<Synthesis example L4 Synthesis of polyamic acid (L4)>
1.5206 g (0.01406 mol) of p-PDA and 0.105 g (0.00287 mol) of 6FAP were dissolved in 35.2 g of NMP, 3.004 g (0.01377 mol) of PMDA was added, and then at 23 ° C. under a nitrogen atmosphere. The reaction was carried out for 22 hours. Then, after adding 0.170 g (0.00115 mol) of PA, the reaction was carried out at 23 ° C. for 22 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 22,100 and the molecular weight distribution was 1.93.

<Comparative Synthesis Example B1 Synthesis of Polyamic Acid (B1)>
1.29 g (0.00107 mol) of p-PDA was dissolved in 43.2 g of NMP, 3.509 g (0.00119 mol) of BPDA was added, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 34,000 and the molecular weight distribution was 2.03.

<Comparative synthesis example B2 Synthesis of polyamic acid (B2)>
2.86 g (0.0089 mol) of TFMB was dissolved in 35.2 g of NMP, 1.944 g (0.00991 mol) of CBDA was added, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 69,200 and the molecular weight distribution was 2.2. The resulting solution was soluble in PGME.

[4] Preparation of Resin Substrate Forming Composition The reaction solutions obtained in Synthesis Example S1 were used as they were as the resin substrate forming composition.

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

[Examples 1-2 to 1-4]
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 L4 were used instead of the reaction solutions obtained in Synthesis Example L1. rice field.

[Comparative Examples 1-1 to 1-2]
The composition for forming a release layer was prepared in the same manner as in Example 1-1, except that the reaction solutions obtained in Comparative Synthesis Examples B1 and B2 were used instead of the reaction solutions obtained in Synthesis Example L1. Obtained.

[6] Preparation of Release Layer and Resin Substrate [Example 2-1]
Using a spin coater (condition: about 30 seconds at a rotation speed of 3,000 rpm), the release layer forming composition L1 obtained in Example 1-1 was subjected to a 100 mm × 100 mm glass substrate as a glass substrate (the same applies hereinafter). Applied on top.
Then, the obtained coating film is heated at 100 ° C. for 2 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). ), Heat at 400 ° C. for 30 minutes, further heat up to 500 ° C. (10 ° C./min), and heat at 500 ° C. for 10 minutes to form a release layer with a thickness of about 0.1 μm on the glass substrate. , A glass substrate with a release layer was obtained. During the temperature rise, the substrate with the film was not taken out of the oven, but was heated in the oven.

Using a bar coater (gap: 250 μm), the resin substrate forming composition S2 was applied onto the release layer (resin thin film) on the glass substrate obtained above. Then, the obtained coating film is heated at 80 ° C. for 30 minutes using a hot plate, then used in an oven to create a nitrogen atmosphere, and then heated at 140 ° C. for 30 minutes to raise the heating temperature to 210 ° C. Warm (2 ° C / min, and so on), heat at 210 ° C for 30 minutes, raise the heating temperature to 300 ° C, heat at 300 ° C for 30 minutes, raise the heating temperature to 400 ° C, 400 ° C. The heating temperature was raised to 500 ° C. for 30 minutes, and the mixture was heated at 500 ° C. for 60 minutes to form a polyimide substrate having a thickness of about 20 μm on the release layer to obtain a resin substrate and a glass substrate with a release layer. During the temperature rise, the substrate with the membrane was not removed from the oven, but was heated in the oven.

[Examples 2-2 to 2-4]
Except that the release layer forming compositions L2 to L4 obtained in Examples 1-2 to 1-4 were used instead of the release layer forming composition L1 obtained in Example 1-1, respectively. A release layer and a polyimide substrate were prepared in the same manner as in Example 2-1 to obtain a glass substrate with a release layer and a resin substrate / glass substrate with a release layer.

[Comparative Examples 2-1 to 2-2]
Except that the release layer forming compositions B1 and B2 obtained in Comparative Examples 1-1 to 1-2 were used instead of the release layer forming composition L1 obtained in Example 1-1, respectively. A release layer and a polyimide substrate were prepared in the same manner as in Example 2-1 to obtain a glass substrate with a release layer and a resin substrate / glass substrate with a release layer.

[7] Evaluation of peelability With respect to the glass substrate with a peeling layer obtained in Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-2, the peelability between the peeling layer and the glass substrate is described below. Confirmed by the method. The following tests were performed on the same glass substrate.

<Cross-cut test peelability evaluation of resin thin film>
The release layers on the glass substrate with the release layer obtained in Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-2 were cross-cut (1 mm intervals in length and width, the same applies hereinafter), and 100 muscats were performed. .. That is, 100 1 mm square squares were formed by this cross cut.
Then, an adhesive tape was attached to the 100 muscat portion, the tape was peeled off, and the peelability was evaluated based on the following criteria. The results are shown in Table 1.
<Criteria>
5B: 0% peeling (no peeling)
4B: Peeling less than 5% 3B: Peeling less than 5-15% 2B: Peeling less than 15-35% 1B: Peeling less than 35-65% 0B: Peeling less than 65% -80% B: 80% -95 Peeling less than% A: Peeling from 95% to less than 100% AA: Peeling from 100% (all peeling)

<Evaluation of peelability of resin substrate>
The resin substrate of the resin substrate / glass substrate with a release layer obtained in Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-2 was cut into strips having a width of 25 mm using a cutter. Then, a cellophane tape was attached to the tip 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 Atonic Co., Ltd. so that the peeling angle was 90 °, and the peelability was evaluated based on the following criteria. The results are shown in Table 1.
<Criteria>
5B: 0% peeling (no peeling)
4B: Peeling less than 5% 3B: Peeling less than 5-15% 2B: Peeling less than 15-35% 1B: Peeling less than 35-65% 0B: Peeling less than 65% -80% B: 80% -95 Peeling less than% A: Peeling from 95% to less than 100% AA: Peeling from 100% (all peeling)

From the results in Table 1, in the release layer of Examples 2-1 to 2-4, only the resin substrate could be peeled off without peeling the release layer from the glass substrate, but Comparative Examples 2-1 and 2-2. It was confirmed that the resin substrate could not be peeled off.

Claims (10)

A step of applying a composition for forming a release layer containing at least one of the polyamic acids represented by the following formulas (1A) to (1B) and an organic solvent on a substrate and firing at a maximum temperature of 450 to 550 ° C. is included. A method for producing a release layer.

[In the formula, X is a tetravalent aromatic group having two carboxylic acid derivatives independent of each other, and Y is a divalent aromatic group independently of each other, Z ¹ and Z ² Are monovalent organic groups independently of each other, in formula (1A) ^{at least one of Y, Z 1} and Z ² has an alkali-soluble group, and in formula (1B) Y and two Z. ¹ has at least one alkali-soluble group, m is to display the natural number independently of each other,
Z ¹ is a monovalent organic group represented by the following formula (10).

(In the formula, Z ³ represents a carboxy group or a hydroxyl group, and ○ represents a bond.)] The method for producing a release layer according to claim 1, wherein the alkali-soluble group is a carboxy group or a phenolic hydroxyl group. The method for producing a release layer according to claim 1 or 2, wherein Y contains an aromatic group represented by the following formulas (2) to (5).

(In the formula, W represents a carboxy group or a hydroxyl group independently of each other, and R ^{1 to} R ³ are independent of each other and may be substituted with a halogen atom. It represents an alkenylene group having 2 to 20 carbon atoms, an alkynylene group having 2 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms or a heteroarylene group having 2 to 20 carbon atoms, an ether group, an ester group or an amide group. Represents a bond.) The method for producing a release layer according to claim 3, wherein Y contains an aromatic group represented by the following formulas (6) to (9).

(In the formula, it is represented, and ○ represents the bond.) The method for producing a release layer according to any one of claims 1 to 4 ^{, wherein Z 2} is a monovalent organic group represented by the following formula (11).

(In the formula, Z ³ represents a carboxy group or a hydroxyl group, and ◯ represents a bond.) The method for producing a release layer according to any one of claims 3 to 5 , wherein Y further contains an aromatic group having no alkali-soluble group. The method for producing a release layer according to claim 6 , wherein the aromatic group having no alkali-soluble group is a phenylene group, a biphenylene group or a terphenylene group. A method for manufacturing a flexible electronic device including a resin substrate, which comprises using a release layer formed by using the manufacturing method according to any one of claims 1 to 7. A step of applying a resin substrate forming composition onto a release layer formed by the production method according to any one of claims 1 to 7 and then firing at a maximum temperature of 450 ° C. or higher to form a resin substrate. A method of manufacturing a flexible electronic device including. The method for manufacturing a flexible electronic device according to claim 8 or 9 , wherein the resin substrate is a polyimide resin substrate.