TW201829668A - Release layer production method - Google Patents

Abstract

A release layer production method is provided which involves a step for coating a substrate with a release layer forming composition and firing at a maximum temperature of no less than 400 DEG C, wherein the release layer forming composition contains an organic solvent, and a polyamic acid having both ends derived from a tetracarboxylic acid, with either one or both of said ends sealed with 2-aminophenol.

Description

Manufacturing method of release layer

This invention relates to the manufacturing method of a peeling layer.

In recent years, in addition to the characteristics of thinness and weight reduction of electronic devices, it is also required to provide flexible functions. Therefore, it is required to use a lightweight flexible plastic substrate instead of a glass substrate that has been conventionally heavy and fragile and cannot be bent. In particular, new-generation displays require the development of active-array full-color TFT display panels that use lightweight flexible plastic substrates (hereinafter referred to as resin substrates). The technology of this new-generation display is expected to be transferred to various fields such as flexible displays, flexible smartphones, and mirror displays.

Therefore, various manufacturing methods of electronic devices using resin films as substrates have been reviewed, and the manufacturing process of new-generation displays that can be transferred to existing TFT display panel manufacturing equipment has been reviewed.

For example, Patent Documents 1, 2, and 3 disclose a method of forming an amorphous silicon thin film layer on a glass substrate, forming a plastic substrate on the thin film layer, and then irradiating laser light from the glass substrate side to make the amorphous silicon Crystallization, the plastic substrate is peeled from the glass substrate by the hydrogen gas accompanying the crystallization.

In addition, Patent Document 4 discloses a method for attaching a peeled layer (described as "transferred layer" in Patent Document 4) to a plastic film using the techniques disclosed in Patent Documents 1 to 3 to complete a liquid crystal display device.

However, the methods disclosed in Patent Documents 1 to 4, especially the method disclosed in Patent Document 4, have the following problems: In order to transmit laser light, a substrate having a high light transmittance must be used; in order to pass through the substrate, To further release the hydrogen contained in the amorphous silicon, irradiation with laser light of sufficient and large energy is required; sometimes the peeled layer is damaged by the irradiation of laser light. Furthermore, when the peeled layer has a large area, it takes a long time for laser processing, so it is difficult to improve the productivity of device manufacturing. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. 10-125929 [Patent Literature 2] Japanese Patent Application Laid-Open No. 10-125931 [Patent Literature 3] International Publication No. 2005/050754 [Patent Literature 4] Japanese Patent Application Laid-Open No. 10-125930 Bulletin

[Problems to be Solved by the Invention]

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a release layer that can be peeled off without damaging the resin substrate of a flexible electronic device. [Means to solve the problem]

As a result of careful review by the present inventors in order to solve the above-mentioned problems, it was found that by using a composition containing one or both of the tetracarboxylic acid terminal-terminated polyamines and an organic solvent blocked with 2-aminophenol, the composition was peeled off. The firing temperature at the time of layer formation is set to be higher than a specific maximum reaching temperature, and it can have excellent adhesion to the substrate and moderate adhesion and moderate peelability to a resin substrate for a flexible electronic device. The peeling layer completes the present invention.

That is, the present invention provides: 1. A method for manufacturing a release layer, which comprises the following steps: Will include two ends from a tetracarboxylic acid, either or both of these ends are subjected to 2-aminophenol A step for applying a closed polyamic acid and a composition for forming a release layer of an organic solvent to a substrate and firing at a maximum temperature of 400 ° C or higher. 2. The method for producing a release layer according to 1, wherein the polyamino acid is a polyamino acid obtained by reacting a diamine component containing an aromatic diamine with an acid dianhydride component containing an aromatic tetracarboxylic dianhydride. . 3. The method for producing the release layer according to 2, wherein the aromatic diamine is an aromatic diamine containing 1 to 5 benzene nuclei. 4. The method for producing a release layer according to 2 or 3, wherein the aromatic tetracarboxylic dianhydride is an aromatic tetracarboxylic dianhydride containing 1 to 5 benzene nuclei. 5. A method for manufacturing a flexible electronic device including a resin substrate, which uses a release layer formed by a manufacturing method according to any one of 1 to 4. 6. A method for manufacturing a flexible electronic device, comprising the following steps: (1) After coating the composition for forming a resin substrate on a release layer formed using the manufacturing method of any one of 1 to 4, The step of firing to form a resin substrate is performed at a temperature of 450 ° C or higher. 7. The method for manufacturing a flexible electronic device according to 5 or 6, wherein the resin substrate is a polyimide resin substrate. [Inventive effect]

By using the production method of the release layer of the present invention, a reproducible release layer having excellent adhesion to a substrate, moderate adhesion to a resin substrate, and moderate peelability is obtained. Therefore, by implementing the manufacturing method of the present invention, in the manufacturing process of the flexible electronic device, the resin substrate formed on the substrate or the circuit provided thereon will not be damaged. The resin substrate is separated from the substrate. Therefore, the manufacturing method of the present invention can provide simplification of the manufacturing process of a flexible electronic device provided with a resin substrate, improvement of its yield rate, and the like. [Form of Implementing Invention]

The present invention is explained in more detail below. The method for producing a release layer according to the present invention comprises the following steps: (i) it comprises a polyamino acid having two ends derived from a tetracarboxylic acid, either or both of which are blocked with 2-aminophenol, and A composition for forming a release layer of an organic solvent, which is applied to a substrate and fired at a maximum temperature of 400 ° C or higher. Therefore, the release layer in the present invention refers to a layer provided directly above a glass substrate for a specific purpose. This typical example can be mentioned in the manufacturing process of a flexible electronic device. In the above substrate, and polyimide, etc. The resin substrate of a flexible electronic device is provided between the resin substrates in order to fix the resin substrate in a specific process, and after an electronic circuit is formed on the resin substrate, the resin substrate can be easily removed from the resin substrate. This substrate peels the provided peeling layer.

The polyamino acid used in the present invention is blocked by reacting one or both of the polymer chain terminals having polyamino acid from both ends of the tetracarboxylic acid with the amine group of 2-aminophenol. And get. That is, the polyamidic acid obtained here is either one or both of the ends of the molecular chain blocked with a hydroxyl-containing phenyl group.

Since the polymer terminal has a hydroxyl group, it can be different from the flexible substrate skeleton used for the upper layer, so the function of the release layer as the obtained film can be improved.

It is sufficient that the hydroxyl group derived from 2-aminophenol is present at any one of the polymer chain ends of the polyamine of the present invention, but the hydroxyl group derived from 2-aminophenol is preferably present at both the polymer chain ends.

In addition, the diamine component and the acid dianhydride component used in the production of the polyamic acid are made from the viewpoint of improving the function of the release layer of the obtained film, the diamine component containing an aromatic diamine and the aromatic tetracarboxylic acid. Polyamic acid obtained by reacting an acid dianhydride component of a dianhydride is preferred.

The aromatic diamine is not particularly limited as long as it has two amine groups in the molecule and has an aromatic ring, but an aromatic diamine containing 1 to 5 benzene nuclei is preferred. Specific examples include 1,4-diaminobenzene (p-phenylenediamine), 1,3-diaminobenzene (m-phenylenediamine), and 1,2-diaminobenzene (o-benzenediamine). Amine), 2,4-diaminotoluene, 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-di Diamines such as amines, 3,5-bis (trifluoromethyl) benzene-1,2-diamine, etc .; one 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- Naphthalene diamine, 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'-diaminobenzidineaniline, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine, 2,2'-dimethyl Benzidine, 3,3'- Aminodiphenylmethane, 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'-diaminodiphenylsulfinium, 3,4'-diaminodiphenylsulfinium , 4,4'-diaminodiphenylsulfene, 3,3'-bis (trifluoromethyl) biphenyl-4,4'-diamine, 3,3 ', 5,5'-tetra Fluorobiphenyl-4,4'-diamine, 4,4'-diamino octafluorobiphenyl, 2- (3-aminophenyl) -5-aminobenzimidazole, 2- (4- Aminophenyl) -5-aminobenzoxazole and other benzene nuclei are two diamines; 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-amine Phenyl) 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-aminophenylsulfide) Benzene, 1,3-bis (3-aminophenylphosphonium) benzene, 1 1,3-bis (4-aminophenylfluorene) benzene, 1,4-bis (4-aminophenylfluorene) benzene, 1,3-bis [2- (4-aminophenyl) isopropyl ] Benzene, 1,4-bis [2- (3-aminophenyl) isopropyl] benzene, 1,4-bis [2- (4-aminophenyl) isopropyl] benzene, 4,4 The benzene nucleus of '' -diamino-p-bitriphenyl, 4,4 ''-diamino-m-bitriphenyl, etc. is three diamines, etc., but it is not limited to these. These can be used alone or in combination of two or more. In addition, in the present invention, it is preferable that the aromatic diamine is used without an ether bond or an ester bond.

Among them, from the viewpoint of improving the function of the release layer as the obtained film, the aromatic ring is composed only of an aromatic ring and an aromatic ring and a heteroaromatic ring which do not have a substituent such as a methyl group on a heterocycle condensed therewith. Diamine is preferred. Specifically, p-phenylenediamine, m-phenylenediamine, 2- (3-aminophenyl) -5-aminobenzimidazole, 2- (4-aminophenyl) -5-amino Benzoxazole and 4,4 ''-diamino-p-bitriphenyl are preferred.

The aromatic tetracarboxylic dianhydride is not particularly limited as long as it has two dicarboxylic anhydride sites in the molecule and has an aromatic ring, but an aromatic tetracarboxylic dianhydride containing 1 to 5 benzene nuclei is preferred.

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'-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-tetracarboxylic dianhydride, phenanthrene-2,3,6,7-tetracarboxylic dianhydride, phenanthrene-2,3,9, 10-tetracarboxylic dianhydride, phenanthrene-3,4,5,6-tetracarboxylic dianhydride, phenanthrene-3,4,9,10-tetracarboxylic dianhydride, etc. are not limited thereto. These can be used alone or in combination of two or more.

Among them, from the viewpoint of improving the function of the release layer as the obtained film, an aromatic carboxylic dianhydride having one or two benzene nuclei is preferred. Specifically, an aromatic tetracarboxylic dianhydride represented by any one of the formulae (C1) to (C12) is preferable, and an aromatic represented by any one of the formulae (C1) to (C7) and (C9) to (C11) Tetracarboxylic dianhydride is more preferred.

In addition, from the viewpoint of improving the flexibility and heat resistance of the obtained release layer, the diamine component used in the present invention may include a diamine other than an aromatic diamine, and the tetracarboxylic dianhydride component used in the present invention may be Tetracarboxylic dianhydride other than aromatic tetracarboxylic dianhydride is included.

In the present invention, the amount of the aromatic diamine in the diamine component is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and still more preferably 95 Molar% or more, preferably 100 Molar%. The amount of the aromatic tetracarboxylic dianhydride in the tetracarboxylic acid component is preferably 70 mol% or more, more preferably 80 mol% or more, and still more preferably 90 mol% or more, and more preferably It is 95 mol% or more, preferably 100 mol%. By using such an amount, a reproducible film having excellent adhesion to a substrate, moderate adhesion to a resin substrate, and moderate peelability is obtained.

As described above, after the diamine component and the tetracarboxylic dianhydride component are reacted, the obtained polyamic acid is reacted with 2-aminophenol to obtain the polymer contained in the composition for forming a release layer of the present invention. Polyamino acids with chain ends blocked by 2-aminophenol.

The input ratio of the diamine component to the tetracarboxylic dianhydride component depends on the molecular weight or molecular weight distribution of the purpose, the type of the diamine, or the type of the tetracarboxylic dianhydride, and it is appropriately determined. At both ends of the molecular chain, the molar number of the tetracarboxylic dianhydride component is preferably larger than the molar number of the diamine component. The specific mole ratio is relative to 1 mole of the diamine component and 1.02 to 3.0 mole of the tetracarboxylic dianhydride component, more preferably 1.07 to 2.5 mole, and still more preferably 1.1 to 2.0 mole.

The organic solvent used for the synthesis of polyamino acid and the end of the molecular chain of the polyamino acid after the synthesis is not particularly limited as long as it does not affect the reaction. Specific examples 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-dimethylpropylamidamine, 3-ethoxy-N, N-dimethylpropylamidamine, 3-propoxy-N, N-dimethylpropyl Hydrazine, 3-isopropoxy-N, N-dimethylpropylamidamine, 3-butoxy-N, N-dimethylpropylamidamine, 3-sec-butoxy-N, N-dimethylpropylamidamine, 3-tert-butoxy-N, N-dimethylpropylamidamine, γ-butyrolactone and the like. Moreover, an organic solvent may be used individually by 1 type, and may use 2 or more types together.

In particular, since the organic solvent used for the reaction sufficiently dissolves diamine, tetracarboxylic dianhydride, and polyamic acid, it is selected from the group consisting of amines represented by formula (S1), and amines represented by (S2) and formula (S3). Preferably, at least one of the amidines represented by) is used.

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, and more preferably 1 or 2.

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

The reaction temperature during the synthesis of the polyamic acid may be appropriately set within a range from the melting point to the boiling point of the solvent to be used, and is usually about 0 to 100 ° C. In order to prevent tritium in the obtained polyamic acid solution Amination, when maintaining a high content of polyamic acid units, is preferably about 0 to 70 ° C, more preferably about 0 to 60 ° C, and even more preferably about 0 to 50 ° C. The reaction time depends on the reaction temperature or the reactivity of the raw materials, so it cannot be specified in general, but usually about 1 to 100 hours.

The reaction temperature at the end of the molecular chain of the polyamic acid is the same as that during the synthesis of the polyamic acid. It can be appropriately set within the range from the melting point to the boiling point of the solvent used. Usually, it is about 0 to 100 ° C. The viewpoint of surely closing the molecular chain end of the synthesized polyamic acid is preferably about 0 to 70 ° C, more preferably about 0 to 60 ° C, and even more preferably about 0 to 50 ° C. The reaction time depends on the reaction temperature or the reactivity of the raw materials, so it cannot be specified in general, but usually about 1 to 100 hours.

The weight average molecular weight of one or both of the molecular chain ends thus obtained, which is blocked by 2-aminophenol, is generally about 5,000 to 500,000. However, the function of the prepared film as a release layer is improved. The viewpoint is preferably about 6,000 to 200,000, and more preferably about 7,000 to 150,000. In the present invention, the weight average molecular weight is a polystyrene conversion value obtained by measurement by gel permeation chromatography (GPC).

In the present invention, the reaction solution after the terminal is usually blocked, or the solution obtained by dilution or concentration can be used as the composition for forming a release layer of the present invention. The reaction solution may be filtered if necessary. Filtration can not only reduce the mixing of impurities that may cause deterioration of the adhesion and peelability of the obtained release layer, but also provide a composition for forming a release layer with high efficiency. After the polyamic acid is isolated from the reaction solution, it can be dissolved again in a solvent and used as a composition for forming a release layer. Examples of the solvent in this case include the organic solvents used in the aforementioned reactions.

The solvent for dilution is not particularly limited, and specific examples thereof may be the same as the specific examples of the reaction solvent of the aforementioned reaction. The solvents for dilution may be used alone or in combination of two or more. Among these, since polyamic acid can be sufficiently dissolved, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and 1,3-diamine are preferred. Methyl-2-imidazolinone, N-ethyl-2-pyrrolidone, and γ-butyrolactone, more preferably N-methyl-2-pyrrolidone.

Moreover, even if it is a solvent which does not dissolve polyamic acid by itself, if it is the range in which polyamic acid does not precipitate, it can mix with the composition for peeling layer formation of this invention. In particular, it can be moderately mixed with ethyl cellosolve, butyl cellosolve, ethylcarbitol, butylcarbitol, ethylcarbitol 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 and other solvents with low surface tension. Accordingly, it is known to improve the uniformity of the coating film when applied to a substrate, and it can also be applied to the composition for forming a release layer of the present invention.

The concentration of the polyamic acid in the release layer-forming composition of the present invention is appropriately set in consideration of the thickness of the release layer to be produced, the viscosity of the composition, and the like, but it is usually about 1 to 30% by mass, preferably 1 ~ 20% by mass. With such a concentration, a releasable layer having a thickness of about 0.05 to 5 μm is obtained with good reproducibility. The concentration of polyamic acid can be adjusted by the amount of diamine and tetracarboxylic dianhydride used as the raw material of polyamic acid. After filtering the reaction solution, the filtrate is diluted or concentrated to separate the When amidine is dissolved in the solvent, the amount is adjusted by adjusting the amount and the like.

In addition, the viscosity of the composition for forming a release layer of the present invention is suitably set in consideration of the thickness of the release layer to be produced, etc., but it is usually 25 when a film having a thickness of about 0.05 to 5 μm is obtained for good reproducibility. The temperature is about 10 to 10,000 mPa ･ s, preferably about 20 to 5,000 mPa ･ s.

Here, the viscosity is a viscometer for measuring the viscosity of a commercially available liquid. For example, the viscosity can be measured at a temperature of 25 ° C. of the composition by referring to the procedure described in JIS K7117-2. It is preferred to use a conical plate type (conical plate type) rotary viscometer for the viscometer, and it is preferable to use a viscometer of the same type. The standard conical rotor is 1 ° 34 '× R24, which can be used at a temperature of 25 ° C. measuring. Examples of such a rotational viscosity meter include TVE-25L manufactured by Toki Sangyo Co., Ltd.

In addition, the composition for forming a release layer of the present invention may contain, in addition to polyamic acid and an organic solvent, for example, a cross-linking agent in order to improve the film strength.

After the above-mentioned composition for forming a release layer is coated on a substrate, a firing method including a step of firing at a maximum temperature of 400 ° C. or higher can be performed by thermally fluorinating the polyamic acid. A release layer made of a polyimide film having excellent adhesion to a substrate, moderate adhesion to a resin substrate, and moderate peelability was obtained. In the present invention, when the maximum temperature during the firing is 400 ° C., and it is in a range below the heat-resistant temperature of polyimide, there is no particular limitation, but it is considered to improve the adhesion with the substrate or the resin substrate. For moderate adhesion and peelability, the temperature is preferably 450 ° C or higher, and more preferably 500 ° C or higher. The upper limit is usually about 550 ° C, but preferably about 510 ° C. By setting the heating temperature to the above range, fragility of the obtained film can be prevented, and the amidation reaction can be sufficiently performed. The heating time varies depending on the heating temperature and cannot be specified in general, but it is usually 1 minute to 5 hours. In addition, the fluorene imidization rate may be within a range of 50 to 100%.

When the temperature at the time of firing is within the above range, a step of firing at a temperature lower than the temperature may be included.较佳 A preferred example of the heating state in the present invention includes a method of gradually increasing the heating temperature in this state after heating at 50 to 150 ° C, and finally heating at 400 ° C or higher. A particularly preferable example of the heating state is a method of heating at 50 to 100 ° C, then heating at a temperature exceeding 100 ° C to less than 400 ° C, and then heating at 400 ° C or higher. In addition, as another example of a better heating state, after heating at 50 to 150 ° C, heating at more than 150 ° C to 350 ° C, then heating at more than 350 ° C to 450 ° C, and finally heating at more than 450 ° C to 510 ° C Approach.

In addition, considering a preferable example of the heating state at the firing time, heating at 50 to 150 ° C for 1 minute to 2 hours can be mentioned, and the heating temperature can be gradually increased in this state, and finally heated at 400 ° C or higher for 30 minutes ~ 4-hour approach. In particular, a more preferable example of heating is heating at 50 to 100 ° C for 1 minute to 2 hours, heating at more than 100 ° C to 400 ° C for 5 minutes to 2 hours, and heating at 400 ° C or higher for 30 minutes to 4 Hours. In addition, as another example of a better heating state, heating at 50 to 150 ° C for 1 minute to 2 hours, heating at more than 150 ° C to 350 ° C for 5 minutes to 2 hours, and then heating at more than 350 ° C to 450 ° C 30 minutes to 4 hours, and finally heating at 450 ° C to 510 ° C for 30 minutes to 4 hours.

When the release layer of the present invention is formed on a substrate, the release layer may be formed on a part of the surface of the substrate or may be formed on the entire surface. Forms where a peeling layer is formed on a part of the surface of the substrate, for example, a form in which a peeling layer is formed only within a specific range of the surface of the substrate, a dot pattern on the entire surface of the substrate, a line width / space pattern, etc. The pattern of the pattern forms the release layer. In addition, in the present invention, the base system refers to a person whose surface is coated with the composition for forming a release layer of the present invention and which can be used for a manufacturer of a flexible electronic device or the like.

Examples of the substrate (substrate) include glass, metal (silicon wafer, etc.), slate, and the like. In particular, since the release layer of the present invention has sufficient adhesion to the substrate, glass is preferred. The surface of the substrate may be composed of a single material, or may be composed of two or more materials. The surface of the substrate is composed of two or more materials. For example, there is a certain material in a certain range of the surface of the substrate, and the other surfaces are composed of other materials. The appearance of materials in other materials as dot patterns, line width / spacing patterns, etc.

The method for applying the composition for forming a release layer of the present invention to a substrate is not particularly limited, and examples thereof include a casting coating method, a spin coating method, a doctor blade coating method, a dip coating method, a roll coating method, and a bar coating method. Method, die coating method, inkjet method, printing method (relief, gravure, lithography, screen printing, etc.) and the like.

Examples of the heating device include a hot plate and an oven. The heating environment can be under air, under inert gas, under normal pressure, or under 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. By adjusting the thickness of the coating film before heating, a desired thickness can be achieved.

The peeling layer described above has excellent adhesion to a substrate, particularly a glass substrate, and moderate adhesion and moderate peelability to a resin substrate. Therefore, in the manufacturing process of a flexible electronic device, the release layer of the present invention does not damage the resin substrate of the device, and is suitable for peeling the resin substrate from a substrate together with a circuit and the like formed on the resin substrate. .

An example of a method for manufacturing a flexible electronic device using the release layer of the present invention will be described below. (2) Using the composition for forming a release layer of the present invention, a release layer is formed on a glass substrate by the method described above. A resin substrate forming solution for forming a resin substrate is applied on this release layer, and the coating film is fired to form a resin substrate fixed to a glass substrate via the release layer of the present invention. The firing temperature of the coating film is appropriately set depending on the type of resin, etc. In the present invention, the maximum temperature during firing is preferably 450 ° C or higher, more preferably 480 ° C or higher, and even more preferably 490 ° C or higher. , And more preferably above 500 ° C. By setting the maximum temperature during firing of the resin substrate to this range, it is possible to further improve the adhesion between the underlying release layer and the substrate, or the appropriate adhesion and release between the release layer and the resin substrate. At this time, when the maximum temperature is within the above range, a step of firing at a temperature lower than this temperature may be included.

A preferred example of the heating state during the production of the resin substrate includes a method of gradually increasing the heating temperature in this state after heating at 50 to 150 ° C, and finally heating at 450 ° C or higher. In particular, a more preferable example of the heating state includes a method of heating at 50 to 100 ° C, then heating at more than 100 ° C to less than 400 ° C, and then heating at 450 ° C or higher. In addition, as another example of a better heating state, after heating at 50 to 100 ° C, heating at more than 100 ° C to 200 ° C, and then heating at more than 200 ° C to 300 ° C, and 300 ° C to 400 Heating at ℃, heating from 400 ℃ to less than 450 ℃, and finally heating at 450 ~ 510 ℃.

In addition, considering a preferable example of the heating state at the firing time, after heating at 50 to 150 ° C for 1 minute to 2 hours, the heating temperature is increased stepwise in this state, and finally heated at 450 ° C or higher for 30 minutes ~ 4-hour approach. In particular, a better example of the heating state includes heating at 50 to 100 ° C for 1 minute to 2 hours, heating at more than 100 ° C to less than 400 ° C for 5 minutes to 2 hours, and heating at 450 ° C or higher for 30 minutes to 4 hours. Approach. In addition, as another example of a better heating state, heating at 50 to 100 ° C for 1 minute to 2 hours, heating at more than 100 ° C to 200 ° C for 5 minutes to 2 hours, and then heating at more than 200 ° C to less than 300 ° C ℃, heating for 30 minutes to 4 hours, heating at 300 ° C to 400 ° C for 30 minutes to 4 hours, heating at 400 ° C to 450 ° C for 30 minutes to 4 hours, and finally heating at 450 to 510 ° C for 30 minutes to 4 Hours.

The resin substrate is entirely covered with the release layer, and the substrate is formed with a larger area than the area of the release layer. Examples of the resin substrate include resin substrates made of polyimide, which are representative of resin substrates for flexible electronic devices. Resin solutions for forming the resin substrate include polyimide solutions or polyamic acid solutions. . The method for forming the resin substrate may be in accordance with a commonly used method.

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

Further, Japanese Patent Application Laid-Open No. 2013-147599 discloses a method for manufacturing a flexible display by using a laser lift-off method (LLO method) used in the manufacture of high-brightness LEDs, three-dimensional semiconductor packages, and the like so far. The above-mentioned LLO method is characterized by irradiating light of a specific wavelength from the glass substrate side, for example, light having a wavelength of 308 nm, on a surface opposite to a surface on which a circuit or the like is formed. The irradiated light penetrates the glass substrate, and only the polymer (polyimide) near the glass substrate absorbs this light, and then evaporates (sublimates). This result determines the performance of the display and does not affect the circuit or the like provided on the resin substrate, and the resin substrate can be selectively peeled from the glass substrate.

The release layer of the present invention has a characteristic of sufficiently absorbing light of a specific wavelength (for example, 308 nm) that can be used by the above-mentioned LLO method, so it can also be used as a sacrificial layer of the LLO method. Therefore, the release layer formed by using the composition of the present invention is fixed on a resin substrate of a glass substrate to form a desired circuit. Then, when the LLO method is performed and the light is emitted at 308 nm, only the release layer absorbs this light. Evaporation (sublimation). Thereby, the peeling layer is sacrificed (acting as a sacrificial layer), and the resin substrate can be selectively peeled from the glass substrate.

[Example]

Examples are given below to explain the present invention in more detail, but the present invention is not limited to those examples.

[1] Abbreviation of compound NMP: N-methylpyrrolidone BCS: butyl cellosolve p-PDA: p-phenylenediamine 2AP: 2-aminophenol BPDA: 3,3-4,4-biphenyltetracarboxylic acid di Anhydride PMDA: pyromellitic dianhydride

[2] Measurement of weight average molecular weight and molecular weight distribution The weight average molecular weight of the polymer (hereinafter referred to as Mw) and the molecular weight distribution are measured using a GPC device (Shodex (registered trademark) column KF803L and KF805L) manufactured by JASCO Corporation. The solvent was measured with dimethylformamide at a flow rate of 1 mL / min and a column temperature: 50 ° C. In addition, Mw is a polystyrene conversion value.

[3] Synthesis of polymer Polyamine is synthesized according to the following method. In addition, from the obtained polymer-containing reaction solution, the polymer was not isolated, but the composition for resin substrate formation or the release layer formation was prepared by diluting the reaction solution as described later.

<Synthesis Example S1 Polyamidic acid (synthesis of S1)> 3.176 g (0.02937 moles) of p-PDA was dissolved in 88.2 g of NMP, and 8.624 g (0.02931 moles) of BPDA was added, and then placed in a nitrogen environment at The reaction was allowed to proceed at 23 ° C for 24 hours. The obtained polymer had an Mw of 107,300 and a molecular weight distribution of 4.6.

<Synthesis of Synthesis Example L1 Polyamic Acid (L1)> 1.507 g (0.0139 mol) of p-PDA was dissolved in 43.2 g of NMP, and 3.166 g (0.01452 mol) of PMDA was added, and then in a nitrogen environment at 23 The reaction was allowed to proceed at 2 ° C for 2 hours. Then, 0.127 g (0.0012 mol) of 2AP was further added, and the reaction was performed at 23 ° C. for 24 hours under a nitrogen environment. The obtained polymer had a Mw of 48,500 and a molecular weight distribution of 2.05.

<Synthesis of Synthesis Example L2 Polyamic Acid (L2)> 1.119 g (0.01103 moles) of p-PDA was dissolved in 35.2 g of NMP, and 3.006 g (0.01378 moles) of PMDA was added, and then in a nitrogen environment at 23 The reaction was allowed to proceed at 2 ° C for 2 hours. Then, 0.602 g (0.00551 mol) of 2AP was further added, and the reaction was performed at 23 ° C. for 24 hours under a nitrogen atmosphere. The obtained polymer had an Mw of 11,700 and a molecular weight distribution of 1.76.

<Synthesis of Synthesis Example L3 Polyamidonic Acid (L3)> 0.681 g (0.00629 mol) of p-PDA was dissolved in 35.2 g of NMP, and 2.746 g (0.01259 mol) of PMDA was added, and then in a nitrogen environment at 23 The reaction was allowed to proceed at 2 ° C for 2 hours. Then, 1.373 g (0.012588 mol) of 2AP was further added, and it was made to react at 23 degreeC for 24 hours in nitrogen environment. The obtained polymer had an Mw of 8,000 and a molecular weight distribution of 1.57.

<Synthesis of Comparative Synthesis Example HL1 Polyamine (HL1)> 1.29 g (0.00107 mol) of p-PDA was dissolved in 43.2 g of NMP, and 3.509 g (0.00119 mol) of BPDA was added. The reaction was allowed to proceed at 23 ° C for 24 hours. The obtained polymer had an Mw of 34,000 and a molecular weight distribution of 2.03.

<Synthesis of Comparative Synthesis Example HL2 Polyamidonic Acid (HL2)> 1. 1.325 g (0.00123 moles) of p-PDA was dissolved in 36 g of NMP, and 2.674 g (0.00123 moles) of PMDA was added, and then in a nitrogen environment at 23 The reaction was allowed to proceed at 2 ° C for 2 hours. Unfortunately, gelation cannot be used.

[4] Preparation of the composition for forming a resin substrate The reaction solutions obtained in Synthesis Example S1 were directly used as the composition for forming a resin substrate, respectively.

[5] Preparation of composition for peeling layer formation [Example 1-1] BCIn the reaction solution obtained in Synthesis Example L1, BCS and NMP were added to dilute the polymer concentration to 5 wt% and BCS to 20 mass% to obtain Composition for release layer formation.

[Examples 1-2 to 1-3] 取代 The reaction liquid obtained in Synthesis Examples L2 to L3 was used instead of the reaction liquid obtained in Synthesis Example L1, and the composition for forming a release layer was obtained in the same manner as in Example 1-1.

[Comparative Example 1-1] 取代 The reaction liquid obtained in Comparative Synthesis Example HL1 was used instead of the reaction liquid obtained in Synthesis Example L1, and the same method as in Example 1-1 was used to obtain a composition for forming a release layer.

[6] Production of release layer and resin substrate [Example 2-1] The composition L1 for release layer formation obtained in Example 1-1 was obtained using a spin coater (condition: 3,000 rpm, about 30 seconds), The glass substrate was coated on a 100 mm × 100 mm glass substrate (the same applies hereinafter). Then, the obtained coating film was heated at 100 ° C for 2 minutes using a hot plate, and then heated at 300 ° C for 30 minutes using an oven, and the heating temperature was increased (10 ° C / minute) to 400 ° C, and then at 400 ° C. After heating for 30 minutes, the heating temperature was increased (10 ° C./minute) to 500 ° C., and then heated at 500 ° C. for 10 minutes to form a release layer having a thickness of about 0.1 μm on the glass substrate to obtain a glass substrate with a release layer. During the temperature rise, the substrate with the film was not removed from the oven, and was heated in the oven.

Using a coating rod (gap: 250 μm), the composition S2 for forming a resin substrate was applied to the release layer (resin film) on the glass substrate obtained above. Then, the obtained coating film was heated at 80 ° C. for 30 minutes, and then an oven was used to form a nitrogen atmosphere, and then heated at 140 ° C. for 30 minutes, and the heating temperature was raised (2 ° C./minute, the same below) to 210 ° C, heat at 210 ° C for 30 minutes, then raise the heating temperature to 300 ° C, heat at 300 ° C for 30 minutes, raise the heating temperature to 400 ° C, heat at 400 ° C for 30 minutes, and then raise the heating temperature to At 500 ° C., and then heating at 500 ° C. for 60 minutes, a polyimide resin substrate having a thickness of about 20 μm was formed on the release layer to obtain a glass substrate with a resin substrate and a release layer. During the temperature rise, the substrate with the film was not removed from the oven, and was heated in the oven.

[Examples 2-2 to 2-3] Except that the compositions for release layer formation L1 and L3 obtained in Example 1-1 were replaced with the compositions for release layer L2 and L3 obtained in Examples 1-2 to 1-3, respectively. In the same manner as in Example 2-1, a release layer and a polyimide resin substrate were formed, and a glass substrate with a release layer and a glass substrate with a resin substrate and a release layer were obtained.

[Comparative Example 2-1] 同样 The same method as in Example 2-1 was used except that the release layer-forming composition HL1 obtained in Comparative Example 1-1 was used instead of the release layer-forming composition L1 obtained in Example 1-1. A release layer and a polyimide resin substrate are formed to obtain a glass substrate with a release layer and a glass substrate with a resin substrate and a release layer.

[7] Evaluation of peelability For the glass substrate with a release layer obtained in the above Examples 2-1 to 2-3 and Comparative Example 2-1, the peelability between the release layer and the glass substrate was confirmed by the following method. The following tests were performed on the same glass substrate.

<Evaluation of peelability of grid film test of resin film> 十字 Cross-cut the peeling layer on the glass substrate with a peeling layer obtained in Examples 2-1 to 2-3 and Comparative Example 2-1 (a 1 mm vertical and horizontal interval, the same applies hereinafter) For 100 squares. That is, 100 squares of 1 mm square are formed by this cross cutting. Then, the adhesive tape was stuck to the 100-square cut portion, and the tape was peeled off, and the peelability was evaluated according to the following criteria (5B to 0B, B, A, AA). The results are shown in Table 1. <Judgment criteria> 5B: 0% peeling (no peeling) 4B: peeling of less than 5% 3B: peeling of 5 to 15% 2B: peeling of 15 to 35% 1B: 35 to 65% Peel 0B: 65% to less than 80% of peel B: 80% to less than 95% of peel A: 95% to less than 100% of peel AA: 100% of peel (all peel)

<Evaluation of the peelability of the resin substrate> ＞ The resin substrates obtained in Examples 2-1 to 2-3 and Comparative Example 2-1 and the glass substrate with a release layer were cut into a 25 mm wide booklet using a dicing blade. . Then, a celluloid tape was stuck to the front end of the cut resin substrate, and this was used as a test piece. This test piece was subjected to a peel test using a push-pull tester manufactured by Attonic at a peel angle of 90 °, and the peelability was evaluated according to the following criteria. The results are shown in Table 1. <Judgment criteria> 5B: 0% peeling (no peeling) 4B: peeling of less than 5% 3B: peeling of 5 to 15% 2B: peeling of 15 to 35% 1B: 35 to 65% Peel 0B: 65% to less than 80% of peel B: 80% to less than 95% of peel A: 95% to less than 100% of peel AA: 100% of peel (all peel)

From the results in Table 1, it was confirmed that the peeling layers of Examples 2-1 to 2-3 did not peel off the glass substrate and could peel only the resin substrate, but Comparative Example 2-1 could not peel.

Claims (7)

A method for producing a release layer, which comprises the following steps: (1) A polyamine acid having two ends derived from a tetracarboxylic acid, either or both of which are blocked with 2-aminophenol, and an organic solvent The step of applying a composition for forming a release layer to a substrate and firing it at a maximum temperature of 400 ° C or higher. The method for producing a release layer according to claim 1, wherein the polyamino acid is a polyamino acid obtained by reacting a diamine component containing an aromatic diamine with an acid dianhydride component containing an aromatic tetracarboxylic dianhydride. . The method for manufacturing a release layer according to claim 2, wherein the aromatic diamine is an aromatic diamine containing 1 to 5 benzene nuclei. For example, the method for producing a release layer according to claim 2 or 3, wherein the aromatic tetracarboxylic dianhydride is an aromatic tetracarboxylic dianhydride containing 1 to 5 benzene nuclei. A method for manufacturing a flexible electronic device including a resin substrate, which uses a release layer formed by the manufacturing method according to any one of claims 1 to 4. A method for manufacturing a flexible electronic device, which includes the following steps: (1) After coating the composition for forming a resin substrate on a release layer formed using the manufacturing method according to any one of claims 1 to 4, the highest The step of firing to form a resin substrate is performed at a temperature of 450 ° C or higher. The method for manufacturing a flexible electronic device according to claim 5 or 6, wherein the resin substrate is a polyimide resin substrate.