JP6743807B2 - Release layer forming composition and release layer - Google Patents

Description

The present invention relates to a release layer-forming composition and a release layer.

2. Description of the Related Art In recent years, electronic devices have been required to have a function of bending and to be thin and lightweight. For this reason, it is required to use a lightweight flexible plastic substrate in place of the conventional heavy, fragile and non-bendable glass substrate. Further, in the new generation display, development of an active full-color TFT display panel using a lightweight flexible plastic substrate is required.

Therefore, various methods for manufacturing an electronic device using a resin film as a substrate have begun to be studied, and for the new-generation display, the manufacturing study is being carried out by a process in which existing TFT equipment can be diverted. In Patent Documents 1, 2 and 3, an amorphous silicon thin film layer is formed on a glass substrate, a plastic substrate is formed on the thin film layer, and then a laser is irradiated from the glass surface side to crystallize the amorphous silicon. A method for peeling a plastic substrate from a glass substrate by using generated hydrogen gas is disclosed.

Further, Patent Document 4 is a method of completing a liquid crystal display device by using a technique disclosed in Patent Documents 1 to 3 to attach a layer to be peeled (described as “transferred layer” in Patent Document 4) to a plastic film. Is disclosed.

However, in the methods disclosed in Patent Documents 1 to 4, particularly in the method disclosed in Patent Document 4, it is essential to use a substrate having high light-transmitting property, and hydrogen contained in amorphous silicon is further passed through the substrate. Since a sufficient amount of energy is given to release the laser beam, it is necessary to irradiate a laser beam having a relatively large energy, which causes a problem that the layer to be peeled is damaged. Further, there is also a problem that it is difficult to increase productivity in device fabrication because laser treatment requires a long time and it is difficult to peel a layer to be peeled having a large area.

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

The present invention has been made in view of the above circumstances, and a release layer forming composition for forming a release layer that can be released without damaging a resin substrate of a flexible electronic device and the release layer. The purpose is to provide.

As a result of repeated intensive studies to solve the above-mentioned problems, the present inventors have found that a composition containing an organic solvent and a polyamic acid obtained by introducing an anchor group into either or both of the polymer chain terminals. The present inventors have completed the present invention by finding that a release layer having excellent adhesion to a substrate, appropriate adhesion to a resin substrate used for a flexible electronic device, and appropriate release property can be formed.

That is, the present invention is
1. A polyamic acid obtained by introducing an anchor group into either or both of the polymer chain terminals, and a release layer forming composition containing an organic solvent,
2. The release layer-forming composition according to 1, wherein the anchor group is a silyl group or a carboxylic acid group,
3. 1 or 2, wherein the polyamic acid is a polyamic acid obtained by reacting a diamine component containing an aromatic diamine with an acid dianhydride component containing an aromatic tetracarboxylic acid dianhydride. A layer-forming composition,
4. 3. The composition for forming a peeling layer according to 3, wherein the aromatic diamine is an aromatic diamine containing 1 to 5 benzene nuclei.
5. The aromatic tetracarboxylic acid dianhydride is an aromatic tetracarboxylic acid dianhydride containing 1 to 5 benzene nuclei, 3 or 4, the composition for forming a peeling layer,
6. A release layer formed using the release layer-forming composition according to any one of 1 to 5,
7. 6. A method for manufacturing a flexible electronic device including a resin substrate, characterized in that the release layer of 6 is used,
8. There is provided the manufacturing method of 7, wherein the resin substrate is a substrate made of polyimide.

By using the composition for forming a release layer of the present invention, a release layer having excellent adhesion to a substrate, appropriate adhesion to a resin substrate, and appropriate release property can be obtained with good reproducibility. Therefore, by using the composition for forming a release layer of the present invention, in the manufacturing process of the flexible electronic device, without damaging the resin substrate formed on the substrate, and further circuits provided thereon, It is possible to separate the resin substrate together with the circuit and the like from the base body. 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 including a resin substrate, improvement of its yield, and the like.

Hereinafter, the present invention will be described in more detail.
The release layer-forming composition of the present invention contains a polyamic acid having an anchor group introduced into either or both of the polymer chain terminals, and an organic solvent. 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 resin such as polyimide in the manufacturing process of a flexible electronic device. It is provided to fix the resin substrate to the resin substrate of the device during a predetermined process, and the resin substrate can be easily peeled from the substrate after forming an electronic circuit or the like on the resin substrate. The peeling layer provided in order to do so is mentioned.

The polyamic acid used in the present invention is not particularly limited as long as it has an anchor group at the polymer chain end, but after reacting a diamine component and a tetracarboxylic dianhydride component, the obtained polyamic acid It can be obtained by reacting with an amine having an anchor group or an acid anhydride having an anchor group. That is, the polyamic acid obtained here is one in which one or both ends of the molecular chain are sealed with an anchor group-containing compound described later.

Examples of such an anchor group include a carboxylic acid group, a silyl group (for example, an alkylsilyl group, an alkoxysilyl group, a vinylsilyl group and an allylsilyl group), a vinyl group, a maleimide group, a phenolic hydroxyl group, and the like. A carboxylic acid group and a silyl group (particularly a silyl group in which one or more groups selected from an alkoxy group, a vinyl group and an allyl group are bonded to a silicon atom) are preferable. By using such an anchor group, since the skeleton of the flexible substrate used as the upper layer can be different, the function of the obtained film as a peeling layer can be improved.

In the present invention, the anchor group may be present on either one of the polymer chain terminals of the polyamic acid, but it is preferable that the anchor group is present on both of the polymer chain terminals.
In addition, between the polyamic acid obtained from the diamine component and the tetracarboxylic dianhydride component and the anchor group, an alkyl group having a carbon number of 1 to 10 or an aryl group having a carbon number which does not significantly reduce heat resistance A spacer group such as a group may be present, and an ether bond, a thioether bond, an ester bond, etc. may be present in these spacer groups.

Specific examples of the amine having an anchor group include 4-aminophenoxytrimethylsilane, 4-aminophenoxydimethylvinylsilane, 4-aminophenoxymethyldivinylsilane, 4-aminophenoxytrivinylsilane, 4-aminophenoxydimethylallylsilane, and 4-amino. Phenoxymethyldiallylsilane, 4-aminophenoxytriallylsilane, 4-aminophenoxydimethylphenylsilane, 4-aminophenoxymethyldiphenylsilane, 4-aminophenoxytriphenylsilane, 4-aminophenoxytrimethoxysilane, 4-aminophenoxydimethoxyvinylsilane , 4-aminophenoxymethoxydivinylsilane, 4-aminophenoxytrivinylsilane, 4-aminophenoxydimethoxyallylsilane, 4-aminophenoxymethoxydiallylsilane, 4-aminophenoxydimethoxyphenylsilane, 4-aminophenoxymethoxydiphenylsilane, 4-amino Phenoxytriethoxysilane, 4-aminophenoxydiethoxyvinylsilane, 4-aminophenoxyethoxydivinylsilane, 4-aminophenoxytrivinylsilane, 4-aminophenoxydiethoxyallylsilane, 4-aminophenoxyethoxydiallylsilane, 4-aminophenoxydiethoxy Phenylsilane, 4-aminophenoxyethoxydiphenylsilane, 3-aminophenoxytrimethylsilane, 3-aminophenoxydimethylvinylsilane, 3-aminophenoxymethyldivinylsilane, 2-aminophenoxytrivinylsilane, 2-aminophenoxytrimethylsilane, 2-amino Phenoxydimethylvinylsilane, 2-aminophenoxymethyldivinylsilane, 2-aminophenoxytrivinylsilane, 3-aminopropyltriethylsilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-ethoxycarbonyl-3-amino Propyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethyl Examples include, but are not limited to, lentriamine, 2-aminophenol, 3-aminophenol, 4-aminophenol, and the like.

Specific examples of the acid anhydride having an anchor group include trimellitic anhydride, vinyl maleic anhydride, 4-vinylnaphthalene-1,2-dicarboxylic acid anhydride, maleic anhydride, and 2,3-dimethylmaleic acid. Examples include, but are not limited to, anhydrides, 4-hydroxyphthalic anhydride, 3-hydroxyphthalic anhydride, and the like.

Further, as the diamine component and the acid dianhydride component used in producing the polyamic acid, from the viewpoint of improving the function as a peeling layer of the obtained film, a diamine component containing an aromatic diamine and an aromatic tetracarboxylic acid dianhydride. A polyamic acid obtained by reacting an acid dianhydride component containing an anhydride is preferable.

The aromatic diamine is not particularly limited as long as it has two amino groups in the molecule and has an aromatic ring, but an aromatic diamine containing 1 to 5 benzene nuclei is preferable.
Specific examples thereof include 1,4-diaminobenzene (p-phenylenediamine), 1,3-diaminobenzene (m-phenylenediamine), 1,2-diaminobenzene (o-phenylenediamine), and 2,4-diamino. Toluene, 2,5-diaminotoluene, 2,6-diaminotoluene, 4,6-dimethyl-m-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, 2,6-dimethyl-p-phenylenediamine, 2 , 4,6-Trimethyl-1,3-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, m-xylylenediamine, p-xylylenediamine, 5-trifluoromethylbenzene-1 ,3-diamine, 5-trifluoromethylbenzene-1,2-diamine, 3,5-bis(trifluoromethyl)benzene-1,2-diamine and the like having one benzene nucleus; 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'-biphenyldiamine, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 4,4'-diaminobenzanilide, 3,3' -Dichlorobenzidine, 3,3'-dimethylbenzidine, 2,2'-dimethylbenzidine, 3,3'-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'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4'-diamino Diphenyl sulfoxide, 3,3'-bis(trifluoromethyl)biphenyl-4,4'-diamine, 3,3',5,5'-tetrafluorobiphenyl-4,4'- Diamine having two benzene nuclei such as diamine, 4,4′-diaminooctafluorobiphenyl, 2-(3-aminophenyl)-5-aminobenzimidazole, and 2-(4-aminophenyl)-5-aminobenzoxazole. 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-aminophenylsulfide)benzene, 1,3-bis( 3-aminophenylsulfone)benzene, 1,3-bis(4-aminophenylsulfone)benzene, 1,4-bis(4-aminophenylsulfone)benzene, 1,3-bis[2-(4-aminophenyl)benzene Isopropyl]benzene, 1,4-bis[2-(3-aminophenyl)isopropyl]benzene, 1,4-bis[2-(4-aminophenyl)isopropyl]benzene, 4,4″-diamino-p- Examples thereof include, but are not limited to, a diamine having three benzene nuclei such as terphenyl and 4,4″-diamino-m-terphenyl. These may be used alone or in combination of two or more. In the present invention, it is preferable to use the aromatic diamine that does not contain an ether bond or an ester bond.

Among them, from the viewpoint of improving the function of the obtained film as a peeling layer, an aromatic ring having no substituent such as a methyl group on the aromatic ring and a heterocycle condensed therewith and an aromatic ring composed only of a heteroaromatic ring. Group diamines are preferred. Specifically, p-phenylenediamine, m-phenylenediamine, 2-(3-aminophenyl)-5-aminobenzimidazole, 2-(4-aminophenyl)-5-aminobenzoxazole, 4,4'. '-Diamino-p-terphenyl and the like are preferable.

The aromatic tetracarboxylic dianhydride is not particularly limited as long as it has two dicarboxylic acid anhydride moieties in the molecule and has an aromatic ring, but it is an aromatic containing 1 to 5 benzene nuclei. Group tetracarboxylic dianhydrides are 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 acid dianhydride, naphthalene-1,2,6,7-tetracarboxylic acid dianhydride, naphthalene-1,2,7,8-tetracarboxylic acid dianhydride, naphthalene- 2,3,5,6-tetracarboxylic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, biphenyl -2,2',3,3'-tetracarboxylic dianhydride, biphenyl-2,3,3',4'-tetracarboxylic dianhydride, biphenyl-3,3',4,4'-tetra Carboxylic dianhydride, Anthracene-1,2,3,4-tetracarboxylic dianhydride, Anthracene-1,2,5,6-tetracarboxylic dianhydride, Anthracene-1,2,6,7- Tetracarboxylic acid dianhydride, Anthracene-1,2,7,8-tetracarboxylic acid dianhydride, Anthracene-2,3,6,7-tetracarboxylic acid 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 acid dianhydride, Phenanthrene-1,2,9,10-tetracarboxylic acid dianhydride, Phenanthrene-2,3,5,6-tetracarboxylic acid dianhydride, Phenanthrene-2,3,6 ,7-Tetracarboxylic acid dianhydride, Phenanthrene-2,3,9,10-tetracarboxylic acid dianhydride, Phenanthrene-3,4,5,6-tetracarboxylic acid dianhydride, Phenanthrene-3,4 Examples thereof include, but are not limited to, 9,10-tetracarboxylic dianhydride. These may be used alone or in combination of two or more.

Of these, aromatic carboxylic acid dianhydrides having one or two benzene nuclei are preferable from the viewpoint of improving the function of the obtained film as a release layer. Specifically, the aromatic tetracarboxylic dianhydride represented by any of the formulas (C1) to (C12) is preferable, and the aromatic tetracarboxylic dianhydride represented by any of the formulas (C1) to (C7) and (C9) to (C11) is preferable. The aromatic tetracarboxylic dianhydride shown is more preferred.

Further, from the viewpoint of improving flexibility, heat resistance, etc. of the obtained release layer, the diamine component used in the present invention may contain a diamine other than the aromatic diamine, and the tetracarboxylic dianhydride component used in the present invention is , And may contain a tetracarboxylic dianhydride other than the aromatic tetracarboxylic dianhydride.

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, even more preferably 90 mol% or more, even more preferably 95 mol% or more, most preferably It is 100 mol %. The amount of the aromatic tetracarboxylic acid dianhydride in the tetracarboxylic acid component is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and further preferably 95 mol%. As mentioned above, it is most preferably 100 mol %. By adopting such an amount used, it is possible to reproducibly obtain a film having excellent adhesion to the substrate, appropriate adhesion to the resin substrate, and appropriate releasability.

After reacting the diamine component and the tetracarboxylic acid dianhydride component described above, by reacting the obtained polyamic acid with an amine having an anchor group or an acid anhydride having an anchor group, the present invention A polyamic acid having an anchor group at the polymer chain end contained in the release layer forming composition can be obtained.

The organic solvent used in such a reaction is not particularly limited as long as it does not adversely affect the reaction, but specific examples thereof include m-cresol, 2-pyrrolidone, N-methyl-2-pyrrolidone and N-. Ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropylamide, 3-ethoxy-N,N-dimethylpropylamide Amide, 3-propoxy-N,N-dimethylpropylamide, 3-isopropoxy-N,N-dimethylpropylamide, 3-butoxy-N,N-dimethylpropylamide, 3-sec-butoxy-N,N-dimethyl Examples include propylamide, 3-tert-butoxy-N,N-dimethylpropylamide, γ-butyrolactone and the like. The organic solvents may be used alone or in combination of two or more.

The charging ratio of the diamine component and the tetracarboxylic dianhydride component cannot be unconditionally specified because the target molecular weight and molecular weight distribution, the type of diamine and the type of tetracarboxylic dianhydride are appropriately determined in consideration. The diamine component is about 0.7 to 1.3, preferably about 0.8 to 1.2, and more preferably about 0.9 to 1.1 with respect to the tetracarboxylic dianhydride component 1.

The amount of the amine having the anchor group and the acid anhydride having the anchor group is about 0.01 to 0.6, preferably 0.05 to 0, of the amine having the anchor group with respect to the tetracarboxylic dianhydride component. About 0.4, more preferably about 0.1 to 0.2, or about 0.01 to 0.52, preferably about 0.05 to 0.32, of an acid anhydride having an anchor group with respect to the diamine component. It is preferably about 0.1 to 0.2.

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

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

The weight average molecular weight of the polyamic acid thus obtained is usually about 5,000 to 500,000, but preferably 10,000 to 200, from the viewpoint of improving the function of the obtained film as a release layer. It is about 000, more preferably about 30,000 to 150,000. In addition, in this invention, a weight average molecular weight is a polystyrene conversion value by gel permeation chromatography (GPC) measurement.

The release layer-forming composition of the present invention contains an organic solvent. Examples of this organic solvent include the same as the specific examples of the reaction solvent for the above reaction. Among them, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-, which dissolves polyamic acid well and is easy to prepare a composition with high uniformity, 2-Imidazolidinone, N-ethyl-2-pyrrolidone and γ-butyrolactone are preferable, and N-methyl-2-pyrrolidone is more preferable.

Even a solvent that does not dissolve the polyamic acid by itself can be used for preparing the composition as long as the polyamic acid does not precipitate. In particular, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy. -2-Propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxy) Solvents having a low surface tension such as propoxy)propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, and isoamyl lactate can be mixed appropriately. This is known to improve the uniformity of the coating film when applied to a substrate, and can be suitably used in the present invention.

The method for preparing the release layer-forming composition of the present invention is arbitrary. A preferable example of the preparation method is a method of filtering the reaction solution containing the target polyamic acid obtained by the method described above. At this time, the filtrate may be diluted or concentrated if necessary for the purpose of adjusting the concentration. By adopting such a method, not only the adhesion of the release layer produced from the composition obtained, it is possible not only to reduce the mixing of impurities that may cause deterioration of the peelability, but also to efficiently release layer forming composition Can be obtained. The solvent used for dilution is not particularly limited, and specific examples thereof include those similar to the specific examples of the reaction solvent for the above reaction. The solvent used for dilution may be used alone or in combination of two or more.

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, etc., but is usually about 1 to 30% by mass, preferably It is about 1 to 20 mass %. With such a concentration, a release layer having a thickness of about 0.05 to 5 μm can be obtained with good reproducibility. The concentration of the polyamic acid is adjusted by adjusting the amount of the diamine and the tetracarboxylic acid dianhydride, which are the raw materials of the polyamic acid, adjusting the amount when the isolated polyamic acid is dissolved in the solvent. You can

The viscosity of the release layer-forming composition of the present invention is appropriately set in consideration of the thickness of the release layer to be produced, etc., but it is particularly preferable to obtain a film having a thickness of about 0.05 to 5 μm with good reproducibility. For the purpose, it is usually about 10 to 10,000 mPa·s at 25° C., preferably about 20 to 5,000 mPa·s.

Here, the viscosity can be measured at a temperature of the composition of 25° C. by using a commercially available liquid viscometer for measuring viscosity, for example, referring to the procedure described in JIS K7117-2. .. Preferably, a conical plate type (cone plate type) rotational viscometer is used as the viscometer, and 1°34′×R24 is used as the standard cone rotor in the same type viscometer, and the temperature of the composition is 25 It can be measured under the condition of °C. Examples of such a rotational viscometer include TVE-25L manufactured by Toki Sangyo Co., Ltd.

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

By applying the release layer-forming composition of the present invention described above to a substrate and heating the resulting coating film to thermally imidize the polyamic acid, excellent adhesion to the substrate and appropriateness with a resin substrate are obtained. It is possible to obtain a peeling layer made of a polyimide film, which has excellent adhesion and proper peeling property.

When such a release layer of the present invention is formed on a substrate, the release layer may be formed on a partial surface of the substrate or may be formed on the entire surface. The mode of forming the release layer on a part of the surface of the substrate is such that the release layer is formed only in a predetermined range on the surface of the substrate, or the release layer is formed on the entire surface of the substrate in a pattern such as a dot pattern or a line and space pattern. There is a mode of forming the like. In addition, in the present invention, the substrate means a substrate whose surface is coated with the composition for forming a release layer of the present invention and which is used for manufacturing a flexible electronic device or the like.

Examples of the substrate (substrate) include glass, plastic (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy, melamine, triacetyl cellulose, ABS, AS, norbornene-based resin, etc.), metal (silicon wafer, etc.), Wood, paper, slate, and the like can be mentioned, but glass is particularly preferable because the release layer of the present invention has sufficient adhesion thereto. The surface of the substrate may be made of a single material or may be made of two or more materials. As a mode in which the substrate surface is composed of two or more materials, a certain range of the substrate surface is composed of a certain material, and the remaining surface is composed of another material. , A line-and-space pattern or other pattern-like material is present in other materials.

The method for applying the release layer-forming composition of the present invention to a substrate is not particularly limited, and examples thereof include cast coating method, spin coating method, blade coating method, dip coating method, roll coating method, bar coating method. Method, die coating method, ink jet method, printing method (letterpress, intaglio, planographic printing, screen printing, etc.).

The heating temperature for imidization is usually appropriately determined within the range of 50 to 550°C, but is preferably more than 150°C to 510°C. By setting the heating temperature in this way, it becomes possible to sufficiently proceed the imidization reaction while preventing the resulting film from becoming brittle. The heating time varies depending on the heating temperature and cannot be specified unconditionally, but is usually 5 minutes to 5 hours. The imidization ratio may be in the range of 50 to 100%.

As a preferred example of the heating mode in the present invention, after heating at 50 to 150° C. for 5 minutes to 2 hours, the heating temperature is raised stepwise as it is, and finally at over 150° C. to 510° C. for 30 minutes to 4 hours. The method of heating is mentioned. In particular, as a more preferable example of the heating mode, after heating at 50 to 100° C. for 5 minutes to 2 hours, 100° C. to 375° C. for 5 minutes to 2 hours, and finally 375° C. to 450° C. for 30 minutes to A method of heating for 4 hours can be mentioned. Furthermore, as another more preferable example of the heating mode, after heating at 50 to 150° C. for 5 minutes to 2 hours, the temperature is more than 150° C. to 350° C. for 5 minutes to 2 hours, and then more than 350° C. to 450° C. for 30 minutes. ˜4 hours, and finally a method of heating at over 450° C. to 510° C. for 30 minutes to 4 hours can be mentioned.

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

The thickness of the release layer is usually about 0.01 to 50 μm, and preferably about 0.05 to 20 μm from the viewpoint of productivity. The desired thickness is achieved by adjusting the thickness of the coating film before heating.

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

Hereinafter, an example of a method for manufacturing a flexible electronic device using the release layer of the present invention will be described.
The release layer-forming composition of the present invention is used to form a release layer on a glass substrate by the method described above. A resin solution for forming a resin substrate is applied onto this release layer, and this coating film is heated to form a resin substrate fixed to a glass substrate through the release layer of the present invention. At this time, the substrate is formed so as to cover the release layer entirely and have a larger area than the area of the release layer. The resin substrate may be a resin substrate made of polyimide, which is a typical resin substrate for flexible electronic devices, and the resin solution for forming the resin substrate may be a polyimide solution or a polyamic acid solution. The resin substrate may be formed by a conventional method.

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

It should be noted that JP-A-2013-147599 reports that the laser lift-off method (LLO method), which has been used in the manufacture of high-brightness LEDs, three-dimensional semiconductor packages and the like, is applied to the manufacture of flexible displays. .. The LLO method is characterized in that a light beam having a specific wavelength, for example, a light beam having a wavelength of 308 nm is irradiated from the glass substrate side from the surface opposite to the surface on which circuits and the like are formed. The irradiated light passes through the glass substrate, and only the polymer (polyimide) near the glass substrate absorbs this light and evaporates (sublimates). As a result, it is possible to selectively peel the resin substrate from the glass substrate without affecting the circuit or the like provided on the resin substrate, which determines the performance of the display.

Since the release layer-forming composition of the present invention has a characteristic of sufficiently absorbing a light beam having a specific wavelength (for example, 308 nm) that enables the application of the LLO method, it can be used as a sacrificial layer for the LLO method. Therefore, when a desired circuit is formed on a resin substrate fixed to a glass substrate through a release layer formed by using the composition of the present invention, and then an LLO method is performed to irradiate a ray of 308 nm. Only the peeling layer absorbs this light ray and evaporates (sublimates). As a result, the peeling layer is sacrificed (acts as a sacrificial layer), and the resin substrate can be selectively peeled from the glass substrate.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
[1] Abbreviation of compound p-PDA:p-phenylenediamine DATP:4,4″-diamino-p-terphenyl TFMB:2,2′-bis(trifluoromethyl)benzidine 6FAP:2,2-bis( 3-Amino-4-hydroxyphenyl)hexafluoropropane PMDA: pyromellitic dianhydride BPDA: 3,3′,4,4′-biphenyltetracarboxylic dianhydride LS-3280:4-aminophenoxydimethylvinylsilane LS -3150: 3-aminopropyltriethoxysilane TMA: trimellitic anhydride IHPA: isophthalaldehyde NMP: N-methyl-2-pyrrolidone

[2] Measurement of weight average molecular weight and molecular weight distribution The weight average molecular weight (hereinafter abbreviated as Mw) of the polymer and the molecular weight distribution are measured by a GPC apparatus manufactured by JASCO Corporation (column: OHpak SB803-HQ manufactured by Shodex, and OHpak SB804-). HQ; eluent: dimethylformamide/LiBr.H ₂ O (29.6 mM)/H ₃ PO ₄ (29.6 mM)/THF (0.1 wt %); flow rate: 1.0 mL/min; column temperature: 40° C. Mw: standard polystyrene conversion value).

[3] Synthesis of Polymer <Synthesis Example F1 Synthesis of Polyamic Acid (F1)>
20.261 g (187 mmol) of p-PDA and 12.206 g (47 mmol) of DATP were dissolved in 617.4 g of NMP. The obtained solution was cooled to 15° C., PMDA (50.112 g, 230 mmol) was added thereto, and the temperature was raised to 50° C. under a nitrogen atmosphere to react for 48 hours. The Mw of the obtained polymer was 82,100, and the molecular weight distribution was 2.7.

<Synthesis Example F2 Synthesis of polyamic acid (F2)>
3.218 g (30 mmol) of p-PDA was dissolved in 88.2 g of NMP. 8.581 g (29 mmol) of BPDA was added to the obtained solution, and the mixture was reacted at 23° C. for 24 hours under a nitrogen atmosphere. The obtained polymer Mw was 107,300, and the molecular weight distribution was 4.6.

<Synthesis example L1 Synthesis of polyamic acid (L1)>
2.66 g (24.6 mmol) of p-PDA and 0.18 g (0.6 mmol) of TFMB were dissolved in 90 g of NMP. PMDA (6.09 g, 27.9 mmol) was added to the resulting solution and reacted at 23° C. for 24 hours under a nitrogen atmosphere, and then LS-3280 (1.08 g, 5.6 mmol) was added and the reaction was continued for another 24 hours. Then, a silyl group was introduced at both ends of the polyamic acid. The obtained polymer Mw was 62,700 and the molecular weight distribution was 2.7.

<Synthesis example L2 Synthesis of polyamic acid (L2)>
2.96 g (27.3 mmol) of p-PDA and 0.19 g (0.6 mmol) of TFMB were dissolved in 90 g of NMP. To the obtained solution, 6.34 g (29.1 mmol) of PMDA was added and reacted at 23° C. for 24 hours under a nitrogen atmosphere, and then 0.52 g (2.3 mmol) of LS-3150 was added and further reacted for 24 hours. Then, a silyl group was introduced at both ends of the polyamic acid. The obtained polymer Mw was 51,100 and the molecular weight distribution was 2.8.

<Synthesis Example L3 Synthesis of polyamic acid (L3)>
p-PDA 3.06 (28.3 mmol) was dissolved in 90 g of NMP. PMDA (6.42 g, 29.4 mmol) was added to the resulting solution, and the mixture was reacted under a nitrogen atmosphere at 23° C. for 24 hours, and then LS-3150 (0.52 g, 2.4 mmol) was added and reacted for another 24 hours. Then, a silyl group was introduced at both ends of the polyamic acid. The obtained polymer Mw was 47,800 and the molecular weight distribution was 2.8.

<Synthesis Example L4 Synthesis of polyamic acid (L4)>
0.78 g (7.2 mmol) of p-PDA was dissolved in 17.6 g of NMP. PMDA (1.51 g, 6.9 mmol) was added to the resulting solution, and the mixture was reacted at 23° C. for 24 hours under a nitrogen atmosphere. Then, TMA (0.11 g, 0.3 mmol) was added and the mixture was further reacted for 24 hours. Carboxylic acid groups were introduced at both ends of the polyamic acid. The obtained polymer Mw was 48,000 and the molecular weight distribution was 3.1.

<Comparative Synthesis Example 1 Synthesis of Polybenzoxazole Precursor (B1)>
3.18 g (0.059 mol) of 6FAP was dissolved in 70 g of NMP. 7.92 g (0.060 mol) of IHPA was added to the obtained solution, and the mixture was reacted at 23° C. for 24 hours under a nitrogen atmosphere. The obtained polymer Mw was 107,300, and the molecular weight distribution was 4.6.

[4] Preparation of Resin Substrate Forming Composition The reaction liquids obtained in Synthesis Examples F1 and F2 were used as they were as resin substrate forming compositions W and X, respectively.

[5] Preparation of release layer-forming composition [Example 1-1]
To 10 g of the reaction solution obtained in Synthesis Example L1, 6 g of NMP and 4 g of butyrocellosolve were added and stirred at room temperature for 24 hours to obtain a composition for forming a release layer.

[Examples 1-2 to 1-3]
A release layer-forming composition was obtained in the same manner as in Example 1-1, except that the reaction liquids obtained in Synthesis Examples L2 to L3 were used instead of the reaction liquid obtained in Synthesis Example L1. It was

[Example 1-4]
To 10 g of the reaction solution obtained in Synthesis Example L4, 9.4 g of NMP and 4.6 g of butyrocellosolve were added and stirred at room temperature for 24 hours to obtain a composition for forming a release layer.

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

[6] Formation of Release Layer and Evaluation thereof [Example 2-1]
Using a spin coater (conditions: rotation speed 3,000 rpm for about 30 seconds), the release layer-forming composition obtained in Example 1-1 was placed on a 100 mm×100 mm glass substrate (hereinafter the same) as a glass substrate. Was applied to.
Then, the obtained coating film is heated at 80° C. for 10 minutes using a hot plate, and then at an oven for 30 minutes at 300° C., and the heating temperature is increased to 400° C. (10° C./minute). ) And further heated at 400° 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-coated substrate was not taken out of the oven, but was heated in the oven.

[Examples 2-2 to 2-4]
Example 2-1 except that the release layer-forming composition obtained in each of Examples 1-2 to 1-4 was used in place of the release layer-forming composition obtained in each of Example 1-1. A release layer was formed in the same manner as in.

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

[7] Evaluation of releasability [Examples 3-1 to 3-4, Comparative example 3-1]
By the following method, a substrate was prepared so as to be a combination of the release layer and the resin substrate shown in Table 1, and the releasability was evaluated.
The peelability of the peeling layer and the glass substrate obtained in Examples 2-1 to 2-4 and the peelability of the peeling layer (resin thin film) and the resin substrate were confirmed. A resin substrate made of polyimide was used as the resin substrate.
First, a cross-cut of the release layer on the glass substrate with the release layer obtained in Examples 2-1 to 2-4 (vertical and horizontal 1 mm intervals, the same applies hereinafter), and a resin substrate/a resin substrate on the glass substrate with the release layer. -100 cross-cuts were performed by cross-cutting the release layer. That is, by this cross-cut, 100 squares of 1 mm square were formed.
Then, an adhesive tape was attached to the 100 muscat portion, the tape was peeled off, and the degree of peeling was evaluated based on the following criteria (5B-0B, B, A, AA) (Examples 3-1 to 3-3). 4). Further, according to the above method, the same test was conducted using the glass substrate with a resin thin film obtained in Comparative Example 2-1 (Comparative Example 3-1). The results are shown in Table 1.

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

The resin substrates of Examples 3-1 to 3-4 and Comparative example 3-1 were formed by the following method.
Using a bar coater (gap: 250 μm), either the resin substrate forming composition W or X 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, and then at 140° C. for 30 minutes using an oven, and the heating temperature was raised to 210° C. (10° C./minute). , The same shall apply hereinafter), and the heating temperature is raised to 300° C. for 30 minutes at 210° C., the heating temperature is raised to 400° C. for 30 minutes at 300° C., and the heating temperature is raised to 400° C. for 60 minutes. A polyimide substrate having a thickness of about 20 μm was formed. During the temperature rising, the film-coated substrate was not taken out from the oven, but was heated in the oven.

As shown in Table 1, it can be seen that the release layer of the example has excellent adhesiveness to the glass substrate and excellent releasability from the resin substrate. On the other hand, it was found that the resin thin film of Comparative Example adhered to the resin layer and did not peel at all when the adhesiveness between the glass substrate and the release layer was low or when the adhesiveness was high.

Claims (7)

A polyamic acid obtained by introducing an anchor group into either or both of the polymer chain terminals, and an organic solvent,
Wherein the anchor group is, the release layer forming composition is a mosquito carboxylic acid group. The polyamic acid is a polyamic acid obtained by reacting a diamine component containing an aromatic diamine with an acid dianhydride component containing an aromatic tetracarboxylic acid dianhydride. A composition for forming a release layer. The composition for forming a release layer according to claim 2, wherein the aromatic diamine is an aromatic diamine containing 1 to 5 benzene nuclei. The composition for forming 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 release layer formed using the release layer-forming composition according to any one of claims 1 to 4. A method of manufacturing a flexible electronic device including a resin substrate, comprising using the release layer according to claim 5. The manufacturing method according to claim 6, wherein the resin substrate is a substrate made of polyimide.