KR102576363B1 - Composition for forming a peeling layer and a peeling layer - Google Patents

Abstract

A composition for forming a release layer is provided, comprising a polyamic acid obtained by introducing an anchor group into one or both ends of the polymer chain, and an organic solvent.

Description

Composition for forming a peeling layer and a peeling layer

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

In recent years, electronic devices have been required to have performance such as bending functions and reduction in thickness and weight. In this regard, it is necessary to use a lightweight flexible plastic substrate instead of the conventional heavy, fragile, and unbendable glass substrate. Additionally, new generation displays require the development of active full-color TFT display panels using lightweight flexible plastic substrates.

Therefore, various methods for manufacturing electronic devices using resin films as substrates have begun to be examined, and for new generation displays, manufacturing processes using existing TFT equipment are being examined. Patent Documents 1, 2, and 3 describe forming an amorphous silicon thin film layer on a glass substrate, forming a plastic substrate on the thin film layer, and then irradiating a laser from the glass surface side to produce hydrogen gas generated by crystallization of amorphous silicon. Disclosed is a method for 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 technology disclosed in Patent Documents 1 to 3. .

However, in the methods disclosed in Patent Documents 1 to 4, especially the method disclosed in Patent Document 4, it is essential to use a substrate with high light transparency, and to provide sufficient energy to pass through the substrate and release hydrogen contained in amorphous silicon. For this purpose, irradiation of laser light with relatively high energy is required, which poses a problem of damaging the layer to be peeled. In addition, there is a problem that it is difficult to increase the productivity of device manufacturing because laser processing requires a long time and it is difficult to peel the layer to be peeled having a large area.

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

The present invention was made in view of the above circumstances, and its purpose is to provide a composition for forming a peeling layer and the peeling layer for forming a peeling layer that can be peeled off without damaging the resin substrate of a flexible electronic device.

The present inventors have conducted extensive studies to solve the above problems, and as a result, a composition containing a polyamic acid obtained by introducing an anchor group to one or both ends of the polymer chain and an organic solvent has excellent adhesion to the substrate and flexibility. The present invention was completed by discovering that a release layer with appropriate adhesion to a resin substrate used in an electronic device and appropriate peelability can be formed.

That is, the present invention

1. A composition for forming a release layer containing a polyamic acid obtained by introducing an anchor group into one or both ends of the polymer chain and an organic solvent,

2. The composition for forming a peeling layer of 1, wherein the anchor group is a silyl group or a carboxylic acid group,

3. Composition for forming a peeling layer of 1 or 2, wherein the polyamic acid is a polyamic acid obtained by reacting a diamine component containing aromatic diamine and an acid dianhydride component containing aromatic tetracarboxylic dianhydride,

4. The composition for forming a peeling layer of 3, wherein the aromatic diamine is an aromatic diamine containing 1 to 5 benzene nuclei,

5. Composition for forming a peeling layer of 3 or 4, wherein the aromatic tetracarboxylic dianhydride is an aromatic tetracarboxylic dianhydride containing 1 to 5 benzene nuclei,

6. A peeling layer formed using the composition for forming a peeling layer of any one of 1 to 5,

7. A method of manufacturing a flexible electronic device having a resin substrate, characterized by using the peeling layer of 6,

8. Manufacturing method of 7, wherein the resin substrate is a substrate made of polyimide.

provides

By using the composition for forming a peeling layer of the present invention, a peeling layer having excellent adhesion to the base, moderate adhesion to the resin substrate, and appropriate peeling 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 a flexible electronic device, the resin substrate formed on the base or the circuit additionally installed thereon, etc. is not damaged, and the resin is formed along with the circuit, etc. It becomes possible to separate the substrate from the gas. Therefore, the composition for forming a release layer of the present invention can contribute to simplifying the manufacturing process of a flexible electronic device equipped with a resin substrate and improving its yield.

Hereinafter, the present invention will be described in more detail.

The composition for forming a release layer of the present invention contains a polyamic acid obtained by introducing an anchor group into one or both ends of the polymer chain, and an organic solvent. Here, the peeling layer in the present invention is a layer provided directly on a glass substrate for a predetermined purpose, and a typical example thereof is a substrate and a resin substrate of a flexible electronic device made of a resin such as polyimide in the manufacturing process of a flexible electronic device. It is installed to fix the resin substrate during a predetermined process, and to enable the resin substrate to be easily peeled from the base after forming an electronic circuit, etc. on the resin substrate. A peeling layer can be mentioned.

The polyamic acid used in the present invention is not particularly limited as long as it has an anchor group at the end of the polymer chain. After reacting the diamine component and the tetracarboxylic dianhydride component, the polyamic acid obtained is mixed with an amine having an anchor group or an amine having an anchor group. It can be obtained by reacting an acid anhydride. 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.

Such anchor groups include carboxylic acid groups, silyl groups (for example, alkylsilyl groups, alkoxysilyl groups, vinylsilyl groups, and allylsilyl groups, etc.), vinyl groups, maleimide groups, and phenolic hydroxyl groups, among others. A carboxylic acid group and a silyl group (in particular, 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, the structure is different from the flexible substrate used in the upper layer, so the function of the obtained film as a peeling layer can be improved.

In the present invention, an anchor group may be present on either end of the polymer chain of the polyamic acid, but it is preferable that an anchor group be present on both ends of the polymer chain.

In addition, between the polyamic acid obtained from the diamine component and the tetracarboxylic dianhydride component and the anchor group, a spacer group such as an alkyl group or aryl group having a carbon number of about 1 to 10 carbon atoms that does not significantly reduce the peelability or heat resistance may be present, An ether bond, a thioether bond, an ester bond, etc. may exist within these spacer groups.

Specific examples of amines having an anchor group include 4-aminophenoxytrimethylsilane, 4-aminophenoxydimethylvinylsilane, 4-aminophenoxymethyldivinylsilane, 4-aminophenoxytrivinylsilane, and 4-aminophenoxytrivinylsilane. -Aminophenoxydimethylallylsilane, 4-aminophenoxymethyldiallylsilane, 4-aminophenoxytriallylsilane, 4-aminophenoxydimethylphenylsilane, 4-aminophenoxymethyldiphenylsilane Phosphorus, 4-aminophenoxytriphenylsilane, 4-aminophenoxytrimethoxysilane, 4-aminophenoxydimethoxyvinylsilane, 4-aminophenoxymethoxydivinylsilane, 4-amino Phenoxytrivinylsilane, 4-aminophenoxydimethoxyallylsilane, 4-aminophenoxymethoxydiallylsilane, 4-aminophenoxydimethoxyphenylsilane, 4-aminophenoxymethoxy Diphenylsilane, 4-aminophenoxytriethoxysilane, 4-aminophenoxydiethoxyvinylsilane, 4-aminophenoxyethoxydivinylsilane, 4-aminophenoxytrivinylsilane, 4 -Aminophenoxydiethoxyallylsilane, 4-aminophenoxyethoxydiallylsilane, 4-aminophenoxydiethoxyphenylsilane, 4-aminophenoxyethoxydiphenylsilane, 3-aminophenoxy Trimethylsilane, 3-aminophenoxydimethylvinylsilane, 3-aminophenoxymethyldivinylsilane, 2-aminophenoxytrivinylsilane, 2-aminophenoxytrimethylsilane, 2-aminophenoxymethylsilane 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-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane , N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 2-aminophenol, 3-aminophenol, 4-aminophenol, etc., but is not limited to these. .

Specific examples of acid anhydrides having an anchor group include trimellitic anhydride, vinylmaleic anhydride, 4-vinylnaphthalene-1,2-dicarboxylic acid anhydride, maleic anhydride, 2,3-dimethylmaleic anhydride, and 4-hydroxyphthalic acid. Anhydride, 3-hydroxyphthalic anhydride, etc. may be mentioned, but it is not limited to these.

In addition, the diamine component and acid dianhydride component used when producing the polyamic acid include a diamine component containing aromatic diamine and an acid dianhydride component containing aromatic tetracarboxylic dianhydride from the viewpoint of improving the function as a peeling layer of the resulting film. A polyamic acid obtained by reacting is preferable.

The aromatic diamine is not particularly limited as long as it has two amino groups in the molecule and an aromatic ring, but an aromatic diamine containing 1 to 5 benzene nuclei is preferable.

Specific examples 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 -Diamines with 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'-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 Payne, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenyl sulfoxide, 3,4'-di Aminodiphenyl sulfoxide, 4,4'-diaminodiphenyl sulfoxide, 3,3'-bis(trifluoromethyl)biphenyl-4,4'-diamine, 3,3',5,5' -Tetrafluorobiphenyl-4,4'-diamine, 4,4'-diaminoctafluorobiphenyl, 2-(3-aminophenyl)-5-aminobenzimidazole, 2-(4-amino Diamines having two benzene nuclei, such as phenyl)-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-aminophenyl sulfide) benzene, 1,3-bis (4-aminophenyl sulfide) 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 〕Diamines with three benzene nuclei, such as benzene, 4,4''-diamino-p-terphenyl, and 4,4''-diamino-m-terphenyl, are included, but are not limited to these. . These may be used individually or in combination of two or more types. Additionally, 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 release layer, aromatic diamines composed only of aromatic rings and heteroaromatic rings that do not have a substituent such as a methyl group on the aromatic ring and the heterocycle condensed thereto are preferable. Specifically, p-phenylenediamine, m-phenylenediamine, 2-(3-aminophenyl)-5-aminobenzimidazole, 2-(4-aminophenyl)-5-aminobenzoxazole, 4 ,4''-diamino-p-terphenyl, etc. are preferred.

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

Specific examples thereof include pyromellitic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, naphthalene-1,2,3,4-tetracarboxylic dianhydride, and naphthalene-1,2,5,6-tetra. 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 acid dianhydride, phenanthrene-2,3,6,7-tetracarboxylic dianhydride, phenanthrene-2,3,9,10-tetracarboxylic dianhydride, phenanthrene-3,4,5,6-tetracarboxylic dianhydride Water, phenanthrene-3,4,9,10-tetracarboxylic dianhydride, etc. may be mentioned, but it is not limited to these. These may be used individually or in combination of two or more types.

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

Additionally, from the viewpoint of improving the flexibility, heat resistance, etc. of the resulting release layer, the diamine component used in the present invention may contain diamines other than aromatic diamine, and the tetracarboxylic dianhydride component used in the present invention is an aromatic tetracarboxylic acid. Tetracarboxylic dianhydride other than dianhydride may be included.

In the present invention, the amount of aromatic diamine in the diamine component is preferably 70 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, further preferably 95 mol% or more, most preferably. In other words, it is 100 mol%. Moreover, the amount of 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, further preferably 95 mol% or more, and most preferably is 100 mol%. By employing such a usage amount, a film having excellent adhesion to the base, moderate adhesion to the resin substrate, and appropriate peelability can be obtained with good reproducibility.

After reacting the above-described diamine component with the tetracarboxylic dianhydride component, the resulting polyamic acid is reacted with an amine having an anchor group or an acid anhydride having an anchor group, thereby forming the polymer chain terminal contained in the composition for forming a peeling layer of the present invention. A polyamic acid having an anchor group can be obtained.

The organic solvent used in this reaction is not particularly limited as long as it does not adversely affect the reaction, and specific examples 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, 3-propoxy-N,N-dimethylpropylamide, 3-isopropoxy-N,N-dimethylpropylamide, 3-butoxy-N,N- Dimethylpropylamide, 3-sec-butoxy-N,N-dimethylpropylamide, 3-tert-butoxy-N,N-dimethylpropylamide, γ-butyrolactone, etc. are mentioned. In addition, the organic solvent may be used individually or in combination of two or more types.

The introduction ratio of the diamine component and the tetracarboxylic dianhydride component cannot be uniformly determined because it is determined appropriately in consideration of the target molecular weight, molecular weight distribution, type of diamine, type of tetracarboxylic dianhydride, etc., but the tetracarboxylic dianhydride component 1 With respect to the diamine component, it is about 0.7 to 1.3, preferably about 0.8 to 1.2, and more preferably about 0.9 to 1.1.

In addition, the amount of the amine having an anchor group and the acid anhydride having an anchor group is about 0.01 to 0.6, preferably about 0.05 to 0.4, more preferably about 0.1 to 0.2 of the amine having an anchor group relative to the tetracarboxylic dianhydride component, or the diamine component. Relative to the acid anhydride having an anchor group, it is about 0.01 to 0.52, preferably about 0.05 to 0.32, and more preferably about 0.1 to 0.2.

The reaction temperature can be appropriately set in the range from the melting point to the boiling point of the solvent used, and is usually around 0 to 100°C. In order to prevent imidization in the resulting polyamic acid solution and maintain a high content of polyamic acid units, it is preferable to use is 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 uniformly specified because it depends on the reaction temperature or the reactivity of the raw materials, but is usually about 1 to 100 hours.

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

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

Moreover, even if it is a solvent that does not dissolve polyamic acid alone, it can be used to prepare a composition as long as it is within the range in which 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-view. Toxy-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. Solvents having low surface tension can be appropriately mixed. It is known that this improves film uniformity when applying to a substrate, and can be suitably used in the present invention as well.

The method for preparing the composition for forming a release layer of the present invention is optional. A preferable example of the preparation method includes filtering the reaction solution containing the target polyamic acid obtained by the method described above. At this time, if necessary for purposes such as concentration adjustment, the filtrate may be diluted or concentrated. By adopting such a method, not only can the inclusion of impurities that may cause deterioration of the adhesion, peelability, etc. of the peeling layer produced from the resulting composition be reduced, but also a composition for forming a peeling layer can be obtained efficiently. . 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 individually or in combination of two or more types.

The concentration of 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., and is usually about 1 to 30% by mass, preferably 1 to 20% by mass. It's about %. By using this concentration, a peeling layer with a thickness of about 0.05 to 5 μm can be obtained with good reproducibility. The concentration of polyamic acid can be adjusted by adjusting the amount of diamine and tetracarboxylic dianhydride used, which are raw materials of polyamic acid, or by adjusting the amount when dissolving the isolated polyamic acid in a solvent.

The viscosity of the composition for forming a release layer of the present invention is set appropriately in consideration of the thickness of the release layer to be produced, etc., especially when the goal is to obtain a film with a thickness of about 0.05 to 5 μm with good reproducibility, 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, with reference to the procedure described in JIS K7117-2, under conditions of a temperature of the composition of 25°C. Preferably, a cone plate type (cone plate type) rotational viscometer is used as a viscometer, and preferably a viscometer of the same type is used as a standard cone rotor, and the composition is measured under conditions of a temperature of 25°C. You can. Examples of such rotational viscometer include TVE-25L manufactured by Toki Sangyo Co., Ltd.

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

By applying the composition for forming a release layer of the present invention described above to a base and heating the resulting coating film to thermally imidize the polyamic acid, a polyimide film having excellent adhesion to the base, moderate adhesion to the resin substrate, and moderate peelability is obtained. A peeling layer consisting of can be obtained.

When forming such a peeling layer of the present invention on a base, the peeling layer may be formed on a part of the surface of the base or may be formed on the entire surface. Examples of forming a peeling layer on a portion of the surface of the aircraft include forming a peeling layer only in a certain area of the surface of the aircraft, forming a peeling layer in a pattern such as a dot pattern or line and space pattern on the entire surface of the aircraft, etc. There is. In addition, in the present invention, the base means that the surface of the base is coated with the composition for forming a peeling layer of the present invention, and is used in the manufacture of flexible electronic devices, etc.

Substrates (substrates) include, for example, glass, plastic (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy, melamine, triacetylcellulose, ABS, AS, norbornene-based resin, etc.), metal (silicon wafer, etc.) ), wood, paper, slate, etc., but glass is particularly preferred because the release layer of the present invention has sufficient adhesion thereto. Additionally, the base surface may be composed of a single material or may be composed of two or more materials. A mode in which the surface of the aircraft is composed of two or more materials includes a mode in which a certain range of the surface of the aircraft is composed of a certain material and the remaining surface is composed of another material, and a pattern such as a dot pattern or line and space pattern on the entire surface of the aircraft. There is a shape, such as the sun, where a certain material exists among other materials.

The method for applying the composition for forming a release layer of the present invention to a base is not particularly limited, and examples include cast coat method, spin coat method, blade coat method, dip coat method, roll coat method, bar coat method, and die coat method. Examples include printing methods, inkjet methods, and printing methods (iron plate, intaglio, flatbed, screen printing, etc.).

The heating temperature for imidization is usually determined appropriately within the range of 50 to 550°C, but is preferably over 150°C to 510°C. By setting the heating temperature in this way, it becomes possible to sufficiently proceed the imidization reaction while preventing brittleness of the resulting film. The heating time cannot be uniformly specified because it varies depending on the heating temperature, but is usually 5 minutes to 5 hours. Additionally, the imidization rate may be in the range of 50 to 100%.

A preferred example of the heating mode in the present invention is a method of heating at 50 to 150°C for 5 minutes to 2 hours, then gradually increasing the heating temperature, and finally heating at over 150°C to 510°C for 30 minutes to 4 hours. I can hear it. In particular, a more preferable example of the heating mode is heating at 50 to 100°C for 5 minutes to 2 hours, then at over 100°C to 375°C for 5 minutes to 2 hours, and finally at over 375°C to 450°C for 30 minutes to 4 hours. There are methods. Another more preferred example of the heating mode is heating at 50 to 150°C for 5 minutes to 2 hours, then at over 150°C to 350°C for 5 minutes to 2 hours, then at over 350°C to 450°C for 30 minutes to 4 hours, and finally at over 350°C to 450°C for 5 minutes to 2 hours. One method is heating at a temperature exceeding 450°C to 510°C for 30 minutes to 4 hours.

Apparatuses used for heating include, for example, hot plates and ovens. The heating atmosphere may be air or an inert gas, and may be at normal pressure or at reduced pressure.

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

The release layer described above has excellent adhesion to the substrate, especially the glass substrate, moderate adhesion to the resin substrate, and moderate peelability. Therefore, the release layer of the present invention can be suitably used in the manufacturing process of a flexible electronic device to peel the resin substrate from the base together with the circuit formed on the resin substrate without damaging the resin substrate of the device. there is.

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 peeling layer of the present invention, a peeling layer is formed on the glass substrate by the method described above. A resin solution for forming a resin substrate is applied onto this release layer, and the coating film is heated to form a resin substrate fixed to the glass substrate through the release layer of the present invention. At this time, the entire peeling layer is covered to form a substrate with a larger area compared to the area of the peeling layer. Examples of the resin substrate include a resin substrate made of polyimide, which is a typical resin substrate for flexible electronic devices, and examples of the resin solution for forming the resin substrate include a polyimide solution and a polyamic acid solution. The method of forming the resin substrate may follow a commercial method.

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

Additionally, in Japanese Patent Laid-Open No. 2013-147599, it is reported that the laser lift-off method (LLO method), which has been used so far in the manufacture of high-brightness LEDs and three-dimensional semiconductor packages, is applied to the manufacture of flexible displays. The LLO method is characterized by irradiating light of a specific wavelength, for example, light of 308 nm, from the side of the glass substrate, from the side opposite to the side on which the circuit, etc., is formed. The irradiated light passes through the glass gas, and only the polymer (polyimide) near the glass gas absorbs this light and evaporates (sublimates). As a result, it becomes possible to selectively peel the resin substrate from the glass body without affecting the circuits installed on the resin substrate that determine the performance of the display.

Since the composition for forming a peeling layer of the present invention has the characteristic of sufficiently absorbing light of a specific wavelength (for example, 308 nm) that enables the application of the LLO method, it can be used as a sacrificial layer in the LLO method. Therefore, when a desired circuit is formed on a resin substrate fixed to a glass substrate through a peeling layer formed using the composition of the present invention, and then the LLO method is performed and 308 nm light is irradiated, only this peeling layer is exposed to this light. It absorbs and evaporates (sublimates). This makes it possible to selectively peel the resin substrate from the glass base by sacrificing the peeling layer (acting as a sacrificial layer).

Example

Hereinafter, the present invention will be described in more detail by way of 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 acid 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) and molecular weight distribution of the polymer were measured using a GPC device manufactured by Nippon Bunko Co., Ltd. (column: OHpak SB803-HQ and OHpak SB804-HQ manufactured by Shodex; eluent: dimethylformamide/LiBr· This was carried out using H ₂ O (29.6mM)/H ₃ PO ₄ (29.6mM)/THF (0.1 wt%); flow rate: 1.0 mL/min; column temperature: 40°C; Mw: standard polystyrene conversion value).

[3] Synthesis of polymers

<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, 50.112 g (230 mmol) of PMDA was added thereto, the temperature was raised to 50°C under a nitrogen atmosphere, and reaction was carried out 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 reaction was performed at 23°C under a nitrogen atmosphere for 24 hours. The Mw of the obtained polymer 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. 6.09 g (27.9 mmol) of PMDA was added to the obtained solution, and reacted at 23°C for 24 hours under a nitrogen atmosphere. Then, 1.08 g (5.6 mmol) of LS-3280 was added and reacted for an additional 24 hours to introduce silyl groups at both ends of the polyamic acid. did. The Mw of the obtained polymer 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. 6.34 g (29.1 mmol) of PMDA was added to the obtained solution, and reacted at 23°C for 24 hours under a nitrogen atmosphere. Then, 0.52 g (2.3 mmol) of LS-3150 was added and reacted for an additional 24 hours to introduce silyl groups at both ends of the polyamic acid. did. The Mw of the obtained polymer 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. 6.42 g (29.4 mmol) of PMDA was added to the obtained solution, and reacted at 23°C for 24 hours under a nitrogen atmosphere. Then, 0.52 g (2.4 mmol) of LS-3150 was added and reacted for an additional 24 hours to introduce silyl groups at both ends of the polyamic acid. did. The Mw of the obtained polymer 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. 1.51 g (6.9 mmol) of PMDA was added to the obtained solution and reacted at 23°C for 24 hours under a nitrogen atmosphere, and then 0.11 g (0.3 mmol) of TMA was added and the reaction was continued for an additional 24 hours to introduce carboxylic acid groups at both ends of the polyamic acid. The Mw of the obtained polymer 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 mole) of 6FAP was dissolved in 70 g of NMP. 7.92 g (0.060 mol) of IHPA was added to the obtained solution, and reaction was performed at 23°C in a nitrogen atmosphere for 24 hours. The Mw of the obtained polymer was 107,300 and the molecular weight distribution was 4.6.

[4] Preparation of composition for forming resin substrate

The reaction solutions obtained in Synthesis Examples F1 and F2 were used as compositions W and X for forming a resin substrate, respectively.

[5] Preparation of composition for forming peeling layer

[Example 1-1]

6 g of NMP and 4 g of butyrocellosolve were added to 10 g of the reaction solution obtained in Synthesis Example L1, and stirred at room temperature for 24 hours to obtain a composition for forming a peeling layer.

[Example 1-2 to 1-3]

A composition for forming a peeling layer was obtained in the same manner as in Example 1-1, except that the reaction solutions obtained in Synthesis Examples L2 and L3 were used instead of the reaction solutions obtained in Synthesis Example L1.

[Example 1-4]

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

[Comparative Example 1-1]

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

[6] Formation of peeling layer and its evaluation

[Example 2-1]

Using a spin coater (conditions: rotation speed of 3,000 rpm for about 30 seconds), the composition for forming a peeling layer obtained in Example 1-1 was applied onto a 100 mm x 100 mm glass substrate (the same hereinafter) as the glass base.

Then, the obtained coating film was heated at 80°C for 10 minutes using a hot plate, and then heated at 300°C for 30 minutes using an oven, the heating temperature was raised to 400°C (10°C/min), and further heated to 400°C. was heated for 30 minutes to form a peeling layer with a thickness of approximately 0.1 μm on the glass substrate. Additionally, while the temperature was rising, the film-attached substrate was not removed from the oven but was heated within the oven.

[Example 2-2 to 2-4]

A release layer was formed in the same manner as in Example 2-1, except that the composition for forming a release layer obtained in Examples 1-2 to 1-4 was used instead of the composition for forming a release layer obtained in Example 1-1. .

[Comparative Example 2-1]

A resin thin film was formed 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.

[7] Evaluation of peelability

[Examples 3-1 to 3-4, Comparative Example 3-1]

A substrate was manufactured using the following method to combine the release layer and the resin substrate shown in Table 1, and the peelability was evaluated.

The peelability of the peeling layer obtained in Examples 2-1 to 2-4 and the glass substrate, and the peelability of the peeling layer (resin thin film) and the resin substrate were confirmed. Additionally, as the resin substrate, a resin substrate made of polyimide was used.

First, crosscuts of the release layer on the glass substrate with a release layer obtained in Examples 2-1 to 2-4 (width and height 1 mm intervals, same hereinafter), and crosscuts of the resin substrate and release layer on the glass substrate with the resin substrate and release layer. By performing a skirt, 100 grid cuts were performed. In other words, 100 square grids of 1 mm were formed by this crosscut.

Then, adhesive tape was attached to this 100 grid cut portion, the tape was removed, and the degree of peeling was evaluated based on the following standards (5B to 0B, B, A, AA) (Examples 3-1 to 3- 4). In addition, a similar test was conducted using the glass substrate with a resin thin film obtained in Comparative Example 2-1 according to the above method (Comparative Example 3-1). The results are shown in Table 1.

5B: 0% peeling (no peeling)

4B: less than 5% delamination

3B: less than 5-15% delamination

2B: less than 15-35% delamination

1B: less than 35-65% delamination

0B: less than 65% to 80% peeling

B: Peeling less than 80% to 95%

A: Peeling less than 95% to 100%

AA: 100% peeled (all peeled)

In addition, 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 composition W or X for forming a resin substrate was applied onto the peeling 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 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), and then heated to 210°C. At ℃ for 30 minutes, the heating temperature is raised to 300℃, at 300℃ for 30 minutes, the heating temperature is raised to 400℃, and then heated at 400℃ for 60 minutes to form a polyimide substrate with a thickness of about 20 μm on the peeling layer. did. While the temperature was rising, the film-attached substrate was not removed from the oven but was heated within the oven.

As shown in Table 1, it can be seen that the release layer of the example has excellent adhesion to the glass substrate and also has excellent peelability to the resin substrate. On the other hand, it was found that the resin thin film of the comparative example adhered closely to the resin layer and did not peel off at all when the adhesiveness between the glass substrate and the peeling layer was low or when the adhesiveness was high.

Types of peeling layers Types of Resin Substrates Peelability of the peeling layer and the glass base Peelability of peeling layer and resin substrate Example 3-1 Example 2-1 W 5B AA Example 3-2 Example 2-2 X 5B AA Example 3-3 Example 2-3 W 5B AA Example 3-4 Example 2-4 W 5B AA Comparative Example 3-1 Comparative Example 2-1 X 5B 5B

Claims (8)

A composition for forming a release layer comprising a polyamic acid obtained by introducing an anchor group into one or both ends of the polymer chain, and an organic solvent, wherein the anchor group is a carboxylic acid group. The composition for forming a release layer according to claim 1, wherein the polyamic acid is a polyamic acid obtained by reacting a diamine component containing aromatic diamine and an acid dianhydride component containing aromatic tetracarboxylic dianhydride. 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 peeling layer according to claim 3, wherein the aromatic tetracarboxylic dianhydride is an aromatic tetracarboxylic dianhydride containing 1 to 5 benzene nuclei. A peeling layer formed using the composition for forming a peeling layer 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. delete