KR102528185B1 - Composition for forming release layer - Google Patents

Abstract

A polyamic acid obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride, and an organic solvent, wherein the aromatic diamine contains an aromatic diamine containing at least one of an ester bond and an ether bond, and/or the aromatic A composition for forming a release layer in which tetracarboxylic dianhydride contains at least one of an ester linkage and an ether linkage is provided.

Description

Composition for forming release layer

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

BACKGROUND OF THE INVENTION [0002] In recent years, electronic devices have been required to have functions such as bending, and performance such as thinning and lightening. In this regard, it is desired to use a lightweight flexible plastic substrate instead of the conventional glass substrate, which is heavy and brittle and cannot be bent. Also, in a new generation display, development of an active full-color TFT display panel using a lightweight flexible plastic substrate is required. Then, various manufacturing methods of electronic devices using a resin film as a substrate are beginning to be examined, and manufacturing examination is progressing with a process capable of diverting existing TFT facilities in a new generation display.

Patent Documents 1, 2 and 3 form an amorphous silicon thin film layer on a glass substrate, form a plastic substrate on the thin film layer, then irradiate a laser from the glass surface side, Disclosed is a method of peeling a plastic substrate from a glass substrate. In addition, Patent Document 4 discloses a method of completing a liquid crystal display device by attaching a layer to be peeled (described as "transferred layer" in Patent Document 4) to a plastic film using the techniques disclosed in Patent Documents 1 to 3. .

However, in the method disclosed in Patent Documents 1 to 4, particularly the method disclosed in Patent Document 4, it is essential to use a substrate having high light transmission properties, and to give enough energy to pass through the substrate and release hydrogen contained in amorphous silicon. , there is a problem that irradiation of a comparatively large laser beam is required, which damages the layer to be separated. In addition, since the laser treatment requires a long time and it is difficult to peel a layer to be separated having a large area, there is also a problem that it is difficult to increase the productivity of device fabrication.

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

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

As a result of repeated intensive studies to solve the above problems, the inventors of the present invention have found that, in a composition containing a polyamic acid obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride, and an organic solvent, the aromatic diamine has an ester bond and When it contains an aromatic diamine containing at least one of ether bonds, and/or the aromatic tetracarboxylic dianhydride contains an aromatic tetracarboxylic dianhydride containing at least one of an ester bond and an ether bond, with a gas They discovered that a composition capable of forming a release layer having excellent adhesion and appropriate adhesion to a resin substrate used as a flexible electronic device and appropriate release property was obtained, and the present invention was completed.

That is, the present invention,

1. Contains a polyamic acid obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride, and an organic solvent,

The aromatic diamine contains an aromatic diamine containing at least one of an ester bond and an ether bond, and/or the aromatic tetracarboxylic acid dianhydride contains an aromatic tetracarboxylic acid dianhydride containing at least one of an ester bond and an ether bond. A composition for forming a release layer, characterized in that

2. The first composition for forming a release layer, wherein the aromatic diamine containing at least one of an ester linkage and an ether linkage is at least one member selected from the group consisting of Formulas (A1) to (A42);

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

4. The composition for forming a release layer according to any one of 1 to 3, wherein the aromatic tetracarboxylic dianhydride further comprises an aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond;

5. The composition for forming a release layer of 4, wherein the aromatic tetracarboxylic acid dianhydride containing neither an ester bond nor an ether bond includes a benzene skeleton, a naphthyl skeleton, or a biphenyl skeleton;

6. The composition for forming a release layer according to item 5, wherein the aromatic tetracarboxylic dianhydride containing neither ester linkage nor ether linkage is at least one member selected from the group consisting of formulas (C1) to (C12);

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

(In the formula, R ¹ and R ² independently represent an alkyl group having 1 to 10 carbon atoms. R ³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. h represents a natural number.)

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

9. A method for manufacturing a flexible electronic device having a resin substrate, characterized by using the peeling layer of 8 above;

10. Method for manufacturing a touch panel sensor having a resin substrate, characterized by using the peeling layer of 8,

11. A manufacturing method of 9 or 10 in which the resin substrate is a substrate made of polyimide is provided.

By using the composition for forming a release layer of the present invention, a film having excellent adhesion to a substrate and appropriate adhesion to a resin substrate and appropriate release properties can be obtained with good reproducibility. In the manufacturing process of a flexible electronic device by using the composition of the present invention, it is possible to separate the resin substrate from the substrate together with the circuit without damaging the resin substrate formed on the substrate or the circuit installed thereon. It becomes possible. Therefore, the composition for forming a release layer of the present invention can contribute to simplification of the manufacturing process of a flexible electronic device having a resin substrate and improvement of its yield.

1 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 includes a polyamic acid obtained by reacting an aromatic diamine with an aromatic tetracarboxylic dianhydride, and an organic solvent, wherein the aromatic diamine contains at least one of an ester bond and an ether bond. It contains amine, and/or the aromatic tetracarboxylic dianhydride contains at least one of an ester bond and an ether bond. Here, the release layer in the present invention is a layer provided directly on the glass substrate for a predetermined purpose, and a typical example thereof is a flexible electronic device made of a substrate and a resin such as polyimide in a manufacturing process of a flexible electronic device. It is provided between the resin substrate and the resin substrate in order to fix the resin substrate during a predetermined process, and is provided so that the resin substrate can be easily separated from the base body after an electronic circuit or the like is formed on the resin substrate. can be heard

The aromatic diamine containing at least one of an ester bond and an ether bond described above contains one of an ester bond and an ether bond in its molecule, or both thereof.

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. A benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring etc. are mentioned as a specific example of the said aromatic ring. Especially, from a viewpoint of ensuring the solubility of a polyamic acid to an organic solvent, the diamine which has a structure in which 2 or 3 aromatic rings were connected by the ester bond or the ether bond is preferable.

In this invention, what is shown below is mentioned as a preferable specific example of the aromatic diamine containing at least one of an ester bond and an ether bond.

The aromatic tetracarboxylic dianhydride containing at least one of an ester bond and an ether bond has one of an ester bond and an ether bond in its molecule, or both of these bonds.

Examples of such aromatic tetracarboxylic dianhydride include tetracarboxylic dianhydride having a structure in which a plurality of aromatic rings having 6 to 20 carbon atoms are connected by ester bonds or ether bonds. As a specific example of the said aromatic ring, the thing similar to the above is mentioned. Especially, from a viewpoint of ensuring the solubility of a polyamic acid to an organic solvent, what has a structure in which 3 or 4 aromatic rings were connected by the ester bond or the ether bond is preferable.

In this invention, what is shown below is mentioned as a preferable specific example of aromatic tetracarboxylic dianhydride containing at least one of an ester bond and an ether bond.

In this invention, diamine other than that can be used with the aromatic diamine containing at least one of the above-mentioned ester bond and ether bond.

Any of an aliphatic diamine and an aromatic diamine may be used as such diamine, but an aromatic diamine containing neither ester bond nor ether bond is preferable from the viewpoint of ensuring strength and heat resistance of the obtained thin film.

Specific examples thereof include 1,4-diaminobenzene (p-phenylenediamine), 1,3-diaminobenzene (m-phenylenediamine), and 1,2-diaminobenzene (o-phenylenediamine). , 2,4-diaminotoluene, 2,5-diaminotoluene, 2,6-diaminotoluene, 4,6-dimethyl-m-phenylenediamine, 2,5-dimethyl-p-phenylene Diamine, 2,6-dimethyl-p-phenylenediamine, 2,4,6-trimethyl-1,3-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylene Diamine, m-xylylenediamine, p-xylylenediamine, 5-trifluoromethylbenzene-1,3-diamine, 5-trifluoromethylbenzene-1,2-diamine, 3,5 -Diamine containing one benzene nucleus, such as bis(trifluoromethyl)benzene-1,2-diamine; 1,2-naphthalenediamine, 1,3-naphthalenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 1,6-naphthalenediamine, 1,7-naphthalenediamine, 1, 8-naphthalenediamine, 2,3-naphthalenediamine, 2,6-naphthalenediamine, 4,4'-biphenyl diamine, 2,2'-bis(trifluoromethyl)-4,4'- Diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 3,3', 5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 4,4'-diaminobenzanilide, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine, 2, 2'-dimethylbenzidine, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,2-bis(3 -Aminophenyl)propane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane , 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenylsulfoxide, 3,4'-diamino Diphenylsulfoxide, 4,4'-diaminodiphenylsulfoxide, 3,3'-bis(trifluoromethyl)biphenyl-4,4'-diamine, 3,3',5,5'- diamines containing two benzene nuclei, such as tetrafluorobiphenyl-4,4'-diamine and 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-aminophenylsulfide)benzene, 1,3-bis(4-aminophenylsulfide)benzene, 1,4-bis(4-aminophenyl) Sulfide)benzene, 1,3-bis(3-aminophenylsulfone)benzene, 1,3-bis(4-aminophenylsulfone)benzene, 1,4-bis(4-aminophenylsulfone)benzene, 1,3- Bis[2-(4-aminophenyl)isopropyl]benzene, 1,4-bis[2-(3-aminophenyl)isopropyl]benzene, 1,4-bis[2-(4-aminophenyl)isopropyl ] Although diamine containing three benzene nuclei, such as benzene, etc. are mentioned, it is not limited to these. These can also be used individually by 1 type or in combination of 2 or more types.

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

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

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

Specific examples thereof include pyromellitic acid dianhydride, benzene-1,2,3,4-tetracarboxylic acid dianhydride, naphthalene-1,2,3,4-tetracarboxylic acid dianhydride, and naphthalene-1,2,5,6-tetracarboxylic acid dianhydride. Carboxylic 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'-tetracarboxylic 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-tetra Carboxylic dianhydride, phenanthrene-2,3,6,7-tetracarboxylic dianhydride, phenanthrene-2,3,9,10-tetracarboxylic dianhydride, phenanthrene-3,4,5,6-tetracarboxylic dianhydride Although water, phenanthrene- 3,4,9,10-tetracarboxylic dianhydride, etc. are mentioned, it is not limited to these. These can also be used individually by 1 type or in combination of 2 or more types.

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

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

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

The organic solvent used in this 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, and N-ethyl-2-pi. Rolidone, 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-dimethylpropyl amide, 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 for the reaction dissolves diamine, tetracarboxylic dianhydride, and polyamic acid well, amides represented by formula (S1), amides represented by (S2), and formula (S3) At least one selected from amides is preferred.

In formula, R ^<1> and R ^<2> represent a C1-C10 alkyl group mutually independently. R ³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. h represents a natural number, and is preferably 1 to 3, more preferably 1 or 2.

As the C1-C10 alkyl group, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group, n-hexyl group, n - A heptyl group, n-octyl group, n-nonyl group, n-decyl group, etc. are mentioned. Among these, an alkyl group having 1 to 3 carbon atoms is preferable, and an alkyl group having 1 or 2 carbon atoms is more preferable.

The reaction temperature may be appropriately set in the range from the melting point to the boiling point of the solvent to be used, and is usually about 0 to 100 ° C. It is preferably about 0 to 70°C, more preferably about 0 to 60°C, and still more preferably about 0 to 50°C.

Although the reaction time cannot be uniformly defined because it depends on the reaction temperature or the reactivity of the raw materials, it is usually about 1 to 100 hours.

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

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

In the present invention, usually, after filtering the reaction solution, the filtrate as it is or a solution obtained by diluting or concentrating can be used as the composition for forming a release layer of the present invention. In this way, it is possible to reduce contamination of impurities that may cause deterioration of adhesiveness, peelability, etc. of the obtained peeling layer, and also to obtain a composition for forming a peeling layer efficiently. Alternatively, after isolating the polyamic acid from the reaction solution, it may be dissolved in a solvent again to obtain a composition for forming a release layer. As a solvent in this case, the organic solvent used for the reaction mentioned above, etc. are mentioned.

The solvent used for dilution is not particularly limited, and specific examples thereof include the same as the specific examples of the reaction solvent in the above reaction. You may use the solvent used for dilution individually by 1 type or in combination of 2 or more types. Among them, since polyamic acid is easily dissolved, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazoli Dinone, N-ethyl-2-pyrrolidone, and γ-butyrolactone are preferred, and N-methyl-2-pyrrolidone is more preferred.

In addition, even if it is a solvent that does not dissolve polyamic acid alone, it can be mixed into the composition for forming a release layer of the present invention as long as the polyamic acid does not precipitate. In particular, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1- Butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol -1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, etc. A solvent having a low surface tension of may be appropriately mixed. It is known that this improves the uniformity of the coating film at the time of application to the substrate, and 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 1 to 20% by mass. is about % With such a concentration, a peeling layer having a thickness of about 0.05 to 5 μm can be obtained with good reproducibility. In addition, the concentration of polyamic acid is adjusted when the amount of diamine and tetracarboxylic dianhydride used as raw materials of polyamic acid is adjusted, the reaction solution is filtered and the filtrate is diluted or concentrated, or the isolated polyamic acid is dissolved in a solvent. It can be adjusted by, for example, adjusting the amount.

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

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

A polyimide having excellent adhesion to a substrate, appropriate adhesion to a resin substrate, and appropriate peelability 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 peeling layer made of a film can be obtained.

When the release layer of the present invention is formed on the substrate, the release layer may be formed on a part of the surface of the substrate or may be formed on the entire surface of the substrate. As an aspect of forming a release layer on a part of the surface of the substrate, an aspect of forming the release layer only in a predetermined range of the surface of the substrate, an aspect of forming the release layer in a pattern shape such as a dot pattern or a line and space pattern on the entire surface of the substrate, etc. there is Further, in the present invention, the substrate means that the composition for forming a release layer according to the present invention is applied to the surface thereof, and is used for manufacturing flexible electronic devices and the like.

As the substrate (substrate), for example, glass, plastic (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy, melamine, triacetyl cellulose, ABS, AS, norbornene-based resin, etc.), metal (silicone) wafers, etc.), wood, paper, slate, etc., but glass is particularly preferable since the release layer obtained from the composition for forming a release layer according to the present invention has sufficient adhesion thereto. In addition, the substrate surface may be composed of a single material or may be composed of two or more materials. As an aspect in which the surface of the aircraft is composed of two or more materials, a certain range of the aircraft surface is composed of a certain material and the remaining surface is composed of other materials, a dot pattern, line and space pattern, etc. There is a mode in which a certain material exists among other materials in the form of a pattern.

The method of application is not particularly limited, but examples thereof include cast coating, spin coating, blade coating, dip coating, roll coating, bar coating, die coating, inkjet, and printing methods (iron plate, intaglio , flat plate, screen printing, etc.).

The heating temperature for imidation is usually appropriately determined within the range of 50 to 550°C, but is preferably 200°C or higher and more preferably 500°C or lower. By setting the heating temperature in this way, it becomes possible to sufficiently advance the imidation reaction while preventing embrittlement of the resulting film. Since the heating time differs depending on the heating temperature, it cannot be uniformly defined, but it is usually 5 minutes to 5 hours. In addition, the imidation ratio may be in the range of 50 to 100%.

A preferable example of the heating mode in the present invention is a method of heating at 50 to 100°C for 5 minutes to 2 hours, then raising the heating temperature step by step as it is, and finally heating at over 375°C to 450°C for 30 minutes to 4 hours. can be heard In particular, after heating at 50 to 100°C for 5 minutes to 2 hours, it is preferable to heat at more than 100°C to 375°C for 5 minutes to 2 hours, and finally to be heated at more than 375°C to 450°C for 30 minutes to 4 hours.

As a mechanism used for heating, a hot plate, an oven, etc. are mentioned, for example. The heating atmosphere may be air or inert gas, and may be under normal pressure or reduced pressure.

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

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

Hereinafter, an example of a method for manufacturing a flexible electronic device using the release layer of the present invention will be described.

Using the 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 peeling layer, a resin solution for forming a resin substrate is applied, and the coated film is heated to form a resin substrate fixed to the glass substrate through the peeling layer according to the present invention. At this time, the resin substrate is formed with an area larger than that 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 representative of a resin substrate for flexible electronic devices, and a polyimide solution and a polyamic acid solution as a resin solution for forming it. The method for forming the resin substrate may be in accordance with a conventional method.

Next, a desired circuit is formed on the resin substrate fixed to the substrate through the release layer according to the present invention, and then, for example, the resin substrate is cut along the release layer, and the resin substrate is separated along with the circuit. By peeling from the layer, the resin substrate and the gas are separated. 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 is possible to suitably peel the polymer substrate from the glass carrier using the laser lift-off method (LLO method), which has been used in the manufacture of high-brightness LEDs, three-dimensional semiconductor packages, etc. so far. It has been reported (Japanese Patent Laid-Open No. 2013-147599). In manufacturing a flexible display, it is necessary to place a polymer substrate made of polyimide or the like on a glass carrier, then form a circuit or the like including electrodes or the like on the substrate, and finally peel the substrate together with the circuit or the like from the glass carrier. there is In this peeling step, the LLO method is employed, that is, when a light ray with a wavelength of 308 nm is irradiated to the glass carrier from the surface opposite to the surface on which the circuit or the like is formed, the light ray of the wavelength permeates the glass carrier, and the light in the vicinity of the glass carrier is irradiated. Only the polymer (polyimide) absorbs this light and evaporates (sublimes). As a result, it is reported that the separation of the substrate from the glass carrier can be performed selectively without affecting the circuit installed on the substrate, which determines the performance of the display.

When a desired circuit is formed on the resin substrate fixed to the base body via the release layer according to the present invention, and then the LLO method is employed, only this release layer absorbs this light beam and evaporates (sublimes). That is, this peeling layer is sacrificed (acting as a sacrificial layer), so that the peeling of the substrate from the glass carrier can be selectively performed. Since the composition for forming a release layer of the present invention has a characteristic of sufficiently absorbing light rays of a specific wavelength (for example, 308 nm) to which the LLO method can be applied, it can be used as a sacrificial layer for the LLO method.

Example

Hereinafter, the present invention will be described in more detail by way of 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 examples and the method of measuring the number average molecular weight and 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-benzoimidazole

APAB-E: 4-aminophenyl-4'-aminobenzoate

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

TFMB: 2,2'-bis(trifluoromethyl)biphenyl-4,4'-diamine

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

TAHQ: p-phenylenebis(trimellitic acid monoester acid anhydride)

PMDA: pyromellitic dianhydride

BPTME: p-biphenylenebis(trimellitic acid monoester acid anhydride)

BPODA: 4,4'-(biphenyl-4,4'-biylbisoxy)bisphthalic dianhydride

CF3-BP-TMA: N,N'-[2,2'-bis(trifluoromethyl)biphenyl-4,4'-diyl]bis(1,3-dioxo-1,3-dihydro isobenzofuran-5-carboamide)

6FDA: 4,4'-(hexafluoroisopropylidene)diphthalic anhydride

CBDA: 1,2,3,4-Cyclobutanetetracarboxylic dianhydride

IPBBT: N,N'-isophthalbis (benzooxazoline-2-thione)

NMP: N-methyl-2-pyrrolidone

BCS: butyl cellosolve

<Measurement of weight average molecular weight and molecular weight distribution>

Measurement of the weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of the polymer was performed using a GPC apparatus manufactured by Nippon Bunko Co., Ltd. (column: OHpak SB803-HQ and OHpak SB804-HQ manufactured by Showa Denko Co., Ltd.; eluent: dye Methylformamide/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) It was carried out using (in the following examples and comparative examples, the same).

[1] Synthesis of polymers

A polyamic acid and a polybenzoxazole precursor were synthesized by the following method.

In addition, a composition for forming a resin substrate or a composition for forming a release layer was prepared by diluting the reaction solution as described later without isolating the polymer from the resulting polymer-containing reaction liquid.

[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 50.112g (230mmol) was added thereto, and the temperature was raised to 50°C under a nitrogen atmosphere, and it was made to react for 48 hours to obtain polyamic acid S1. Mw of polyamic acid S1 was 82,100, and Mw/Mn was 2.7.

[Synthesis Example S2] Synthesis of polyamic acid S2

3.218 g (30 mmol) of p-PDA was dissolved in 88.2 g of NMP. BPDA 8.581g (29mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and polyamic acid S2 was obtained. Mw of polyamic acid S2 was 107,300, and Mw/Mn was 4.6.

[Synthesis Example S3] Synthesis of polyamic acid S3

17.8 g (56 mmol) of TFMB, 0.4 g (1 mmol) of BAPB and 2.5 g (23 mmol) of p-PDA were dissolved in 430 g of NMP. 6FDA 6.3g (14mmol) and CF3-BP-TMA 42.8g (64mmol) were added to the obtained solution, it was made to react at 23 degreeC under nitrogen atmosphere for 24 hours, and polyamic acid S3 was obtained. Mw of polyamic acid S3 was 38,700, and Mw/Mn was 2.1.

[Synthesis Example S4] Synthesis of polyamic acid S4

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

[Synthesis Example L1] Synthesis of polyamic acid L1

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

[Synthesis Example L2] Synthesis of polyamic acid L2

1.836 g (17 mmol) of p-PDA and 0.287 g (1.9 mmol) of DBA were dissolved in 88 g of NMP. BPTME 9.878g (18mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L2 was obtained. 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. BPTME 9.461g (18mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L3 was obtained. 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. BPTME 8.016g (15mmol) was added to the obtained solution, it was made to react at 23 degreeC in nitrogen atmosphere for 24 hours, and the polyamic acid L4 was obtained. Mw of polyamic acid L4 was 42,600, and Mw/Mn was 3.9.

[Synthesis Example L5] Synthesis of polyamic acid L5

5.17 g (14 mmol) of BAPB was dissolved in 88 g of NMP. BPTME 6.83g (13mmol) was added to the obtained solution, it was made to react at 23 degreeC under nitrogen atmosphere for 24 hours, and the polyamic acid L5 was obtained. Mw of polyamic acid L5 was 52,100, and Mw/Mn was 2.7.

[Synthesis Example L6] Synthesis of polyamic acid L6

5.89 g (12 mmol) of FAPB was dissolved in 88 g of NMP. BPTME 6.11g (11mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and polyamic acid L6 was obtained. Mw of polyamic acid L6 was 87,700, and Mw/Mn was 3.3.

[Synthesis Example L7] Synthesis of polyamic acid L7

3.60 g (16 mmol) of APAB was dissolved in 88 g of NMP. BPTME 8.40g (16mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and polyamic acid L7 was obtained. Mw of polyamic acid L7 was 58,300, and Mw/Mn was 2.8.

[Synthesis Example L8] Synthesis of polyamic acid L8

2.322 g (12 mmol) of DDE was dissolved in 35.2 g of NMP. PMDA 2.478g (11mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L8 was obtained. 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. TAHQ 3.038g (7mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and polyamic acid L9 was obtained. 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, it was made to react at 23 degreeC by 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. BPODA 3.086g (6mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L11 was obtained. Mw of polyamic acid L11 was 27,000, and Mw/Mn was 2.4.

[Synthesis Example L12] Synthesis of polyamic acid L12

0.931 g (9 mmol) of p-PDA was dissolved in 35.2 g of NMP. TAHQ 3.868g (8mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L12 was obtained. Mw of polyamic acid L12 was 45,000, and Mw/Mn was 2.7.

[Synthesis Example L13] Synthesis of polyamic acid L13

0.839 g (8 mmol) of p-PDA and 0.093 g (1 mmol) of m-PDA were dissolved in 35.2 g of NMP. TAHQ 3.868g (8mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L13 was obtained. Mw of polyamic acid L13 was 39,100, and Mw/Mn was 2.6.

[Synthesis Example L14] Synthesis of polyamic acid L14

0.652 g (6 mmol) of p-PDA and 0.280 g (3 mmol) of m-PDA were dissolved in 35.2 g of NMP. TAHQ 3.868g (8mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L14 was obtained. Mw of polyamic acid L14 was 42,700, and Mw/Mn was 2.6.

[Synthesis Example L15] Synthesis of polyamic acid L15

0.931 g (9 mmol) of m-PDA was dissolved in 35.2 g of NMP. TAHQ 3.868g (8mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L15 was obtained. 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 3.765g (8mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L16 was obtained. 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. TAHQ 3.575g (8mmol) was added to the obtained solution, it was made to react at 23 degreeC under nitrogen atmosphere for 24 hours, and the polyamic acid L17 was obtained. Mw of polyamic acid L17 was 46,000, and Mw/Mn was 2.6.

[Synthesis Example L18] Synthesis of polyamic acid L18

0.832 g (8 mmol) of p-PDA and 0.130 g (1 mmol) of DBA were dissolved in 35.2 g of NMP. TAHQ 3.838g (8mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L18 was obtained. Mw of polyamic acid L18 was 57,000, and Mw/Mn was 3.0.

[Synthesis Example L19] Synthesis of polyamic acid L19

0.822 g (8 mmol) of p-PDA and 0.183 g (1 mmol) of HAB were dissolved in 35.2 g of NMP. TAHQ 3.794g (8mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L19 was obtained. Mw of polyamic acid L19 was 54,200, and Mw/Mn was 2.7.

[Synthesis Example L20] Synthesis of polyamic acid L20

0.616 g (6 mmol) of p-PDA and 0.528 g (2 mmol) of HAB were dissolved in 35.2 g of NMP. TAHQ 3.655g (8mmol) was added to the obtained solution, it was made to react at 23 degreeC in nitrogen atmosphere for 24 hours, and polyamic acid L20 was obtained. Mw of polyamic acid L20 was 55,900, and Mw/Mn was 2.6.

[Synthesis Example L21] Synthesis of polyamic acid L21

1.239 g (5 mmol) of APAB-E was dissolved in 17.6 g of NMP. PMDA 1.160g (5mmol) was added to the obtained solution, it was made to react at 23 degreeC by nitrogen atmosphere for 24 hours, and the polyamic acid L21 was obtained. Mw of polyamic acid L21 was 20,900, and Mw/Mn was 2.1.

[Synthesis Example L22] Synthesis of polyamic acid L22

1.060 g (5 mmol) of APAB-E was dissolved in 17.6 g of NMP. 1.339 g (5 mmol) of BPDA was added to the obtained solution, and it was made to react at 23 degreeC under nitrogen atmosphere for 24 hours, and the polyamic acid L22 was obtained. Mw of polyamic acid L22 was 26,600, and Mw/Mn was 2.3.

[Comparative Synthesis Example 1] Synthesis of polybenzoxazole precursor B1

5.49 g (0.015 mol) of 6FAP was dissolved in 27 g of NMP. IPBBT 6.48g (0.015 mol) was added to the obtained solution, and it was made to react at 23 degreeC in nitrogen atmosphere for 3 hours. Then, this solution was injected into 300 g of pure water, and after stirring for 24 hours, the precipitate was filtered. Then, it dried under reduced pressure and obtained the polybenzoxazole precursor B1. Mw of polybenzoxazole precursor B1 was 2,1000, and Mw/Mn was 3.9.

[2] Preparation of a composition for forming a resin substrate

The reaction liquids obtained in Synthesis Examples S1 to S4 were used as compositions W, X, Y, and Z for forming a resin substrate as they were, respectively.

[3] Preparation of a composition for forming a release layer

[Example 1-1]

BCS was added to the reaction solution obtained in Synthesis Example L1, and diluted with NMP so that the polymer concentration was 5% by mass and the BCS was 20% by mass, thereby obtaining a composition for forming a release layer.

[Examples 1-2 to 1-22]

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

[Comparative Example 1]

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

[4] Formation of release layer and its evaluation

[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 x 100 mm glass substrate (the same below) using a spin coater (condition: rotation speed of 3000 rpm for about 30 seconds).

Then, the obtained coated film was heated at 80° C. for 10 minutes using a hot plate, then heated at 300° C. for 30 minutes using an oven, and the heating temperature was raised to 400° C. (10° C./min), followed by heating at 400° C. It was further heated at °C for 30 minutes to form a peeling layer having a thickness of about 0.1 μm on the glass substrate. During the temperature rise, the film-attached substrate was heated in the oven without taking it out of the oven.

[Examples 2-2 to 2-22]

A release layer was prepared in the same manner as in Example 2-1, except that the release layer-forming composition obtained in Examples 1-2 to 1-22 was used instead of the release layer-forming composition obtained in Example 1-1. formed

[Example 2-23]

The composition for forming a release layer obtained in Example 1-12 was applied onto a 100 mm x 100 mm glass substrate using a spin coater (condition: rotation speed of 3000 rpm for about 30 seconds).

Then, the obtained coated film was heated at 80° C. for 10 minutes using a hot plate, then heated at 140° C. for 30 minutes using an oven, and the heating temperature was raised to 250° C. (2° C./min), followed by heating at 250° C. It was further heated at °C for 60 minutes to form a peeling layer having a thickness of about 0.1 μm on the glass substrate. During the temperature rise, the film-attached substrate was heated in the oven without taking it out of the oven.

[Example 2-24]

The composition for forming a release layer obtained in Example 1-8 was applied onto a 100 mm x 100 mm glass substrate as a glass base using a spin coater (condition: rotation speed of 3000 rpm for about 30 seconds).

Then, the obtained coated film was heated at 80° C. for 10 minutes using a hot plate, then heated at 300° C. for 30 minutes in a nitrogen atmosphere using an oven, and the heating temperature was raised 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 rise, the film-attached substrate was heated in the oven without taking it out of the oven.

[Example 2-25]

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

[Comparative Example 2]

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

[5] Evaluation of peelability

[Examples 3-1 to 3-47, Comparative Example 3]

The peelability of the peeling layer obtained in Examples 2-1 to 2-25 and the glass substrate, and the peelability of the peeling layer (resin thin film) and the resin substrate were confirmed. In addition, as the resin substrate, a resin substrate made of polyimide was used.

First, cross-cutting of the release layer on the glass substrate with a release layer obtained in Examples 2-1 to 2-25 (1 mm intervals in length and width, the same hereinafter), and cross-cutting of the resin substrate and the release layer on the glass substrate with a resin substrate and release layer By performing the cut, 100 lattice cell cuts were performed. That is, 100 lattice cells of 1 mm square were formed by this cross-cutting.

Then, adhesive tape was applied to these 100 mass cut parts, 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). Furthermore, the same test was done according to the said method 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% exfoliation (no exfoliation)

4B: less than 5% peeling

3B: 5 to 15% peeling

2B: 15 to less than 35% peeling

1B: 35 to less than 65% peeling

0B: 65% to less than 80% peeling

B: 80% to less than 95% peeling

A: 95% to less than 100% peeling

AA: 100% exfoliation (all exfoliation)

The resin substrates of Examples 3-1 to 3-41 and 3-44 to 3-47 and Comparative Example 3 were formed by the following method.

Using a bar coater (gap: 250 μm), either the composition W or X for forming a resin substrate was applied onto the release layer (resin thin film) on the glass substrate. Then, the obtained coating film was heated at 80° C. for 10 minutes using a hot plate, then heated at 140° C. for 30 minutes using an oven, and the heating temperature was raised to 210° C. (10° C./min, hereinafter the same), , The heating temperature was raised to 300 ° C at 210 ° C for 30 minutes, the heating temperature was raised to 400 ° C for 30 minutes at 300 ° C, and the heating temperature was raised to 400 ° C for 60 minutes, and a polyimide substrate having a thickness of about 20 μm was formed on the release layer. has formed During the temperature rise, the film-attached substrate was heated in the oven without taking it out of 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 composition Y or Z for forming a resin substrate was applied on the release layer on the glass substrate. Then, the obtained coated film was heated at 80° C. for 10 minutes using a hot plate, then heated at 140° C. for 30 minutes using an oven, and the heating temperature was raised to 250° C. (2° C./min), followed by heating at 250° C. It was heated at °C for 60 minutes to form a polyimide substrate having a thickness of about 0.8 μm on the release layer. During the temperature rise, the film-attached substrate was heated in the oven without taking it out of the oven.

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

[6] Evaluation of transmittance

[Example 4]

Using a spin coater (condition: rotation speed of 800 rpm for about 30 seconds), the composition for forming a release layer obtained in Example 2-8 was applied as a glass base onto a 100 mm x 100 mm glass substrate (same as below).

Then, the obtained coating film was heated at 80°C for 10 minutes using a hot plate, then heated at 300°C for 30 minutes using an oven, and the heating temperature was raised to 400°C (10°C/min), followed by heating at 400°C. was further heated for 30 minutes to form a peeling layer having a thickness of about 0.4 μm on the glass substrate. During the temperature rise, the film-attached substrate was heated in the oven without taking it out of the oven. The transmittance|permeability of the obtained film was measured using the ultraviolet-visible spectrophotometer (SIMADSU UV-2550 type|model manufactured by Shimadzu Corporation).

Results are shown in FIG. 1 . The transmittance of the obtained film was 1% or less with respect to a wavelength of 308 nm, indicating transmittance usable as a sacrificial layer.

Claims (11)

A polyamic acid obtained by reacting an aromatic diamine with an aromatic tetracarboxylic dianhydride and an organic solvent,
wherein the aromatic diamine comprises an aromatic diamine comprising an ester bond, and/or the aromatic tetracarboxylic acid dianhydride comprises an aromatic tetracarboxylic acid dianhydride comprising an ester bond;
The aromatic diamine containing an ester bond is at least one selected from the group consisting of formulas (A4) to (A6), (A13) to (A24) and (A34) to (A39),

A composition for forming a release layer, characterized in that the aromatic tetracarboxylic dianhydride containing an ester bond is at least one selected from the group consisting of formulas (B1), (B2), (B5) to (B7) and (B11) .

According to claim 1,
A composition for forming a release layer, characterized in that the aromatic tetracarboxylic dianhydride further comprises an aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond. According to claim 2,
A composition for forming a release layer, wherein the aromatic tetracarboxylic dianhydride containing neither an ester bond nor an ether bond includes a benzene skeleton, a naphthyl skeleton or a biphenyl skeleton. According to claim 3,
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).

According to claim 1,
For forming a release layer, characterized in that the organic solvent contains at least one selected from amides represented by formula (S1), amides represented by formula (S2), and amides represented by formula (S3). composition.

(In the formula, R ¹ and R ² independently represent an alkyl group having 1 to 10 carbon atoms. R ³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. h represents a natural number.) A release layer formed using the composition for forming a release layer according to claim 1. A method for manufacturing a flexible electronic device having a resin substrate, characterized by using the peeling layer according to claim 6. The manufacturing method of the touchscreen sensor provided with the resin substrate characterized by using the peeling layer of Claim 6. According to claim 7 or 8,
A manufacturing method characterized in that the resin substrate is a substrate made of polyimide. delete delete

Images