JP7092114B2 - A composition for forming a release layer and a release layer - Google Patents

Description

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 the function of bending and the performance of thinning and weight reduction. For this reason, it is required to use a lightweight flexible plastic substrate instead of the conventional heavy, fragile and inflexible glass substrate.
In particular, in the new generation display, there is a demand for the development of an active matrix type full-color TFT display panel using a lightweight flexible plastic substrate (hereinafter referred to as a resin substrate). The technology related to this new generation display 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 for new-generation displays, manufacturing studies are being carried out by a process in which existing TFT equipment can be diverted. 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 a laser is irradiated from the glass surface side to crystallize the amorphous silicon. Disclosed is a method of peeling a plastic substrate from a glass substrate by the hydrogen gas generated in the process.

Further, in Patent Document 4, a method of attaching a peelable layer (described as “transferred layer” in Patent Document 4) to a plastic film using the techniques disclosed in Patent Documents 1 to 3 to complete a liquid crystal display device. Is disclosed.

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

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

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

As a result of diligent studies to solve the above problems, the present inventors have made the release layer formed on the substrate a release layer containing a polyamic acid having a specific structure and an organic solvent in the production of a resin substrate. By forming using the forming composition, it is possible to obtain a release layer having excellent adhesion to a substrate, appropriate adhesion to a resin substrate used as a flexible electronic device, and appropriate peelability. Find out and complete the invention.

［（式中、Ｘ¹は、フェニル基又はビフェニル基を表し、Ｚ¹は、下記式［Ｚ１］で表される基であり、ｎ¹は自然数を表す。）

（式［Ｚ１］中、
Ｙ¹は、単結合又は結合基を表し、
Ｙ²は、単結合、炭素数１～１５のアルキレン基若しくは－ＣＨ₂－ＣＨ（ＯＨ）－ＣＨ₂－を表すか、又はベンゼン環、シクロヘキサン環及び複素環からなる群から選ばれる２価の環状基を表し、上記環状基上の任意の水素原子が、炭素数１～３のアルキル基、炭素数１～３のアルコキシ基、炭素数１～３のフッ化アルキル基、炭素数１～３のフッ化アルコキシ基又はフッ素原子で置換されていてもよく、
Ｙ³は、単結合又は炭素数１～１５のアルキレン基を表し、
Ｙ⁴は、単結合を表すか、又はベンゼン環、シクロヘキサン環及び複素環からなる群から選ばれる２価の環状基、又は炭素数１７～３０のステロイド骨格を有する２価の有機基を表し、上記環状基上の任意の水素原子が、炭素数１～３のアルキル基、炭素数１～３のアルコキシ基、炭素数１～３のフッ化アルキル基、炭素数１～３のフッ化アルコキシ基又はフッ素原子で置換されていてもよく、
Ｙ⁵は、ベンゼン環、シクロヘキサン環及び複素環からなる群から選ばれる２価の環状基を表し、これらの環状基上の任意の水素原子が、炭素数１～３のアルキル基、炭素数１～３のアルコキシ基、炭素数１～３のフッ化アルキル基、炭素数１～３のフッ化アルコキシ基又はフッ素原子で置換されていてもよく、
ｎは０～４の整数を表し、ｎが２以上の場合、Ｙ⁵同士は同一でも異なっていてもよく、
Ｙ⁶は、水素原子、炭素数１～１８のアルキル基、炭素数１～１８のフッ化アルキル基、炭素数１～１８のアルコキシ基又は炭素数１～１８のフッ化アルコキシ基を表し、
Ｙ²及びＹ³におけるアルキレン基、並びに、上記環状基上の置換基又はＹ⁶におけるアルキル基、フッ化アルキル基、アルコキシ基及びフッ素含有アルコキシ基は、直鎖状、枝分かれ状、若しくは環状の何れか又はそれらの組み合わせであってもよく、
またＹ²及びＹ³におけるアルキレン基、並びに、Ｙ⁶におけるアルキル基、フッ化アルキル基、アルコキシ基及びフッ素含有アルコキシ基は、結合基同士が隣り合わない限り１～３の結合基で中断されていてもよく、
さらにＹ²、Ｙ⁴若しくはＹ⁵が２価の環状基を表すか、又はＹ⁴がステロイド骨格を有する２価の有機基を表すか、又はＹ²が－ＣＨ₂－ＣＨ（ＯＨ）－ＣＨ₂－を表すか、又はＹ²若しくはＹ³がアルキレン基を表すか、又はＹ⁶がアルキル基若しくはフッ化アルキル基を表すとき、該２価の環状基、該ステロイド骨格を有する２価の有機基、該－ＣＨ₂－ＣＨ（ＯＨ）－ＣＨ₂－、該アルキレン基、該アルキル基及び該フッ化アルキル基は、それらに隣接する基と結合基を介して結合していてもよく、
そして上記結合基は、－Ｏ－、－ＣＨ₂Ｏ－、－ＣＯＯ－、－ＯＣＯ－、－ＮＨ－、－ＮＨＣＯ－、－ＮＨ－ＣＯ－Ｏ－及び－ＮＨ－ＣＯ－ＮＨ－からなる群から選ばれる基を表し、
但し、Ｙ²～Ｙ⁶がそれぞれ表すところの単結合、炭素数１～１５のアルキレン基、ベンゼン環、シクロヘキサン環、複素環、ステロイド骨格を有する２価の有機基、－ＣＨ₂－ＣＨ（ＯＨ）－ＣＨ₂－、炭素数１～１８のアルキル基、炭素数１～１８のフッ化アルキル基、炭素数１～１８のアルコキシ基及び炭素数１～１８のフッ化アルコキシ基の炭素数の合計は６～３０である。）］
２． 上記Ｚ¹が、下記式［Ｚ２］で表される基である１の剥離層形成用組成物、

（式中、Ｙ¹は、単結合、－Ｏ－又は－ＮＨ－を表し、
Ｙ⁵は、ベンゼン環及びシクロヘキサン環からなる群から選ばれる２価の環状基を表し、
ｎは１～３の整数を表し、ｎが２以上の場合、Ｙ⁵同士は同一でも異なっていてもよく、
Ｙ⁶は、炭素数１～１８のアルキル基を表す。）
３． 上記Ｚ¹が、下記式［Ｚ３］、［Ｚ４］又は［Ｚ５］で表される基である２の剥離層形成用組成物、

（式中、Ｙ⁶は、互いに独立して、炭素数１～１８のアルキル基を表す。）
４． 上記有機溶剤が、式（Ｓ１）で表されるアミド類、式（Ｓ２）で表されるアミド類及び式（Ｓ３）で表されるアミド類から選ばれる少なくとも１つを含む１～３のいずれかの剥離層形成用組成物、

（式中、Ｒ¹及びＲ²は、互いに独立して、炭素数１～１０のアルキル基を表し、Ｒ³は、水素原子、又は炭素数１～１０のアルキル基を表し、ｈは、自然数を表す。）
５． １～４のいずれかの剥離層形成用組成物を用いて形成される剥離層、
６． １～４のいずれかの剥離層形成用組成物を基体に塗布し、焼成することを含む剥離層の製造方法、
７． １～４のいずれかの剥離層形成用組成物を基体上に塗布し、焼成して剥離層を形成する工程、
上記剥離層上に、被剥離体を形成する工程、及び
上記被剥離体を、上記剥離層から剥離する工程
を含む被剥離体の製造方法、
８． ５の剥離層を用いることを特徴とする、樹脂基板を備えるフレキシブル電子デバイスの製造方法、
９． ５の剥離層を用いることを特徴とする、樹脂基板を備えるタッチパネルセンサーの製造方法、
１０． 上記樹脂基板が、ポリイミド樹脂基板である７又は８の製造方法、
１１． フレキシブル電子デバイスに適用される積層体であって、
基体と、
上記基体上に形成される剥離層と、
上記剥離層上に形成される樹脂基板と
を有し、上記剥離層が１～４のいずれかの剥離層形成用組成物により形成され、かつ、上記樹脂基板と上記剥離層との密着力が、上記剥離層と上記基体との密着力より大きいことを特徴とする積層体
を提供する。That is, the present invention
1. 1. A composition for forming a release layer containing a polyamic acid having a weight average molecular weight of 5,000 or more including a structural unit represented by the following formula (1) and an organic solvent.

[(In the formula, X ¹ represents a phenyl group or a biphenyl group, Z ¹ is a group represented by the following formula [Z 1], and n ¹ represents a natural number.)

(In the formula [Z1],
Y ¹ represents a single bond or a binding group
Y ² represents a single bond, an alkylene group having 1 to 15 carbon atoms or -CH ₂ -CH (OH) -CH _2- , or a divalent group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocycle. Representing a cyclic group, any hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an alkyl fluoride group having 1 to 3 carbon atoms, and 1 to 3 carbon atoms. May be substituted with a fluorinated alkoxy group or a fluorine atom of
Y ³ represents a single bond or an alkylene group having 1 to 15 carbon atoms.
Y ⁴ represents a single bond or a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocycle, or a divalent organic group having a steroid skeleton having 17 to 30 carbon atoms. Any hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an alkyl fluoride group having 1 to 3 carbon atoms, and an alkoxy fluoride group having 1 to 3 carbon atoms. Alternatively, it may be substituted with a fluorine atom.
Y ⁵ represents a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocycle, and any hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms and 1 carbon atom. It may be substituted with an alkoxy group having 3 to 3, an alkyl fluoride group having 1 to 3 carbon atoms, an alkoxy fluoride group having 1 to 3 carbon atoms, or a fluorine atom.
n represents an integer from 0 to 4, and when n is 2 or more, Y ⁵ may be the same or different.
Y ⁶ represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms or an alkoxy group having 1 to 18 carbon atoms.
The alkylene group in Y ² and Y ³ and the substituent on the cyclic group or the alkyl group, fluorinated alkyl group, alkoxy group and fluorine-containing alkoxy group in Y ⁶ are linear, branched or cyclic. Or a combination thereof,
Further, the alkylene group in Y ² and Y ³ and the alkyl group, fluorinated alkyl group, alkoxy group and fluorine-containing alkoxy group in Y ⁶ are interrupted by 1 to 3 bonding groups unless the bonding groups are adjacent to each other. May,
Further, Y ² , Y ⁴ or Y ⁵ represents a divalent cyclic group, Y ⁴ represents a divalent organic group having a steroid skeleton, or Y ² represents -CH ₂ -CH (OH) -CH. When ₂ -represents, or Y ² or Y ³ represents an alkylene group, or Y ⁶ represents an alkyl group or a fluorinated alkyl group, the divalent cyclic group, a divalent organic having the steroid skeleton. The group, the -CH ₂ -CH (OH) -CH _2- , the alkylene group, the alkyl group and the fluoride alkyl group may be bonded to a group adjacent to them via a bonding group.
The binding group consists of -O-, -CH ₂ O-, -COO-, -OCO-, -NH-, -NHCO-, -NH-CO-O- and -NH-CO-NH-. Represents a group selected from
However, a single bond represented by Y ² to Y ⁶ , an alkylene group having 1 to 15 carbon atoms, a benzene ring, a cyclohexane ring, a heterocycle, a divalent organic group having a steroid skeleton, and -CH ₂ -CH (OH). ) -CH _2- , the total number of carbon atoms of the alkyl group having 1 to 18 carbon atoms, the alkyl group having 1 to 18 carbon atoms, the alkoxy group having 1 to 18 carbon atoms and the alkoxy group having 1 to 18 carbon atoms. Is 6 to 30. )]
2. 2. The composition for forming a release layer of 1, wherein Z ¹ is a group represented by the following formula [Z 2].

(In the equation, Y ¹ represents a single bond, -O- or -NH-, and represents.
Y ⁵ represents a divalent cyclic group selected from the group consisting of a benzene ring and a cyclohexane ring.
n represents an integer of 1 to 3, and when n is 2 or more, Y ⁵ may be the same or different.
Y ⁶ represents an alkyl group having 1 to 18 carbon atoms. )
3. 3. The composition for forming a release layer of 2, wherein Z ¹ is a group represented by the following formula [Z3], [Z4] or [Z5].

(In the formula, Y ⁶ represents an alkyl group having 1 to 18 carbon atoms independently of each other.)
4. Any of 1 to 3 in which the organic solvent contains at least one selected from amides represented by the formula (S1), amides represented by the formula (S2) and amides represented by the formula (S3). Composition for forming a release layer,

(In the formula, R ¹ and R ² represent an alkyl group having 1 to 10 carbon atoms independently of each other, R ³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and h is a natural number. Represents.)
5. A peeling layer formed by using the composition for forming a peeling layer according to any one of 1 to 4.
6. A method for producing a release layer, which comprises applying the composition for forming a release layer according to any one of 1 to 4 to a substrate and firing the composition.
7. A step of applying the composition for forming a release layer according to any one of 1 to 4 onto a substrate and firing it to form a release layer.
A method for producing a stripped body, which comprises a step of forming a stripped body on the peeled layer and a step of peeling the stripped body from the peeled layer.
8. A method for manufacturing a flexible electronic device including a resin substrate, which comprises using the release layer of 5.
9. A method for manufacturing a touch panel sensor including a resin substrate, which comprises using the release layer of 5.
10. The method for manufacturing 7 or 8 in which the resin substrate is a polyimide resin substrate,
11. A laminate applied to flexible electronic devices,
With the substrate
The peeling layer formed on the substrate and
It has a resin substrate formed on the peeling layer, the peeling layer is formed by any of the peeling layer forming compositions 1 to 4, and the adhesive force between the resin substrate and the peeling layer is strong. Provided is a laminate characterized by having a greater adhesion between the release layer and the substrate.

By using the composition for forming a release layer of the present invention, it is possible to obtain a release layer having excellent adhesion to a substrate, appropriate adhesion to a resin substrate, and appropriate peelability with good reproducibility. By using the composition for forming a release layer of the present invention, in the manufacturing process of a flexible electronic device, the circuit or the like can be used without damaging the resin substrate formed on the substrate or the circuit or the like provided on the substrate. At the same time, the resin substrate can be separated from the substrate. Therefore, the composition for forming a release layer of the present invention can contribute to the simplification of the manufacturing process of the flexible electronic device provided with the resin substrate and the improvement of the yield thereof.

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 having a weight average molecular weight of 5,000 or more including a structural unit represented by the following formula (1) and an organic solvent.

In the above formula (1), X ¹ represents a phenyl group or a biphenyl group, Z ¹ represents a group represented by the following formula [Z 1], and n ¹ represents a natural number.

In the above formula [Z1], Y ¹ represents a single bond or a linking group, and Y ² represents a single bond, an alkylene group having 1 to 15 carbon atoms or -CH ₂ -CH (OH) -CH _2- , or. Represents a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and any hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms and an alkoxy group having 1 to 3 carbon atoms. , May be substituted with an alkyl fluoride group having 1 to 3 carbon atoms, a fluorinated alkoxy group having 1 to 3 carbon atoms or a fluorine atom, and Y ³ represents a single bond or an alkylene group having 1 to 15 carbon atoms. Y ⁴ represents a single bond or a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocycle, or a divalent organic group having 17 to 30 carbon atoms and having a steroid skeleton. , The arbitrary hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an alkyl fluoride group having 1 to 3 carbon atoms, and an alkoxy fluoride having 1 to 3 carbon atoms. It may be substituted with a group or a fluorine atom, and Y ⁵ represents a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and any hydrogen atom on these cyclic groups is carbon. It may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an alkyl fluoride group having 1 to 3 carbon atoms, a fluorinated alkoxy group having 1 to 3 carbon atoms or a fluorine atom. Represents an integer of 0 to 4, and when n is 2 or more, Y ⁵ may be the same or different, and Y ⁶ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, and a hook having 1 to 18 carbon atoms. Represents an alkyl group, an alkoxy group having 1 to 18 carbon atoms or a fluorinated alkoxy group having 1 to 18 carbon atoms, an alkylene group in Y ² and Y ³ , and a substituent on the cyclic group or an alkyl group in Y ⁶ . , The alkyl fluoride group, the alkoxy group and the fluorine-containing alkoxy group may be linear, branched or cyclic or a combination thereof, and the alkylene group in Y ² and Y ³ and Y. The alkyl group, fluorinated alkyl group, alkoxy group and fluorine-containing alkoxy group in ⁶ may be interrupted by 1 to 3 bonding groups as long as the bonding groups are not adjacent to each other, and further Y ² , Y ⁴ or Y ⁵ Represents a divalent cyclic group, Y ⁴ represents a divalent organic group having a steroid skeleton, Y ² represents -CH ₂ -CH (OH) -CH _2- , or Y ² Or Y ³ Representing an alkylene group, or when Y ⁶ represents an alkyl group or an alkyl fluoride group, the divalent cyclic group, the divalent organic group having the steroid skeleton, the -CH ₂ -CH (OH) -CH _2- , The alkylene group, the alkyl group and the fluoride alkyl group may be attached to a group adjacent to them via a binding group, and the binding group is -O-, -CH ₂ O. Represents a group selected from the group consisting of-, -COO-, -OCO-, -NH-, -NHCO-, -NH-CO-O- and -NH-CO-NH-, but Y ² to Y ⁶ Represents a single bond, an alkylene group having 1 to 15 carbon atoms, a benzene ring, a cyclohexane ring, a heterocycle, a divalent organic group having a steroid skeleton, -CH ₂ -CH (OH) -CH _2- , carbon. The total number of carbon atoms of the alkyl group having 1 to 18 carbon atoms, the fluoroalkyl group having 1 to 18 carbon atoms, the alkoxy group having 1 to 18 carbon atoms and the fluoroalkoxy group having 1 to 18 carbon atoms is 6 to 30.

Here, in the present invention, the release layer is a layer provided directly above a substrate (glass substrate or the like) on which a resin substrate is formed. As a typical example, in the manufacturing process of a flexible electronic device, the resin substrate is fixed between the substrate and the resin substrate of the flexible electronic device made of a resin such as a polyimide resin or an acrylic resin in a predetermined process. In addition, there is a release layer provided on the resin substrate so that the resin substrate can be easily peeled off from the substrate after the electronic circuit or the like is formed on the resin substrate.

The polyamic acid used in the present invention is not particularly limited as long as it has the above structure, but can be obtained by reacting a diamine component containing a diamine having the following specific structure with a tetracarboxylic acid dianhydride component. Can be done. That is, the polyamic acid obtained here has Z ¹ in the side chain.

In the present invention, the above Z ¹ refers to a group represented by the following formula [Z 1].

In formula [Z1], Y ¹ represents a single bond or a binding group. The binding group consists of a group consisting of -O-, -CH ₂ O-, -COO-, -OCO-, -NH-, -NHCO-, -NH-CO-O- and -NH-CO-NH-. Represents the group chosen.

In the formula [Z1], Y ² represents a single bond, an alkylene group having 1 to 15 carbon atoms or -CH ₂ -CH (OH) -CH _2- .
Examples of Y ² include a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and any hydrogen atom on these cyclic groups is an alkyl group having 1 to 3 carbon atoms. , It may be substituted with an alkoxy group having 1 to 3 carbon atoms, an alkyl fluoride group having 1 to 3 carbon atoms, a fluorinated alkoxy group having 1 to 3 carbon atoms or a fluorine atom.

Examples of the alkylene group having 1 to 15 carbon atoms include a divalent group obtained by removing one hydrogen atom from the alkyl group having 1 to 15 carbon atoms among the alkyl groups having 1 to 18 carbon atoms, which will be described later. Examples include methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene groups and the like.

Specific examples of the above heterocycle include a pyrazole ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a quinoline ring, a pyrazoline ring, an isoquinolin ring, a carbazole ring, a purine ring, a thiadiazole ring, and a pyridazine ring. , Pyrazoline ring, triazine ring, pyrazolidine ring, triazole ring, pyrazine ring, benzimidazole ring, cinnoline ring, phenanthroline ring, indole ring, quinoxalin ring, benzothiazole ring, phenothiazine ring, oxadiazole ring, acrydin ring and the like. More preferably, a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyrazoline ring, a carbazole ring, a pyridazine ring, a pyrazoline ring, a triazine ring, a pyrazolidine ring, a triazole ring, a pyrazine ring, and a benzimidazole ring are preferable. ..

Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group and a cyclopropyl group, and examples of the alkoxy group having 1 to 3 carbon atoms include the above 1 to 1 carbon atoms. As a specific example of the alkyl group of No. 3, a group in which an oxygen atom —O— is bonded to the group mentioned can be mentioned. Further, as the fluorinated alkyl group having 1 to 3 carbon atoms and the fluorinated alkoxy group having 1 to 3 carbon atoms, any hydrogen among the alkyl group having 1 to 3 carbon atoms and the alkoxy group having 1 to 3 carbon atoms is used. A group in which the atom is replaced with a fluorine atom can be mentioned.

Among the divalent cyclic groups selected from the group consisting of the benzene ring, the cyclohexane ring and the heterocycle, the divalent cyclic group selected from the benzene ring and the cyclohexane ring is preferable from the viewpoint of easiness of synthesis. ..

In the above formula [Z1], Y ³ represents a single bond or an alkylene group having 1 to 15 carbon atoms. Examples of the alkylene group having 1 to 15 carbon atoms include the same groups as those mentioned above.

In the above formula [Z1], Y ⁴ represents a single bond or a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocyclic ring, and any hydrogen atom on these cyclic groups can be used. It may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an alkyl fluoride group having 1 to 3 carbon atoms, a fluorinated alkoxy group having 1 to 3 carbon atoms or a fluorine atom. Examples of the above-mentioned heterocycle and the alkyl group mentioned as the substituent include the same ones mentioned in the above-mentioned Y ² .

Further, the above Y ⁴ may be a divalent organic group having 17 to 30 carbon atoms and having a steroid skeleton. Preferred examples are cholesteryl, androsteryl , β-cholesteryl, epiandrosteryl, ergosteryl, estril, 11α-hydroxymethylsteryl, 11α-progesteryl, lanosteryl, mestranol, methyltestrosteryl, noretisteryl, pregrenolonyl, β-. It is a divalent organic group having a structure in which two hydrogen atoms are removed from a structure selected from citosteryl, stigmasteryl, teststeryl, acetate cholesterol ester and the like. More specifically, for example, the divalent organic group shown below can be mentioned.

（式中、＊は結合位置を表す。）

(In the formula, * represents the bond position.)

Among these, from the viewpoint of ease of synthesis, the above Y ⁴ is a divalent cyclic group selected from a benzene ring and a cyclohexane ring, and a divalent organic having 17 to 30 carbon atoms and a steroid skeleton. It is preferably a group.

In the formula [Z1], Y ⁵ represents a divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring and a heterocycle, and any hydrogen atom on these cyclic groups is an alkyl having 1 to 3 carbon atoms. It may be substituted with a group, an alkoxy group having 1 to 3 carbon atoms, an alkyl fluoride group having 1 to 3 carbon atoms, a fluorinated alkoxy group having 1 to 3 carbon atoms or a fluorine atom. Among these, Y ⁵ is preferably a divalent cyclic group selected from a benzene ring and a cyclohexane ring. Examples of the above-mentioned heterocycle and the alkyl group mentioned as the substituent include the same ones mentioned in the above ^- mentioned Y4.

In the formula [Z1], n represents an integer of 0 to 4, and when n is 2 or more, Y ⁵ may be the same group or different groups. Among them, n is preferably 1 to 3 and more preferably 2 to 3 from the viewpoint of availability of raw materials and ease of synthesis.

In the formula [Z1], Y ⁶ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms. Represents a group.
Among them, Y ⁶ may be an alkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms. preferable. More preferably, Y ⁶ is an alkyl group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms. Particularly preferably, Y ⁶ is an alkyl group having 1 to 9 carbon atoms and an alkoxy group having 1 to 9 carbon atoms.
When Y ⁴ is a divalent organic group having a steroid skeleton, Y ⁶ is preferably a hydrogen atom.

The alkylene group, alkyl group, fluorinated alkyl group, alkoxy group and fluorine-containing alkoxy group mentioned in the definition in the above formula [Z1] are linear, branched, cyclic, or a combination thereof. May be good.

Examples of the alkyl group having 1 to 18 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and an n-pentyl group. 1-Methyl-n-butyl group, 2-methyl-n-butyl group, 3-methyl-n-butyl group, 1,1-dimethyl-n-propyl group, 1,2-dimethyl-n-propyl group, 2 , 2-Dimethyl-n-propyl group, 1-ethyl-n-propyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group , 4-Methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2,2-dimethyl-n -Butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2- Trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, n-heptyl group , 1-Methyl-n-hexyl group, 2-methyl-n-hexyl group, 3-methyl-n-hexyl group, 1,1-dimethyl-n-pentyl group, 1,2-dimethyl-n-pentyl group, 1,3-dimethyl-n-pentyl group, 2,2-dimethyl-n-pentyl group, 2,3-dimethyl-n-pentyl group, 3,3-dimethyl-n-pentyl group, 1-ethyl-n- Pentyl group, 2-ethyl-n-pentyl group, 3-ethyl-n-pentyl group, 1-methyl-1-ethyl-n-butyl group, 1-methyl-2-ethyl-n-butyl group, 1-ethyl -2-Methyl-n-butyl group, 2-methyl-2-ethyl-n-butyl group, 2-ethyl-3-methyl-n-butyl group, n-octyl group, 1-methyl-n-heptyl group, 2-Methyl-n-heptyl group, 3-methyl-n-heptyl group, 1,1-dimethyl-n-hexyl group, 1,2-dimethyl-n-hexyl group, 1,3-dimethyl-n-hexyl group , 2,2-Dimethyl-n-hexyl group, 2,3-dimethyl-n-hexyl group, 3,3-dimethyl-n-hexyl group, 1-ethyl-n-hexyl group, 2-ethyl-n-hexyl Group, 3-ethyl-n-hexyl group, 1-methyl-1-ethyl-n-pentyl group, 1-methyl-2-ethyl-n-pentyl group, 1-methyl-3-ethyl-n-pentyl Group, 2-methyl-2-ethyl-n-pentyl group, 2-methyl-3-ethyl-n-pentyl group, 3-methyl-3-ethyl-n-pentyl group, n-nonyl group, n-decyl group , N-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group and the like.

Examples of the alkoxy group having 1 to 18 carbon atoms include a group in which an oxygen atom (—O—) is bonded to the above-mentioned alkyl group having 1 to 18 carbon atoms. Specific examples thereof include methoxy, ethoxy, n-propoxy, i-propoxy, c-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, c-butoxy, n-pentoxy, c-pentoxy, Examples thereof include n-hexoxy, n-decyloxy, n-pentadecyloxy, n-octadecyloxy group and the like.

Examples of the fluoroalkyl group having 1 to 18 carbon atoms include a group in which at least one hydrogen atom in the above alkyl group is replaced with a fluorine atom. Specific examples thereof include fluoromethyl, difluoromethyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, heptafluoropropyl, 2,2,3,3,3-pentafluoropropyl, 2, 2,3,3-Tetrafluoropropyl, 2,2,2-trifluoro-1- (trifluoromethyl) ethyl, nonafluorobutyl, 4,4,4-trifluorobutyl, undecafluoropentyl, 2,2 , 3,3,4,4,5,5,5-nonafluoropentyl, 2,2,3,3,4,5,5-octafluoropentyl, tridecafluorohexyl, 2,2,3 3,4,4,5,5,6,6-Undecafluorohexyl, 2,2,3,3,4,5,5,6,6-decafluorohexyl, 3,3,4 , 4, 5, 5, 6, 6, 6-nonafluorohexyl and the like.

Examples of the fluoroalkoxy group having 1 to 18 carbon atoms include a group in which an oxygen atom (—O—) is bonded to the above-mentioned alkyl fluoride group having 1 to 18 carbon atoms. Specific examples thereof include fluoromethoxy, difluoromethoxy, trifluoromethoxy, pentafluoroethoxy, 2,2,2-trifluoroethoxy, heptafluoropropoxy, 2,2,3,3,3-pentafluoropropoxy, 2, 2,3,3-Tetrafluoropropoxy, 2,2,2-trifluoro-1- (trifluoromethyl) ethoxy, nonafluorobutoxy, 4,4,4-trifluorobutoxy, undecafluoropentyloxy, 2, 2,3,3,4,4,5,5-Nonafluoropentyloxy, 2,2,3,3,4,5,5-octafluoropentyloxy, tridecafluorohexyloxy, 2, 2,3,3,4,4,5,5,6,6-Undecafluorohexyloxy, 2,2,3,3,4,4,5,5,6,6-decafluorohexyloxy , 3,3,4,4,5,5,6,6,6-nonafluorohexyloxy group and the like.

The alkylene group in Y ² and Y ³ and the substituent on the cyclic group or the alkyl group, fluorinated alkyl group, alkoxy group and fluorine-containing alkoxy group in Y ⁶ are linear, branched or cyclic. It may be any or a combination thereof.
Further, the alkylene group in Y ² and Y ³ and the alkyl group, the fluoroalkyl group, the alkoxy group and the fluorine-containing alkoxy group in Y ⁶ are interrupted by 1 to 3 bonding groups unless the bonding groups are adjacent to each other. May be.

Further, Y ² , Y ⁴ or Y ⁵ represents a divalent cyclic group, Y ⁴ represents a divalent organic group having a steroid skeleton, or Y ² represents -CH ₂ -CH (OH)-. When CH ₂ -represents, or Y ² or Y ³ represents an alkylene group, or Y ⁶ represents an alkyl group or a fluorinated alkyl group, the divalent cyclic group, the divalent having the steroid skeleton. The organic group, the -CH ₂ -CH (OH) -CH _2- , the alkylene group, the alkyl group and the fluoride alkyl group may be bonded to a group adjacent to them via a bonding group.
The binding group is a group selected from the group consisting of -O-, -CH ₂ O-, -COO-, -OCO-, -NHCO-, -NH-CO-O- and -NH-CO-NH-. Represents.

In addition, a single bond represented by Y ² to Y ⁶ , an alkylene group having 1 to 15 carbon atoms, a benzene ring, a cyclohexane ring, a heterocycle, a divalent organic group having a steroid skeleton, and -CH ₂ -CH (OH). ) -CH _2- , the total number of carbon atoms of the alkyl group having 1 to 18 carbon atoms, the alkyl group having 1 to 18 carbon atoms, the alkoxy group having 1 to 18 carbon atoms and the alkoxy group having 1 to 18 carbon atoms. Is 6 to 30, for example 6 to 20.
Of these, in consideration of properties such as peelability, Z ¹ is preferably a group containing an alkyl group having 7 to 18 carbon atoms, and preferably a group containing an alkyl group having 8 to 15 carbon atoms. More preferred.

Preferred embodiments of Z ¹ include, for example, a hydrocarbon group having about 6 to 20 carbon atoms. Examples of the hydrocarbon group having 6 to 20 carbon atoms include a linear, branched or cyclic alkyl group having 6 to 20 carbon atoms or a hydrocarbon group having 6 to 20 carbon atoms including an aromatic group.

In a more preferable embodiment of Z ¹ , for example, Y ¹ , Y ² and Y ⁴ are single bonds, Y ³ is a single bond or an alkylene group having 1 to 15 carbon atoms, and n is 0. Examples thereof include an alkyl group in which Y ⁶ has 1 to 18 carbon atoms and Y ³ and Y ⁶ have a total carbon number of 6 to 20. Examples of such an alkyl group include an alkyl group (a-1) having a total carbon number of 6 to 20 among the above-mentioned alkyl groups.

In another preferred embodiment of Z ¹ , for example, Y ¹ to Y ⁴ are single bonds, n is 2 to 3, and Y ⁵ is a divalent cyclic group selected from a benzene ring and a cyclohexane ring. Examples thereof include a group (a-2) in which Y ⁶ is an alkyl group having 1 to 18 carbon atoms. Examples of such a group (a-2) include groups represented by the following formulas (a-2-1) to (a-2-7).

（式中、Ｙ⁶は、炭素数１～１８のアルキル基である。）

(In the formula, Y ⁶ is an alkyl group having 1 to 18 carbon atoms.)

In still another preferred embodiment of Z ¹ , for example, Y ¹ to Y ³ are single bonds, Y ⁴ is a divalent organic group having 17 to 30 carbon atoms and having a steroid skeleton, and n. Is 0, and a group (a-3) in which Y ⁶ is a hydrogen atom can be mentioned. Examples of such a group (a-3) include groups represented by the following formulas (a-3-1) to (a-3-8).

（式中、＊は結合位置を表す。）

(In the formula, * represents the bond position.)

As the Z ¹ , a group represented by the following formula [Z 2] is particularly preferable from the viewpoint of peelability.

In the formula, Y ¹ represents a single bond, -O- or -NH-, Y ⁵ represents a divalent cyclic group selected from the group consisting of a benzene ring and a cyclohexane ring, and n is an integer of 1 to 3. When n is 2 or more, Y ⁵ may be the same or different, and Y ⁶ represents an alkyl group having 1 to 18 carbon atoms.

Further, the Z ¹ is particularly preferably a group represented by the following formulas [Z 3], [Z 4] and [Z 5].

In the formula, Y ⁶ independently represents an alkyl group having 1 to 18 carbon atoms.

As described above, the polyamic acid represented by the above formula (1) can be obtained by reacting a diamine component containing a diamine having a specific structure with a tetracarboxylic acid dianhydride component. Hereinafter, the diamine component and the tetracarboxylic acid dianhydride component that can be used for the synthesis of the polyamic acid used in the present invention will be described in detail.

Examples of the diamine that can be used for the synthesis of the polyamic acid include diamines represented by the following formula (B1), and diamines represented by the following formulas (B1-1) and (B1-2) are preferable. In the present invention, the diamine represented by the formula (B1-2), which enables peeling with a weaker force, is more preferable.

（式中、Ｚ¹は上記と同じ。）

(In the formula, Z ¹ is the same as above.)

（式中、Ｚ¹は上記と同じ。）

(In the formula, Z ¹ is the same as above.)

Particularly preferred specific examples are 1,3-diamino-4- [4- (trans-4- (trans-4-n-heptylcyclohexyl) phenoxy] benzene, 1- (trans-4-normal heptylcyclohexyl) -2. , 4-Diaminobenzene, 1- (trans-4-normal heptylcyclohexyl) -3,5-diaminobenzene, 1,3-diamino-4- {4- [trans-4- (trans-4-n-pentylcyclohexyl) ) Cyclohexyl] phenoxy} benzene, 1,3-diamino-4- {4- [4- (trans-4-n-pentylcyclohexyl) phenyl] phenoxy} benzene and the like.

In formula (1), as described above, X ¹ is a phenyl group or a biphenyl group.

The phenyl group and biphenyl group that X ¹ can take can be synthesized by using the following aromatic tetracarboxylic acid dianhydride when synthesizing the polyamic acid used in the present invention.
That is, pyromellitic acid dianhydride, 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride, 2,3,3', 4'-biphenyltetracarboxylic acid dianhydride and the like can be mentioned.

Among them, the aromatic tetracarboxylic acid dianhydride represented by any of the following formulas (C1) to (C6) is preferable from the viewpoint of improving the function of the obtained film as a release layer, and the following formulas (C1) to (C1) to ( The aromatic tetracarboxylic acid dianhydride represented by any of C5) is more preferable.

The weight average molecular weight of the polyamic acid having the monomer unit represented by the formula (1) used in the present invention needs to be 5,000 or more, preferably 15,000 or more, more preferably 20,000 or more, and more. More preferably, it is 30,000 or more. On the other hand, the upper limit of the weight average molecular weight of the polyamic acid used in the present invention is usually 2,000,000 or less, but it is possible to prevent the viscosity of the resin composition from becoming excessively high and the resin thin film has high flexibility. It is preferably 1,000,000 or less, more preferably 200,000 or less, in consideration of obtaining good reproducibility.

The polyamic acid used in the present invention contains the monomer unit represented by the formula (1) in an amount of 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, and further. It is preferably contained in an amount of 90 mol% or more. By using a polyamic acid having a content of such a monomer unit, a resin thin film having properties suitable for a release film can be obtained with good reproducibility.

According to a preferred embodiment of the present invention, the polyamic acid contained in the composition for forming a release layer of the present invention is a polymer consisting only of a monomer unit represented by the formula (1), that is, a monomer represented by the formula (1). It is a polymer contained in 100 mol% of units. At this time, the monomer unit in such a polyamic acid may be only one specific type or two or more types as long as it is represented by the formula (1). In the latter case, the number of monomer units of the formula (1) contained in the polyamic acid is preferably 2 to 4, more preferably 2 to 3.

The polyamic acid used in the present invention may contain other monomer units in addition to the monomer unit represented by the formula (1). The content of such other monomer units should be less than 50 mol%, preferably less than 40 mol%, more preferably less than 30 mol%, and less than 20 mol%. Is even more preferably less than 10 mol%.

Examples of such other monomer units include the monomer unit of the formula (2).

In the formula (2), X ² represents a tetravalent organic group derived from tetracarboxylic acid dianhydride, Y ^a represents a divalent organic group derived from a diamine, and n represents a natural number.

Examples of the diamine that provides such other monomer units include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 5-methyl-1,3-phenylenediamine, and the like. 4-Methyl-1,3-phenylenediamine, 2- (trifluoromethyl) -1,4-phenylenediamine, 2- (trifluoromethyl) -1,3-phenylenediamine and 4- (trifluoromethyl) -1 , 3-Phenylenediamine, Benzidine, 2,2'-dimethylbenzidine, 3,3'-dimethylbenzidine, 2,3'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) benzidine, 3,3'- Bis (trifluoromethyl) benzidine, 2,3'-bis (trifluoromethyl) benzidine, 4,4'-diphenyl ether, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-diaminobenzanilide , 5-Amino-2- (3-aminophenyl) -1H-benzoimidazole, 9,9-bis (4-aminophenyl) fluorene and other diamines.

Examples of the tetracarboxylic acid dianhydride include pyromellitic acid, 3,3', 4,4'-biphenyltetracarboxylic acid, 3,3', 4,4'-benzophenone tetracarboxylic acid, 3,3. ', 4,4'-diphenyl ether tetracarboxylic acid, 3,3', 4,4'-diphenyl sulfone tetracarboxylic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid Aromatic tetracarboxylic acids such as, dianhydrides thereof and derivatives thereof, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid. Acid, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetra Carboxylic acid, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, 2,3,5-tricarboxy-2-cyclopentaneacetic acid, bicyclo [2. 2.2] Like Oct-7-en-2,3,5,6-tetracarboxylic acid, 2,3,4,5-tetratetracarboxylic acid, 3,5,6-tricarboxy-2-norbornanacetic acid. Alicyclic tetracarboxylic acids, dianhydrides thereof and derivatives thereof, aliphatic tetracarboxylic acids such as 1,2,3,4-butanetetracarboxylic acid, dianhydrides thereof and derivatives thereof, etc. Can be mentioned. Further, as the above-mentioned hand tetracarboxylic acid component having an organic group having fluorine, 2,2-bis (3,4-dicarboxyphenyl) hexafluoroisopropyridene having a trifluoromethyl group or a hexafluoroisopropyride group. , 4,4'-Hexafluoroisopropyridendiphthalic acid, dianhydrides thereof and derivatives thereof, and the like, but are not limited to these compounds.
Further, as the tetracarboxylic acid component, one kind or a combination of two or more kinds of compounds from tetracarboxylic acid and its derivatives can be used.

According to a preferred embodiment of the present invention, the polyamic acid used in the present invention reacts an aromatic tetracarboxylic acid dianhydride as an acid dianhydride with a diamine component containing a diamine represented by the formula (B1). Can be obtained by

In the above reaction, the charging ratio (molar ratio) of the aromatic tetracarboxylic acid dianhydride and the diamine component containing the diamine represented by the above formula (B1) is the desired molecular weight of the polyamic acid, the ratio of the monomer unit, and the like. Although it can be appropriately set in consideration of consideration, the acid anhydride component is usually about 0.7 to 1.3, preferably about 0.8 to 1.2, with respect to the diamine component 1. ..

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

In particular, the organic solvent used in the reaction dissolves the above-mentioned diamine, tetracarboxylic acid dianhydride, dicarboxylic acid, polyamic acid and polyamide well, so the amides represented by the formula (S1) are represented by the formula (S2). At least one selected from the amides to be used and the amides represented by the formula (S3) is preferable.

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

Alkyl groups 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 and n-. Examples thereof include a hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group and the like. Of these, an alkyl group having 1 to 3 carbon atoms is preferable, and an alkyl group having 1 or 2 carbon atoms is more preferable.

The reaction temperature may be appropriately set in the range from the melting point to the boiling point of the solvent to be used, and is usually about 0 to 100 ° C., but the imidization of the obtained polyamic acid is prevented and the high content of the polyamic acid unit is maintained. Therefore, it is preferably about 0 to 70 ° C, more preferably about 0 to 60 ° C, and even more preferably about 0 to 50 ° C.
The reaction time cannot be unconditionally defined because it depends on the reaction temperature and the reactivity of the raw material, but it is usually about 1 to 100 hours.

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

In the present invention, a solution obtained by filtering the above reaction solution and then using the filtrate as it is, or by diluting or concentrating the solution can be used as the composition for forming a release layer of the present invention. By doing so, it is possible not only to reduce the mixing of impurities that may cause deterioration of the adhesiveness and peelability of the obtained peeling layer, but also to efficiently obtain a composition for forming the peeling layer.
The solvent used for dilution or concentration is not particularly limited, and examples thereof include the same as the specific examples of the reaction solvent for the above reaction, and they may be used alone or in combination of two or more. ..

Among the above specific examples, considering that a highly flat resin thin film can be obtained with good reproducibility, the solvents used include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and 1. , 3-Dimethyl-2-imidazolidinone, N-ethyl-2-pyrrolidone, γ-butyrolactone are preferred.

The concentration of the polyamic acid with respect to the total mass of the composition for forming the release layer is appropriately set in consideration of the thickness of the thin film (release layer) to be produced, the viscosity of the composition, etc., but is usually 0.5 to 30 mass. %, Preferably about 5 to 25% by mass.

The viscosity of the composition for forming a release layer is appropriately set in consideration of the thickness of the thin film to be produced, and the purpose is to obtain a resin thin film having a thickness of about 0.05 to 5 μm with good reproducibility. In this case, it is usually about 10 to 10,000 mPa · s at 25 ° C., preferably about 20 to 1,000 mPa · s, and more preferably about 20 to 200 mPa · s. Here, the viscosity can be measured using a commercially available viscometer for measuring the viscosity of a liquid, for example, with reference to the procedure described in JIS K7117-2, under the condition that the temperature of the composition is 25 ° C. .. Preferably, a conical plate type (cone plate type) rotational viscometer is used as the viscometer, and 1 ° 34'× R24 is preferably used as the standard cone rotor in the viscometer of the same type, and the temperature of the composition is 25. It can be measured under the condition of ° C. Examples of such a rotational viscometer include TVE-25H manufactured by Toki Sangyo Co., Ltd.

The composition for forming a release layer according to the present invention may contain various components in addition to the polyamic acid and the organic solvent. For example, a cross-linking agent (hereinafter, also referred to as a cross-linking compound) can be mentioned, but the present invention is not limited thereto.

Examples of the crosslinkable compound include a compound containing two or more epoxy groups, a melamine derivative, a benzoguanamine derivative or glycoluril having a group in which the hydrogen atom of the amino group is substituted with a methylol group, an alkoxymethyl group or both. However, it is not limited to these.

Specific examples of the crosslinkable compound are given below, but the present invention is not limited thereto.
Examples of the compound containing two or more epoxy groups include cyclohexene structures such as Epolide GT-401, Epolide GT-403, Epolide GT-301, Epolide GT-302, Celoxide 2021, and Celoxide 3000 (all manufactured by Daicel Co., Ltd.). Epoxy compounds possessed; Epicoat 1001, Epicoat 1002, Epicoat 1003, Epicoat 1004, Epicoat 1007, Epicoat 1009, Epicoat 1010, Epicoat 828 (all manufactured by Japan Epoxy Resin Co., Ltd. (currently manufactured by Mitsubishi Chemical Co., Ltd., jER (registered trademark)) Bisphenol A type epoxy compound such as (series)); Bisphenol F type epoxy compound such as Epicoat 807 (manufactured by Japan Epoxy Resin Co., Ltd.); Epicoat 152, Epicoat 154 (all manufactured by Japan Epoxy Resin Co., Ltd.) , JER® series)), EPPN201, EPPN202 (all manufactured by Nippon Kayaku Co., Ltd.) and other phenol novolac type epoxy compounds; ECON-102, ECON-103S, ECON-104S, ECON-1020, ECON- Cresol novolak type epoxy compounds such as 1025, ECON-1027 (all manufactured by Nippon Kayaku Co., Ltd.), Epicoat 180S75 (manufactured by Japan Epoxy Resin Co., Ltd. (currently Mitsubishi Chemical Co., Ltd., jER (registered trademark) series)); Naphthalene type epoxy compounds such as V8000-C7 (manufactured by DIC Co., Ltd.); Denacol EX-252 (manufactured by Nagase ChemteX Corporation), CY175, CY177, CY179, Araldite CY-182, Araldite CY-192, Araldite CY-184 ( Above, BASF), Epicron 200, Epicron 400 (above, DIC Co., Ltd.), Epicoat 871, Epicoat 872 (above, Japan Epoxy Resin Co., Ltd. (currently: Mitsubishi Chemical Co., Ltd., jER (registered trademark) series) )), ED-5661, ED-5662 (all manufactured by Ceranies Coating Co., Ltd.) and other alicyclic epoxy compounds; Denacol EX-611, Denacol EX-612, Denacol EX-614, Denacol EX-622, Denacol EX. -411, Denacol EX-512, Denacol EX-522, Denacol EX-421, Denacol EX-313, Denacol EX-314, Denacol EX-312 (above, Nagasechem) Examples thereof include aliphatic polyglycidyl ether compounds (manufactured by TEX Co., Ltd.).

As a melamine derivative, a benzoguanamine derivative or glycol uryl having a group in which the hydrogen atom of the amino group is substituted with a methylol group, an alkoxymethyl group or both, an average of 3.7 methoxymethyl groups are substituted per triazine ring. MX-750, MW-30 in which an average of 5.8 methoxymethyl groups are substituted per triazine ring (all manufactured by Sanwa Chemical Co., Ltd.); Cymel 300, Cymel 301, Cymel 303, Cymel 350, Cymel 370, Cymel 771, Cymel 325, Cymel 327, Cymel 703, Cymel 712 and other methoxymethylated melamines; Butoxymethylated melamines such as Cymel 506, Cymel 508; carboxy group-containing methoxymethylated isobutoxymethylated melamines such as Cymel 1141; methoxymethylated ethoxymethylated benzoguanamines such as Cymel 1123; Cymel 1123-10. Methyl methoxymethylated butoxymethylated benzoguanamine; butoxymethylated benzoguanamine such as Cymel 1128; carboxy group-containing methoxymethylated ethoxymethylated benzoguanamine such as Cymel 1125-80; butoxymethylated glycoluril such as Cymel 1172; Examples thereof include methylolated glycol urilu (all manufactured by Mitsui Sianamid Co., Ltd. (currently Nippon Cytec Industries Co., Ltd.)).

By applying the composition for forming a release layer of the present invention described above to a substrate and heating it, a thin film (release layer) made of polyimide having high heat resistance, appropriate flexibility, and an appropriate linear expansion coefficient. Can be obtained.

Examples of the substrate (base material) include glass, plastic (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy, melamine, triacetyl cellulose, ABS, AS, norbornene resin, etc.), metal (silicon wafer, etc.), and the like. Examples thereof include wood, paper, slate and the like, and those containing glass or silicon wafer are preferable. In particular, glass is more preferable because the release layer obtained from the release layer forming composition according to the present invention has sufficient adhesion to the release layer. The surface of the substrate may be made of a single material or may be made of two or more materials. As an embodiment in which the surface of the substrate is composed of two or more materials, a certain range of the surface of the substrate is composed of a certain material, and the remaining surface is composed of other materials, and a dot pattern is formed on the entire surface of the substrate. , A mode in which a patterned material such as a line-and-space pattern is present in other materials.

The method of coating is not particularly limited, but is, for example, a cast coating method, a spin coating method, a blade coating method, a dip coating method, a roll coating method, a bar coating method, a die coating method, an inkjet method, and a printing method (projection printing method). , Intaglio, lithographic printing, screen printing, etc.).

Further, as a method for imidizing the polyamic acid contained in the composition for forming a release layer of the present invention, thermal imidization in which the composition applied on the substrate is heated as it is, and heating by adding a catalyst to the composition are performed. Catalytic imidization to be performed.

For catalytic imidization of polyamic acid, a catalyst is added to the composition for forming a release layer of the present invention, and the catalyst-added composition is prepared by stirring, and then applied to a substrate and heated to form a resin thin film (release layer). ) Is obtained. The amount of the catalyst is 0.1 to 30 mol times, preferably 1 to 20 mol times, the amic acid group. Further, acetic anhydride or the like can be added as a dehydrating agent to the catalyst-added composition, and the amount thereof is 1 to 50 mol times, preferably 3 to 30 mol times, that of the amic acid group.

It is preferable to use a tertiary amine as the imidization catalyst. As the tertiary amine, pyridine, substituted pyridines, imidazole, substituted imidazoles, picoline, quinoline, isoquinoline and the like are preferable.

The heating temperature at the time of thermal imidization and catalytic imidization is usually appropriately determined within the range of 50 to 550 ° C, but is preferably 200 ° C or higher, and preferably 450 ° C or lower. By setting the heating temperature in this way, it becomes possible to sufficiently proceed the imidization reaction while preventing the resulting film from becoming fragile. The heating time cannot be unconditionally specified because it varies depending on the heating temperature, but it is usually 5 minutes to 5 hours. The imidization rate may be in the range of 50 to 100%.

As a preferable example of the heating embodiment in the present invention, considering the heat resistance of the obtained resin thin film and the versatility of the apparatus used, the applied composition is heated at 50 to 150 ° C. for 5 minutes to 2 hours and then stepwise as it is. A method of raising the heating temperature and finally heating at 200 to 300 ° C. for 30 minutes to 2 hours can be mentioned. In particular, it is preferable to heat at 80 to 120 ° C. for 5 to 30 minutes, and then at 230 to 300 ° C. for 30 minutes to 1 hour.

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

The thickness of the release layer is usually about 0.01 to 10 μm, preferably about 0.05 to 5 μm, and the thickness of the coating film before heating is adjusted to realize a resin thin film having a desired thickness.

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

Hereinafter, an example of a method for manufacturing a flexible electronic device using the release layer of the present invention will be described.
Using the composition for forming a release layer according to the present invention, a release layer is formed on a glass substrate by the above-mentioned method. A resin solution for forming a resin substrate is applied on the release layer, and the coating film is heated to form a resin substrate fixed to the glass substrate via the release layer according to the present invention. .. At this time, the resin substrate is formed with an area larger than the area of the release layer so as to cover the entire release layer. Examples of the resin substrate include a resin substrate made of a polyimide resin and an acrylic resin, which are typical resin substrates for flexible electronic devices, and examples of the resin solution for forming the resin substrate include a polyimide solution, a polyamic acid solution, and an acrylic polymer. The solution can be mentioned. The method for forming the resin substrate may be a conventional method.

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

In this case, the material to be peeled off may be one layer or a plurality of layers. In order to fabricate various devices, it is realistic to have multiple layers.
Of the layers to be peeled off, the layer directly above the peeling layer (usually the resin substrate) depends on the peeling layer used, but has good peelability from the peeling layer, in other words, adherence to the peeling layer used. It is better to use the one with poor sex.

The present invention also provides the following method for producing an object to be exfoliated.
A step of applying the composition for forming a release layer of the present invention onto a substrate and firing it to form a release layer.
Provided is a method for producing a peeled body, which comprises a step of forming a peeled body on the peeled layer and a step of peeling the peeled body from the peeled layer.

In the above-mentioned manufacturing method, the above-mentioned conditions can be adopted as the firing conditions for forming the release layer.
Further, the "exfoliated body" may be one layer or a plurality of layers. The layer directly above the peeling layer (usually the resin substrate) of the "exfoliated body" depends on the peeling layer used, but has good peelability from the peeling layer, in other words, the peeling layer used. It is better that the adhesiveness is not good.

Further, the present invention is a laminate applied to a flexible electronic device.
With the substrate
The peeling layer formed on the substrate and
It has a resin substrate formed on the release layer, the release layer is formed by the composition for forming a release layer of the present invention, and the adhesive force between the resin substrate and the release layer is the release layer. Provided is a laminate characterized by having a greater adhesion than the above-mentioned substrate.
The magnitude of the adhesion force referred to here can be confirmed, for example, by a cross-cut test or the like shown in Examples described later.

Hereinafter, the present invention will be described in more detail with reference to synthetic examples, comparative synthetic examples, examples and comparative examples, but the present invention is not limited to these examples.
[1] Abbreviation of compound NMP: N-methylpyrrolidone BCS: Butyl cellosolve PGME: Propropylene glycol Monomethyl ether TFMB: 2,2'-bis (trifluoromethyl) benzidine PCH7AB: 1- (trans-4-normal heptyl cyclohexyl) -2 , 4-Diaminobenzene m-PCH7AB: 1- (Trans-4-normal heptylcyclohexyl) -3,5-Diaminobenzene PBCH5DAB: 1,3-Diamino-4- {4- [Trans-4- (Trans-4-) n-pentylcyclohexyl) cyclohexyl] phenoxy} benzeneBPTP: bis (4-aminophenoxy) terephthalate CBDA: cyclobutanoic acid dianhydride PMDA: pyromellitic acid dianhydride BODAxx: bicyclo [2.2.2] octa-2-exo , 3-exo, 5-exo, 6-exo-tetracarboxylic acid-2, 3: 5,6-dianhydride

[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 are eluted using a GPC apparatus (column: Shodex® KF803L and KF805L) manufactured by Nippon Kogaku Co., Ltd. As a solvent, dimethylformamide was measured under the conditions of a flow rate of 1 mL / min and a column temperature of 50 ° C. In addition, Mw was a polystyrene conversion value.

[3] Polymer synthesis <Synthesis example S1 Synthesis of polyimide (S1) for film>
25.61 g (0.08 mol) of TFMB was placed in a 250 mL reaction three-necked flask equipped with a nitrogen inlet / outlet, a mechanical stirrer and a cooler. Then, 173.86 g of γ-butyrolactone was added, and stirring was started. Immediately after the TFMB was completely dissolved in the solvent, 10 g (0.04 mol) of stirred BODAxx, 7.84 g (0.04 mol) of CBDA and 43.4 g of γ-butyrolactone were added and heated to 140 ° C. under nitrogen. did. Then, 0.348 g of 1-ethylpiperidine was added into the solution, and the mixture was heated to 180 ° C. under nitrogen for 7 hours. Finally, heating was stopped, the reaction solution was diluted to 10% and stirring was maintained overnight. The polyimide reaction solution is added to 2,000 g of methanol and stirred for 30 minutes, and then the polyimide is purified by filtering the polyimide solid, and then the polyimide solid is stirred in 2,000 g of methanol for 30 minutes to obtain the polyimide solid. Filtered. The purification procedure of stirring and filtering the polyimide solid was repeated three times. The methanol residue in the polyimide was removed by drying in a vacuum oven at 150 ° C. for 8 hours to finally obtain 31.16 g of dried polyimide S1, but the weight percent yield of the polyimide S1 was 74% ( Mw = 169,802, Mn = 55,308).

<Synthesis example L1 Synthesis of polyamic acid (L1)>
4.022 g (9.253 mmol) of PBCH5DAB was dissolved in 44 g of NMP, 1.977 g (9.068 mmol) of PMDA was added, and then the reaction was carried out at 23 ° C. for 2 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 10,400 and the molecular weight distribution was 1.89.

<Synthesis example L2 Synthesis of polyamic acid (L2)>
3.842 g (10.10 mmol) of m-PCH7AB was dissolved in 44 g of NMP, 2.158 g (9.8934 mmol) of PMDA was added, and then the reaction was carried out at 23 ° C. for 2 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 173,900 and the molecular weight distribution was 4.19.

<Synthesis example L3 Synthesis of polyamic acid (L3)>
3.842 g (10.10 mmol) of PCH7AB was dissolved in 44 g of NMP, 2.158 g (9.8934 mmol) of PMDA was added, and then the reaction was carried out at 23 ° C. for 2 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 12,100 and the molecular weight distribution was 1.85.

<Synthesis example L4 Synthesis of polyamic acid (L4)>
PCH7AB 1.974 g (5.1883 mmol) and BPTP 1.807 g (5.1883 mmol) were dissolved in NMP 44 g, PMDA 2.218 g (10.17 mmol) was added, and then the mixture was reacted at 23 ° C. for 2 hours under a nitrogen atmosphere. rice field. The Mw of the obtained polymer was 53,700 and the molecular weight distribution was 1.89.

<Comparative synthesis example Polyamic acid (HL1) synthesis>
2.86 g (0.0089 mol) of TFMB was dissolved in 35.2 g of NMP, 1.944 g (0.00991 mol) of CBDA was added, and the mixture was reacted at 23 ° C. for 24 hours under a nitrogen atmosphere. The Mw of the obtained polymer was 69,200 and the molecular weight distribution was 2.2. The resulting solution was soluble in PGME.

[4] Preparation of Composition for Forming a Resin Substrate The polyimide S1 obtained in Synthesis Example S1 was dissolved in γ-butyrolactone in an amount of 15% by mass and used as a composition for forming a resin substrate.

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

[Examples 1-2 to 1-4]
The composition for forming a release layer L2 to the same method as in Example 1-1, except that the reaction solutions obtained in Synthesis Examples L2 to L4 were used instead of the reaction solutions obtained in Synthesis Example L1. Obtained L4.

[Comparative Example 1-1]
14 g of γ-butyrolactone was added to 20 g of MA-ST sol (silica sol manufactured by Nissan Chemical Industries, Ltd.), and methanol was distilled off under reduced pressure with an evaporator to prepare 20 g of a γ-butyrolactone solution of silica sol. On the other hand, 3 g of the polyimide S1 obtained in Synthesis Example S1 was dissolved in 67 g of the γ-butyrolactone solution to prepare a γ-butyrolactone solution of the polyimide S1. Then, the two solutions were stirred at 23 ° C. for 2 hours to obtain a release layer forming composition HL1.

[6] Preparation of release layer and resin substrate [Example 2-1]
Using a spin coater (condition: rotation speed of 3,000 rpm for about 30 seconds), the release layer forming composition L1 obtained in Example 1-1 was applied to a 100 mm × 100 mm glass substrate (same below) as a glass substrate. Applied on top.
Then, the obtained coating film was heated at 120 ° C. for 5 minutes using a hot plate, and then heated at 240 ° C. for 60 minutes in the presence of air using an oven, and the thickness was about 0. A 1 μm release layer was formed to obtain a glass substrate with a release layer.

Using a bar coater (gap: 250 μm), the composition for forming a resin substrate was applied onto the release layer (resin thin film) on the glass substrate. Then, the obtained coating film is heated at 120 ° C. for 10 minutes using a hot plate, and then heated at 250 ° C. for 60 minutes in the presence of air using an oven to have a thickness of about 20 μm on the release layer. A resin substrate was formed, and a resin substrate and a glass substrate with a release layer were obtained.

[Examples 2-2 to 2-4]
Except that the release layer forming compositions L2 to L4 obtained in Examples 1-2 to 1-4 were used instead of the release layer forming composition L1 obtained in Example 1-1, respectively. A release layer and a resin substrate were formed in the same manner as in Example 2-1 to prepare a glass substrate with a release layer and a resin substrate / a glass substrate with a release layer.

[Comparative Example 2-1]
The same as in Example 2-1 except that the release layer forming composition HL1 obtained in Comparative Example 1-1 was used instead of the release layer forming composition L1 obtained in Example 1-1. A release layer and a resin substrate were formed by the method, and a glass substrate with a release layer and a resin substrate / a glass substrate with a release layer were produced.

[7] Evaluation of peelability With respect to the glass substrate with a peeling layer obtained in Examples 2-1 to 2-4 and Comparative Example 2-1 above, the peelability between the peeling layer and the glass substrate was determined by the resin substrate / peeling layer. Regarding the attached glass substrate, the peelability between the release layer and the resin substrate was confirmed by the following method.
<Cross-cut test peelability evaluation of resin thin film>
The peeling layers on the glass substrate with the peeling layer obtained in Examples 2-1 to 2-4 and Comparative Example 2-1 were cross-cut (at intervals of 1 mm in length and width, the same applies hereinafter), and 100 muscats were performed. That is, by this cross cut, 100 squares of 1 mm square were formed.
Then, an adhesive tape was attached to the 100 muscat portion, the tape was peeled off, and the degree of peeling was evaluated based on the following criteria (5B to 0B, B, A, AA). The results are shown in Table 1.
<Judgment criteria>
5B: 0% peeling (no peeling)
4B: Peeling less than 5% 3B: Peeling less than 5-15% 2B: Peeling less than 15-35% 1B: Peeling less than 35-65% 0B: Peeling less than 65% -80% B: 80% -95 Peeling less than% A: Peeling from 95% to less than 100% AA: Peeling 100% (all peeling)

<Evaluation of initial peeling force of resin substrate>
The resin substrate of the resin substrate / glass substrate with a release layer obtained in Examples 2-1 to 2-4 and Comparative Example 2-1 was cut into strips having a width of 25 mm using a cutter. Then, a cellophane tape was attached to the tip of the cut resin substrate, and this was used as a test piece. This test piece is subjected to a peeling test using a push-pull tester manufactured by Atonic Co., Ltd. so that the peeling angle is 90 °, and the peeling force is determined based on the following criteria (5B to 0B, B, A, AA). evaluated. The results are shown in Table 1.
<Judgment criteria>
5B: 0% peeling (no peeling)
4B: Peeling less than 5% 3B: Peeling less than 5-15% 2B: Peeling less than 15-35% 1B: Peeling less than 35-65% 0B: Peeling less than 65% -80% B: 80% -95 Peeling less than% A: Peeling from 95% to less than 100% AA: Peeling 100% (all peeling)

As shown in Table 1, it was confirmed that the peeling layers of Examples 2 to 1 to 2-4 were excellent in adhesion to the glass substrate and also excellent in peelability to the resin substrate.
On the other hand, it was confirmed that the peeling layer of Comparative Example 2-1 was excellent in adhesion to the glass substrate but inferior in peelability to the resin substrate.

Claims (10)

A composition for forming a release layer containing a polyamic acid having a weight average molecular weight of 5,000 or more including a structural unit represented by the following formula (1) and an organic solvent.

[(In the formula, X ¹ represents a phenyl group or a biphenyl group, Z ¹ is a group represented by the following formula [Z 2], and n ¹ represents a natural number.)

(In the equation, Y ¹ represents a single bond, -O- or -NH-, and represents.
Y ⁵ represents a divalent cyclic group selected from the group consisting of a benzene ring and a cyclohexane ring.
n represents an integer of 1 to 3, and when n is 2 or more, Y ⁵ may be the same or different.
Y ⁶ represents an alkyl group having 1 to 18 carbon atoms. )] The composition for forming a release layer according to claim 1, wherein Z ¹ is a group represented by the following formula [Z 3], [Z 4] or [Z 5].

(In the formula, Y ⁶ represents an alkyl group having 1 to 18 carbon atoms independently of each other.) Claim 1 or 2 in which the organic solvent comprises at least one selected from the amides represented by the formula (S1), the amides represented by the formula (S2) and the amides represented by the formula (S3). The composition for forming a release layer according to the above.

(In the formula, R ¹ and R ² represent an alkyl group having 1 to 10 carbon atoms independently of each other, R ³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and h is a natural number. Represents.) A release layer formed by using the composition for forming a release layer according to any one of claims 1 to 3. A method for producing a release layer, which comprises applying the composition for forming a release layer according to any one of claims 1 to 3 onto a substrate and firing the composition. A step of applying the composition for forming a release layer according to any one of claims 1 to 3 onto a substrate and firing it to form a release layer.
A method for producing a stripped body, which comprises a step of forming a stripped body on the peeled layer and a step of peeling the stripped body from the peeled layer. A method for manufacturing a flexible electronic device including a resin substrate, which comprises using the release layer according to claim 4. A method for manufacturing a touch panel sensor including a resin substrate, which comprises using the release layer according to claim 4. The manufacturing method according to claim 7 or 8 , wherein the resin substrate is a polyimide resin substrate. A laminate applied to flexible electronic devices,
With the substrate
The peeling layer formed on the substrate and
It has a resin substrate formed on the release layer, the release layer is formed by the composition for forming a release layer according to any one of claims 1 to 3, and the resin substrate and the release layer are formed. A laminate characterized in that the adhesion with the peeling layer is greater than the adhesion between the release layer and the substrate.