WO2016129546A1

WO2016129546A1 - Composition for forming release layer

Info

Publication number: WO2016129546A1
Application number: PCT/JP2016/053624
Authority: WO
Inventors: 江原　和也; 和也進藤
Original assignee: 日産化学工業株式会社
Priority date: 2015-02-10
Filing date: 2016-02-08
Publication date: 2016-08-18
Also published as: TWI720965B; JP6729403B2; CN111234217A; JP2021119243A; JP2020019960A; TW201943767A; KR102602473B1; JP6939862B2; CN107250277B; TW201700540A; KR20220091609A; CN113402882B; TWI768234B; CN113402882A; JP7131651B2; KR20170116065A; KR102528185B1; CN107250277A; JPWO2016129546A1

Abstract

Provided is a composition for forming a release layer, which comprises a polyamic acid produced by reacting an aromatic diamine with an aromatic tetracarboxylic dianhydride and an organic solvent, wherein the aromatic diamine comprises an aromatic diamine containing an ester bond and/or an ether bond and/or the aromatic tetracarboxylic dianhydride contains an ester bond and/or an ether bond.

Description

Release layer forming composition

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

In recent years, electronic devices have been required to have the functions of bending, thinning and lightening. For this reason, it is required to use a lightweight flexible plastic substrate in place of the conventional glass substrate that is fragile and cannot be bent. In the new generation display, development of an active full-color TFT display panel using a lightweight flexible plastic substrate is required. Therefore, various methods for manufacturing electronic devices using a resin film as a substrate are being studied, and in the new generation display, manufacturing studies are being carried out in a process that can divert existing TFT equipment.

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

However, in the methods disclosed in Patent Documents 1 to 4, particularly the method disclosed in Patent Document 4, it is essential to use a highly light-transmitting substrate. In order to give sufficient energy to release the contained hydrogen, it is necessary to irradiate a relatively large laser beam, and there is a problem that the layer to be peeled is damaged. In addition, since laser treatment takes a long time and it is difficult to peel off a peeled layer having a large area, there is a problem that it is difficult to increase the productivity of device fabrication.

JP 10-125929 A Japanese Patent Laid-Open No. 10-125931 International Publication No. 2005/050754 JP-A-10-125930

This invention is made | formed in view of the said situation, and it aims at providing the composition for peeling layer formation which can peel without damaging the resin substrate of a flexible electronic device.

As a result of intensive studies to solve the above problems, the inventors of the present invention include a polyamic acid obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride, and a composition containing an organic solvent. The aromatic diamine includes an aromatic diamine containing at least one of an ester bond and an ether bond, and / or the aromatic tetracarboxylic dianhydride includes at least one of an ester bond and an ether bond. When an anhydride is contained, a composition capable of forming a release layer having excellent adhesion to a substrate and appropriate adhesion to a resin substrate used as a flexible electronic device and appropriate release properties can be obtained. The headline and the present invention were completed.

That is, the present invention
1. A polyamic acid obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride, and an organic solvent,
The aromatic diamine includes an aromatic diamine containing at least one of an ester bond and an ether bond, and / or the aromatic tetracarboxylic dianhydride includes at least one of an ester bond and an ether bond. A composition for forming a release layer, comprising an acid dianhydride,
2. 1. A composition for forming a release layer, wherein the aromatic diamine containing at least one of an ester bond and an ether bond is at least one selected from the group consisting of formulas (A1) to (A42);

3. The composition for forming a release layer according to 1 or 2, wherein the aromatic tetracarboxylic dianhydride containing at least one of an ester bond and an ether bond is at least one selected from the group consisting of formulas (B1) to (B14) ,

4). The release layer-forming composition according to any one of 1 to 3, wherein the aromatic tetracarboxylic dianhydride further contains an aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond,
5. 4. The composition for forming a release layer, wherein the aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond contains a benzene skeleton, a naphthyl skeleton, or a biphenyl skeleton,
6). 5. A composition for forming a release layer, wherein the aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond is at least one selected from the group consisting of formulas (C1) to (C12);

7). Any of 1 to 6, wherein the organic solvent includes at least one selected from amides represented by the formula (S1), amides represented by the formula (S2), and amides represented by the formula (S3) A release layer forming composition,

(In the formula, R ¹ and R ² each 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 represents a natural number. Represents.)
8). A release layer formed using the release layer-forming composition of any one of 1 to 7,
9. A method for producing a flexible electronic device comprising a resin substrate, comprising using a release layer of 8;
10. A method for producing a touch panel sensor comprising a resin substrate, comprising using a release layer of 8;
11. The manufacturing method according to 9 or 10, wherein the resin substrate is a substrate made of polyimide.

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

6 is a graph showing the transmittance measured in Example 4.

Hereinafter, the present invention will be described in more detail.
The composition for forming a release layer of the present invention comprises a polyamic acid obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride, and an organic solvent, wherein the aromatic diamine is an ester. An aromatic diamine including at least one of a bond and an ether bond, and / or the aromatic tetracarboxylic dianhydride includes an aromatic tetracarboxylic dianhydride including at least one of an ester bond and an ether bond. . Here, the release layer in the present invention is a layer provided immediately above a glass substrate for a predetermined purpose. As a typical example, in a manufacturing process of a flexible electronic device, a flexible electronic made of a substrate and a resin such as polyimide is used. Provided between the resin substrate of the device to fix the resin substrate in a predetermined process, and after the electronic circuit or the like is formed on the resin substrate, the resin substrate is easily peeled off from the base The thing provided in order to be able to do is mentioned.

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

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

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

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

Examples of such aromatic tetracarboxylic dianhydrides include tetracarboxylic dianhydrides having a structure in which a plurality of aromatic rings having 6 to 20 carbon atoms are connected by ester bonds or ether bonds. Specific examples of the aromatic ring include the same ones as described above. Among these, those having a structure in which three or four aromatic rings are connected by an ester bond or an ether bond are preferable from the viewpoint of ensuring the solubility of polyamic acid in an organic solvent.

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

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

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

Specific examples thereof include 1,4-diaminobenzene (p-phenylenediamine), 1,3-diaminobenzene (m-phenylenediamine), 1,2-diaminobenzene (o-phenylenediamine), and 2,4-diamino. Toluene, 2,5-diaminotoluene, 2,6-diaminotoluene, 4,6-dimethyl-m-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, 2,6-dimethyl-p-phenylenediamine, 2 , 4,6-trimethyl-1,3-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, m-xylylenediamine, p-xylylenediamine, 5-trifluoromethylbenzene-1 , 3-diamine, 5-trifluoromethylbenzene-1,2-diamine, 3,5-bis (trifluoromethyl) benzene-1,2-dialysis Diamine containing one benzene nucleus such as 1,2-naphthalenediamine, 1,3-naphthalenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 1,6-naphthalenediamine, 1,7-naphthalene Diamine, 1,8-naphthalenediamine, 2,3-naphthalenediamine, 2,6-naphthalenediamine, 4,4'-biphenyldiamine, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 3,3 ', 5,5'-tetramethyl-4,4'- Diaminodiphenylmethane, 4,4'-diaminobenzanilide, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine, 2,2'-dimethylbenzidine, 3,3'-diaminodipheni Methane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 2,2-bis (3-aminophenyl) propane, 2,2-bis (4-aminophenyl) propane, 2,2-bis ( 3-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-bis (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4'-diaminodiphenyl sulfoxide, 3,3'-bis (trifluoromethyl) biphenyl-4,4'-diamine, 3,3 Diamines containing two benzene nuclei such as', 5,5'-tetrafluorobiphenyl-4,4'-diamine, 4,4'-diaminooctafluorobiphenyl; 1,5-diaminoanthracene, 2,6-diaminoanthracene 9,10-diaminoanthracene, 1,8-diaminophenanthrene, 2,7-diaminophenanthrene, 3,6-diaminophenanthrene, 9,10-diaminophenanthrene, 1,3-bis (3-aminophenyl) benzene, 1, 3-bis (4-aminophenyl) benzene, 1,4-bis (3-aminophenyl) benzene, 1,4-bis (4-aminophenyl) benzene, 1,3-bis (3-aminophenyl sulfide) benzene 1,3-bis (4-aminophenylsulfide) benzene, 1,4-bis (4-aminophenylsulfide) benzene, 1,3-bis (3-aminophenylsulfone) benzene, 1,3-bis (4 -Aminophenylsulfone) benzene, 1,4-bis (4-aminophenylsulfone) benzene, 1,3-bis [2- (4-aminophenyl) isopropyl] benzene Examples of the diamine include three benzene nuclei such as 1,4-bis [2- (3-aminophenyl) isopropyl] benzene and 1,4-bis [2- (4-aminophenyl) isopropyl] benzene. It is not limited to these. These may be used alone or in combination of two or more.

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

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

Such a tetracarboxylic dianhydride may be either an aliphatic tetracarboxylic dianhydride or an aromatic tetracarboxylic dianhydride, but from the viewpoint of ensuring the strength and heat resistance of the resulting thin film, an ester bond And an aromatic tetracarboxylic dianhydride which does not contain any ether bond.

Specific examples thereof include pyromellitic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, naphthalene-1,2,3,4-tetracarboxylic dianhydride, naphthalene-1 , 2,5,6-tetracarboxylic dianhydride, naphthalene-1,2,6,7-tetracarboxylic dianhydride, naphthalene-1,2,7,8-tetracarboxylic dianhydride, naphthalene- 2,3,5,6-tetracarboxylic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, biphenyl -2,2 ', 3,3'-tetracarboxylic dianhydride, biphenyl-2,3,3', 4'-tetracarboxylic dianhydride, biphenyl-3,3 ', 4,4'-tetra Carboxylic dianhydride, anthracene-1,2,3,4-tetracarboxylic dianhydride, anthracene-1, 2,5,6-tetracarboxylic dianhydride, anthracene-1,2,6,7-tetracarboxylic dianhydride, anthracene-1,2,7,8-tetracarboxylic dianhydride, anthracene-2 , 3,6,7-tetracarboxylic dianhydride, phenanthrene-1,2,3,4-tetracarboxylic dianhydride, phenanthrene-1,2,5,6-tetracarboxylic dianhydride, phenanthrene- 1,2,6,7-tetracarboxylic dianhydride, phenanthrene-1,2,7,8-tetracarboxylic dianhydride, phenanthrene-1,2,9,10-tetracarboxylic dianhydride, phenanthrene -2,3,5,6-tetracarboxylic dianhydride, phenanthrene-2,3,6,7-tetracarboxylic dianhydride, phenanthrene-2,3,9,10-tetracarboxylic dianhydride, Phenanthrene-3,4,5,6-tetracar Phosphate dianhydride, although phenanthrene-3,4,9,10-tetracarboxylic dianhydride, and the like, without limitation. These may be used alone or in combination of two or more.

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

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

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

The organic solvent used in such a reaction is not particularly limited as long as it does not adversely affect the reaction. Specific examples thereof include m-cresol, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2- Pyrrolidone, N-vinyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, 3-methoxy-N, N-dimethylpropylamide, 3-ethoxy-N, N-dimethylpropylamide, 3- Propoxy-N, N-dimethylpropylamide, 3-isopropoxy-N, N-dimethylpropylamide, 3-butoxy-N, N-dimethylpropylamide, 3-sec-butoxy-N, N-dimethylpropylamide, 3 -Tert-butoxy-N, N-dimethylpropylamide, γ-butyrolactone and the like. In addition, you may use an organic solvent individually by 1 type or in combination of 2 or more types.

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

In the formula, R ¹ and R ² each 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 represents a natural number, preferably 1 to 3, more preferably 1 or 2.

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

The reaction temperature may be appropriately set in the range from the melting point to the boiling point of the solvent used, and is usually about 0 to 100 ° C., but it prevents imidization in the solution of the resulting polyamic acid and contains a high content of polyamic acid units. In order to maintain the amount, it is preferably about 0 to 70 ° C, more preferably about 0 to 60 ° C, and still more preferably about 0 to 50 ° C.

The reaction time depends on the reaction temperature and the reactivity of the raw material, and cannot be specified unconditionally, but is usually about 1 to 100 hours.

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

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

In the present invention, usually, after filtering the reaction solution, a solution obtained by diluting or concentrating the filtrate as it is can be used as the release layer forming composition of the present invention. By doing in this way, not only can mixing of the impurity which can cause deterioration of the adhesiveness of the obtained peeling layer, peelability, etc., but the composition for peeling layer formation can be obtained efficiently. Further, after isolating the polyamic acid from the reaction solution, it may be dissolved again in a solvent to form a release layer forming composition. Examples of the solvent in this case include organic solvents used in the above-described reaction.

The solvent used for dilution is not particularly limited, and specific examples thereof include those similar to the specific examples of the reaction solvent for the reaction. The solvent used for dilution may be used singly or in combination of two or more. Among them, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2 are used because they dissolve polyamic acid well. -Pyrrolidone and γ-butyrolactone are preferred, and N-methyl-2-pyrrolidone is more preferred.

Further, even if the solvent alone does not dissolve the polyamic acid, it can be mixed with the release layer forming composition of the present invention as long as the polyamic acid does not precipitate. In particular, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy -2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxy A solvent having a low surface tension such as propoxy) propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate and isoamyl lactate can be mixed appropriately. Thereby, it is known that the coating film uniformity is improved upon application to the substrate, and it is also suitably used in the composition for forming a release layer of the present invention.

The concentration of the polyamic acid in the composition for forming a release layer of the present invention is appropriately set in consideration of the thickness of the release layer to be produced, the viscosity of the composition, etc., but is usually about 1 to 30% by mass, preferably It is about 1 to 20% by mass. By setting such a concentration, a release layer having a thickness of about 0.05 to 5 μm can be obtained with good reproducibility. The concentration of the polyamic acid is adjusted to adjust the amount of diamine and tetracarboxylic dianhydride used as the raw material of the polyamic acid. After the reaction solution is filtered, the filtrate is diluted or concentrated. The amount can be adjusted by, for example, adjusting the amount thereof when dissolved in a solvent.

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

In addition, the composition for forming a release layer 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.

By applying the release layer-forming composition of the present invention described above to a substrate, and heating the resulting coating to thermally imidize the polyamic acid, it has excellent adhesion to the substrate, and moderate to the resin substrate. It is possible to obtain a release layer made of a polyimide film having good adhesion and moderate peelability.

When the release layer of the present invention is formed on a substrate, the release layer may be formed on a part of the substrate or the entire surface. As an aspect of forming a release layer on a part of the surface of the substrate, an embodiment in which the release layer is formed only within a predetermined range of the substrate surface, a release layer is formed in a pattern such as a dot pattern or a line and space pattern on the entire surface of the substrate. There are forms to be formed. In addition, in this invention, a base | substrate means what is used for manufacture of a flexible electronic device etc. by which the composition for peeling layer formation concerning this invention is applied to the surface.

Examples of the substrate (substrate) include glass, plastic (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy, melamine, triacetyl cellulose, ABS, AS, norbornene resin, etc.), metal (silicon wafer, etc.), Although wood, paper, slate, etc. are mentioned, since the peeling layer obtained from the composition for peeling layer formation which concerns on this invention has sufficient adhesiveness with respect to it, glass is preferable. In addition, the base | substrate surface may be comprised with the single material and may be comprised with two or more materials. As an aspect in which the substrate surface is constituted by two or more materials, a certain range of the substrate surface is constituted by a certain material, and the other surface is constituted by another material. A dot pattern is formed on the entire substrate surface. There is a mode in which a material in a pattern such as a line and space pattern is present in other materials.

The coating method is not particularly limited. For example, a cast coating method, a spin coating method, a blade coating method, a dip coating method, a roll coating method, a bar coating method, a die coating method, an ink jet method, a printing method (a relief plate, an intaglio plate, a planographic plate). , Screen printing, etc.).

The heating temperature for imidization is usually appropriately determined within the range of 50 to 550 ° C., but is preferably 200 ° C. or higher, and preferably 500 ° C. or lower. By setting the heating temperature in this way, it is possible to sufficiently advance the imidization reaction while preventing the obtained film from being weakened. The heating time varies depending on the heating temperature, and cannot be generally defined, but is usually 5 minutes to 5 hours. The imidization rate may be in the range of 50 to 100%.

As a preferred example of the heating mode in the present invention, after heating at 50 to 100 ° C. for 5 minutes to 2 hours, the heating temperature is raised stepwise as it is, and finally from 375 ° C. to 450 ° C. for 30 minutes to 4 hours. The method of heating is mentioned. In particular, after heating at 50 to 100 ° C. for 5 minutes to 2 hours, it is preferable to heat at over 100 ° C. to 375 ° C. for 5 minutes to 2 hours, and finally at over 375 ° C. to 450 ° C. for 30 minutes to 4 hours.

Examples of equipment used for heating include a hot plate and an oven. The heating atmosphere may be under air or under an inert gas, and may be under normal pressure or under reduced pressure.

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

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

Hereinafter, an example of the manufacturing method of the flexible electronic device using the peeling layer of this invention is demonstrated.
By using the composition for forming a release layer according to the present invention, a release layer is formed on a glass substrate by the method described above. On this release layer, a resin solution for forming a resin substrate is applied, and this coating film is heated to form a resin substrate fixed to the glass substrate via the release layer according to the present invention. . At this time, the resin substrate is formed with a larger area than the area of the release layer so as to cover the entire release layer. Examples of the resin substrate include a resin substrate made of polyimide which is typical as a resin substrate of a flexible electronic device, and examples of the resin solution for forming the resin substrate include a polyimide solution and a polyamic acid solution. The method for forming the resin substrate may follow a conventional method.

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

On the other hand, in the manufacture of flexible displays, it has been reported that the polymer substrate can be suitably peeled from the glass carrier using the laser lift-off method (LLO method) that has been used in the manufacture of high-brightness LEDs, three-dimensional semiconductor packages, and the like. (JP 2013-147599 A). In manufacturing a flexible display, a polymer substrate made of polyimide or the like is provided on a glass carrier, and then a circuit or the like including an electrode or the like is formed on the substrate. Finally, the substrate is peeled off from the glass carrier together with the circuit or the like. There is a need. In this peeling step, the LLO method is adopted, that is, when a glass carrier is irradiated with a light beam having a wavelength of 308 nm from the surface opposite to the surface on which a circuit or the like is formed, the light beam with the wavelength passes through the glass carrier, Only the nearby polymer (polyimide) absorbs this light and evaporates (sublimates). As a result, it has been reported that peeling of the substrate from the glass carrier can be performed selectively without affecting the circuit or the like provided on the substrate, which determines the performance of the display.

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

Hereinafter, the present invention will be described in more detail with reference to synthesis examples, comparative synthesis examples, examples, and comparative examples, but the present invention is not limited to these examples. In addition, the abbreviation of the compound used in the following example and the measuring method of a number average molecular weight and a weight average molecular weight are as follows.

<Abbreviation of compound>
p-PDA: p-phenylenediamine m-PDA: m-phenylenediamine DATP: 4,4 ′ ″-diamino-p-terphenyl DBA: 3,5-diaminobenzoic acid HAB: 3,3′-dihydroxybenzidine DDE : 4,4'-oxydianiline BAPB: 4,4'-bis (4-aminophenoxy) biphenyl FAPB: 4,4'-bis (4-amino-2-trifluoromethylphenoxy) biphenyl APAB: 5-amino -2- (4-aminophenyl) -1H-benzimidazole APAB-E: 4-aminophenyl-4′-aminobenzoate 6FAP: 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane TFMB: 2,2′-bis (trifluoromethyl) biphenyl-4,4′-diamine BPDA: 2,3 ′, 4,4′-biphenyltetracarboxylic acid Anhydride TAHQ: p-phenylenebis (trimellitic acid monoester acid anhydride)
PMDA: pyromellitic dianhydride BPTME: p-biphenylenebis (trimellitic acid monoester anhydride)
BPODA: 4,4 ′-(biphenyl-4,4′-diylbisoxy) bisphthalic dianhydride CF3-BP-TMA: N, N ′-[2,2′-bis (trifluoromethyl) biphenyl-4 , 4'-diyl] bis (1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxamide)
6FDA: 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride IPBBT: N, N′-isophthalbis (benzoxazoline-2-thione) )
NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve

<Measurement of weight average molecular weight and molecular weight distribution>
The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the polymer were measured using a GPC apparatus manufactured by JASCO Corporation (column: OHpak SB803-HQ and OHpak SB804-HQ manufactured by Showa Denko KK); : Dimethylformamide / LiBr.H ₂ O (29.6 mM) / H ₃ PO ₄ (29.6 mM) / THF (0.1% by mass); flow rate: 1.0 mL / min; column temperature: 40 ° C .; Mw: (Standard polystyrene equivalent value) was used (same in the following examples and comparative examples).

[1] Synthesis of polymer A polyamic acid and a polybenzoxazole precursor were synthesized by the following method.
In addition, the polymer was not isolated from the obtained polymer containing reaction liquid, but the composition for resin substrate formation or the composition for peeling layer formation was prepared by diluting a reaction solution as mentioned later.

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

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

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

[Synthesis Example S4] Synthesis of polyamic acid S4 30.6 g (153 mmol) of DDE was dissolved in 440 g of NMP. CBDA 29.4g (150mmol) was added to the obtained solution, and it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and polyamic acid S4 was obtained. Polyamic acid S4 had Mw of 29,800 and Mw / Mn of 2.2.

[Synthesis Example L1] Synthesis of polyamic acid L1 2.054 g (19 mmol) of p-PDA was dissolved in 88 g of NMP. BPTME 9.946g (19mmol) was added to the obtained solution, and it was made to react at 23 degreeC under nitrogen atmosphere for 24 hours, and polyamic acid L1 was obtained. Polyamic acid L1 had Mw of 57,500 and Mw / Mn of 3.0.

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

[Synthesis Example L3] Synthesis of polyamic acid L3 1.367 g (13 mmol) of p-PDA and 1.172 g (5.4 mmol) of HAB were dissolved in 88 g of NMP. To the obtained solution, 9.461 g (18 mmol) of BPTME was added and reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L3. Mw of polyamic acid L3 was 43,600 and Mw / Mn 2.6.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[Synthesis Example L20] Synthesis of polyamic acid L20 0.616 g (6 mmol) of p-PDA and 0.5528 g (2 mmol) of HAB were dissolved in 35.2 g of NMP. To the obtained solution, 3.655 g (8 mmol) of TAHQ was added and reacted at 23 ° C. for 24 hours under a nitrogen atmosphere to obtain polyamic acid L20. Polyamic acid L20 had Mw of 55,900 and Mw / Mn of 2.6.

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

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

[Comparative Synthesis Example 1] Synthesis of polybenzoxazole precursor B1 6.49 g (0.015 mol) of 6FAP was dissolved in 27 g of NMP. 6.48 g (0.015 mol) of IPBBT was added to the resulting solution, and the mixture was reacted at 23 ° C. for 3 hours under a nitrogen atmosphere. Thereafter, this solution was poured into 300 g of pure water, and after stirring for 24 hours, the precipitate was filtered. Then, it dried under reduced pressure and obtained polybenzoxazole precursor B1. Mw of the polybenzoxazole precursor B1 was 2,1000, and Mw / Mn was 3.9.

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

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

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

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

[4] Formation and evaluation of release layer [Example 2-1]
The composition for forming a release layer obtained in Example 1-1 was applied as a glass substrate onto a 100 mm × 100 mm glass substrate (hereinafter the same) using a spin coater (condition: about 30 seconds at a rotation speed of 3000 rpm). .
The obtained coating film was heated at 80 ° C. for 10 minutes using a hot plate, and then heated at 300 ° C. for 30 minutes using an oven, and the heating temperature was raised to 400 ° C. (10 ° C./min. And then heated at 400 ° C. for 30 minutes to form a release layer having a thickness of about 0.1 μm on the glass substrate. During the temperature increase, the film-coated substrate was not removed from the oven but heated in the oven.

[Examples 2-2 to 2-22]
Example 2-1 was used except that the release layer forming composition obtained in Examples 1-2 to 1-22 was used in place of the release layer forming composition obtained in Example 1-1. A release layer was formed in the same manner as described above.

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

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

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

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

[5] Evaluation of peelability [Examples 3-1 to 3-47, Comparative Example 3]
The peelability of the release layer and the glass substrate obtained in Examples 2-1 to 2-25 and the peelability of the release layer (resin thin film) and the resin substrate were confirmed. As the resin substrate, a resin substrate made of polyimide was used.
First, the release layer cross-cut (length and width 1 mm spacing, hereinafter the same) on the glass substrate with release layer obtained in Examples 2-1 to 2-25, and the resin substrate on the glass substrate with release substrate and release layer -A 100 muscut was made by cross-cutting the release layer. That is, 100 crosses of 1 mm square were formed by this cross cut.
Then, an adhesive tape was applied to the 100 muscat portion, the tape was peeled off, and the degree of peeling was evaluated based on the following criteria (5B to 0B, B, A, AA) (Examples 3-1 to 3- 47). Moreover, according to the said method, the same test was done using the glass substrate with a resin thin film obtained by the comparative example 2 (comparative example 3). The results are shown in Table 1. In addition, the evaluation criteria of peelability in Table 1 are as follows.

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

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

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

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

[6] Evaluation of transmittance [Example 4]
Using a spin coater (condition: about 30 seconds at 800 rpm), the release layer forming composition obtained in Example 2-8 was applied as a glass substrate onto a 100 mm × 100 mm glass substrate (hereinafter the same). .
The obtained coating film was heated at 80 ° C. for 10 minutes using a hot plate, and then heated at 300 ° C. for 30 minutes using an oven, and the heating temperature was raised to 400 ° C. (10 ° C./min. And then heated at 400 ° C. for 30 minutes to form a release layer having a thickness of about 0.4 μm on the glass substrate. During the temperature increase, the film-coated substrate was not removed from the oven but heated in the oven. The transmittance of the obtained film was measured using an ultraviolet-visible spectrophotometer (SIMADSU UV-2550 model number, manufactured by Shimadzu Corporation).
The results are shown in FIG. The transmittance of the obtained film was 1% or less with respect to the wavelength of 308 nm, indicating a transmittance that can be used as a sacrificial layer.

Claims

A polyamic acid obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride, and an organic solvent,
The aromatic diamine includes an aromatic diamine containing at least one of an ester bond and an ether bond, and / or the aromatic tetracarboxylic dianhydride includes at least one of an ester bond and an ether bond. A release layer-forming composition comprising an acid dianhydride.
The release layer forming composition according to claim 1, wherein the aromatic diamine containing at least one of an ester bond and an ether bond is at least one selected from the group consisting of formulas (A1) to (A42).
The release layer according to claim 1 or 2, wherein the aromatic tetracarboxylic dianhydride containing at least one of the ester bond and the ether bond is at least one selected from the group consisting of formulas (B1) to (B14). Forming composition.
The composition for forming a release layer according to any one of claims 1 to 3, wherein the aromatic tetracarboxylic dianhydride further includes an aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond. object.
The composition for forming a release layer according to claim 4, wherein the aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond contains a benzene skeleton, a naphthyl skeleton or a biphenyl skeleton.
6. The release layer forming layer according to claim 5, wherein the aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond is at least one selected from the group consisting of formulas (C1) to (C12). Composition.
The organic solvent contains at least one selected from amides represented by the formula (S1), amides represented by the formula (S2), and amides represented by the formula (S3). The composition for forming a release layer according to any one of the above.

(In the formula, R 1 and R 2 each 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 represents a natural number. Represents.)
A release layer formed using the release layer forming composition according to any one of claims 1 to 7.
A method for producing a flexible electronic device comprising a resin substrate, wherein the release layer according to claim 8 is used.
A method for manufacturing a touch panel sensor comprising a resin substrate, wherein the release layer according to claim 8 is used.
The manufacturing method according to claim 9 or 10, wherein the resin substrate is a substrate made of polyimide.