CN109476951B

CN109476951B - Composition for forming release layer and release layer

Info

Publication number: CN109476951B
Application number: CN201780046634.2A
Authority: CN
Inventors: 江原和也; 进藤和也
Original assignee: Nissan Chemical Corp
Current assignee: Nissan Chemical Corp
Priority date: 2016-08-03
Filing date: 2017-08-03
Publication date: 2022-07-29
Anticipated expiration: 2037-08-03
Also published as: CN109476951A; KR20230020011A; KR20190037265A; JP7063266B2; TW201817775A; JPWO2018025953A1; WO2018025953A1; TWI737781B

Abstract

The present invention provides a composition for forming a release layer, which comprises a polyamic acid represented by the following formula (1) and an organic solvent. Wherein X represents an aromatic group represented by the following formula (2a) or (2b), Y represents an aromatic group having a valence of 2 of a fluorine atom, Z represents an aromatic group represented by the following formula (3a) or (4a) independently of each other in the case where X is the formula (2a), represents an aromatic group represented by the following formula (3b) or (4b) independently of each other in the case where X is the formula (2b), and m represents a natural number.

Description

Composition for forming release layer and release layer

Technical Field

The present invention relates to a composition for forming a release layer and 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. From this reason, it is required to use a lightweight flexible plastic substrate instead of a conventional heavy, fragile, and inflexible glass substrate.

In particular, for the next-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. The technology related to this new-generation display is expected to be applied to various fields such as flexible displays, flexible smart phones, and mirror displays.

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. In addition, in the touch panel type display, a countermeasure for efficiently manufacturing a resin substrate for a transparent electrode of a touch panel used in combination with a display panel is being studied. In general, a resin substrate used for a touch panel is a film substrate such as a polyimide resin substrate, an acrylic resin substrate, a polyethylene terephthalate (PET) resin substrate, or a cycloolefin resin substrate, which has transparency equivalent to that of glass, similarly to a TFT display panel.

As a method for manufacturing a flexible display, a direct method is mainly known (non-patent document 1). As a direct method, there is a method in which a previously prepared resin substrate is attached to a glass substrate via an adhesive layer, and a pixel circuit including a TFT and an organic EL are directly formed on the substrate; a method for manufacturing a resin substrate on a glass substrate, and directly forming a pixel circuit including a TFT and an organic EL on the substrate.

In the direct method, a resin substrate having a pixel circuit and the like formed on a glass substrate is peeled off by various methods described later, and the peeled resin substrate is used for manufacturing a target electronic device such as a display panel.

For example, 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, thereby completing a liquid crystal display device.

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 (resin substrate) such as a polyimide film is formed on the release layer, an ITO transparent electrode, a TFT, and the like are formed and sealed on the film by a vacuum process, and then the glass base is finally peeled and removed.

On the other hand, in the next-generation display, a large area of a substrate is required to meet the demand for a large screen, improvement in yield, and the like. In general, a slit coating system using a slit coater or the like is considered to be advantageous in uniformly coating a resin composition on a large-area coating surface. The slit coating method is a coating method using a slit nozzle, and is widely adopted from the viewpoint of reduction in the amount of the resin composition used and safety of the process because it is not necessary to rotate the substrate as in the conventional spin coating method. However, in the slit coating method, from the viewpoint of improving productivity, it is desired to increase the speed of the coating process. In order to realize a high speed slit coating method, it is necessary to suppress the occurrence of stripe unevenness at the time of coating, and therefore it is necessary to reduce the viscosity of the solution, which is one of the most important parameters.

For example, patent documents 6 and 7 disclose compositions using a so-called low viscosity solvent such as propylene glycol monomethyl ether acetate or propylene glycol monomethyl ether as a composition suitable for a photoresist of a slit coating system. However, resins (or precursors thereof) such as polyimide resins generally used in release layer-forming compositions are insoluble in these low-viscosity solvents, and it is therefore difficult to apply the slit coating method to the formation of release layers. Therefore, if the resin (or its precursor) used in the release layer-forming composition can be dissolved in the low-viscosity solvent, not only the coatability by the conventional spin coating method is improved, but also it can be suitably used in the slit coating method.

Documents of the prior art

Patent document

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

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

Patent document 3: international publication No. 2005/050754

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

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

Patent document 6: international publication No. 2011/030744

Patent document 7: japanese laid-open patent publication No. 2008-70480

Non-patent document

Non-patent document 1: NHK technical research R & D/No.145/2014.5

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 composition for forming a release layer which is soluble in a so-called low viscosity solvent such as propylene glycol monomethyl ether and can be easily applied to a slit coating method, and which gives a release layer that can be released without damaging a resin substrate of a flexible electronic device formed thereon, particularly a film substrate formed using a polyimide resin, an acrylic resin, a cycloolefin polymer resin, or the like.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems, and as a result, have found that a polyamic acid having a specific structure can be easily dissolved in a low-viscosity solvent, and that a composition comprising the polyamic acid and an organic solvent gives a release layer having excellent adhesion to a substrate such as a glass substrate, and suitable adhesion and suitable releasability to a resin substrate for a flexible electronic device, particularly a resin substrate having a light transmittance of 80% or more at a wavelength of 400nm, and have completed the present invention.

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

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

[ solution 1]

(wherein X represents an aromatic group represented by the following formula (2a) or (2b), Y represents an aromatic group having a valence of 2 of a fluorine atom, Z represents an aromatic group represented by the following formula (3a) or (4a) independently of each other in the case where X is an aromatic group represented by the following formula (2a), represents an aromatic group represented by the following formula (3b) or (4b) independently of each other in the case where X is an aromatic group represented by the following formula (2b), and m represents a natural number.)

[ solution 2]

[ solution 3]

[2] [1] the composition for forming a release layer, wherein Y is an aromatic group represented by the following formula (5).

[ solution 4]

[3] [2] the composition for forming a release layer, wherein Y is an aromatic group represented by the following formula (6).

[ solution 5]

[4] The composition for forming a release layer according to any one of [1] to [3], wherein in the X, the aromatic group represented by the formula (2a) is an aromatic group represented by the following formula (7a) or (8a), and the Z's are each independently an aromatic group represented by the following formula (9a) or (10 a).

[ solution 6]

[ solution 7]

[5] The composition for forming a release layer according to any one of [1] to [3], wherein in the X, the aromatic group represented by the formula (2b) is an aromatic group represented by the following formula (7b) or (8b), and the Z's are each independently an aromatic group represented by the following formula (9b) or (10 b).

[ solution 8]

[ solution 9]

[6] The composition for forming a release layer according to any one of [1] to [5], wherein the organic solvent is at least 1 selected from organic solvents having a structure represented by the following formulae (S1) to (S7).

[ solution 10]

(in the formula, R ¹ ～R ⁸ Independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R ⁹ And R ¹⁰ Independently of each other, a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 10 carbon atoms, b and n are natural numbers)

[7] [6] the composition for forming a release layer, wherein the organic solvent is propylene glycol monomethyl ether or propylene glycol monomethyl ether acetate.

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

[9] A method for producing a resin substrate, which comprises using the release layer described in [8 ].

[10] [9] the production method according to, wherein the resin substrate is a polyimide resin substrate or a resin substrate having a light transmittance of 80% or more at a wavelength of 400 nm.

ADVANTAGEOUS EFFECTS OF INVENTION

By using the composition for forming 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. In particular, since polyamic acid used in the present invention has excellent solubility in a low-viscosity solvent, a composition applicable to a slit coating system can be easily prepared by using a low-viscosity solvent, and uniform coating can be easily performed on a large-area coating surface. Further, in the manufacturing process of the flexible electronic device, the resin substrate formed on the base body and the circuit and the like provided thereon can be separated from the base body together with the circuit and the like without damaging the resin substrate. Therefore, the release layer-forming composition of the present invention can contribute to speeding up 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 composition for forming a release layer of the present invention comprises a polyamic acid represented by the following formula (1) and an organic solvent.

In the present invention, the peeling layer is a layer provided directly above a base (glass base or the like) on which the resin substrate is to be formed. Typical examples thereof include a release layer provided in a process for manufacturing a flexible electronic device so as to fix the resin substrate between the base and a resin substrate of the flexible electronic device made of polyimide resin, acrylic resin, or the like in a predetermined process, and provided so as to allow the resin substrate to be easily released from the base after forming an electronic circuit or the like on the resin substrate.

[ solution 11]

In formula (1), X represents an aromatic group represented by formula (2a) or (2b) below, Y represents a 2-valent aromatic group having a fluorine atom, Z represents an aromatic group represented by formula (3a) or (4a) below independently of each other in the case where X is formula (2a), represents an aromatic group represented by formula (3b) or (4b) below independently of each other in the case where X is formula (2b), and m represents a natural number.

[ solution 12]

[ solution 13]

In the above X, the aromatic group represented by the above formula (2a) is preferably an aromatic group represented by the following formula (7a) or (8a), and the aromatic group represented by the above formula (2b) is preferably an aromatic group represented by the following formula (7b) or (8 b).

[ solution 14]

[ solution 15]

In addition, in the above Z, the aromatic group represented by the above formula (3a) or (4a) is preferably an aromatic group represented by the following formula (9a) or (10a), and the aromatic group represented by the above formula (3b) or (4b) is preferably an aromatic group represented by the following formula (9b) or (10 b).

[ chemical 16]

[ solution 17]

The above Y is preferably an aromatic group having a fluorine atom and containing 1 to 5 benzene rings, more preferably an aromatic group selected from the following formula (5), and still more preferably an aromatic group selected from the following formula (6).

[ solution 18]

[ solution 19]

The number m may be a natural number, but is preferably a natural number of 100 or less, and more preferably a natural number of 2 to 100.

The polyamic acid represented by the formula (1) is obtained by reacting a predetermined tetracarboxylic dianhydride component with a diamine component.

As the tetracarboxylic dianhydride component, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride is used. In the present invention, in particular, from the viewpoint of improving the solubility in a low-viscosity solvent and improving the function as a release layer of the resulting film, a polyamic acid obtained by reacting the above-mentioned pyromellitic dianhydride or biphenyltetracarboxylic dianhydride with a diamine component containing the above-mentioned aromatic diamine is preferable, and a wholly aromatic polyamic acid obtained by reacting the above-mentioned tetracarboxylic dianhydride with an aromatic diamine is more preferable.

The pyromellitic dianhydride component, the biphenyltetracarboxylic dianhydride, and the diamine component that can be used for synthesizing the polyamic acid having the structure represented by the formula (1) will be described in detail below.

The pyromellitic dianhydride is not particularly limited as long as it has 2 dicarboxylic anhydride sites in the molecule and a benzene ring. Specific examples thereof include pyromellitic dianhydride and benzene-1, 2,3, 4-tetracarboxylic dianhydride, and pyromellitic dianhydride is preferred in the present invention. One kind of these may be used alone, or 2 or more kinds may be used in combination.

The biphenyltetracarboxylic dianhydride is not particularly limited as long as it has 2 dicarboxylic anhydride sites in the molecule and a biphenyl group. Specific examples thereof include 2,2 ', 3, 3' -biphenyltetracarboxylic dianhydride, 2,3,3 ', 4' -biphenyltetracarboxylic dianhydride, and 3,3 ', 4, 4' -biphenyltetracarboxylic dianhydride is preferable in the present invention. One kind of these may be used alone, or 2 or more kinds may be used in combination.

On the other hand, the aromatic diamine is not particularly limited as long as it has a fluorine atom and 2 amino groups directly bonded to the aromatic ring in the molecule, and is preferably an aromatic diamine containing 1 to 5, particularly 1 to 2, and further 2 benzene rings. Further, it preferably has a fluoroalkyl group or a perfluoroalkyl group, and a perfluoroalkyl group is more preferred. Examples of the perfluoroalkyl group include a trifluoromethyl group, a pentafluoroethyl group, an n-heptafluoropropyl group, and an i-heptafluoropropyl group.

Specific examples of the aromatic diamine include, but are not limited to, 5-trifluoromethylbenzene-1, 3-diamine, 5-trifluoromethylbenzene-1, 2-diamine, 2 '-bis (trifluoromethyl) -4, 4' -diaminobiphenyl, and 3,3 '-bis (trifluoromethyl) biphenyl-4, 4' -diamine. In the present invention, among these, 2 '-bis (trifluoromethyl) -4, 4' -diaminobiphenyl can be particularly preferably used. One kind of these may be used alone, or 2 or more kinds may be used in combination.

The feed ratio of the diamine component and the tetracarboxylic dianhydride component is appropriately determined in consideration of the target molecular weight, molecular weight distribution, kinds of diamine and tetracarboxylic dianhydride, and the like, and therefore it cannot be generally specified that the number of moles of the tetracarboxylic dianhydride component is preferably slightly larger than the number of moles of the diamine component in order to obtain the polyamic acid of the formula (1). The specific molar ratio is preferably 1.05 to 2.5 moles, more preferably 1.07 to 1.5 moles, and still more preferably 1.1 to 1.3 moles of the tetracarboxylic dianhydride component to 1 mole of the diamine component.

The polyamic acid contained in the release layer-forming composition of the present invention can be obtained by reacting the tetracarboxylic dianhydride component described above with the diamine component.

The organic solvent used for the synthesis of polyamic acid 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, N-isopropyloxy-N, N-dimethylpropionamide, and N, N-dimethylpropionamide, 3-sec-butoxy-N, N-dimethylpropionamide, 3-tert-butoxy-N, N-dimethylpropionamide, γ -butyrolactone, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate, and the like. The organic solvents may be used alone in 1 kind or in combination of 2 or more kinds.

The reaction temperature at the time of synthesizing the polyamic acid may be appropriately set in a range from the melting point to the boiling point of the solvent used, and is usually about 0 to 100 ℃, and from the viewpoint of preventing imidization of the obtained polyamic acid in the solution and maintaining a high content of the polyamic acid unit, it is preferably about 0 to 70 ℃, more preferably about 0 to 60 ℃, and further preferably about 0 to 50 ℃. 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 way is usually about 5,000 to 500,000, and from the viewpoint of improving the function as a release layer of the obtained film, it is preferably about 10,000 to 200,000, and more preferably about 10,000 to 150,000. In the present invention, the weight average molecular weight is a polystyrene equivalent value measured by Gel Permeation Chromatography (GPC).

Specific examples of the polyamic acid that can be preferably used in the present invention include, but are not limited to, polyamic acids represented by the following formulae.

[ solution 20]

(wherein m1 and m2 represent the number of repeating units, and the total of m1 and m2 is the same as m.)

[ solution 21]

The release layer-forming composition of the present invention contains an organic solvent. As the organic solvent, the same organic solvents as the specific examples of the reaction solvent of the above reaction can be used, and from the viewpoint of dissolving the polyamic acid of the present invention well and easily producing a composition with high uniformity, organic solvents selected from amides, alcohols, esters, ethers, and ketones are preferable, and at least 1 species having structures represented by the following formulae (S1) to (S7) is particularly preferable.

[ solution 22]

In the above formula, R ¹ ～R ⁸ Independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms. R ⁹ And R ¹⁰ Independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, or an acyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms. b represents a natural number, preferably a natural number of 1 to 5, and more preferably a natural number of 1 to 3. n represents a natural number, preferably a natural number of 1 to 5, and more preferably a natural number of 1 to 3.

Specific examples of the alkyl group having 1 to 10 carbon atoms include straight-chain, branched and cyclic alkyl groups, and examples thereof include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1-dimethyl-n-propyl, 1, 2-dimethyl-n-propyl, 2-dimethyl-n-propyl, 1-ethyl-n-propyl, cyclopentyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1-dimethyl-n-butyl, 1, 2-dimethyl-n-butyl, 1, 3-dimethyl-n-butyl, 2-dimethyl-n-butyl, 2, 3-dimethyl-n-butyl, 3, 3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1, 2-trimethyl-n-propyl group, 1,2, 2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group and the like.

Specific examples of the acyl group having 1 to 10 carbon atoms include formyl group, acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, hexanoyl group, isohexanoyl group, heptanoyl group, isoheptanoyl group, octanoyl group, isooctanoyl group, nonanoyl group, isononanoyl group, decanoyl group, isodecanoyl group, and benzoyl group.

Specific examples of the organic solvent represented by the above formulae (S1) to (S7) include the following organic solvents.

Formula (S1): 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

Formula (S2): 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone

Formula (S3): n, N-dimethylformamide, N-dimethylacetamide, N-dimethylpropionamide, N-dimethylbutanamide

Formula (S4): gamma-butyrolactone

Formula (S5): cyclopentanone, cyclohexanone, cycloheptanone

Formula (S6): methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, propyl 2-hydroxyisobutyrate, butyl 2-hydroxyisobutyrate

Formula (S7): ethyl cellosolve, butyl cellosolve, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, propylene glycol monomethyl ether, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate

In the present invention, among these, N-methyl-2-pyrrolidone, butyl cellosolve, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are preferable, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are more preferable, and propylene glycol monomethyl ether is further preferable. These organic solvents may be used 1 kind alone or in combination of 2 or more kinds.

In particular, when a so-called low viscosity solvent such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate is used as the organic solvent, a low viscosity composition for forming a release layer that can be suitably applied to slit coating can be obtained. When the release layer-forming composition of the present invention is used for slit coating, the proportion of the low-viscosity solvent in the entire solvent is preferably 60 mass% or more, more preferably 70 mass% or more, and most preferably 80 mass% or more.

The solvent which does not dissolve the polyamic acid alone may be used for the preparation of the composition as long as the polyamic acid is not precipitated. In particular, solvents having a low surface tension such as ethyl carbitol, butyl carbitol, ethyl carbitol acetate, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, and the like can be suitably mixed. It is known that the uniformity of the coating film is improved when the coating film is applied to a substrate, and the coating film can be suitably used in the present invention.

The composition for forming a release layer of the present invention can be prepared by a conventional method. As a preferable example of the production method, the reaction solution containing the target polyamic acid obtained by the above-described method is filtered, and the concentration of the obtained filtrate is adjusted to a predetermined concentration by using the above-described organic solvent. By adopting such a method, it is possible to obtain a composition for forming a release layer with high efficiency while reducing the mixing of impurities that may cause deterioration in adhesion, releasability, and the like of the release layer produced from the obtained composition.

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 setting the concentration to this level, 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 the diamine component, the tetracarboxylic dianhydride component, and the aromatic monoamine, which are raw materials of the polyamic acid, or adjusting the amounts of the isolated polyamic acid when dissolved in a solvent.

The viscosity of 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, 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 ℃. When the composition for forming a release layer of the present invention is used in a slit coating method, the viscosity thereof may be about 2 to 100mPa · s, and preferably about 2 to 25mPa · s from the viewpoint of productivity.

The viscosity can be measured at a temperature of 25 ℃ in 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, the measurement can be performed under the condition that the temperature of the composition is 25 ℃ in a homotypic viscometer using 1 ° 34' × R24 as a standard conical rotor. An example of such a rotational viscometer is TVE-25L manufactured by Toyobo industries, Ltd.

The release layer forming composition of the present invention may contain a crosslinking agent or the like in addition to the polyamic acid and the organic solvent, for example, to improve the film strength.

By applying the release layer-forming composition of the present invention described above to a substrate and heating the obtained coating film to thermally imidize the polyamic acid, a release layer made of a polyimide film having excellent adhesion to the substrate, appropriate adhesion to a resin substrate, and appropriate releasability can be obtained.

When the release layer of the present invention is formed on a substrate, the release layer may be formed on a part of the surface of the substrate or may be formed on the entire surface. Examples of the form of forming the release layer on a part of the substrate surface include a form of forming the release layer only in a predetermined range on the substrate surface, 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 substrate surface. In the present invention, the substrate means a member to be used for the production of a flexible electronic device or the like, on the surface of which the composition for forming a release layer of the present invention is applied.

Examples of the substrate (base material) include glass, plastics (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy, melamine, triacetyl cellulose, ABS, AS, norbornene-based resins, etc.), metals (silicon wafers, etc.), wood, paper, slate, and the like. In the present invention, a glass substrate can be preferably used particularly from the viewpoint that the peeling layer has sufficient adhesion. 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 composed of 2 or more kinds of materials, there is a form in which a certain range of the substrate surface is composed of one kind of material and the remaining range is composed of another material; a pattern in which a certain material exists in other materials in a dot pattern, a line pattern, a space pattern, or the like over the entire surface of the substrate.

The method for applying the release layer-forming composition of the present invention to a substrate is not particularly limited, and examples thereof include a casting method, a spin coating method, a slit coating method, a doctor 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 (relief printing, gravure printing, offset printing, screen printing, etc.).

The heating temperature for imidization is suitably determined in the range of usually 50 to 550 ℃, and preferably more than 150 ℃ and 510 ℃ or less. By setting the heating temperature to such a temperature, the imidization reaction can be sufficiently advanced while preventing the resultant film from becoming brittle. The heating time varies depending on the heating temperature, and therefore cannot be generally specified, but is usually 5 minutes to 5 hours. The imidization ratio may be in the range of 50 to 100%.

As a preferred example of the heating method in the present invention, the following method can be mentioned: after heating at 50 to 150 ℃ for 5 minutes to 2 hours, the heating temperature is raised in stages, and finally the heating is carried out at more than 150 ℃ and 510 ℃ for 30 minutes to 4 hours. Particularly preferred are: heating for 5 minutes to 2 hours at 50 to 150 ℃, heating for 5 minutes to 2 hours at the temperature of more than 150 ℃ and below 350 ℃, and finally heating for 30 minutes to 4 hours at the temperature of more than 350 ℃ and below 450 ℃.

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 preferably about 0.05 to 20 μm from the viewpoint of productivity. Further, the thickness of the coating film before heating is adjusted to achieve a 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 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 solution for forming a resin substrate is applied to the release layer, and the coating film is heated, whereby a resin substrate fixed to a glass substrate is formed via the release layer of the present invention. At this time, the substrate is formed to have an area larger than that of the peeling layer so as to cover the entire peeling layer. As the resin substrate, a substrate made of a polyimide resin, an acrylic resin, a cycloolefin polymer resin, which is a representative of a resin substrate of a flexible electronic device, may be cited, and as the resin solution for forming the same, a polyimide solution, a polyamic acid solution, an acrylic polymer solution, a cycloolefin polymer solution, and the like may be cited. The resin substrate can be formed by a conventional method. Further, as the resin substrate having high transparency, a resin substrate formed of an acrylic resin or a cycloolefin polymer resin can be exemplified, and a resin substrate having a light transmittance of 80% or more at a wavelength of 400nm is particularly preferable.

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, and the resin substrate is separated from the base. At this time, a part of the base may be cut together with the peeling layer.

Furthermore, japanese patent application laid-open No. 2013-147599 reports that the 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 and the like are formed. The irradiated light passes through the glass substrate, and only the polymer (polyimide resin) near 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 a circuit or the like provided on the resin substrate, which determines the performance of the display.

The composition for forming a release layer of the present invention has a characteristic of sufficiently absorbing light having a specific wavelength (for example, 308nm) that enables application of the LLO method, and therefore can be used as a sacrificial layer of the LLO method. Therefore, a desired circuit is formed on a resin substrate fixed to a glass substrate via a release layer formed using the composition of the present invention, and then, if the LLO method is performed and light of 308nm is irradiated, only the release layer absorbs the light and evaporates (sublimes). Thus, the release layer sacrifices (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 with reference to the following examples, but the present invention is not limited to these examples.

[1] Abbreviations for Compounds

p-PDA: p-phenylenediamine

TPDA: 4, 4' -diamino-p-terphenyl

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

BPDA: 3,3 ', 4, 4' -Biphenyltetracarboxylic dianhydride

And (3) PMDA: pyromellitic dianhydride

DMCBDA: 1, 3-dimethylcyclobutanetetracarboxylic dianhydride

CBDA: cyclobutanetetracarboxylic dianhydride

MMA: methacrylic acid methyl ester

MAA: methacrylic acid

HEMA: 2-Hydroxyethyl methacrylate

AIBN: azobisisobutyronitrile

CHMI: cyclohexyl maleimide

EPOLEAD GT-401: preparation of butane tetracarboxylic acid tetra (3, 4-epoxycyclohexylmethyl) ester-modified epsilon-caprolactone and xylonite

Celloxin 2021P: preparation of 3 ', 4' -epoxycyclohexylmethyl 3, 4-epoxycyclohexanecarboxylate and xylonite

Vestigon B1530: エボニックジャパン Kabushiki Kaisha

NMP: n-methyl-2-pyrrolidone

BCS: butyl cellosolve

PGME: propylene glycol monomethyl ether

PGMEA: propylene glycol monomethyl ether acetate

[2] Method for measuring 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 by using GPC apparatus (columns: KD801 and KD805, Shodex, Ltd.; eluent: dimethylformamide/LiBr. H) ₂ O(29.6mM)/H ₃ PO ₄ (29.6mM)/THF (0.1 mass%); flow rate: 1.0 mL/min; column temperature: 40 ℃; mw: standard polystyrene conversion).

[3] Synthesis of polymers

The following methods were used to synthesize various polymers used in examples and comparative examples.

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 Synthesis of Polyamic acid (S1)

88.2g of NMP was dissolved with 3.218g (30mmol) of p-PDA. To the resulting solution was added 8.581g (29mmol) of BPDA, and the mixture was reacted at 23 ℃ for 24 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 107,300, with a molecular weight distribution of 4.6.

Synthesis example S2 Synthesis of Polyamic acid (S2)

p-PDA 20.261g (0.1875mol) and TPDA 12.206g (0.0469mol) were dissolved in NMP 617.4g, cooled to 15 ℃ and then PMDA 50.112g (0.2298mol) was added thereto, and the mixture was reacted at 50 ℃ for 48 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 82,100 with a molecular weight distribution of 2.7.

Synthesis example S3 Synthesis of acrylic Polymer (S3)

MMA 7.20g (0.0719mol), HEMA 7.20g (0.0553mol), CHMI 10.8g (0.0603mol), MAA 4.32g (0.0502mol), and AIBN 2.46g (0.0150mol) were dissolved in PGMEA 46.9g and reacted at 60 to 100 ℃ for 20 hours to obtain an acrylic polymer solution (solid content concentration: 40 mass%). The obtained acrylic polymer had Mn of 3,800 and Mw of 7,300.

Synthesis of Polyamic acid (L1) in Synthesis example L1

2.73g (8.53mmol) of TFMB was dissolved in 38.5g of NMP. To the resulting solution was added 2.06g (9.47mmol) of PMDA, and the mixture was reacted at 23 ℃ for 24 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 17,100 with a molecular weight distribution of 1.7. When 1g of the obtained polymer solution was added to 10g of PGME, no precipitation was observed.

< Synthesis example Synthesis of polyamic acid (L2) L2

2.73g (8.53mmol) of TFMB was dissolved in 40g of PGME. To the resulting solution was added 2.06g (9.47mmol) of PMDA, and the mixture was reacted at 23 ℃ for 24 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 20,100 with a molecular weight distribution of 1.8.

< Synthesis example Synthesis of polyamic acid (L3) L3

23.7g (74.2mmol) of TFMB was dissolved in 352g of NMP. To the resulting solution was added 24.2g (82.5mmol) of BPDA, and the mixture was reacted under a nitrogen atmosphere at 23 ℃ for 24 hours. The Mw of the resulting polymer was 16,500 with a molecular weight distribution of 1.7. When 1g of the obtained polymer solution was added to 10g of PGME, no precipitation was observed.

< Synthesis example Synthesis of polyamic acid (L4) L4

9.89g (30.9mmol) of TFMB was dissolved in PGME380 g. To the resulting solution was added BPDA (10.0 g, 34.3mmol), and the mixture was reacted at 50 ℃ for 72 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 14,700 with a molecular weight distribution of 1.7.

< comparative Synthesis example HL1 Synthesis of Polyamic acid (HL1) >

3.90g (3.60mmol) of p-PDA was dissolved in 35.2g of NMP. To the resulting solution was added 9.27g (4.00mmol) of DMCBDA, and the mixture was reacted at 23 ℃ for 24 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 45,000 with a molecular weight distribution of 3.9. 1g of the obtained polymer solution was added to 10g of PGME, and as a result, polyamic acid was precipitated.

< comparative Synthesis example Synthesis of polyamic acid HL2 (HL2)

2.86g (8.91mmol) of TFMB was dissolved in 35.2g of NMP. To the resulting solution, 1.94g (9.91mmol) of CBDA was added, and the mixture was reacted at 23 ℃ for 24 hours under a nitrogen atmosphere. The Mw of the resulting polymer was 69,200, with a molecular weight distribution of 2.2. When 1g of the obtained polymer solution was added to 10g of PGME, no precipitation was observed.

[4] Preparation of composition for Forming resin substrate

A resin substrate-forming composition was prepared by the following method.

< preparation example 1 resin substrate-forming composition F1 >

The reaction solution obtained in synthesis example S1 was used as it was as a resin substrate-forming composition F1.

< preparation example 2 composition F2 for Forming resin substrate

The reaction solution obtained in synthesis example S2 was used as it was as a resin substrate-forming composition F2.

< preparation example 3 composition F3 for Forming resin substrate

EPOLEAD GT-4010.60 g and PGMEA 11.8g were added to 10g of the reaction solution obtained in Synthesis example S3, and the mixture was stirred at 23 ℃ for 24 hours to prepare a composition F3 for forming a resin substrate.

< preparation example 4 resin substrate-forming composition F4 >

CELLOXIDE 2021P 0.80g and PGMEA 11.8g were added to 10g of the reaction solution obtained in Synthesis example S3, and the mixture was stirred at 23 ℃ for 24 hours to prepare a resin substrate-forming composition F4.

< preparation example 5 resin substrate-forming composition F5 >

To 10g of the reaction solution obtained in Synthesis example S3, VESTAGON B15300.60 g and PGMEA 11.8g were added, and the mixture was stirred at 23 ℃ for 24 hours to prepare a composition F5 for forming a resin substrate.

< preparation example 6 resin substrate-forming composition F6 >

Into an eggplant-shaped flask containing 100g of carbon tetrachloride were charged 10g of ZEONOR (registered trademark) 1020R (manufactured by Nippon Rukusho Co., Ltd., cycloolefin polymer resin) and GT-4013 g. This solution was stirred and dissolved for 24 hours under a nitrogen atmosphere, to prepare a composition F6 for forming a resin substrate.

< preparation example 7 resin substrate-forming composition F7 >

To an eggplant-shaped flask containing 100g of carbon tetrachloride was added 10g of ZEONOR (registered trademark) 1060R (a cycloolefin polymer resin, manufactured by nippon corporation). This solution was stirred and dissolved for 24 hours under a nitrogen atmosphere, to prepare a composition F7 for forming a resin substrate.

[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 5 mass% and the BCS became 20 mass%, to obtain a composition for forming a release layer.

[ examples 1-2]

The reaction solution obtained in synthesis example L2 was used as it was as a composition for forming a release layer.

[ examples 1 to 3]

BCS and NMP were added to the reaction solution obtained in synthesis example L3, and diluted so that the polymer concentration became 5 mass% and the BCS became 20 mass%, to obtain a composition for forming a release layer.

[ examples 1 to 4]

The reaction solution obtained in synthesis example L4 was used as it was as a composition for forming a release layer.

Comparative examples 1 to 1

BCS and NMP were added to the reaction solution obtained in comparative synthesis example HL1, and diluted so that the polymer concentration became 5 mass% and the BCS became 20 mass%, to obtain a composition for forming a release layer.

Comparative examples 1 and 2

BCS and NMP were added to the reaction solution obtained in comparative synthesis example HL2, and diluted so that the polymer concentration became 5 mass% and the BCS became 20 mass%, to obtain a composition for forming a release layer.

[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: about 30 seconds at a rotation speed of 3,000 rpm).

Then, the obtained coating film was heated at 80 ℃ for 10 minutes using a hot plate, then at 300 ℃ for 30 minutes using an oven, the heating temperature was raised (10 ℃/minute) to 400 ℃, and further at 400 ℃ for 30 minutes, to form a release layer having a thickness of about 0.1 μm on a glass substrate, thereby obtaining a glass substrate with a release layer. During the temperature rise, the substrate with the film was not taken out of the oven and heated in the oven.

Using a bar coater (gap: 250 μm), the release layer (resin film) on the glass substrate obtained above was coated with a resin substrate-forming composition F1. Then, the obtained coating film was heated at 80 ℃ for 30 minutes using a hot plate, and then heated at 140 ℃ for 30 minutes using an oven, the heating temperature was raised to 210 ℃ for 30 minutes at 210 ℃, the heating temperature was raised to 300 ℃ for 30 minutes at 300 ℃, the heating temperature was raised to 400 ℃ for 60 minutes at 400 ℃, and a resin 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 warming, the substrate with the film was not removed from the oven and heated in the oven.

[ examples 2-2]

A release layer and a resin substrate were produced in the same manner as in example 2-1 except that the resin substrate-forming composition F2 was used in place of the resin substrate-forming composition F1 used in example 2-1, and a glass substrate with a release layer and a glass substrate with a resin substrate/release layer were obtained.

[ examples 2 to 3]

A release layer and a resin substrate were produced in the same manner as in example 2-1 except that the release layer-forming composition L2 obtained in example 1-2 was 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/release layer were obtained.

[ examples 2 to 4]

The release layer-forming composition L2 obtained in example 1-2 was used as a release layer-forming composition, the resin substrate-forming composition F2 used in example 2-2 was used as a resin substrate-forming composition, and a release layer and a resin substrate were produced in the same manner as in example 2-1 to obtain a glass substrate with a release layer and a glass substrate with a resin substrate/release layer.

[ examples 2 to 5]

A release layer-forming composition L1 obtained in example 1-1 was used as a release layer-forming composition, a resin substrate-forming composition F4 was used as a resin substrate-forming composition, and a release layer and a resin substrate were produced in the same manner as in example 2-1 to obtain a glass substrate with a release layer and a glass substrate with a resin substrate and a release layer.

[ examples 2 to 6]

A release layer-forming composition L1 obtained in example 1-1 was used as a release layer-forming composition, a resin substrate-forming composition F5 was used as a resin substrate-forming composition, and a release layer and a resin substrate were produced in the same manner as in example 2-1 to obtain a glass substrate with a release layer and a glass substrate with a resin substrate and a release layer.

[ examples 2 to 7]

The release layer-forming composition L2 obtained in example 1-2 was used as a release layer-forming composition, and the resin substrate-forming composition F5 was used as a resin substrate-forming composition, and a release layer and a resin substrate were produced in the same manner as in example 2-1, thereby obtaining a glass substrate with a release layer and a glass substrate with a resin substrate and a release layer.

[ examples 2 to 8]

A release layer was formed using the release layer-forming composition L1 obtained in example 1-1 in the same manner as in example 2-1, to obtain a glass substrate with a release layer.

Immediately thereafter, a composition F6 for forming a resin substrate was applied to the release layer (resin film) on the glass substrate using a spin coater (conditions: about 15 seconds at a rotation speed of 200 rpm). The obtained coating film was heated at 80 ℃ for 2 minutes using a hot plate, and then at 230 ℃ for 30 minutes using a hot plate, to form a resin substrate having a thickness of about 3 μm on the release layer, thereby obtaining a glass substrate with a resin substrate/release layer. Then, the light transmittance was measured using an ultraviolet-visible spectrophotometer (UV-2600, Shimadzu corporation), and the resin substrate showed a transmittance of 80% or more at 400 nm.

[ examples 2 to 9]

A release layer and a resin substrate were produced in the same manner as in examples 2 to 8 except that the release layer-forming composition L2 obtained in example 1-2 was 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/release layer were obtained.

[ examples 2 to 10]

Immediately thereafter, the resin substrate-forming composition F7 was applied to the release layer (resin film) on the glass substrate using a spin coater (conditions: rotation speed: 200rpm for about 15 seconds). The obtained coating film was heated at 80 ℃ for 2 minutes using a hot plate, and then at 230 ℃ for 30 minutes using a hot plate, to form a resin substrate having a thickness of about 3 μm on the release layer, thereby obtaining a glass substrate with a resin substrate/release layer. Then, the light transmittance was measured using an ultraviolet-visible spectrophotometer (UV-2600, Shimadzu corporation), and the resin substrate showed a transmittance of 80% or more at 400 nm.

[ examples 2 to 11]

A release layer and a resin substrate were produced in the same manner as in examples 2 to 10 except that the release layer-forming composition L2 obtained in example 1-2 was 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/release layer were obtained.

Comparative examples 2-1 to 2-4

A release layer and a resin substrate were produced in the same manner as in the above examples except that the release layer-forming composition obtained in comparative examples 1-1 to 1-2 was used instead of the release layer-forming composition obtained in example 1-1, and a glass substrate with a release layer and a glass substrate with a resin substrate/release layer were obtained. The combination of the release layer and the resin substrate is as shown in table 1.

[ examples 2 to 12]

The composition L3 for forming a release layer obtained in examples 1 to 3 was applied to a 100mm X100 mm glass substrate (the same applies below) as a glass substrate by using a spin coater (conditions: about 30 seconds at a rotation speed of 3,000 rpm).

The release layer (resin film) on the glass substrate obtained above was coated with the resin substrate-forming composition F3 using a spin coater (conditions: rotation speed 800rpm for about 10 seconds). Then, the obtained coating film was heated at 80 ℃ for 30 minutes using a hot plate, and then at 230 ℃ for 30 minutes using an oven, to form an acryl substrate having a thickness of about 3 μm on the release layer. During the warming, the substrate with the film was not removed from the oven and heated in the oven.

[ examples 2 to 13]

A release layer and a resin substrate were produced in the same manner as in examples 2 to 12 except that the resin substrate-forming composition F4 was used in place of the resin substrate-forming composition F3 used in examples 2 to 12, and a glass substrate with a release layer and a glass substrate with a resin substrate/release layer were obtained.

[ examples 2 to 14]

A release layer and a resin substrate were produced in the same manner as in examples 2 to 12 except that the resin substrate-forming composition F5 was used in place of the resin substrate-forming composition F3 used in examples 2 to 12, and a glass substrate with a release layer and a glass substrate with a resin substrate/release layer were obtained.

[ examples 2 to 15]

A release layer and a resin substrate were produced in the same manner as in examples 2 to 12 except that the release layer-forming composition L4 obtained in examples 1 to 4 was used in place of the release layer-forming composition L3 obtained in examples 1 to 3, and a glass substrate with a release layer and a glass substrate with a resin substrate/release layer were obtained.

[ examples 2 to 16]

The release layer-forming composition L4 obtained in examples 1 to 4 was used as a release layer-forming composition, the resin substrate-forming composition F5 used in examples 2 to 14 was used as a resin substrate-forming composition, and a release layer and a resin substrate were produced in the same manner as in examples 2 to 12, thereby obtaining a glass substrate with a release layer and a glass substrate with a resin substrate and a release layer.

[ examples 2 to 17]

Using the composition for forming a peeling layer L3 obtained in examples 1 to 3, a peeling layer was formed in the same manner as in examples 2 to 12, and a glass substrate with a peeling layer was obtained.

[ examples 2 to 18]

A release layer and a resin substrate were produced in the same manner as in examples 2 to 17 except that the release layer-forming composition L4 obtained in examples 1 to 4 was used in place of the release layer-forming composition L3 obtained in examples 1 to 3, and a glass substrate with a release layer and a glass substrate with a resin substrate/release layer were obtained.

[ examples 2 to 19]

Using the composition for forming a release layer L3 obtained in examples 1 to 3, a release layer was formed in the same manner as in examples 2 to 12, and a glass substrate with a release layer was obtained.

Immediately thereafter, a composition F7 for forming a resin substrate was applied to the release layer (resin film) on the glass substrate using a spin coater (conditions: about 15 seconds at a rotation speed of 200 rpm). The obtained coating film was heated at 80 ℃ for 2 minutes using a hot plate, and then at 230 ℃ for 30 minutes using a hot plate, to form a resin substrate having a thickness of about 3 μm on the release layer, thereby obtaining a glass substrate with a resin substrate/release layer. Then, the light transmittance was measured using an ultraviolet-visible spectrophotometer (UV-2600, Shimadzu corporation), and the resin substrate showed a transmittance of 80% or more at 400 nm.

[ examples 2 to 20]

A release layer and a resin substrate were produced in the same manner as in examples 2 to 19 except that the release layer-forming composition L4 obtained in examples 1 to 4 was used in place of the release layer-forming composition L3 obtained in examples 1 to 3, and a glass substrate with a release layer and a glass substrate with a resin substrate/release layer were obtained.

Comparative examples 2 to 5

A release layer and a resin substrate were produced in the same manner as in examples 2 to 12 except that the release layer-forming composition HL1 obtained in comparative example 1-1 was used in place of the release layer-forming composition L3 obtained in example 1-3, and a glass substrate with a release layer and a glass substrate with a resin substrate/release layer were obtained. The combination of the release layer and the resin substrate is as shown in table 2.

Comparative examples 2 to 6

The release layer-forming composition HL2 obtained in comparative example 1-2 was used as a composition for forming a release layer, the resin substrate-forming composition F4 used in examples 2-13 was used as a composition for forming a resin substrate, and a release layer and a resin substrate were produced in the same manner as in examples 2-12, thereby obtaining a glass substrate with a release layer and a glass substrate with a resin substrate/release layer.

[7] Evaluation of solvent resistance of Release layer

0.1ml of NMP and PGME was dropped onto the release layer of the glass substrate with the release layer prepared in examples 2-1 to 2-20 and comparative examples 2-1 to 2-6 using a pipette. After 1 minute, the release layer was washed with pure water, and the state of the release layer was visually observed at the portion where the solvent was dropped, to evaluate the solvent resistance of the release layer. The criteria for determination are as follows. The results are shown in tables 1 and 2.

< decision criteria >

O: in particular, no trace of the droplets was observed, and no dissolution was observed.

And (delta): traces of droplets were seen, and a residual film was seen.

X: and (4) dissolving.

The release layer being insoluble in the solvent dropped means that the release layer is insoluble in an organic solvent contained in the composition for forming a resin substrate when the resin substrate is formed on the release layer, meaning that the resin substrate can be peeled from the glass substrate without damage.

[8] Evaluation of peelability

With respect to the glass substrates with the resin substrate and the peeling layer obtained in examples 2-1 to 2-20 and comparative examples 2-1 to 2-6, the peeling property between the peeling layer and the glass substrate was confirmed by the following method. The following tests were carried out using the same glass substrate.

< evaluation of releasability of release layer from glass substrate >

The peeling layers on the glass substrates with peeling layers obtained in examples 2-1 to 2-20 and comparative examples 2-1 to 2-6 were cross-cut (1 mm interval in vertical and horizontal directions, the same applies hereinafter) and cut into 100 meshes. That is, by this cross cutting, 100 meshes of 1mm squares are formed.

Then, a tape was attached to the 100 mesh cut portions, the tape was peeled off, and the degree of peeling was evaluated based on the following criteria (5B to 0B, B, A, AA).

Further, the glass substrates with the resin substrate and the release layer prepared in examples 2-5 to 2-20 were used for all the substrates to be peeled, and a peeling force evaluation test was performed. The test method was carried out by making a long resin substrate of a glass substrate with a resin substrate/release layer into a rectangular shape having a width of 25mm × 50mm, and making a cut so as to penetrate the back surface of the resin substrate with a paper cutter. Further, after a transparent tape (NICIBAN CT-24) was attached to the prepared strip, the strip was peeled off at 90 degrees to the surface of the substrate, i.e., in the vertical direction, using AUTOGRAPH AG-500N (manufactured by Shimadzu corporation), and the peel force was measured, and the case where the peel force was less than 0.1N/25mm and the peel force was 100% (total peel) was designated as AAA.

The results are shown in tables 1 and 2.

< decision criteria >

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

4B: peeling of less than 5%

3B: 5% or more and less than 15% peeling

2B: peeling of 15% or more and less than 35%

1B: peeling of 35% or more and less than 65%

0B: peeling of 65% or more and less than 80%

B: 80% or more and less than 95% peeling

A: peeling of 95% or more and less than 100%

AA: 100% peel (Total peel)

AAA: 100% peeling and peeling force less than 0.1N/25mm

< evaluation of releasability of a releasing layer from a resin substrate >

The glass substrates with the resin substrate and the release layer obtained in examples 2-1 to 2-20 and comparative examples 2-1 to 2-6 were evaluated for releasability by the same procedure as that for the above-described releasability evaluation. The results are shown in tables 1 and 2.

[ Table 1]

[ Table 2]

As shown in tables 1 and 2, it was confirmed that the peeling layers of examples 2-1 to 2-20 had excellent adhesion to the glass substrate and were easily peeled from the resin film. It was also confirmed from the results of the solubility test that the resin composition was not dissolved in the organic solvent contained in the resin substrate-forming composition.

On the other hand, it was confirmed that the release layers of comparative examples 2-1 to 2-6 had excellent adhesion to the glass substrate, but had poor releasability from the resin substrate.

Claims

1. A laminate comprising a glass substrate, a release layer formed from a release layer-forming composition, and resin substrates formed from a polyimide resin, an acrylic resin, or a cycloolefin polymer resin, which are laminated in this order,

the adhesion between the peeling layer and the glass substrate is larger than the adhesion between the peeling layer and the resin substrate,

the composition for forming a release layer comprises a polyamic acid represented by the following formula (1) and an organic solvent,

[ solution 1]

Wherein X represents an aromatic group represented by the following formula (2a) or (2b), Y represents an aromatic group having a valence of 2 of a fluorine atom, Z represents an aromatic group represented by the following formula (3a) or (4a) independently of each other in the case where X is an aromatic group represented by the following formula (2a), represents an aromatic group represented by the following formula (3b) or (4b) independently of each other in the case where X is an aromatic group represented by the following formula (2b), and m represents a natural number,

[ solution 2]

[ solution 3]

2. The laminate according to claim 1, wherein Y is an aromatic group represented by the following formula (5),

[ solution 4]

3. The laminate according to claim 2, wherein Y is an aromatic group represented by the following formula (6),

[ solution 5]

4. The laminate according to any one of claims 1 to 3, wherein in X, the aromatic group represented by the formula (2a) is an aromatic group represented by the following formula (7a) or (8a), and Z are each independently an aromatic group represented by the following formula (9a) or (10a),

[ solution 6]

[ solution 7]

5. The laminate according to any one of claims 1 to 3, wherein in X, the aromatic group represented by the formula (2b) is an aromatic group represented by the following formula (7b) or (8b), and Z's are each independently an aromatic group represented by the following formula (9b) or (10b),

[ solution 8]

[ solution 9]

6. The laminate according to any one of claims 1 to 5, wherein the organic solvent is at least 1 selected from organic solvents having a structure represented by one of formulae (S1) to (S7),

[ solution 10]

In the formula, R ¹ ～R ⁸ Independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R ⁹ And R ¹⁰ Independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an acyl group having 1 to 10 carbon atoms, and b and n represent natural numbers.

7. The laminate according to claim 6, wherein the organic solvent is propylene glycol monomethyl ether or propylene glycol monomethyl ether acetate.

8. The laminate according to any one of claims 1 to 7, wherein the resin substrate is a polyimide resin substrate or a resin substrate having a light transmittance of 80% or more at a wavelength of 400 nm.