JPWO2018124006A1 - Composition for forming substrate protective layer - Google Patents

Abstract

After the resin substrate is formed on the substrate, the resin substrate is peeled to produce a resin substrate. Provided is a composition for forming a substrate protective layer that functions as a protective layer for the resin substrate, comprising a polyamic acid and an organic solvent.

Description

  The present invention relates to a composition for forming a substrate protective layer.

In recent years, electronic devices have been required to have a function of being able to bend in addition to the characteristics of thinning and lightening. For this reason, it is required to use a lightweight flexible plastic substrate in place of the conventional glass substrate that is fragile and cannot be bent.
In particular, in the new generation display, development of an active matrix type full color TFT display panel using a lightweight flexible plastic substrate (hereinafter referred to as a resin substrate) is required. This new generation display technology is expected to be diverted to various fields such as flexible displays, flexible smartphones, and mirror displays.

  Therefore, various methods for manufacturing electronic devices using a resin film as a substrate have begun to be studied, and a process for diverting existing TFT display panel manufacturing equipment to a new generation display is being promoted.

  For example, 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 laser irradiation is performed from the glass substrate side to crystallize amorphous silicon. A method of peeling a plastic substrate from a glass substrate by hydrogen gas generated along with the crystallization is disclosed.

  In Patent Document 4, a layer to be peeled (described as “transfer target layer” in Patent Document 4) is attached to a plastic film using the technique disclosed in Patent Documents 1 to 3, and a liquid crystal display device is formed. A method of completion is disclosed.

However, in the methods disclosed in Patent Documents 1 to 4, particularly the method disclosed in Patent Document 4, it is essential to use a highly light-transmitting substrate in order to transmit laser light, and the substrate passes through. In addition, it is necessary to irradiate laser light with a relatively large energy sufficient to release hydrogen contained in amorphous silicon, and the layer to be peeled may be damaged by the laser light irradiation. There is a problem.
In addition, when the layer to be peeled has a large area, it takes a long time for the laser treatment, and it is difficult to increase the productivity of device fabrication.

  As means for solving such problems, in Patent Document 5, a current glass substrate is used as a substrate (hereinafter referred to as a glass substrate), and a release layer is formed on the glass substrate using a polymer such as a cyclic olefin copolymer. After forming a heat-resistant resin film (resin substrate) such as a polyimide film on the release layer, ITO transparent electrodes, TFTs, etc. are formed and sealed on the film by a vacuum process, and finally the glass substrate is peeled off. The manufacturing process to remove is employ | adopted.

By the way, as a TFT, a low-temperature polysilicon TFT having a mobility twice as fast as that of an amorphous silicon TFT is currently used. This low-temperature polysilicon TFT needs to be subjected to dehydrogenation annealing at 400 ° C. or higher after amorphous silicon deposition, and irradiated with a pulse laser to crystallize silicon (hereinafter referred to as TFT process). The temperature of the annealing step is equal to or higher than the glass transition temperature (hereinafter Tg) of the existing polymer.
However, it is known that the existing polymer has improved adhesion when heated to a temperature of Tg or higher (see, for example, Patent Document 6), and the adhesion between the release layer, the substrate and the resin substrate after the heat treatment. In some cases, it becomes difficult to peel the resin substrate from the substrate.

  Moreover, although the heat resistant polymer applicable to such a process is restricted to some high heat resistant high molecular compounds, such as a polyimide, it cannot be dissolved in a common solvent. For this reason, when the said polyimide was used for the peeling layer, it was difficult to remove the peeling layer remaining on the glass substrate after peeling the resin substrate and to reuse the glass substrate.

Japanese Patent Laid-Open No. 10-125929 Japanese Patent Laid-Open No. 10-125931 International Publication No. 2005/050754 JP-A-10-125930 JP 2010-1111853 A JP 2008-188792 A

  The present invention has been made in view of the above circumstances, and can facilitate the reuse of the substrate, can be peeled from the substrate together with the resin substrate of the flexible electronic device, and can damage the resin substrate. An object of the present invention is to provide a composition for forming a substrate protective layer that does not significantly change the thickness of the substrate.

  As a result of intensive studies to solve the above problems, the present inventor has formed a resin substrate on the substrate, and then peeled off the resin substrate to produce a resin substrate. Use a composition containing a polyamic acid and an organic solvent as a composition for forming a protective layer of a substrate that is interposed between the substrate and has an easy releasability from the substrate and functions as a protective layer for the resin substrate after peeling. Thus, it was found that a substrate protective layer having appropriate adhesion to the substrate and appropriate peelability and excellent adhesion to the resin substrate used in the flexible electronic device can be formed, and the present invention has been completed.

（式中、Ｘは、下記式（２）で表される芳香族基を表し、Ｙは、フッ素原子を有する２価の芳香族基を表し、ｎは、自然数を表す。）

３． 上記Ｙが、下記式（３）で表される芳香族基である２の基板保護層形成用組成物、

４． 上記Ｙが、下記式（４）で表される芳香族基である２又は３の基板保護層形成用組成物、

５． 上記有機溶媒が、下記式（Ｓ１）〜（Ｓ７）で表される構造を有するものから選ばれる少なくとも１種である１〜４のいずれかの基板保護層形成用組成物、

（式中、Ｒ¹〜Ｒ⁸は、互いに独立して、水素原子、又は炭素数１〜１０のアルキル基を表し、Ｒ⁹及びＲ¹⁰は、互いに独立して、水素原子、炭素数１〜１０のアルキル基、又は炭素数１〜１０のアシル基を表し、ｂ及びｎは自然数を表す）
６． 上記樹脂基板上に、さらに電子デバイスを作製し、上記樹脂基板とともに電子デバイスを上記基体から剥離する際に、上記基体からの易剥離性を有するとともに剥離後の樹脂基板の保護層として機能する１の基板保護層形成用組成物、
７． １〜６のいずれかの基板保護層形成用組成物から得られる基板保護層、
８． 基体上に６の基板保護層形成用組成物を塗布し、最高温度５００℃以上で焼成して上記基体からの易剥離性を有する基板保護層を形成する工程と、
該基板保護層の上に樹脂基板形成用組成物を塗布し、最高温度５００℃以上で焼成して樹脂基板を形成する工程と、
この樹脂基板上に電子デバイスを作製する工程と、
上記基体から上記基板保護層および上記樹脂基板とともに上記電子デバイスを剥離する工程と、を含むことを特徴とするフレキシブル電子デバイスの製造方法、
９． 上記樹脂基板が、ポリイミド樹脂基板である８のフレキシブル電子デバイスの製造方法、
１０． 基体上に１〜５のいずれかの基板保護層形成用組成物を塗布し、最高温度５００℃以上で焼成して基板保護層を形成した後、該基板保護層の上に樹脂基板形成用組成物を塗布し、最高温度５００℃以上で焼成して、樹脂基板を形成した後、上記樹脂基板を上記基板保護層とともに基体から剥離することを特徴とする保護層付き樹脂基板の製造方法、
１１． 上記樹脂基板が、ポリイミド樹脂基板である１０の製造方法
を提供する。That is, the present invention
1. After the resin substrate is formed on the substrate, when the resin substrate is peeled from the substrate together with the resin substrate, the resin substrate is interposed between the substrate and the resin substrate, and has easy peelability from the substrate. A composition for forming a protective layer of a substrate that functions as a protective layer for the resin substrate after peeling, comprising a polyamic acid and an organic solvent,
2. 1 composition for forming a substrate protective layer comprising a polyamic acid represented by the following formula (1) and an organic solvent;

(In the formula, X represents an aromatic group represented by the following formula (2), Y represents a divalent aromatic group having a fluorine atom, and n represents a natural number.)

3. 2 is a composition for forming a substrate protective layer, wherein Y is an aromatic group represented by the following formula (3):

4). 2 or 3 composition for forming a substrate protective layer, wherein Y is an aromatic group represented by the following formula (4):

5. The substrate protective layer forming composition according to any one of 1 to 4, wherein the organic solvent is at least one selected from those having a structure represented by the following formulas (S1) to (S7):

(In the formula, R ^{1 to} R ⁸ each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ⁹ and R ¹⁰ each independently represent a hydrogen atom, 10 represents an alkyl group or an acyl group having 1 to 10 carbon atoms, and b and n represent natural numbers)
6). When an electronic device is further produced on the resin substrate and the electronic device is peeled from the substrate together with the resin substrate, it has an easy releasability from the substrate and functions as a protective layer for the resin substrate after peeling. A substrate protective layer forming composition,
7). A substrate protective layer obtained from the substrate protective layer forming composition according to any one of 1 to 6;
8). A step of applying a composition for forming a substrate protective layer 6 on a substrate and firing at a maximum temperature of 500 ° C. or higher to form a substrate protective layer having easy peelability from the substrate;
Applying a composition for forming a resin substrate on the substrate protective layer, and baking at a maximum temperature of 500 ° C. or higher to form a resin substrate;
Producing an electronic device on the resin substrate;
Peeling the electronic device together with the substrate protective layer and the resin substrate from the substrate, and a method for producing a flexible electronic device,
9. The method for producing a flexible electronic device according to 8, wherein the resin substrate is a polyimide resin substrate,
10. A substrate protective layer-forming composition of any one of 1 to 5 is applied onto a substrate and baked at a maximum temperature of 500 ° C. or higher to form a substrate protective layer, and then a resin substrate-forming composition is formed on the substrate protective layer A method for producing a resin substrate with a protective layer, comprising: applying a product, firing at a maximum temperature of 500 ° C. or higher to form a resin substrate, and then peeling the resin substrate from the substrate together with the substrate protective layer;
11. The manufacturing method of 10 whose said resin substrate is a polyimide resin substrate is provided.

  By using the composition for forming a substrate protective layer of the present invention, it is possible to obtain a substrate protective layer having appropriate adhesion to the substrate, appropriate peelability and excellent adhesion to the resin substrate with good reproducibility. Therefore, by using the composition for forming a substrate protective layer of the present invention, in the manufacturing process of the flexible electronic device, there is no damage to the resin substrate formed on the substrate or the circuit provided on the substrate. The resin substrate and the substrate protective layer can be separated from the substrate together with the circuit and the like. Therefore, the composition for forming a substrate protective layer of the present invention can promote reuse of the substrate, and can contribute to simplification of the production 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 composition for forming a substrate protective layer of the present invention contains a polyamic acid and an organic solvent. Here, the substrate protective 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 comprising a substrate and a resin such as polyimide in a flexible electronic device manufacturing process. A layer provided for fixing the resin substrate in a predetermined process between the device and the resin substrate of the device is exemplified. The substrate protective layer is different from the conventional release layer in that after the electronic circuit or the like is formed on the resin substrate, the substrate protective layer is peeled from the substrate together with the resin substrate.

  As the diamine component and acid dianhydride component used when producing the polyamic acid, the resin substrate has the property of peeling from the substrate together with the resin substrate after the above-described production process, that is, the resin substrate. Although it will not specifically limit if it provides the polyimide film which has adhesiveness with an aromatic diamine from a viewpoint of fully exhibiting the property of easy peelability from the said base | substrate and the adhesiveness with respect to a resin substrate. A polyamic acid obtained by reacting a diamine component and an acid dianhydride component including an aromatic tetracarboxylic dianhydride is preferable, and in particular, a biphenyltetracarboxylic acid diacid represented by the following formula (1): A polyamic acid obtained using an anhydride and an aromatic diamine having a fluorine atom is preferred.

In the formula (1), X represents an aromatic group derived from biphenyltetracarboxylic acid represented by the following formula (2), and Y represents a divalent fluorine atom-containing aromatic derived from an aromatic diamine having a fluorine atom. Represents a group.
n represents a natural number, but an integer of 2 or more is preferable.

  Examples of the biphenyltetracarboxylic dianhydride that gives a divalent group derived from the biphenyltetracarboxylic acid represented by the above formula (2) include those represented by the following formulas (C1) to (C3). In the present invention, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride represented by the formula (C1) is particularly suitable. In addition, (C1) to (C3) may be used alone or in combination of two or more.

Moreover, in this invention, in addition to the said biphenyl tetracarboxylic dianhydride, other tetracarboxylic dianhydrides can also be used.
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, 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 Anhydride, and the like. These alone, it may be used in combination of two or more.

  In the polyamic acid used in the present invention, the amount of biphenyltetracarboxylic dianhydride in the tetracarboxylic acid component is 70 mol% considering that the above-described easy peelability from the substrate and the adhesion to the resin substrate are compatible. The above is preferable, 80 mol% or more is more preferable, 90 mol% or more is more preferable, 95 mol% or more is further preferable, and 100 mol% is most preferable.

  On the other hand, specific examples of the aromatic diamine having a fluorine atom that gives Y are 5-trifluoromethylbenzene-1,3-diamine, 5-trifluoromethylbenzene-1,2-diamine, and 3,5-bis. (Trifluoromethyl) benzene-1,2-diamine, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl (2,2′-bis (trifluoromethyl) benzidine), 3,3 '-Bis (trifluoromethyl) -4,4'-diaminobiphenyl (3,3'-bis (trifluoromethyl) benzidine), 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′-bis (trifluorome B) Biphenyl-4,4′-diamine, 3,3 ′, 5,5′-tetrafluorobiphenyl-4,4′-diamine, 4,4′-diaminooctafluorobiphenyl, and the like. It may be used or two or more types may be used in combination.

Among these, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl (2,2 ′) is taken into consideration that the above-described easy peelability from the substrate and the adhesion to the resin substrate are compatible. -Bis (trifluoromethyl) benzidine), 3,3'-bis (trifluoromethyl) -4,4'-diaminobiphenyl (3,3'-bis (trifluoromethyl) benzidine) is preferred, and 2,2 ' -Bis (trifluoromethyl) -4,4'-diaminobiphenyl (2,2'-bis (trifluoromethyl) benzidine) is even more preferred.
Therefore, as suitable Y in Formula (1), the bivalent aromatic group represented by Formula (3) and (4) is mentioned.

In the present invention, in addition to the aromatic diamine having a fluorine atom, other diamines can also be used.
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 1,4,6-trimethyl-1,3-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, m-xylylenediamine, p-xylylenediamine, etc., one diamine nucleus; 1,2-naphthalenediamine, 1,3-naphthalenediamine, 1,4-naphthalenediamine, 1,5-naphthalene Amine, 1,6-naphthalenediamine, 1,7-naphthalenediamine, 1,8-naphthalenediamine, 2,3-naphthalenediamine, 2,6-naphthalenediamine, 4,4'-biphenyldiamine, 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, , 3′-diaminodiphenyl sulfoxide, 3,4′-diaminodiphenyl sulfoxide, 4,4′-diaminodiphenyl sulfoxide, 2- (3-aminophenyl) -5-aminobenzimidazole, 2- (4-aminophenyl)- Diamines having two benzene nuclei such as 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-aminophenyl) Sulfone) 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] benzene, 4,4 ″ -diamino-p-terphenyl, 4 , 4 ″ -diamino-m-terphenyl, etc., benzene nuclei include three diamines, and these may be used alone or in combination of two or more. May be used.

  In the polyamic acid used in the present invention, the amount of the aromatic diamine having a fluorine atom in the diamine component is 70 mol% or more considering that the above-described easy peelability from the substrate and the adhesion to the resin substrate are compatible. Preferably, 80 mol% or more is more preferable, 90 mol% or more is more preferable, 95 mol% or more is further preferable, and 100 mol% is most preferable.

The polyamic acid contained in the composition for forming a substrate protective layer of the present invention can be obtained by reacting the diamine component and the tetracarboxylic dianhydride component described above in an organic solvent.
The organic solvent used in this reaction is not particularly limited as long as it does not adversely affect the reaction. Specific examples thereof include m-cresol, 2-pyrrolidone, N-methyl-2-pyrrolidone, 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, Examples include 3-tert-butoxy-N, N-dimethylpropylamide and γ-butyrolactone. In addition, an organic solvent can be used individually by 1 type or in combination of 2 or more types.

  The charge ratio (molar ratio) between the diamine component and the tetracarboxylic dianhydride component is determined appropriately in consideration of the target molecular weight, molecular weight distribution, diamine type, tetracarboxylic dianhydride type, etc. 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. It is.

  What is necessary is just to set reaction temperature suitably in the range from melting | fusing point to the boiling point of the solvent to be used, and it is about 0-100 degreeC normally, However, Imidation in the solution of the obtained polyamic acid is prevented and high content of a polyamic acid unit is contained. In order to maintain the amount, the temperature is preferably about 0 to 70 ° C, more preferably about 0 to 60 ° C, and still more preferably about 0 to 50 ° C.

  Although the reaction time depends on the reaction temperature and the reactivity of the raw material, it cannot be defined unconditionally, but 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 resulting film as a substrate protective layer. About 30,000, more preferably about 30,000 to 150,000. In addition, in this invention, a weight average molecular weight is a polystyrene conversion value by a gel permeation chromatography (GPC) measurement.

In the polyamic acid used in the present invention, one or both of the polymer chain ends may be further reacted with an amine having an anchor group or an acid anhydride having an anchor group.
Examples of such anchor groups include carboxylic acid groups, silyl groups (for example, alkylsilyl groups, alkoxysilyl groups, vinylsilyl groups, and allylsilyl groups), vinyl groups, maleimide groups, phenolic hydroxyl groups, and the like. Carboxylic acid groups and silyl groups (particularly silyl groups in which one or more groups selected from alkoxy groups, vinyl groups and allyl groups are bonded to silicon atoms) are preferred.
Moreover, between the polyamic acid obtained from a diamine component and a tetracarboxylic dianhydride component, and an anchor group, the C1-C10 alkyl group and aryl which do not reduce remarkably and heat resistance remarkably Spacer groups such as groups may be present.

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

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

  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 of the amine having an anchor group with respect to the tetracarboxylic dianhydride component 1 in a molar ratio, preferably About 0.05 to 0.4, more preferably about 0.1 to 0.2, or about 0.01 to 0.52 of an acid anhydride having an anchor group with respect to the diamine component 1, preferably 0.05 to It is about 0.32, more preferably about 0.1-0.2.

  The composition for forming a substrate protective layer of the present invention contains an organic solvent in addition to the polyamic acid described above. Although it does not specifically limit as this organic solvent, The solvent chosen from the following is preferable.

（式中、Ｒ¹〜Ｒ⁸は、互いに独立して、水素原子、又は炭素数１〜１０のアルキル基を表し、Ｒ⁹及びＲ¹⁰は、互いに独立して、水素原子、炭素数１〜１０のアルキル基、又は炭素数１〜１０のアシル基を表し、ｂ及びｍは自然数を表す）

(In the formula, R ^{1 to} R ⁸ each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ⁹ and R ¹⁰ each independently represent a hydrogen atom, 10 represents an alkyl group or an acyl group having 1 to 10 carbon atoms, and b and m represent natural numbers)

Although b and m represent a natural number, Preferably it is 1-3, More preferably, it is 1 or 2.
Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group, n- A hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, etc. are mentioned. Among these, a C1-C3 alkyl group is preferable and a C1-C2 alkyl group is more preferable.
Examples of the acyl group having 1 to 10 carbon atoms include alkanoyl groups having 1 to 8 carbon atoms (for example, formyl group, acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, and pivaloyl group), and 3 to 6 carbon atoms. Cycloalkylcarbonyl group (for example, cyclopropylcarbonyl group, cyclopentylcarbonyl group, cyclohexylcarbonyl group, etc.), benzoyl group and the like, and acetyl group is preferable.

  Among them, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-, which dissolve polyamic acid well and is easy to prepare a highly uniform composition. 2-Imidazolidinone, N-ethyl-2-pyrrolidone and γ-butyrolactone are preferred, and N-methyl-2-pyrrolidone is more preferred.

  In addition, even if it is a solvent which does not dissolve polyamic acid alone, it can be used for the preparation of the composition as long as 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 Propoxy) A solvent having a low surface tension such as propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate and the like can be mixed appropriately. Thereby, it is known that the coating film uniformity is improved at the time of application to the substrate, and can be suitably used in the present invention.

  The preparation method of the composition for substrate protective layer formation of this invention is arbitrary. A preferable example of the preparation method includes 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 can the contamination of the substrate protective layer manufactured from the resulting composition be deteriorated in adhesion, peelability, etc., but also efficiently reduce the substrate protective layer formation. A 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 can be used individually by 1 type or in combination of 2 or more types.

  The concentration of the polyamic acid in the composition for forming a substrate protective layer of the present invention is appropriately set in consideration of the thickness of the substrate protective layer to be produced, the viscosity of the composition, etc., but usually about 1 to 30% by mass, Preferably it is about 1-20 mass%. By setting such a concentration, a substrate protective layer having a thickness of about 0.05 to 5 μm can be obtained with good reproducibility. The concentration of the polyamic acid should be adjusted by adjusting the amount of diamine and tetracarboxylic dianhydride used as the raw material for the polyamic acid, adjusting the amount when the isolated polyamic acid is dissolved in the solvent, etc. Can do.

  The viscosity of the composition for forming a substrate protective layer of the present invention is appropriately set in consideration of the thickness of the substrate protective layer to be produced, etc., but a film having a thickness of about 0.05 to 5 μm is particularly reproducible. When it is intended to obtain, it is usually about 10 to 10,000 mPa · s, preferably about 20 to 5,000 mPa · s at 25 ° C.

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

  In addition, the composition for substrate protective layer formation of this invention may contain the crosslinking agent etc. in order to improve film | membrane intensity | strength other than a polyamic acid and an organic solvent, for example.

After applying the composition for forming a release layer described above on a substrate, the polyamic acid is thermally imidized by a baking method including a step of baking at a maximum temperature of 500 ° C. or higher, thereby easily peeling from the substrate and A resin substrate protective layer made of a polyimide film having excellent adhesion to the resin substrate can be obtained.
In the present invention, the maximum temperature during the baking is not particularly limited as long as it is in the range of 500 ° C. or more and not more than the heat resistant temperature of polyimide. The upper limit is usually about 550 ° C, preferably about 520 ° C, more preferably about 510 ° C. By making heating temperature into the said range, it becomes possible to fully advance an imidation reaction, preventing weakening of the film | membrane obtained.
The heating time varies depending on the heating temperature and cannot be defined unconditionally, but is usually 5 minutes to 5 hours. Moreover, the imidation ratio should just be the range of 50 to 100%.

Moreover, as long as the maximum temperature becomes the said range, the temperature at the time of the said baking may include the process baked at the temperature below it.
As a preferable example of the heating mode in the present invention, there is a method in which after heating at 50 to 150 ° C., the heating temperature is gradually raised as it is and finally heated at 500 ° C. or higher. In particular, as a more preferable example of the heating mode, a method of heating at 50 to 100 ° C., heating at a temperature exceeding 100 ° C. to less than 500 ° C., and heating at 500 ° C. or more can be cited. Furthermore, as another more preferable example of the heating mode, after heating at 50 to 100 ° C., heating at 200 to 300 ° C., heating at over 300 ° C. to less than 500 ° C., and finally heating at 500 to 510 ° C. A method is mentioned.

  Moreover, as a preferable example of the heating mode in consideration of the firing time, after heating at 50 to 150 ° C. for 1 minute to 2 hours, the heating temperature is increased stepwise and finally at 500 ° C. or higher for 30 minutes. A method of heating for ~ 4 hours can be mentioned. In particular, as a more preferable example of the heating mode, heating is performed at 50 to 100 ° C. for 1 minute to 2 hours, heating is performed at a temperature exceeding 100 ° C. to less than 500 ° C. for 5 minutes to 2 hours, and heating is performed at 500 ° C. or more for 30 minutes to 4 hours. The technique to do is mentioned. Furthermore, as another more preferable example of the heating mode, after heating at 50 to 100 ° C. for 1 minute to 2 hours, 200 to 300 ° C. for 5 minutes to 2 hours, more than 300 ° C. to less than 500 ° C. for 5 minutes to 2 And a method of heating at 500 to 510 ° C. for 1 minute to 2 hours.

  When such a substrate protective layer of the present invention is formed on a substrate, the substrate protective layer may be formed on a partial surface of the substrate or may be formed on the entire surface. As a mode of forming a substrate protective layer on a part of the surface of the substrate, a mode in which the substrate protective layer is formed only in a predetermined range on the surface of the substrate, a substrate in a pattern such as a dot pattern or a line and space pattern on the entire surface of the substrate. There is an embodiment in which a protective layer is formed. In addition, in this invention, a base | substrate means what is used for manufacture of a flexible electronic device etc. by which the composition for board | substrate protective layer formation of this invention is coated on the surface.

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

  The method for applying the substrate protective layer-forming composition of the present invention to the substrate is not particularly limited, and examples thereof include cast coating, spin coating, blade coating, dip coating, roll coating, bar coating, and the like. Examples thereof include a coating method, a die coating method, an inkjet method, and a printing method (such as a relief plate, an intaglio plate, a lithographic plate, and a screen printing).

  Examples of the appliance 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 substrate protective layer is usually about 0.01 to 50 μm, and preferably about 0.05 to 20 μm from the viewpoint of productivity. In addition, desired thickness is implement | achieved by adjusting the thickness of the coating film before a heating.

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

Although the resin substrate formed on the said board | substrate protective layer is not specifically limited, From a heat resistant viewpoint, the thing whose 1% weight reduction temperature in a thermogravimetric analysis is 500 degreeC or more is suitable.
Examples of such a resin substrate include a resin substrate using a wholly aromatic polymer such as wholly aromatic polyimide, polybenzoxazole, polybenzothiazole, and polybenzimidazole. Further, a hybrid film in which silica sol, titania sol or the like is added to the polymer may be used.

Hereinafter, an example of the manufacturing method of the flexible electronic device using the board | substrate protective layer of this invention is demonstrated.
A substrate protective layer is formed on a glass substrate by the method described above using the composition for forming a substrate protective layer of the present invention. Resin fixed to the glass substrate via the substrate protective layer of the present invention by applying a resin substrate forming solution for forming a resin substrate on the substrate protective layer and baking this coating film A substrate is formed.

The firing temperature of the coating film is appropriately set according to the type of resin and the like. In the present invention, the maximum temperature during firing is preferably 500 ° C. or higher. The upper limit is usually about 550 ° C, preferably about 520 ° C, more preferably about 510 ° C.
By setting the maximum temperature during firing during resin substrate preparation within this range, the peelability between the protective layer and the substrate as the base, and the appropriate adhesion and peelability between the substrate protective layer and the resin substrate are further improved. Can be made.

In this case, as long as the maximum temperature falls within the above range, a step of baking at a temperature lower than that may be included.
As a preferable example of the heating mode at the time of preparing the resin substrate, there is a method of heating at 50 to 150 ° C., then increasing the heating temperature stepwise as it is, and finally heating at 500 ° C. or higher. In particular, as a more preferable example of the heating mode, a method of heating at 50 to 100 ° C., heating at a temperature exceeding 100 ° C. to less than 500 ° C., and heating at 500 ° C. or more can be cited. Furthermore, as another more preferable example of the heating mode, after heating at 50 to 100 ° C., heating at over 100 ° C. to 200 ° C., heating at over 200 ° C. to 300 ° C., over 300 ° C. to less than 500 ° C. A method of heating and finally heating at 500 to 510 ° C can be mentioned.

  Moreover, as a preferable example of the heating mode in consideration of the firing time, after heating at 50 to 150 ° C. for 1 minute to 2 hours, the heating temperature is increased stepwise and finally at 500 ° C. or higher for 30 minutes. A method of heating for ~ 4 hours can be mentioned. In particular, as a more preferable example of the heating mode, heating is performed at 50 to 100 ° C. for 1 minute to 2 hours, heating is performed at a temperature exceeding 100 ° C. to less than 500 ° C. for 5 minutes to 2 hours, and heating is performed at 500 ° C. or more for 30 minutes to 4 hours. The technique to do is mentioned. Furthermore, as another more preferable example of the heating mode, after heating at 50 to 100 ° C. for 1 minute to 2 hours, more than 100 ° C. to 200 ° C. for 5 minutes to 2 hours, more than 200 ° C. to 300 ° C. for 5 minutes to A method of heating for 2 hours, above 300 ° C. to less than 500 ° C. for 5 minutes to 2 hours, and finally at 500 to 510 ° C. for 30 minutes to 4 hours may be mentioned.

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

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

  The composition for forming a substrate protective layer of the present invention has a feature of sufficiently absorbing light having a specific wavelength (for example, 308 nm) that allows application of the LLO method, and can therefore be used as a sacrificial layer for the LLO method. . Therefore, a desired circuit is formed on a resin substrate fixed to a glass substrate through a substrate protective layer formed using the composition according to the present invention, and then an LLO method is performed to irradiate a light beam of 308 nm. Then, only the substrate protective layer absorbs this light and evaporates (sublimates). As a result, the substrate protective layer is sacrificed (acts as a sacrifice layer), and the resin substrate can be selectively peeled from the glass substrate.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to these Examples.

[1] Abbreviations of compounds p-PDA: p-phenylenediamine TFMB: 2,2′-bis (trifluoromethyl) benzidine BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PMDA: pyro Mellitic acid dianhydride CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve PGME: Propylene glycol monomethyl ether

[2] Measuring method of weight average molecular weight and molecular weight distribution The weight average molecular weight (hereinafter abbreviated as Mw) and molecular weight distribution of a polymer are measured by GPC apparatus manufactured by JASCO Corporation (column: KD801 and KD805 manufactured by Shodex; 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 (Converted value).

[3] Synthesis of polymer Polyamic acid was synthesized by the following method.
In addition, the polymer was not isolated from the obtained polymer containing reaction liquid, but the resin liquid formation composition or the composition for board | substrate protective layer formation was prepared by diluting a reaction liquid as mentioned later.

<Synthesis Example S1 Synthesis of Polyamic Acid (S1)>
3.176 g (0.02937 mol) of p-PDA was dissolved in 88.2 g of NMP, and 8.624 g (0.02931 mol) of BPDA was added, followed by reaction at 23 ° C. for 24 hours in a nitrogen atmosphere. Mw of the obtained polymer was 107,300, and the molecular weight distribution was 4.6.

<Synthesis Example L1 Synthesis of polyamic acid (L1)>
23.7 g (74.2 mmol) of TFMB was dissolved in 352 g of NMP. To the obtained solution, 24.2 g (82.5 mmol) of BPDA was added and reacted at 23 ° C. for 24 hours under a nitrogen atmosphere. Mw of the obtained polymer was 76,400 and molecular weight distribution 2.2. The resulting solution was soluble in PGME.

<Synthesis Example L2 Synthesis of polyamic acid (L2)>
9.89 g (30.9 mmol) of TFMB was dissolved in 380 g of PGME. To the resulting solution, 10.0 g (34.3 mmol) of BPDA was added and reacted at 50 ° C. for 72 hours under a nitrogen atmosphere. Mw of the obtained polymer was 76,400 and molecular weight distribution 2.2.

<Synthesis of Comparative Synthesis Example HL1 Polyamic Acid (HL1)>
2.73 g (8.53 mmol) of TFMB was dissolved in 38.5 g of NMP. To the obtained solution, 2.06 g (9.47 mmol) of PMDA was added and reacted at 23 ° C. for 24 hours under a nitrogen atmosphere. Mw of the obtained polymer was 76,400 and molecular weight distribution 2.2. The resulting solution was soluble in PGME.

<Synthesis of Comparative Synthesis Example HL2 Polyamic Acid (HL2)>
2.86 g (8.91 mmol) of TFMB was dissolved in 35.2 g of NMP. CBDA 1.94 g (9.91 mmol) was added to the resulting solution, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere. Mw of the obtained polymer was 69,200 and molecular weight distribution 2.2. The resulting solution was soluble in PGME.

[4] Preparation of resin substrate forming composition [Preparation Example 1]
The reaction solution obtained in Synthesis Example S1 was used as it was as a resin substrate forming composition.

[5] Preparation of composition for forming substrate protective layer [Example 1-1]
BCS and NMP were added to the reaction solution obtained in Synthesis Example L1, and diluted such that the polymer concentration was 5 wt% and the BCS was 20 mass% to obtain a composition for forming a substrate protective layer.

[Example 1-2]
The reaction solution obtained in Synthesis Example L2 was directly used as the substrate protective layer forming composition.

[Comparative Example 1-1]
BCS and NMP were added to the reaction solution obtained in Comparative Synthesis Example HL1, and diluted such that the polymer concentration was 5 wt% and the BCS was 20 mass% to obtain a composition for forming a substrate protective layer.

[Comparative Example 1-2]
BCS and NMP were added to the reaction solution obtained in Comparative Synthesis Example HL2, and diluted such that the polymer concentration was 5 wt% and BCS was 20 mass% to obtain a composition for forming a substrate protective layer.

[6] Preparation of substrate protective layer and resin substrate [Example 2-1]
Using a spin coater (conditions: about 3,000 rpm for about 30 seconds), the substrate protective layer forming composition obtained in Example 1-1 was used as a glass substrate of 100 mm × 100 mm glass substrate (hereinafter the same). It was applied on top.
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 and at 400 ° C. for 30 minutes using an oven, and further at 500 ° C. for 10 minutes. The substrate was heated to form a substrate protective layer having a thickness of about 0.1 μm on the glass substrate, thereby obtaining a glass substrate with a substrate protective layer. The heating rate between the heating temperatures was 5 ° C./min. During the heating, the film-coated substrate was not removed from the oven and heated in the oven.

  The composition for resin substrate formation was apply | coated on the board | substrate protective layer (resin thin film) on the glass substrate obtained above using the bar coater (gap: 250 micrometers). The obtained coating film was heated at 80 ° C. for 40 minutes using a hot plate, and then heated at 140 ° C., 210 ° C., 300 ° C. and 400 ° C. for 30 minutes using an oven, and then further heated to 500 ° C. The substrate was heated at 60 ° C. for 60 minutes to form a polyimide resin substrate having a thickness of about 10 μm on the substrate protective layer to obtain a glass substrate with a resin substrate / substrate protective layer. In addition, the temperature increase rate between each heating temperature was 2 degree-C / min, and it heated in oven, without taking out a board | substrate with a film | membrane from oven during temperature rising.

[Example 2-2]
Instead of the substrate protective layer forming composition obtained in Example 1-1, the same composition as in Example 2-1 was used except that the substrate protective layer forming composition obtained in Example 1-2 was used. By the method, a substrate protective layer and a polyimide resin substrate were formed, and a glass substrate with a substrate protective layer and a glass substrate with a resin substrate / substrate protective layer were obtained.

[Comparative Examples 2-1 to 2-2]
Example 2 except that the substrate protective layer-forming composition obtained in Comparative Examples 1-1 to 1-2 was used instead of the substrate protective layer-forming composition obtained in Example 1-1. The substrate protective layer and the polyimide resin substrate were formed by the same method as -1, and a glass substrate with a substrate protective layer and a glass substrate with a resin substrate / substrate protective layer were obtained.

[7] Evaluation of peelability The resin substrate and the substrate protective layer of the glass substrate with the resin substrate / substrate protective layer obtained in Examples 2-1 to 2-2 and Comparative Examples 2-1 to 2-2 were cut with a cutter. It was cut into strips with a width of 2 cm and a length of 5 cm. And the adhesive tape was affixed on the edge part of the cut resin substrate, and this was made into the test piece. The test piece was subjected to a peel test using an Atonic Co., Ltd. push-pull tester so that the peel angle was 170 °, and peelability was evaluated based on the following criteria. The results are shown in Table 1.
<Evaluation criteria for releasability between glass substrate and substrate protective layer>
○: The substrate protective layer is peeled off from the glass substrate.
Δ: The resin substrate can be peeled off, but a part of the substrate protective layer remains on the glass substrate.
X: The resin substrate and the substrate protective layer cannot be peeled from the glass substrate.
Moreover, the surface of the glass surface of the peeled site | part was shaved with the cutter, and the remaining film property was evaluated based on the following references | standards. The results are shown in Table 1.
<Evaluation criteria of remaining film property of substrate protective layer on glass substrate>
○: The substrate protective layer does not remain.
Δ: A part of the substrate protective layer remains.
X: The substrate protective layer remains.
―: Evaluation is not possible because the resin substrate does not peel off.

  As shown in Table 1, the substrate protective layers of Examples 2-1 to 2-2 were easily peeled off together with the resin substrate, and it was confirmed that the substrate protective layer did not remain on the glass substrate. On the other hand, the resin substrates of Comparative Examples 2-1 to 2-2 were firmly attached to the glass substrate via the substrate protective layer, and could not be peeled from the glass substrate.

[9] Physical properties of resin film The mechanical properties of the resin substrate obtained in Example 2-1 were measured. For comparison, a resin substrate prepared by directly applying the resin substrate-forming composition S1 on a substrate and baking it without forming a substrate protective layer was used. At that time, the substrate was changed from a glass substrate to a silicon substrate, and a resin substrate was formed by the same method as in Example 2-1. The obtained resin film was designated as SF1.

<Linear expansion coefficient>
A 20 mm × 5 mm strip-shaped test piece is prepared from the film obtained above, and a linear expansion coefficient from 50 ° C. to 500 ° C. is obtained using TMA-4000SA (manufactured by Bruker AXS Co., Ltd.). It was measured. The results are shown in Table 2.

<Weight reduction>
From the film obtained above, a strip-shaped test piece of 20 mm × 3 mm was prepared, and the weight was reduced from 50 ° C. to 600 ° C. using TGA-DTA-2000SR (manufactured by Bruker AXS Co., Ltd.). The temperature at which 1% weight loss was observed was confirmed. The results are shown in Table 2.

  As shown in Table 2, it was confirmed that there was no difference in mechanical properties between the resin substrate with a substrate protective layer produced in Example and the resin substrate produced without forming the substrate protective layer. From the above results, it was confirmed that the substrate protective layer does not affect the mechanical properties of the resin substrate produced.

Claims (11)

  After the resin substrate is formed on the substrate, when the resin substrate is peeled from the substrate together with the resin substrate, the resin substrate is interposed between the substrate and the resin substrate, and has easy peelability from the substrate. A composition for forming a protective layer of a substrate, which functions as a protective layer for the resin substrate after peeling, comprising a polyamic acid and an organic solvent. The composition for substrate protective layer formation of Claim 1 containing the polyamic acid represented by following formula (1), and an organic solvent.

(In the formula, X represents an aromatic group represented by the following formula (2), Y represents a divalent aromatic group having a fluorine atom, and n represents a natural number.)

The composition for forming a substrate protective layer according to claim 2, wherein Y is an aromatic group represented by the following formula (3).

4. The substrate protective layer forming composition according to claim 2 or 3, wherein Y is an aromatic group represented by the following formula (4).

The said organic solvent is at least 1 sort (s) chosen from what has a structure represented by following formula (S1)-(S7), The composition for board | substrate protective layer formation of any one of Claims 1-4.

(In the formula, R ^{1 to} R ⁸ each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ⁹ and R ¹⁰ each independently represent a hydrogen atom, 10 represents an alkyl group or an acyl group having 1 to 10 carbon atoms, and b and n represent natural numbers)   An electronic device is further produced on the resin substrate, and when the electronic device is peeled from the substrate together with the resin substrate, it has an easy peelability from the substrate and functions as a protective layer for the resin substrate after peeling. Item 2. The substrate protective layer-forming composition according to Item 1.   The board | substrate protective layer obtained from the composition for board | substrate protective layer formation of any one of Claims 1-6. Applying a composition for forming a substrate protective layer according to claim 6 on a substrate and firing at a maximum temperature of 500 ° C. or higher to form a substrate protective layer having easy peelability from the substrate;
Applying a composition for forming a resin substrate on the substrate protective layer, and baking at a maximum temperature of 500 ° C. or higher to form a resin substrate;
Producing an electronic device on the resin substrate;
And a step of peeling the electronic device together with the substrate protective layer and the resin substrate from the substrate.   The method for manufacturing a flexible electronic device according to claim 8, wherein the resin substrate is a polyimide resin substrate.   A substrate protective layer-forming composition according to any one of claims 1 to 5 is applied onto a substrate, fired at a maximum temperature of 500 ° C or higher to form a substrate protective layer, and then formed on the substrate protective layer. A resin substrate with a protective layer, wherein a resin substrate forming composition is applied and baked at a maximum temperature of 500 ° C. or more to form a resin substrate, and then the resin substrate is peeled off from the substrate together with the substrate protective layer. Manufacturing method.   The manufacturing method according to claim 10, wherein the resin substrate is a polyimide resin substrate.