CN110062784B

CN110062784B - Method for producing release layer

Info

Publication number: CN110062784B
Application number: CN201780075600.6A
Authority: CN
Inventors: 江原和也; 进藤和也
Original assignee: Nissan Chemical Corp
Current assignee: Nissan Chemical Corp
Priority date: 2016-12-08
Filing date: 2017-12-07
Publication date: 2023-01-10
Anticipated expiration: 2037-12-07
Also published as: KR20190089208A; JP6954308B2; WO2018105676A1; CN110062784A; JPWO2018105676A1; TWI755459B; TW201842019A; KR102481072B1

Abstract

The present invention provides a method for producing a release layer, which comprises a step of applying a composition for forming a release layer, which comprises at least one of polyamic acids represented by the following formulae (1A) to (1C) and an organic solvent, onto a substrate and firing the composition at a maximum temperature of 450 to 550 ℃.

(wherein X is a 4-valent aromatic group having 2 carboxylic acid derivatives, Y is a 2-valent aromatic group, and Z is ¹ And Z ² Independently of one another, are 1-valent organic radicals of the formula (1A), Y, Z ¹ And Z ² At least one of which has an alkali-soluble group, in the formula (1B), Y and 2Z ¹ Has an alkali-soluble group, in the formula (1C), Y and 2Z ² Has an alkali-soluble group, and m represents a natural number independently of each other).

Description

Method for producing release layer

Technical Field

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

Background

In recent years, electronic devices are required to have a function of being bendable in addition to characteristics of being thinner and lighter. In view of this, it is required to use a lightweight flexible plastic substrate instead of a conventional heavy, fragile, and inflexible glass substrate.

In particular, for a new generation display, development of an active matrix type full color TFT display panel using a light 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 been studied, and for a new-generation display, a process capable of using an existing device for manufacturing a TFT display panel has been studied. Patent documents 1,2, and 3 disclose the following methods: after an amorphous silicon thin film layer is formed on a glass substrate and a plastic substrate is formed on the thin film layer, laser light is irradiated from the glass substrate side to crystallize amorphous silicon, and the plastic substrate is peeled from the glass substrate by hydrogen gas generated along with the crystallization.

Patent document 4 discloses a method of: a layer to be peeled (described as a "layer to be transferred" in patent document 4) is attached to a plastic film by using the techniques disclosed in patent documents 1 to 3, and a liquid crystal display device is completed.

However, the methods disclosed in patent documents 1 to 4, particularly the method disclosed in patent document 4, have the following problems: in order to transmit laser light, a substrate having high light transmittance must be used; irradiation with laser light of relatively large energy sufficient to cause hydrogen contained in amorphous silicon to be released through the substrate; the layer to be peeled may be damaged by laser irradiation.

Further, when the layer to be peeled has a large area, the laser processing requires a long time, and thus it is difficult to improve the productivity of device fabrication.

As a means for solving such a problem, patent document 5 adopts the following manufacturing process: a conventional glass substrate is used as a base (hereinafter referred to as a glass base), a release layer is formed on the glass base using a polymer such as a cyclic olefin copolymer, a heat-resistant resin film such as a polyimide film is formed on the release layer, an ITO transparent electrode, a TFT, and the like are formed on the film by a vacuum process and sealed, and then the glass base is finally peeled and removed.

However, at present, as the TFT, a low-temperature polysilicon TFT having 2 times faster mobility than an amorphous silicon TFT is used. In the low-temperature polysilicon TFT, after amorphous silicon vapor deposition, dehydrogenation annealing is performed at 400 ℃ or higher, and silicon is crystallized by irradiation with a pulse laser (hereinafter, these are referred to as TFT process), and the temperature in the dehydrogenation annealing process is equal to or higher than the glass transition temperature (hereinafter, referred to as Tg) of a conventional polymer.

However, it is known that when a conventional polymer is heated to a temperature of Tg or higher, adhesion is improved (for example, see patent document 6), adhesion between a release layer and a resin substrate after heat treatment is improved, and it is sometimes difficult to peel the resin substrate from a base.

Documents of the prior art

Patent literature

Patent document 1: japanese patent laid-open publication No. 10-125929

Patent document 2: japanese patent laid-open publication No. 10-125931

Patent document 3: international publication No. 2005/050754

Patent document 4: japanese patent laid-open publication No. 10-125930

Patent document 5: japanese patent laid-open No. 2010-111853

Patent document 6: japanese patent laid-open No. 2008-188792

Disclosure of Invention

Problems to be solved by the invention

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 manufacturing a release layer that can be peeled off without damaging a resin substrate of a flexible electronic device.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems, and as a result, have found that: the present inventors have found that a composition containing a polyamic acid having an alkali-soluble group in a molecule and an organic solvent can be used to form a release layer having excellent adhesion to a substrate, appropriate adhesion to a resin substrate used for a flexible electronic device, and appropriate releasability by setting the firing temperature at the time of forming the release layer to a predetermined maximum temperature or higher, and have completed the present invention.

Namely, the present invention provides:

1. a method for producing a release layer, comprising a step of applying a composition for forming a release layer comprising at least one of polyamic acids represented by the following formulae (1A) to (1C) and an organic solvent to a substrate and firing the composition at a maximum temperature of 450 to 550 ℃,

[ solution 1]

(wherein X is a 4-valent aromatic group having 2 carboxylic acid derivatives, Y is a 2-valent aromatic group, and Z is ¹ And Z ² Independently of one another, are 1-valent organic radicals of the formula (1A), Y, Z ¹ And Z ² Has an alkali-soluble group, in the formula (1B), Y and 2Z ¹ Has an alkali-soluble group, in the formula (1C), Y and 2Z ² Has an alkali-soluble group, and m represents a natural number independently of each other. )

2.1 the method for producing a release layer, wherein the alkali-soluble group is a carboxyl group or a phenolic hydroxyl group,

3.1 or 2, wherein Y contains an aromatic group represented by the following formulas (2) to (5),

[ solution 2]

(wherein W independently represents a carboxyl group or a hydroxyl group, R ¹ ～R ³ Independently of one another, represents an alkylene group having 1 to 20 carbon atoms, 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, which may be substituted with a halogen atom, and O represents a bonding end. )

4.3A method for producing a release layer, wherein Y contains an aromatic group represented by the following formulas (6) to (9),

[ solution 3]

(wherein O represents a bonding end.)

5.1 to 4, wherein Z is ¹ Is a 1-valent organic group represented by the following formula (10),

[ solution 4]

(in the formula, Z ³ Denotes a carboxyl group or a hydroxyl group, and a bonding end. )

6.1 to 5, wherein Z is ² Is a 1-valent organic group represented by the following formula (11),

[ solution 5]

(in the formula, Z ³ Denotes a carboxyl group or a hydroxyl group, and O denotes a bonding end. )

7.3 to 6, wherein Y further contains an aromatic group having no alkali-soluble group,

8.7 the method for producing a release layer, wherein the aromatic group having no alkali-soluble group is phenylene, biphenylene, or terphenylene,

9. a method for manufacturing a flexible electronic device provided with a resin substrate, characterized by using a release layer formed by the manufacturing method of any one of 1 to 8,

10. a method for manufacturing a flexible electronic device, comprising the steps of: applying a resin substrate-forming composition to a release layer formed by the production method of any one of 1 to 8, and then firing the release layer at a maximum temperature of 450 ℃ or higher to form a resin substrate,

11.9 or 10, wherein the resin substrate is a polyimide resin substrate.

ADVANTAGEOUS EFFECTS OF INVENTION

By using the method for producing a release layer of the present invention, a release layer having excellent adhesion to a base, appropriate adhesion to a resin substrate, and appropriate releasability can be obtained with good reproducibility. Therefore, by carrying out the manufacturing method of the present invention, it becomes possible to separate the resin substrate from the base body together with the circuit and the like without damaging the resin substrate formed on the base body and the circuit and the like provided thereon in the manufacturing process of the flexible electronic device. Therefore, the manufacturing method of the present invention can contribute to simplification of the manufacturing process of a flexible electronic device provided with a resin substrate, improvement of the yield thereof, and the like.

Detailed Description

The present invention will be described in more detail below.

The method for producing a release layer according to the present invention is characterized by comprising a step of applying a composition for forming a release layer comprising at least one of polyamic acids represented by the following formulae (1A) to (1C) and an organic solvent to a substrate and firing the composition at a maximum temperature of 450 to 550 ℃.

The release layer in the present invention is a layer provided directly above the glass substrate for a predetermined purpose, and typical examples thereof include a release layer provided between the substrate and a resin substrate of a flexible electronic device made of resin such as polyimide in a process for manufacturing the flexible electronic device so as to fix the resin substrate in a predetermined process, and provided so as to enable easy release of the resin substrate from the substrate after forming an electronic circuit or the like on the resin substrate.

[ solution 6]

In each of the above formulae, X is independently a 4-valent aromatic group having 2 carboxylic acid derivatives, Y is independently a 2-valent aromatic group, and Z ¹ And Z ² Independently of one another, are 1-valent organic radicals of the formula (1A), Y, Z ¹ And Z ² At least one of which has an alkali-soluble group, in the formula (1B), Y and 2Z ¹ Has an alkali-soluble group, in the formula (1C), Y and 2Z ² Has an alkali-soluble group.

m independently represents a natural number, preferably an integer of 2 or more.

The X preferably contains a 4-valent aromatic ring having 1 to 5 benzene rings, more preferably a 4-valent benzene ring, a 4-valent naphthalene ring, and a 4-valent biphenyl ring, and even more preferably a 4-valent benzene ring and a 4-valent biphenyl ring.

The 2-valent aromatic group of Y is preferably an aromatic group containing 1 to 5 benzene rings, and more preferably a group represented by the following formulae (2 ') to (5').

[ solution 7]

In the above formulae (2 ') to (5'), R ¹ ～R ³ Independently of each other, a C1-20 alkylene group, a C2-20 alkenylene group, a C2-20 alkynylene group, a C6-20 arylene group, or a C2-20 heteroarylene group, an ether group, an ester group, or an amide group, each of which may be substituted with a halogen atom, and O represents a bonding end.

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 a linear, branched or cyclic alkylene group, and examples thereof include a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group.

The alkenylene group having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, may be any of linear, branched and cyclic alkenylene groups, and examples thereof include vinylene, propenylene, butenylene, pentenylene, hexenylene, heptenylene, octenylene and nonenylene groups.

The alkynylene group having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, may be a linear, branched or cyclic alkynylene group, and examples thereof include an ethynylene group, an propynyl group, a butynyl group, a pentynyl group, a hexynyl group, a heptynyl group, an octynyl group, and a nonynyl group.

In addition, when Y is a 2-valent 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, particularly, more preferably an organic group containing 2 or more benzene rings substituted with at least one alkali-soluble group, further preferably aromatic groups represented by the following formulas (2) to (5), particularly, more preferably structures represented by the following formulas (6) to (9), and most preferably structures represented by the formulas (6), (7) and (9) having a phenolic hydroxyl group at the ortho-position with respect to the bonding end which is adjacent thereto.

[ solution 8]

(wherein W represents an alkali-soluble group, preferably a carboxyl group or a phenolic hydroxyl group, and R ¹ ～R ³ And O represents the same meaning as described above. )

[ solution 9]

(wherein O represents a bonding end.)

In the polyamic acid used in the present invention, the above Y may comprise: both of a 2-valent aromatic group having an alkali-soluble group and a 2-valent aromatic group having no alkali-soluble group.

In this case, the proportion of the aromatic group having a valence of 2 of the alkali-soluble group in the total Y may be about 0.1 to 99.9 mol%, preferably 1 to 50 mol%, more preferably 1 to 10 mol%.

In the above formulae (1A) to (1C), Z ¹ And Z ² Is a 1-valent organic group, preferably a 1-valent organic group containing a benzene ring, preferably a 1-valent organic group containing 1 benzene ring, Z bonded to the terminal side of the tetracarboxylic acid ¹ Preferably a 1-valent organic group represented by the following formula (10A), withZ bonded to the terminal side of diamine ² The 1-valent organic group represented by the following formula (11A) is preferable.

[ solution 10]

(wherein O represents a bonding end.)

In addition, in Z ¹ And Z ² In the case of a 2-valent aromatic group having an alkali-soluble group, the alkali-soluble group is preferably directly bonded to the aromatic ring, and the number of the alkali-soluble group is preferably 1.

More specifically, Z bonded to the terminal side of a tetracarboxylic acid ¹ The 1-valent organic group represented by the following formula (10B) is preferable, and the 1-valent organic group represented by the following formula (10) in which an alkali-soluble group is present in an ortho position to NH is more preferable, and Z bonded to the terminal side of the diamine ² The 1-valent organic group represented by the following formula (11B) is preferable, and the 1-valent organic group represented by the following formula (11) in which an alkali-soluble group is present in an ortho position with respect to CO is more preferable.

In particular, since the polymer has a hydroxyl group at the end, a difference between the flexible substrate used for the upper layer and the skeleton can be formed, and thus the function of the obtained film as a release layer can be improved.

[ solution 11]

[ solution 12]

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.

The aromatic tetracarboxylic dianhydride component and the aromatic diamine component used for synthesizing the polyamic acid used in the production method of the present invention will be described below.

The aromatic tetracarboxylic dianhydride used for synthesizing the polyamic acid represented by the above formulas (1A) to (1C) is not particularly limited as long as it has 2 dicarboxylic anhydride sites in the molecule and has an aromatic ring, and an aromatic tetracarboxylic dianhydride containing 1 to 5 benzene nuclei is preferred.

<xnotran> , , - - , - - , - - , - - , - - , - - , - - , - - , - ', ' - , - ',4' - , - ', ' - , - - , - - , - - , - - , - - , - - , - - , - - , - - , - - , - - , - - , - - , - - , - - , ', ' - , ', ' - , ', ' - , - - - -1- , - (- ) , ' - , </xnotran> These may be used alone, or 2 or more may be used in combination.

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, still more preferably an aromatic diamine containing an aromatic ring having a carboxyl group or a phenolic hydroxyl group, and yet still more preferably an aromatic diamine containing an aromatic group substituted with a phenolic hydroxyl group.

Examples of the aromatic diamine having a phenolic hydroxyl group include 3,3 '-diamino-4,4' -dihydroxybiphenyl (4 BP), 3,3 '-diamino-2,2' -dihydroxybiphenyl (2 BP), 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), 3754 zxft 54' -diamino-84 zxft 494984 '-dihydroxybenzophenone (PK), 3,3' -diamino-4,4 '-dihydroxy-phenylate (AH3272' -diamino-AHzft 3472 '-diaminoazz-4949494984' -dihydroxybenzophenone (PAK), and Bis (BAXP) aniline (BAF-3-amino-3-hydroxy phenyl) phenyl-794-phenylene ether (BAPF), 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) sulfide, bis (4-amino-3,5-dihydroxyphenyl) sulfide, 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' -dihydroxydiphenyl (3 BP), 4,4 '-diamino-3,3' -dihydroxy-5,5 '-dimethyldiphenyl, 4,4' -diamino-3,3 '-dihydroxy-5,5' -dimethoxydiphenyl, 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) phenyl ] sulfone, bis [4- (3-amino-4-hydroxyphenoxy) phenyl ] propane, or 1,4-bis (4-aminophenoxy) benzene, but is not limited thereto.

Among the diamine components, preferred are 3,3' -diamino-4,4 ' -dihydroxybiphenyl (4 BP), 3,3' -diamino-2,2 ' -dihydroxybiphenyl (2 BP), 2,2' -bis (3-amino-4-hydroxyphenyl) hexafluoropropane (BAHF), 2,2-bis (4-amino-3,5-dihydroxyphenyl) hexafluoropropane, 3524 zxft 24-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-45 zxft 45 ' -dihydroxy-benzophenone (AHPE), 3232323272 ' -diamino-34zxft 4984 ' -dihydroxybenzophenone (AHPK), bis (3-amino-3-hydroxyphenyl) phenyl ] hexafluoropropane (BAPF), bis (BAPF-3-amino-4-hydroxyphenylsulfone) (357935), 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) sulfide, bis (4-amino-3,5-dihydroxyphenyl) sulfide, bis (3-amino-4-hydroxyphenyl) ether, bis (3-amino-4-hydroxyphenyl) methane, bis (3-amino-4-hydroxyphenyl) sulfone, 4,4 '-diamino-3,3' -dihydroxydiphenyl (3 BP), 4,4 '-diamino-3,3' -dihydroxy-3584 zxft Dimethyl diphenyl, 4,4 '-diamino-3,3' -dihydroxy-5623 '-dimethoxy diphenyl, 4284' -dimethoxy diphenyl, 62 zxft 9843-diamino-6256-bis (3-amino-354-hydroxyphenyl) benzene, bis (3-amino-325756-phenoxy) benzene, bis (3-amino-3238-phenoxy) benzene, bis (3-amino-325756) phenoxy, bis (345749) benzene, bis (3-amino-3272) phenoxy) benzene, bis (345756).

Particularly preferred diamine components include bis (3-amino-4-hydroxyphenyl) methane (BAPF), 2,2 '-bis (3-amino-4-hydroxyphenyl) propane (BAPA), 2,2' -bis (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) aniline (AHPA), bis-N, N '- (p-aminobenzoyl) -hexafluoro-2,2' -bis (4-hydroxyphenyl) propane (BABPA), and the like.

Examples of the aromatic diamine having a carboxyl group include 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,6-diamino-1,3-phthalic acid, 2,5-diamino-1,4-phthalic acid, bis (4-amino-3-carboxyphenyl) ether, bis (4-amino-3,5-dicarboxyphenyl) ether, bis (4-amino-3-carboxyphenyl) sulfone, bis (4-amino-3,5-dicarboxyphenyl) sulfone, 4,4' -diamino-3734 zxft 34' -dicarboxyphenyl, 4,4' -diamino-5852 zxft 353575 ' -dimethylbiphenyl, 3625 ' -diamino-3825-5450 ' -dicarboxyphenyl [ 3' -dicarboxyphenyl ] biphenyl, bis (3-amino-743-dicarboxyphenyl) phenoxy [ 3' -dicarboxyphenyl ] propane, bis (4-amino-3-dicarboxyphenyl) sulfone, bis (4-amino-3,5-dicarboxyphenyl) sulfone, bis (4-5046-dicarboxyphenyl) bis (3-5046-dicarboxyphenyl) bis (4 ' -diamino-50413-dicarboxyphenyl) sulfone, and-50415427-dicarboxyphenyl-504127-bis (bis-dicarboxyphenyl) phenoxy).

As described above, an aromatic diamine having no alkali-soluble group can be used as the diamine component used for synthesizing the polyamic acid.

Specific examples of the aromatic diamine 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 '-diaminodiphenyl methane, 3,4' -diaminodiphenyl methane, 3,3 '-diaminodiphenyl methane, 4,4-methylene-bis (2-methylaniline), 4,4' -methylene-bis (2,6-dimethylaniline), 4,4-methylene-bis (4235-diethyltoluidine), 5258-zxft 6267 '-methylene-bis (4258-isopropyltoluene-6258' -methylenediphenyl sulfone), 4258 '-isopropyltoluene-bis (2-tolylaniline), 356258-isopropyl-methyl-6258' -diaminodiphenyl sulfone, 4258 '-isopropyl-methyl-4258' -diphenylsulfone, and isopropyl-methyl-4258 '-diphenyl sulfone 2,6' -tetramethylbenzidine, 2,6-bis (4-aminophenoxy) benzene, 2,6-bis (3-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl ] sulfone, bis [4- (3-aminophenoxy) phenyl ] sulfone, 2,6-bis [4- (4-aminophenoxy) phenyl ] propane, 2,2-bis [4- (3-aminophenoxy) phenyl ] propane.

The feeding ratio of the diamine component to the tetracarboxylic dianhydride component is appropriately determined in consideration of the target molecular weight, molecular weight distribution, kind of diamine, kind of tetracarboxylic dianhydride, and the like, and therefore cannot be generally specified, and may be 1: the ratio of 1 (molar ratio) is set to a desired molecular chain end, and when both ends of the molecular chain of the tetracarboxylic acid are provided (formula (1B)), the tetracarboxylic dianhydride component is preferably 1.05 to 3.0 mol, more preferably 1.07 to 2.5 mol, and still more preferably 1.1 to 2.0 mol, relative to 1 mol of the diamine component, and when both ends of the molecular chain of the diamine are provided (formula (1C)), the diamine component is preferably 1.00 to 2.5 mol, more preferably 1.01 to 1.5 mol, and still more preferably 1.02 to 1.3 mol, relative to 1 mol of the tetracarboxylic dianhydride component.

The organic solvent used in 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, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-dimethylacetamide, N-dimethylformamide, 3-methoxy-N, N-dimethylpropionamide, 3-ethoxy-N, N-dimethylpropionamide, 3-propoxy-N, N-dimethylpropionamide, 3-isopropoxy-N, N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide, 3-sec-butoxy-N, N-dimethylpropionamide, 3-tert-butoxy-N, N-dimethylpropionamide, γ -butyrolactone, and the like. Note that, 1 kind of the organic solvent may be used alone or 2 or more kinds may be used in combination.

In particular, the organic solvent used for the reaction is preferably at least one selected from the group consisting of amides represented by the formula (S1), amides represented by the formula (S2), and amides represented by the formula (S3), in view of sufficiently dissolving the diamine, the tetracarboxylic dianhydride, and the polyamic acid.

[ solution 13]

In the formula, R ¹ And R ² Independently represent an alkyl group having 1 to 10 carbon atoms. R ³ Represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. h representsThe natural number is preferably 1 to 3, and more preferably 1 or 2.

Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group and the like. Among 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 is suitably set in a range from the melting point to the boiling point of the solvent used, and is usually about 0 to 100 ℃, and the content of the polyamic acid unit is preferably about 0 to 70 ℃, more preferably about 0 to 60 ℃, and still more preferably about 0 to 50 ℃ in order to prevent imidization of the obtained polyamic acid in the solution.

The reaction time is not generally specified because it depends on the reaction temperature and the reactivity of the raw material, but is usually about 1 to 100 hours.

Further causing administration of Z ¹ And/or Z ² The polyamic acid represented by the formulae (1A) to (1C) can be obtained by reacting the above-described tetracarboxylic dianhydride component and diamine component with the polyamic acid obtained by reacting the terminal capping compound having an alkali-soluble group or the terminal capping compound having no alkali-soluble group.

More specifically, as Z for imparting bonding to the terminal side of tetracarboxylic acid ¹ The end capping compound of (3) can preferably use an aromatic monoamine.

The aromatic monoamine is preferably an aromatic monoamine having an aromatic ring having 6 to 30 carbon atoms, preferably an aromatic monoamine having an aromatic ring having 6 to 15 carbon atoms, more preferably an aromatic monoamine having an aromatic ring having 6 to 10 carbon atoms, and preferably contains 1 benzene ring as described above.

Specific examples of the aromatic monoamine having no alkali-soluble group include aniline, 1-naphthylamine, 2-naphthylamine, 1-aminoanthracene, 2-aminoanthracene, 9-aminophenanthrene, 2-aminobiphenyl, 3-aminobiphenyl, and 4-aminobiphenyl.

Specific examples of the aromatic monoamine having an alkali-soluble group include aromatic monoamines having a phenolic hydroxyl group such as 2-aminophenol, 3-aminophenol and 4-aminophenol; and aromatic monoamines having a carboxyl group such as 2-aminobenzoic acid, 3-aminobenzoic acid, and 4-aminobenzoic acid.

Of these, as administration Z ¹ The end capping compound of (3) is preferably an aromatic monoamine having an alkali-soluble group, more preferably an aromatic monoamine having a phenolic hydroxyl group, and further preferably 2-aminophenol.

On the other hand, as Z for imparting linkage to the terminal side of diamine ² The end capping compound of (2) can be preferably an aromatic carboxylic acid.

The aromatic carboxylic acid is preferably an aromatic carboxylic acid having an aromatic ring having 6 to 30 carbon atoms, preferably an aromatic carboxylic acid having an aromatic ring having 6 to 15 carbon atoms, more preferably an aromatic carboxylic acid having an aromatic ring having 6 to 10 carbon atoms, and preferably an aromatic carboxylic acid having 1 benzene ring as described above.

Specific examples of the aromatic carboxylic acid having no alkali-soluble group after the end capping include aromatic monocarboxylic acids such as benzoic acid, 1-naphthoic acid, 2-naphthoic acid, 1-anthracenecarboxylic acid, 2-anthracenecarboxylic acid, 9-anthracenecarboxylic acid, 2-phenylbenzoic acid, 3-phenylbenzoic acid, and 4-phenylbenzoic acid.

Specific examples of the aromatic carboxylic acid having an alkali-soluble group after end-capping include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; aromatic monocarboxylic acids having a phenolic hydroxyl group such as salicylic acid, 3-hydroxybenzoic acid and 4-hydroxybenzoic acid.

The carboxylic acid may be in the form of an acid halide or an acid anhydride.

Of these, as administration Z ² The end-capping compound of (3) is preferably an aromatic carboxylic acid having an alkali-soluble group after end-capping, preferably an aromatic dicarboxylic acid, and more preferably phthalic acid.

In the case where only the diamine component having no alkali-soluble group is used as the diamine component (that is, in the case where all Y has no alkali-soluble group), Z is a diamine component represented by the formulae (1A) to (1C) of the present invention ¹ And/or Z ² In the case where it is necessary to have an alkali-soluble group, either or both of the molecular chain ends of the synthesized polyamic acid may be blocked with the monoamine or carboxylic acid having an alkali-soluble group.

The amount of the end-capping compound to be fed may be 1 mol or more, preferably 2 mol or more, more preferably 2 to 4 mol, and still more preferably 2 to 3 mol based on 1 mol of the polyamic acid. In the case of using an aromatic monoamine, the amount of the aromatic monoamine to be added is preferably 0.1 mol or more, more preferably 0.2 to 4 mol, and still more preferably 0.2 to 3 mol, based on 1 mol of tetracarboxylic dianhydride used in the synthesis of the polyamic acid. The amount of the aromatic carboxylic acid to be added is preferably 0.1 mol or more, more preferably 0.2 to 4 mol, and still more preferably 0.2 to 3 mol, based on 1 mol of the diamine component used for the synthesis of the polyamic acid.

The organic solvent used for blocking the molecular chain ends of the polyamic acid is not particularly limited as long as it does not adversely affect the reaction, and the same solvents as those exemplified in the synthesis of the polyamic acid can be used.

The reaction temperature at the time of blocking 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 used, as in the case of synthesis of the polyamic acid, and is usually about 0 to 100 ℃. The reaction time is not generally specified because it depends on the reaction temperature and the reactivity of the raw material, but is usually about 1 to 100 hours.

The weight average molecular weight of the polyamic acid obtained in this manner and having either or both molecular chain ends blocked is usually about 5,000 to 500,000, and is preferably about 6,000 to 200,000, and more preferably about 7,000 to 150,000, from the viewpoint of improving the function as a release layer of the obtained film. 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 reaction solution after end capping can be usually used as it is or a solution obtained by diluting or concentrating the reaction solution can be used as the composition for forming a release layer of the present invention. The reaction solution may be filtered if necessary. By performing filtration, it is possible to reduce the mixing of impurities that may cause deterioration in adhesion, peeling properties, and the like of the obtained peeling layer, and to efficiently obtain the composition for forming a peeling layer. Further, the polyamic acid may be isolated from the reaction solution and then dissolved in the solvent again to prepare a composition for forming a release layer. Examples of the solvent in this case include organic solvents used in the above-mentioned reaction.

The solvent used for the dilution is not particularly limited, and specific examples thereof include the same solvents as those of the reaction solvent of the above reaction. The solvents for dilution may be used 1 kind alone or 2 or more kinds in combination. Among them, from the viewpoint of sufficiently dissolving the polyamide acid, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2-pyrrolidone, γ -butyrolactone are preferable, and N-methyl-2-pyrrolidone is more preferable.

The composition for forming a release layer of the present invention may be mixed with a solvent that does not dissolve polyamide acid, if only in such a range that polyamide acid does not precipitate. In particular, solvents having a low surface tension, such as 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-ethoxypropoxy) propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, and isoamyl lactate, can be suitably mixed. It is known that the coating film uniformity is improved when the composition is applied to a substrate, and the composition is preferably used also in the release layer-forming composition of the present invention.

The concentration of the polyamic acid in the composition for forming a release layer of the present invention is suitably set in consideration of the thickness of the release layer to be produced, the viscosity of the composition, and the like, and is usually about 1 to 30 mass%, and preferably about 1 to 20 mass%. By forming the concentration in this manner, 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 can be adjusted by adjusting the amounts of diamine and tetracarboxylic dianhydride used as raw materials of the polyamic acid, by diluting or concentrating the filtrate obtained by filtering the reaction solution, or by adjusting the amounts of the isolated polyamic acid when dissolved in a solvent.

The viscosity of the composition for forming a release layer is suitably set in consideration of the thickness of the release layer to be produced, and in particular, when a film having a thickness of about 0.05 to 5 μm is to be obtained with good reproducibility, the viscosity is usually about 10 to 10,000mpa · s, preferably about 20 to 5,000mpa · s at 25 ℃.

The viscosity can be measured at a temperature of 25 ℃ of the composition using a commercially available viscometer for measuring the viscosity of a liquid, for example, according to the procedure described in JIS K7117-2. Preferably, as the viscometer, a conical flat plate type (cone plate type) rotational viscometer is used, preferably, in a homotypic viscometer using 1 ° 34' × R24 as a standard conical spindle, can be measured under the condition of the temperature of the composition of 25 ℃. An example of such a rotational viscometer is TVE-25L manufactured by Toyobo industries, ltd.

The release layer forming composition according to the present invention may contain a component such as a crosslinking agent in addition to the polyamic acid and the organic solvent, for example, in order to improve the film strength.

After the release layer-forming composition described above is applied to a substrate, a polyamic acid is thermally imidized by a firing method including a step of firing at a maximum temperature of 450 to 550 ℃.

In the present invention, the maximum temperature at the time of the firing is not particularly limited as long as it is in a range of 450 to 550 ℃ and the heat-resistant temperature of the polyimide or less, but it is preferably 500 ℃ or more in consideration of improving the above-mentioned adhesion to the base, appropriate adhesion to the resin substrate, and peeling properties. The upper limit is usually about 550 ℃ and preferably about 510 ℃. By setting the heating temperature in the above range, the imidization reaction can be sufficiently performed while preventing the resultant film from being brittle.

The heating time varies depending on the heating temperature, and therefore cannot be generally specified, and is usually 1 minute to 5 hours. The imidization ratio may be in the range of 50 to 100%.

The temperature at the time of firing may include a step of firing at a temperature lower than the above range, as long as the maximum temperature is within the above range.

As a preferred example of the heating method in the present invention, the following method can be mentioned: after heating at 50-150 deg.C, the heating temperature is directly raised in stages, and finally the heating is carried out at 450-550 deg.C. In particular, as a more preferable example of the heating method, the following method can be mentioned: heating at 50-100 deg.C, heating at more than 100 deg.C and less than 450 deg.C, and heating at above 450 deg.C. Further, as another more preferable example of the heating method, the following method can be mentioned: heating at 50-150 deg.C, heating at more than 150 deg.C and below 350 deg.C, heating at more than 350 deg.C and below 450 deg.C, and heating at 450-550 deg.C.

In addition, as a preferable example of the heating method in consideration of the firing time, the following method can be mentioned: after heating at 50-150 deg.C for 1 min-2 hr, the heating temperature is raised stepwise and finally heated at 400 deg.C or higher for 30 min-4 hr. Particularly, as a more preferable example of the heating method, heating at 50 to 100 ℃ for 1 minute to 2 hours, heating at more than 100 ℃ and less than 450 ℃ for 5 minutes to 2 hours, and heating at 450 ℃ or more for 30 minutes to 4 hours can be given. Further, as another more preferable example of the heating method, the following method can be mentioned: heating at 50-150 deg.c for 1 min-2 hr, heating at 150 deg.c to 350 deg.c for 5 min-2 hr, heating at 350 deg.c to 450 deg.c for 30 min-4 hr, and heating at 450-510 deg.c for 30 min-4 hr.

In the case where the release layer of the present invention is formed over a substrate, the release layer may be formed over part of the surface of the substrate or may be formed over the entire surface. Examples of the form of forming the release layer on a partial surface of the base include a form of forming the release layer only in a predetermined range on the surface of the base, and a form of forming the release layer in a pattern such as a dot pattern, a line pattern, or a space pattern on the entire surface of the base. In the present invention, the substrate means a member to be used for the production of a flexible electronic device or the like, to which the composition for forming a release layer of the present invention is applied on the surface thereof.

Examples of the base (substrate) include glass, metal (e.g., silicon wafer), and stone plate, and particularly, glass is preferable because the release layer obtained from the release layer-forming composition of the present invention has sufficient adhesion to the release layer. The surface of the substrate may be made of a single material or 2 or more materials. As a form in which the substrate surface is made of 2 or more kinds of materials, there is a form in which a certain range of the substrate surface is made of a certain material and the remaining surface is made of another material; and a pattern in which a certain material is present in other materials in a dot pattern, a line pattern, a space pattern, or the like over the entire surface of the substrate. As a form in which the surface of the substrate is formed of 2 or more kinds of materials, there is a form in which a certain range is formed of a certain material on the surface of the substrate and the remaining surface is formed of another material; and a pattern of dots, lines, and spaces on the entire surface of the substrate, wherein the pattern is formed by another material.

The coating method is not particularly limited, and examples thereof include a casting method, a spin coating method, a doctor blade coating method, a dip coating method, a roll coating method, a bar coating method, a die coating method, an ink jet method, and a printing method (relief printing, gravure printing, offset printing, screen printing, etc.).

Examples of the heating device include a hot plate and an oven. The heating atmosphere may be air or an inert gas, or may be normal pressure or reduced pressure.

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

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

An example of a method for manufacturing a flexible electronic device using the release layer of the present invention will be described below.

The composition for forming a release layer of the present invention is used to form a release layer on a glass substrate by the above-described method. A resin substrate forming solution for forming a resin substrate is applied to the release layer, and the coating film is baked, thereby forming a resin substrate fixed to a glass substrate via the release layer of the present invention.

The baking temperature of the coating film is appropriately set according to the kind of resin, and in the present invention, the maximum temperature at the time of baking is preferably 450 to 550 ℃. When the maximum temperature at the time of firing in the production of the resin substrate is in this range, the adhesion between the release layer as a base and the base, and the appropriate adhesion and releasability between the release layer and the resin substrate can be further improved.

In this case, the firing step may be performed at a temperature lower than the maximum temperature as long as the maximum temperature is within the above range.

As a preferred example of the heating method in the production of the resin substrate, the following method can be mentioned: after heating at 50 to 150 ℃, the heating temperature is directly raised in stages, and finally the heating is carried out at 450 to 550 ℃. In particular, as a more preferable example of the heating method, the following method can be mentioned: heating at 50-100 deg.C, heating at more than 100 deg.C and less than 450 deg.C, and heating at above 450 deg.C. Further, as another more preferable example of the heating method, the following method can be mentioned: heating at 50-100 deg.C, heating at more than 100 deg.C and below 200 deg.C, heating at more than 200 deg.C and below 300 deg.C, heating at more than 300 deg.C and below 400 deg.C, heating at more than 400 deg.C and below 450 deg.C, and finally heating at 450-550 deg.C.

In addition, as a preferable example of the heating method in consideration of the firing time, the following method can be mentioned: after heating at 50-150 deg.C for 5 min-2 hr, the heating temperature is raised in stages directly, and finally at 450-550 deg.C for 30 min-4 hr. Particularly, as a more preferable example of the heating method, heating at 50 to 100 ℃ for 5 minutes to 2 hours, heating at more than 100 ℃ and less than 450 ℃ for 5 minutes to 2 hours, and heating at 450 ℃ or more for 30 minutes to 4 hours can be given. Further, as another more preferable example of the heating method, the following method can be mentioned: heating at 50-100 deg.C for 5 min-2 hr, heating at more than 100 deg.C and below 200 deg.C for 5 min-2 hr, heating at more than 200 deg.C and below 300 deg.C for 30 min-4 hr, heating at more than 300 deg.C and below 400 deg.C for 30 min-4 hr, heating at more than 400 deg.C and below 450 deg.C for 30 min-4 hr, and finally heating at 450-550 deg.C for 30 min-4 hr.

The resin substrate is formed to have an area larger than the area of the release layer so as to cover the release layer entirely. As the resin substrate, a resin substrate made of polyimide, which is a representative of a resin substrate for a flexible electronic device, may be cited, and as the resin solution for forming the same, a polyimide solution and a polyamic acid solution may be cited. 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 base via the peeling layer of the present invention, and then, for example, the resin substrate is cut along the peeling layer, and the resin substrate is peeled from the peeling layer together with the circuit, thereby separating the resin substrate from the base. At this time, a part of the base may be cut together with the peeling layer.

In addition, japanese patent application laid-open No. 2013-147599 reports that a laser lift-off method (LLO method) used in the manufacture of high-brightness LEDs, three-dimensional semiconductor packages, and the like has been applied to the manufacture of flexible displays. The LLO method is characterized in that light having a specific wavelength, for example, light having a wavelength of 308nm is irradiated from the glass substrate side from the side opposite to the side on which the circuit or the like is formed. The irradiated light is transmitted through the glass substrate, and only the polymer (polyimide) in the vicinity of the glass substrate absorbs the light to evaporate (sublimate). As a result, the resin substrate can be selectively peeled from the glass substrate without affecting circuits and the like provided on the resin substrate, which determine the performance of the display.

The release layer of the present invention can be used as a sacrificial layer in the LLO method because it has a characteristic of sufficiently absorbing light having a specific wavelength (for example, 308 nm) to which the LLO method described above can be applied. Therefore, in the present invention, a desired circuit is formed on a resin substrate fixed to a glass substrate via a release layer formed using the composition, and then, when 308nm light is irradiated by the LLO method, only the release layer absorbs the light and evaporates (sublimes). Thus, the release layer is sacrificial (functions as a sacrificial layer), and the resin substrate can be selectively released from the glass base.

Examples

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

[1] Abbreviations for the Compounds

NMP: n-methyl pyrrolidone

BCS: butyl cellosolve

p-PDA: p-phenylenediamine

6FAP:2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane

2AP: 2-aminophenols

BPDA:3,3-4,4 Biphenyltetracarboxylic dianhydride

TFMB:2,2' -bis (trifluoromethyl) benzidine

And (3) PMDA: pyromellitic 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 the molecular weight distribution of the polymer were measured at a column temperature of 50 ℃ at a flow rate of 1 ml/min using a GPC device (Shodex (registered trademark) columns KF803L and KF805L, manufactured by japan spectrographic corporation) such that the flow rate of dimethylformamide as an elution solvent was 1 ml/min. Mw is a polystyrene equivalent.

[3] Synthesis of polymers

The polyamic acid was synthesized by the following method.

The polymer is not isolated from the obtained reaction solution containing the polymer, and the reaction solution is diluted as described later to prepare a composition for forming a resin substrate or a composition for forming a release layer.

Synthesis example S1 Polyamic acid (Synthesis of S1) >

p-PDA3.176g (0.02937 mol) was dissolved in NMP88.2g, BPDA8.624g (0.02931 mol) was added, and then the reaction was carried out at 23 ℃ for 24 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 107300 with a molecular weight distribution of 4.6.

Synthesis example Synthesis of polyamic acid (L1) L1

p-PDA1.507g (0.0139 mol) was dissolved in NMP43.2g, and PMDA3.166g (0.01452 mol) was added thereto, followed by reaction at 23 ℃ for 2 hours under nitrogen atmosphere. Then, 2AP0.127g (0.0012 mol) was further added thereto, and the mixture was reacted at 23 ℃ for 24 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 48500 with a molecular weight distribution of 2.08.

Synthesis example Synthesis of polyamic acid (L2) L2

p-PDA1.119g (0.01103 mol) was dissolved in NMP35.2g, PMDA3.006g (0.01378 mol) was added, and then the mixture was reacted at 23 ℃ for 2 hours under a nitrogen atmosphere. Then, 2AP0.602g (0.00551 mol) was further added thereto, and the mixture was reacted at 23 ℃ for 24 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 11700 and the molecular weight distribution was 1.76.

Synthesis example Synthesis of polyamic acid (L3) L3

0.681g (0.00629 mol) of p-PDA0.681g was dissolved in NMP35.2g, and PMDA2.746g (0.01259 mol) was added thereto, followed by reaction at 23 ℃ for 2 hours under a nitrogen atmosphere. Then, 2AP1.373g (0.012588 mol) was further added, and the mixture was reacted at 23 ℃ for 24 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 8000 and the molecular weight distribution was 1.57.

Synthesis example Synthesis of polyamic acid (L4) L4

p-PDA1.5206g (0.01406 mol) and 6FAP0.105g (0.00287 mol) were dissolved in NMP35.2g, and PMDA3.004g (0.01377 mol) was added, followed by reaction at 23 ℃ for 22 hours under a nitrogen atmosphere. Then, PA0.170g (0.00115 mol) was further added thereto, and then the mixture was reacted at 23 ℃ for 22 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 22100 and the molecular weight distribution was 1.93.

< comparative Synthesis example B1 Synthesis of Polyamic acid (B1)

1.29g (0.00107 mol) of p-PDA1 was dissolved in NMP43.2g, and BPDA3.509g (0.00119 mol) was added, followed by reaction at 23 ℃ for 24 hours under nitrogen atmosphere. The Mw of the resulting polymer was 34000 and the molecular weight distribution was 2.03.

< comparative Synthesis example B2 Synthesis of Polyamic acid (B2)

TFMB2.86g (0.0089 mol) was dissolved in NMP35.2g, CBDA1.944g (0.00991 mol) was added, and the mixture was reacted at 23 ℃ for 24 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 69200 with a molecular weight distribution of 2.2. The resulting solution was soluble in PGME.

[4] Preparation of composition for Forming resin substrate

The reaction solutions obtained in synthesis example S1 were each used as they were as a resin substrate-forming composition.

[5] Preparation of composition for Forming 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 became 5wt% and BCS became 20 mass%, to obtain a composition for forming a release layer.

Examples 1-2 to 1-4

The release layer-forming composition 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 solution obtained in synthesis example L1.

Comparative examples 1-1 to 1-2

A release layer-forming composition was obtained in the same manner as in example 1-1, except that the reaction liquids obtained in comparative synthesis examples B1 and B2 were used instead of the reaction liquid obtained in synthesis example L1.

[6] Production of Release layer and resin substrate

[ example 2-1]

The composition L1 for forming a release layer obtained in example 1-1 was applied to a 100mm X100 mm glass substrate (the same applies below) as a glass substrate by using a spin coater (conditions: rotation speed 3000rpm, about 30 seconds).

Then, the obtained coating film was heated at 100 ℃ for 2 minutes using a hot plate, and then heated at 300 ℃ for 30 minutes using an oven, the heating temperature was raised (10 ℃/minute) to 400 ℃, the heating temperature was raised at 400 ℃ for 30 minutes, further raised (10 ℃/minute) to 500 ℃, the heating temperature was raised at 500 ℃ for 10 minutes, and a release layer having a thickness of about 0.1 μm was formed on the glass substrate, thereby obtaining a glass substrate with a release layer. Note that during the temperature rise, the substrate with the film was not taken out of the oven but heated in the oven.

The release layer (resin film) on the glass substrate obtained above was coated with the resin substrate-forming composition S2 using a bar coater (gap: 250 μm). Then, the obtained coating film was heated at 80 ℃ for 30 minutes using a hot plate, and then, after a nitrogen atmosphere was formed using an oven, the film was heated at 140 ℃ for 30 minutes, the heating temperature was raised to 210 ℃ for 30 minutes, the heating temperature was raised to 300 ℃ for 30 minutes, the heating temperature was raised to 400 ℃ for 30 minutes, the heating temperature was raised to 500 ℃ for 60 minutes, and a polyimide substrate having a thickness of about 20 μm was formed on the release layer, thereby obtaining a glass substrate with a resin substrate/release layer. During the temperature rise, the substrate with the film was not removed from the oven but heated inside the oven.

Examples 2-2 to 2-4

A release layer and a polyimide substrate were formed in the same manner as in example 2-1 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, and a glass substrate with a release layer and a glass substrate with a resin substrate and a release layer were obtained.

Comparative examples 2-1 and 2-2

A release layer and a polyimide substrate were formed in the same manner as in example 2-1 except that the release layer-forming compositions B1 and B2 obtained in comparative examples 1-1 to 1-2 were used in place of the release layer-forming composition L1 obtained in example 1-1, and a glass substrate with a release layer and a glass substrate with a resin substrate and a release layer were obtained.

[7] Evaluation of peelability

The release properties of the release layer and the glass substrate were confirmed by the following methods for the glass substrates with the release layer obtained in examples 2-1 to 2-4 and comparative examples 2-1 to 2-2. The following tests were performed using the same glass substrate.

< evaluation of Peel Property in Cross cut test of resin film >

The peeling layers on the glass substrates with peeling layers obtained in examples 2-1 to 2-4 and comparative examples 2-1 to 2-2 were cross-cut (1 mm interval in vertical and horizontal directions, the same applies hereinafter), and 100 meshes (マスカット) were cut. That is, 100 meshes of 1mm square are formed by the cross cutting.

Then, an adhesive tape was attached to the 100 mesh cut portions, and the tape was peeled off, and the peelability was evaluated based on the following criteria. The results are shown in table 1.

< decision reference >

5B:0% Peel off (No Peel off)

4B: peeling of less than 5%

3B:5 to less than 15% exfoliation

2B:15 to less than 35% peeling

1B:35 to less than 65% peeling

0B:65% to less than 80% peeling

B:80% to less than 95% peeling

A:95% to less than 100% peeling

AA:100% peel (Total peel)

< evaluation of releasability of resin substrate >

The resin substrates of the glass substrates with the resin substrate/release layer obtained in examples 2-1 to 2-4 and comparative examples 2-1 to 2-2 were cut into long strips of 25mm in width using a cutting tool. Then, a cellophane tape was stuck to the front end of the cut resin substrate to prepare a test piece. The test piece was subjected to a peeling test using a push-pull tester manufactured by アトニック, strain (ltd.), so that the peeling angle was 90 °, and the peeling property was evaluated based on the following criteria. The results are shown in Table 1.

< decision reference >

5B:0% Peel off (No Peel off)

4B: peeling of less than 5%

3B:5 to less than 15% peeling

2B: peeling of 15 to less than 35%

1B:35 to less than 65% peeling

0B:65% to less than 80% peeling

B:80% to less than 95% peeling

A:95% to less than 100% peeling

AA:100% peel (Total peel)

[ Table 1]

From the results of table 1, it was confirmed that: in the release layers of examples 2-1 to 2-4, only the resin substrate could be peeled without peeling the release layer from the glass substrate, but the resin substrates could not be peeled in comparative examples 2-1 and 2-2.

Claims

1. A method for producing a release layer, comprising a step of applying a composition for forming a release layer comprising at least one of polyamic acids represented by the following formulae (1A) to (1B) and an organic solvent to a substrate and firing the composition at a maximum temperature of 450 to 550 ℃,

wherein X is independently a 4-valent aromatic group having 2 carboxylic acid derivatives, Y is independently a 2-valent aromatic group which may have an alkali-soluble group, and Z ¹ Is a 1-valent organic group represented by the following formula (10), Z ² Is a 1-valent organic group represented by the following formula (11), m independently represents an integer of 2 or more,

in formula (10), Z ³ Represents a carboxyl group or a hydroxyl group,. Smallcircle.represents a bonding end,

in formula (11), Z ³ Denotes a carboxyl group or a hydroxyl group, and O denotes a bonding end.

2. The method for producing a release layer according to claim 1, wherein the alkali-soluble group is a carboxyl group or a phenolic hydroxyl group.

3. 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),

wherein W independently of one another represents a carboxyl group or a hydroxyl group, R ¹ ～R ³ Independently of each other, a C1-20 alkylene group, a C2-20 alkenylene group, a C2-20 alkynylene group, a C6-20 arylene group, or a C2-20 heteroarylene group, an ether group, an ester group, or an amide group, each of which may be substituted with a halogen atom, and O represents a bonding end.

4. 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),

where, o denotes a bonding end.

5. The method for producing a peeling layer according to claim 3, wherein the Y further contains an aromatic group having no alkali-soluble group.

6. The method for manufacturing the peeling layer according to claim 5, wherein the aromatic group having no alkali-soluble group is a phenylene group, a biphenylene group, or a terphenylene group.

7. A method for manufacturing a flexible electronic device provided with a resin substrate, characterized by using a release layer formed by the manufacturing method according to any one of claims 1 to 6.

8. A method for manufacturing a flexible electronic device, comprising the steps of: a resin substrate is formed by applying a resin substrate-forming composition to a release layer formed by the production method according to any one of claims 1 to 6 and then firing the release layer at a maximum temperature of 450 ℃ or higher.

9. The method of manufacturing a flexible electronic device according to claim 7 or 8, wherein the resin substrate is a polyimide resin substrate.