TW201919912A - Method for manufacturing substrate for flexible device - Google Patents

Abstract

The purpose of the present invention is to provide a method for forming a resin thin film laminate that makes it possible to preserve the exceptional performance attributes of exceptional heat resistance, low retardation, exceptional flexibility, and exceptional transparency, said resin thin film laminate being applied to a plastic thin film having exceptional performance as a base film of a flexible device substrate such as a flexible display substrate that can be easily peeled from a glass carrier. A method for producing a resin thin film laminate, said resin thin film laminate being characterized in that after a peeling layer is formed on a support substrate using a peeling-layer-forming composition containing a heat resistant polymer and an organic solvent, a resin thin film is formed on the peeling layer using a resin thin film-forming composition containing a heat resistant polymer and an organic solvent, and the peeling layer and the resin thin film are subsequently peeled from the support substrate as a single entity, said method being further characterized in that silicon dioxide particles having an average particle diameter of 100 nm or less as calculated from the specific surface area measured by nitrogen adsorption are incorporated in substantially only the resin thin film-forming composition.

Description

Manufacturing method of flexible device substrate

The present invention relates to a method for manufacturing a substrate for a flexible device, particularly a resin film laminate used as a base film for a flexible printed circuit board such as a flexible display. More specifically, the present invention relates to a method for laminating a support substrate onto a substrate. A heat-resistant polymer laminate of a transparent laminate.

In recent years, with the rapid advancement of electronics in liquid crystal displays, organic electroluminescence displays, and the like, thinner or lighter devices have been demanded, and even the effect of flexibility has been demanded. In these devices, various electronic components are formed on a glass substrate, for example, a thin film transistor or a transparent electrode is formed. However, it is highly expected that the glass material can be replaced by a soft and lightweight resin material, and the device is expected. The body can be thinned, lightened, and flexible. Rhenium can be used as the type of these resin materials, and polyimide has attracted great attention. Therefore, there have been many reports about polyimide films.

For example, Patent Document 1 discloses an invention of a polyimide suitable as a plastic substrate for a flexible display and a precursor thereof, which is composed of a cycloaliphatic structure containing cyclohexyl tetracarboxylic acid and the like. Polyfluorene imide obtained by reacting carboxylic acids with various diamines has excellent transparency and heat resistance.

In addition, in Patent Document 2, the addition of silica gel to polyimide can improve the shortcomings of conventional plastic substrates, which cannot combine the effects of linear expansion coefficient, transparency, and low birefringence, and can be expected. Used in plastic substrates for flexible displays.

In addition, the mention of the advantages of plastic substrates often causes problems, that is, the rationality or dimensional stability of the plastic substrate body. That is, when a plastic substrate is formed into a thin film, it is extremely difficult to prevent wrinkles or cracks, or positional accuracy when a functional layer such as a thin film transistor (TFT) or an electrode is laminated, or to maintain dimensional accuracy after the functional layer is formed. Among them, in Non-Patent Document 1, a plastic substrate coated and fixed on glass is proposed. After forming a specific functional layer, a laser is irradiated from the glass side, and a plastic substrate having an organic energy layer is made of glass. Method of forced separation (so-called Laser Lift-Off process (EPLaR method (Electronics on Plastic by Laser Release) method). [Prior Art Documents] [Patent Documents]

[Patent Document 1] JP 2008-231327 [Patent Document 2] International Publication No. 2015/152178 [Non-Patent Document]

[Non-Patent Document 1] E.I. Haskal et. Al. "Flexible OLED Displays Made with the EPLaR Process", Proc. Eurodisplay '07, pp. 36-39 (2007)

[Problems to be solved by the invention]

In the technique described in the above-mentioned Non-Patent Document 1, in order to use glass as a support substrate, a functional layer is formed on a plastic substrate fixed to glass, and the handleability or dimensional stability of the resin substrate is ensured. However, this EPLaR method (laser lift-off method) uses a method in which the interface between the resin substrate and the support substrate is destroyed by laser irradiation when the resin substrate is separated from the support substrate, and therefore causes a problem. The impact of the laser light caused damage to the functional layer (TFT, etc.) around the irradiated part, or the resin substrate body was greatly damaged to reduce the transmittance, etc., and the resin substrate and the functions formed thereon The characteristics of the layer may deteriorate.

The present invention is to propose a plastic film having excellent properties to the base film of a flexible device substrate such as a flexible display substrate without relying on the above-mentioned laser lift-off technology, in view of those circumstances. A method for producing a resin film laminate, in particular, a resin that can maintain excellent properties such as excellent heat resistance, low retardation, excellent flexibility, and excellent transparency, and can ensure its handleability or dimensional stability The purpose is to produce a thin film laminate (a substrate for a flexible device). [Solution to the problem]

The inventors have conducted repeated and intensive studies to achieve the above-mentioned object, and found that when forming a resin film obtained by adding silicon dioxide to a heat-resistant polymer having both heat resistance and optical characteristics, The method of providing a release layer between the substrates can achieve a resin film laminate that maintains excellent heat resistance, low hysteresis, excellent softness, and excellent transparency, and is easily peeled from the supporting substrate. The present invention has been completed.

That is, the first aspect of the present invention is a method for manufacturing a resin film laminate, which is characterized by comprising: forming a release layer containing a heat-resistant polymer A and an organic solvent on a supporting substrate; A step of forming a release layer from a composition, a step of forming a resin film on the release layer using a composition for forming a resin film containing a heat-resistant polymer B and an organic solvent, and releasing the release layer from the supporting substrate together with the resin film And the step of preparing a resin film laminate; the composition for forming a resin film further contains silicon dioxide particles having an average particle diameter of 100 nm or less calculated from a specific surface area value measured by a nitrogen adsorption method, but the aforementioned peeling The layer-forming composition does not contain silicon dioxide particles. The second viewpoint is the manufacturing method according to the first viewpoint, wherein the heat-resistant polymer A and the heat-resistant polymer B are the same polymer. A third aspect is the production method according to the first aspect, wherein the heat-resistant polymer A and the heat-resistant polymer B are each independently made of polyimide, polybenzoxazole, or polybenzobisoxane A polymer selected from at least one of azole, polybenzimidazole and polybenzothiazole. A fourth aspect is the production method according to the first aspect, wherein the heat-resistant polymer A and the heat-resistant polymer B are each independently a tetracarboxylic dianhydride component containing an alicyclic tetracarboxylic dianhydride Polyfluorene acid obtained by reacting with a diamine component containing a fluorine-containing aromatic diamine, and polyfluorene imine obtained by fluorene imidization. A fifth aspect is the production method according to the fourth aspect, wherein the alicyclic tetracarboxylic dianhydride includes the tetracarboxylic dianhydride represented by the formula (C1). [In the formula, B ¹ represents a 4-valent basis selected from the group consisting of formulas (X-1) to (X-12). (In the formula, plural R represents a hydrogen atom or a methyl group independent of each other, and * represents a bonding bond)]. A sixth aspect is the production method according to the fourth aspect, wherein the fluorine-containing aromatic diamine includes a diamine represented by the formula (A1) (In the formula, B ² represents a divalent basis selected from the group consisting of formulae (Y-1) to (Y-34)). (In the formula, * represents a bond bond). A seventh aspect is the manufacturing method according to the fourth aspect, wherein the polyimide includes a monomer unit represented by formula (1), a monomer unit represented by formula (2), or a combination thereof Single unit. An eighth aspect is the manufacturing method according to the first aspect, wherein the composition for forming a resin film contains the heat-resistant polymer B and the silica particles in a mass ratio of 7: 3 to 3: 7. . A ninth aspect is the manufacturing method according to the first aspect, wherein the silicon dioxide particles have an average particle diameter of 60 nm or less. A tenth aspect is the manufacturing method according to the first aspect, wherein the composition for forming a release layer or the composition for forming a resin film further contains a crosslinking agent. An eleventh aspect is the manufacturing method according to the first aspect, which is a case where the method is cured by heat or ultraviolet rays. A twelfth aspect is the manufacturing method according to the first aspect, wherein the adhesiveness between the release layer and the resin film can be peeled from 0 to 5% in the CCJ series (JIS5400) classification, and the support substrate Adhesiveness to the aforementioned release layer can be removed by 50% in the CCJ series (JIS5400) classification. A thirteenth aspect is the manufacturing method according to the first aspect, wherein the release layer has a thickness of 100 μm to 1 nm. A fourteenth aspect is the production method according to the first aspect, wherein the step of preparing the resin film laminate is performed by a method selected by cutting with a blade, mechanical separation, and tensile peeling. A fifteenth aspect is a flexible substrate produced by the manufacturing method according to any one of the first aspect to the fourteenth aspect. [Effect of the invention]

According to the method for producing a resin film laminate according to one aspect of the present invention, since the resin film laminate is easily peeled from the supporting substrate, it can be easily produced with sufficient reproducibility without compromising low linear expansion. Resin film laminate with properties such as coefficient, excellent heat resistance, low hysteresis, and excellent flexibility. In addition, the obtained resin film laminate exhibits low coefficient of linear expansion, high transparency (high light transmittance, low yellowness), and low hysteresis. In addition, it also has excellent flexibility, so it is extremely suitable for use in Flexible devices, especially substrates for flexible displays. The aforementioned method for producing a resin film laminate of the present invention can fully correspond to characteristics requiring high flexibility, low coefficient of linear expansion, high transparency (high light transmittance, low yellowness), and low hysteresis. Progress in the field of substrates for flexible devices, particularly substrates for flexible displays.

Hereinafter, the present invention will be described in detail. The method for producing a resin film laminate of the present invention is to use a composition for forming a release layer containing a heat-resistant polymer A and an organic solvent on a supporting substrate to form a release layer, and then use the heat-resistant polymer B and an organic solvent. In the composition for forming a resin film, a resin film is formed on the release layer, and the release layer and the resin film are integrated (as a whole) to be peeled off from the supporting substrate to obtain a resin film laminate. The composition for forming a thin film further contains silicon dioxide particles having an average particle diameter of 100 nm or less calculated from a specific surface area value measured by a nitrogen adsorption method. From the viewpoint of achieving the effect of the present invention, it is an essential feature that the silicon dioxide particles are substantially contained only in the composition for forming a resin film, and that the silicon dioxide particles are not substantially contained in the composition for forming a release layer. In addition, the meaning of the silicon dioxide particles in the present invention is "substantially not contained", which means that they are not included in the manufacturing process of the composition, etc., and exclude the meaning of unintentional mixing of silicon dioxide particles. When mixing occurs, the content of the heat-resistant polymer B in the composition for forming a release layer is lower than the content of silicon dioxide particles in the heat-resistant polymer A of the composition for forming a resin film. meaning. It is assumed that the content of the silicon dioxide particles when the composition for forming the peeling layer is mixed with the silicon dioxide particles is, specifically, less than the content of the silicon dioxide particles relative to the content of the heat-resistant polymer A of the composition for forming a resin film. 5% is better. Hereinafter, first, each component constituting these compositions in the composition for forming a release layer and the composition for forming a resin film used in the method for producing a resin film laminate will be described.

[Heat-resistant polymer (A and B)] The composition for forming a release layer and the composition for forming a resin film used in the present invention include a heat-resistant polymer A and a heat-resistant polymer B, respectively. In the present invention, it is preferable that the heat-resistant polymer A contained in the composition for forming a release layer is the same as the heat-resistant polymer B contained in the composition for forming a resin film (hereinafter, the heat-resistant polymer A and heat-resistant Polymer B, also collectively referred to as heat-resistant polymer).的 The heat-resistant polymer used in the present invention is preferably at least one selected from the group consisting of polyimide, polybenzoxazole, polybenzobisoxazole, polybenzimidazole, and polybenzothiazole. Among them, polyfluorene imine is more preferable, in particular, a specific polyfluorene imide described later, that is, a tetracarboxylic dianhydride component containing an alicyclic tetracarboxylic dianhydride and a fluorine-containing aromatic diamine The polyamidoacid obtained by the reaction of the diamine component is preferably the polyamidoimide obtained by the imidization. In addition, in the description of the present case, the heat-resistant polymer means a polymer having a weight reduction of 5% or less at a temperature of 350 ° C or higher.

[Polyimide] In the present invention, a polyimide suitable for use is a reaction of a tetracarboxylic dianhydride component containing an alicyclic tetracarboxylic dianhydride and a diamine component containing a fluorine-containing aromatic diamine. The polyimide obtained is polyimide obtained by imidization. Among them, those in which the alicyclic tetracarboxylic dianhydride contains a tetracarboxylic dianhydride represented by the following formula (C1), and the fluorine-containing aromatic diamine contains a compound represented by the following formula (A1) Diamine is preferred.

[In the formula, B ¹ represents a 4-valent basis selected from the group consisting of formulas (X-1) to (X-12). (In the formula, plural R represents a hydrogen atom or a methyl group independent of each other, and * represents a bonding bond)].

(In the formula, B ² represents a divalent basis selected from the group consisting of formulae (Y-1) to (Y-34)). (In the formula, * represents a bond bond).

Among the tetracarboxylic dianhydrides represented by the formula (C1), B ¹ in the formula is represented by the formulas (X-1), (X-4), (X-6), and (X-7). Compounds are preferred. Among the diamines represented by the above (A1), B ² in the formula is preferably a compound represented by the formulae (Y-12) and (Y-13). A preferred example is a polyfluorene acid obtained by reacting a tetracarboxylic dianhydride represented by the above formula (C1) with a diamine represented by the above formula (A1), and a polyfluorene obtained by imidization. The imine includes a monomer unit represented by the formula (2) described later.

For the purpose of preparing a resin film laminate having the characteristics of low linear expansion coefficient, low hysteresis, and high transparency, and excellent softness, the alicyclic ring is relative to the total mole number of the tetracarboxylic dianhydride component. The tetracarboxylic dianhydride of the formula, for example, the tetracarboxylic dianhydride represented by the above formula (C1) is preferably 90 mol% or more, more preferably 95 mol% or more, and particularly all (100 mol%) Tetracarboxylic dianhydride represented by the above formula (C1) is most preferred. Also, similarly, in order to obtain a resin film laminate having the above-mentioned low linear expansion coefficient, low hysteresis, and high transparency and excellent flexibility, the fluorine-containing aromatic compound is relative to the total mole number of the diamine component. The group diamine, for example, the diamine represented by the formula (A1) is preferably 90 mol% or more, and more preferably 95 mol% or more. Moreover, the diamine component (100 mol%) may be all the diamine represented by said Formula (A1).

An example of a preferable aspect is that the polyimide used in the present invention contains a monomer unit represented by the following formula (1).

The monomer unit represented by the formula (1) is preferably represented by the formula (1-1) or (1-2), and more preferably represented by the formula (1-1).

According to a preferred embodiment of the present invention, the polyimide used in the present invention contains a monomer unit represented by the formula (2). The polyfluorene imide used in the present invention may contain both a monomer unit represented by the formula (1) and a monomer unit represented by the formula (2).

The monomer unit represented by the formula (2) is preferably represented by the formula (2-1) or (2-2), and more preferably represented by the formula (2-1).

When the polyfluorene imine used in the present invention contains the monomer unit represented by the above formula (1) and the monomer unit represented by the formula (2), the molar ratio of the polyfluorene imine chain is represented by the formula The monomer unit represented by (1): The ratio of the monomer unit represented by formula (2) = 10: 1 to 1:10 is more preferable, and the ratio of 10: 1 to 3: 1 is more preferable.

The polyfluorene imide of the present invention, in addition to the alicyclic tetracarboxylic dianhydride component containing the tetracarboxylic dianhydride represented by the aforementioned formula (C1), and the diamine component containing the diamine represented by the formula (A1) The derived monomer unit may include other monomer units in addition to the monomer units represented by the formulas (1) and (2). The content ratio of the other monomer units can be arbitrarily determined as long as the characteristics of the resin film laminate formed by the composition for forming a release layer and the resin film formation of the present invention are not impaired. This ratio is based on the ratio of the alicyclic tetracarboxylic dianhydride component containing the tetracarboxylic dianhydride represented by the formula (C1) to the monoamine derived from the diamine component containing the diamine represented by the formula (A1). The bulk unit is, for example, a molar unit represented by the formula (1) or a mole number of the monomer unit represented by the formula (2), or a monomer unit represented by the formula (1) and the unit represented by the formula (2). The total number of moles of the monomer unit is preferably less than 20 mole%, more preferably less than 10 mole%, and more preferably less than 5 mole%.

These other monomer units are, for example, monomer units having other polyfluorene imine structures represented by formula (3), but they are not limited to these.

In formula (3), A represents a tetravalent organic group, and is preferably a tetravalent group represented by any one of the following formulae (A-1) to (A-4). In the above formula (3), B represents a divalent organic group, and is preferably a divalent group represented by any one of the following formulae (B-1) to (B-11). In each formula, * represents a bond. When A is a tetravalent base represented by any of the following formulae (A-1) to (A-4) in formula (3), B may be the formulae (Y-1) to (Y -34) when the divalent base represented by any one of formulas (3) or B is a divalent base represented by any one of the following formulae (B-1) to (B-11) A may be a tetravalent base represented by any one of the aforementioned formulae (X-1) to (X-12).

When the polyfluorene imide used in the present invention contains a monomer unit represented by the formula (3), A and B may contain, for example, only a monomer unit composed of only one of the groups exemplified by the following formula At least one of A, B and B may be a monomer unit containing two or more kinds selected from two or more kinds of groups exemplified below. In the following formula, * represents a bond.

In the polyfluorene imine used in the present invention, the monomer units can be combined in any order.

A preferred example is a polyimide having a monomer unit represented by the above formula (1), which is composed of a bicyclic [2,2,2] octane-2,3, which is a tetracarboxylic dianhydride component. 5,6-tetracarboxylic dianhydride and a diamine represented by the following formula (4) as a diamine component are polymerized in an organic solvent to obtain a polyfluorinated acid, which is obtained by imidization. When the polyfluorene imine used in the present invention has a monomer unit represented by the formula (2), the polyfluorene imide is composed of 1,2,3,4 as a tetracarboxylic dianhydride component. -Cyclobutane tetracarboxylic dianhydride and a polyamine obtained by polymerizing a diamine represented by the following formula (4) as a diamine component in an organic solvent; In addition, the polyfluorene imide used in the present invention contains a monomer unit represented by the formula (2) in addition to the monomer unit represented by the formula (1), and contains the formula (1) and the formula (2). Polyimide of each monomer unit represented by) is composed of tetracarboxylic dianhydride as the tetracarboxylic dianhydride component, and 1,2,3,4-cyclobutane tetracarboxylic dianhydride A polyamidic acid obtained by polymerizing a diamine represented by the following formula (4) as a diamine component in an organic solvent is obtained by sulfonation.

The diamine represented by the formula (4) is, for example, 2,2'-bis (trifluoromethyl) benzidine, 3,3'-bis (trifluoromethyl) benzidine, 2,3'-bis ( Trifluoromethyl) benzidine and the like. Among them, the point that the linear expansion coefficient of the diamine component is lower than the linear expansion coefficient of the resin film laminate of the present invention, and the transparency is higher than the transparency of the resin film laminate. The 2,2'-bis (trifluoromethyl) benzidine represented by the formula (4-1) or the 3,3'-bis (trifluoromethyl) benzidine represented by the following formula (4-2) Preferably, 2,2'-bis (trifluoromethyl) benzidine is used.

The polyfluorene imide used in the present invention is an alicyclic tetracarboxylic dianhydride component having a tetracarboxylic dianhydride represented by the aforementioned formula (C1), and contains a dicarboxylic acid represented by the formula (A1). The monomer unit derived from the diamine component of the amine has, for example, a monomer unit represented by the formula (1) and a monomer unit represented by the formula (2), and has other monomers represented by the formula (3). In the case of a bulk unit, polyimide containing each monomer unit represented by formula (1), formula (2), and formula (3) is composed of the above two types of tetracarboxylic acid dianhydride as a tetracarboxylic dianhydride component. In addition to the anhydride, a tetracarboxylic dianhydride represented by the following formula (5), a diamine represented by the above formula (4) as a diamine component, and a diamine represented by the following formula (6) are organic. The polyfluorinated acid obtained by polymerization in a solvent is obtained by fluorimidination.

A in formula (5) and B in formula (6) have the same meanings as A and B in formula (3), respectively.

Specifically, the tetracarboxylic dianhydride represented by Formula (5) is, for example, pyromellitic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3', 4 , 4'-benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3', 4,4'-diphenylphosphonium tetracarboxylic acid Dianhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic dianhydride, 11,11-bis (trifluoromethyl) -1H-difluoro [3,4-b: 3', 4 ' -i] dibenzopiperan-1,3,7,9- (11H-tetraone), 6,6'-bis (trifluoromethyl)-[5,5'-diisobenzofuran]- 1,1 ', 3,3'-tetraone, 4,6,10,12-tetrafluorodifluoro [3,4-b: 3', 4'-i] dibenzo [b, e] [1 , 4] dioxane-1,3,7,9-tetraone, 4,8-bis (trifluoromethoxy) benzo [1,2-c: 4,5-c '] di Furan-1,3,5,7-tetraone, and N, N '-[2,2'-bis (trifluoromethyl) biphenyl-4,4'-diyl] bis (1,3-di Oxa-1,3-dihydroisobenzofuran-5-carboxamide) and other aromatic tetracarboxylic acids; 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid Dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1 , 2,3,4-cyclohexanetetracarboxylic dianhydride, and 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride Alicyclic tetracarboxylic dianhydride; and 1,2,3,4-butane tetracarboxylic dianhydride and aliphatic tetracarboxylic dianhydride and the like, but is not limited to the plurality of content. Among these, A in formula (5) is preferably a tetravalent dianhydride having a tetravalent group represented by any one of the aforementioned formulae (A-1) to (A-4), that is, 11,11-bis (trifluoromethyl) -1H-difluoro [3,4-b: 3 ', 4'-i] dibenzopiperan-1,3,7,9- (11H-tetraone ), 6,6'-bis (trifluoromethyl)-[5,5'-diisobenzofuran] -1,1 ', 3,3'-tetraone, 4,6,10,12-tetrakis Fluorodifluoro [3,4-b: 3 ', 4'-i] dibenzo [b, e] [1,4] dioxane-1,3,7,9-tetraone, and 4,8-bis (trifluoromethoxy) benzo [1,2-c: 4,5-c '] difuran-1,3,5,7-tetraone is a preferred exemplary compound.

The diamine represented by formula (6) is, for example, 2- (trifluoromethyl) benzene-1,4-diamine, 5- (trifluoromethyl) benzene-1,3-diamine, 5- (Trifluoromethyl) benzene-1,2-diamine, 2,5-bis (trifluoromethyl) -benzene-1,4-diamine, 2,3-bis (trifluoromethyl) -benzene- 1,4-diamine, 2,6-bis (trifluoromethyl) -benzene-1,4-diamine, 3,5-bis (trifluoromethyl) -benzene-1,2-diamine, tetra (Trifluoromethyl) -1,4-phenylene diamine, 2- (trifluoromethyl) -1,3-phenylene diamine, 4- (trifluoromethyl) -1,3-phenylene diamine Amine, 2-methoxy-1,4-phenylenediamine, 2,5-dimethoxy-1,4-phenylenediamine, 2-hydroxy-1,4-phenylenediamine, 2, 5-dihydroxy-1,4-phenylene diamine, 2-fluorobenzene-1,4-diamine, 2,5-difluorobenzene-1,4-diamine, 2-chlorobenzene-1,4- Diamine, 2,5-dichlorobenzene-1,4-diamine, 2,3,5,6-tetrafluorobenzene-1,4-diamine, 4,4 '-(perfluoropropane-2,2 -Diyl) diphenylamine, 4,4'-oxobis [3- (trifluoromethyl) aniline], 1,4-bis (4-aminophenoxy) benzene, 1,3'-bis ( 4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, benzidine, 2-methylbenzidine, 3-methylbenzidine, 2- (trifluoromethyl) ) Benzidine, 3- (trifluoromethyl) benzidine, 2,2'-dimethylbenzidine (m-toluidine), 3, 3'-dimethylbenzidine (o-toluidine), 2,3'-dimethylbenzidine, 2,2'-dimethoxybenzidine, 3,3'-dimethoxybenzidine, 2,3'-dimethoxybenzidine, 2,2'-dihydroxybenzidine, 3,3'-dihydroxybenzidine, 2,3'-dihydroxybenzidine, 2,2'-difluorobenzidine Aniline, 3,3'-difluorobenzidine, 2,3'-difluorobenzidine, 2,2'-dichlorobenzidine, 3,3'-dichlorobenzidine, 2,3'-dichlorobenzidine Aniline, 4,4'-diaminobenzidine aniline, 4-aminophenyl-4'-aminobenzoate, octafluorobenzidine, 2,2 ', 5,5'-tetramethyl Benzidine, 3,3 ', 5,5'-tetramethylbenzidine, 2,2', 5,5'-tetrakis (trifluoromethyl) benzidine, 3,3 ', 5,5'-tetra (Trifluoromethyl) benzidine, 2,2 ', 5,5'-tetrachlorobenzidine, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3 -Aminophenoxy) biphenyl, 4,4'-fluorene [3,3 "-bis (trifluoromethyl)-(1,1 ': 3', 1" -bitriphenyl) -4,4 "-Diyl] -bis (oxy) fluorene diphenylamine, 4,4'-fluorene [(perfluoropropane-2,2-diyl) bis (4,1-phenylene)] bis (oxy) Perylene diphenylamine, and 1- (4-aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-indene-5 ( 6) Aromatic diamines such as amines; 4,4'-methylenebis (cyclohexylamine), 4,4'-methylenebis (3-methylcyclohexylamine), isophoronediamine , Trans-1,4-cyclohexanediamine, cis-1,4-cyclohexanediamine, 1,4-cyclohexanebis (methylamine), 2,5-bis (aminemethyl) bicyclo [2.2.1] heptane, 2,6-bis (aminemethyl) bicyclo [2.2.1] heptane, 3,8-bis (aminemethyl) tricyclo [5.2.1.0] decane, 1, 3-diamine fund adamantane, 2,2-bis (4-aminocyclohexyl) propane, 2,2-bis (4-aminocyclohexyl) hexafluoropropane, 1,3-propanediamine, 1, 4-Tetramethylenediamine, 1,5-Tetramethylenediamine, 1,6-Tetramethylenediamine, 1,7-Tetramethylenediamine, 1,8-Tetramethylenediamine, and 1, Aliphatic diamines such as 9-methylene diamine and the like are not limited to these. Among these, B in the formula (6) is preferably a divalent aromatic diamine represented by any one of the aforementioned formulae (B-1) to (B-11), that is, 2 , 2'-bis (trifluoromethoxy)-(1,1'-biphenyl) -4,4'-diamine [also known as: 2,2'-dimethoxybenzidine], 4,4 '-(Perfluoropropane-2,2-diyl) diphenylamine, 2,5-bis (trifluoromethyl) benzene-1,4-diamine, 2- (trifluoromethyl) benzene-1,4 -Diamine, 2-fluorobenzene-1,4-diamine, 4,4'-oxobis [3- (trifluoromethyl) aniline], 2,2 ', 3,3', 5,5 ' , 6,6'-octafluoro [1,1'-biphenyl] -4,4'-diamine [also known as: octafluorobenzidine], 2,3,5,6-tetrafluorobenzene-1,4 -Diamine, 4,4'-fluorene [3,3 "-bis (trifluoromethyl)-(1,1 ': 3', 1" -bitriphenyl) -4,4 "-diyl]- Bis (oxy) fluorene diphenylamine, 4,4'-fluorene [(perfluoropropane-2,2-diyl) bis (4,1-phenylene)] bis (oxy) fluorene diphenylamine, and 1 -(4-Aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-indene-5 (or 6) amine is an example of a preferred diamine.

<Synthesis of Polyamic Acid> As described above, the polyimide used in the present invention is a tetracarboxylic dianhydride component containing an alicyclic tetracarboxylic dianhydride represented by the above formula (C1). A polyamidic acid obtained by reacting with a diamine component containing a fluorine-containing aromatic diamine represented by the above formula (A1), which is obtained by imidization. Specifically, for example, a preferred one is exemplified by bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, preferably 1,2,3,4-ring The butane tetracarboxylic dianhydride is more preferably a tetracarboxylic dianhydride component formed by combining the tetracarboxylic dianhydride represented by the above-mentioned formula (5) expected to be used with the dicarboxylic acid dianhydride represented by the above-mentioned formula (4). The amine and the diamine component formed by blending the diamine component represented by the formula (6) used above are prepared by polymerizing a polyamic acid in an organic solvent and subjecting it to imidization.反应 The reaction of generating polyamic acid from the two components described above is advantageous because it can be carried out more easily in an organic solvent and no by-products are formed.

When the tetracarboxylic dianhydride component reacts with the diamine component, the addition ratio (mole ratio) of the diamine component can be determined by considering polyamic acid or polyimide obtained by subsequent imidization. The molecular weight of the amine is appropriately set. Generally, the tetracarboxylic dianhydride component is generally about 0.8 to 1.2, such as about 0.9 to 1.1, and preferably about 0.95 to 1.02 with respect to the diamine component 1. As with a normal polycondensation reaction, the molecular weight of the polyamidic acid produced when the molar ratio is closer to 1.0 is larger.

The organic solvent used when the tetracarboxylic dianhydride component reacts with the diamine component is not particularly limited as long as it does not adversely affect the reaction and can dissolve the generated polyamic acid. This specific example will be listed below. For example, m-cresol, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N, N- Dimethylformamide, N, N-dimethylacetamide, 3-methoxy-N, N-dimethylpropylamide, 3-ethoxy-N, N-dimethylpropyl Pyridoxamine, 3-propoxy-N, N-dimethylpropylpyridine, 3-isopropoxy-N, N-dimethylpropylpyridine, 3-butoxy-N, N -Dimethylpropylamidamine, 3-sec-butoxy-N, N-dimethylpropylamidamine, 3-tert-butoxy-N, N-dimethylpropylamidamine, γ -Butyrolactone, N-methylcaprolactam, dimethyl sulfene, tetramethyl urea, pyridine, dimethyl fluorene, hexamethyl fluorene, isopropanol, methoxymethylpentanol, dimethyl Pentene, ethylpentanone, methyl nonanone, methyl ethyl ketone, methyl isopentanone, methyl isoacetone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, Ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, Propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl , Dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, Dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl -3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, pentyl acetate, butyl butyrate, butyl ether, diisobutanone, methylcyclohexene, di Propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, acetic acid Methyl ester, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, isopropyl 3-ethoxypropionate, 3 -Ethyl methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diethylene glycol di Ether (glyme), and 4-hydroxy-4-methyl-2-pentanone, etc., but not Only limited to these contents. These can be used individually or in combination of 2 or more types. In addition, even if the solvent of the polyamic acid is not dissolved, as long as the range of the generated polyamic acid is not precipitated, it can be mixed and used in the above-mentioned solvent. In addition, the moisture in the organic solvent is to hinder the polymerization reaction and to cause hydrolysis of the produced polyamic acid. Therefore, it is preferable to use as much organic solvent as possible for dehydration and drying.

For the method for reacting the tetracarboxylic dianhydride component and the diamine component in an organic solvent, for example, a dispersion or solution obtained by dispersing or dissolving the diamine component in an organic solvent may be used for stirring, and then the tetracarboxylic acid di A method for adding an anhydride component without treatment, a method for adding a solution obtained by dispersing or dissolving a tetracarboxylic acid component in an organic solvent, and a dispersion obtained by dispersing or dissolving an organic solvent in which a tetracarboxylic dianhydride component is dispersed or dissolved A method of adding a diamine component to a solution or a solution, or a method of alternately adding a tetracarboxylic dianhydride component and a diamine compound component, etc., any of these methods may be used. In addition, when the tetracarboxylic dianhydride component and / or the diamine component are formed of a plurality of types of compounds, the reaction may be performed in a state of being mixed in advance, or the reactions may be performed sequentially or individually. The subsequent low-molecular weight body may be mixed to form a high-molecular weight body.

The temperature during the synthesis of the polyamic acid can be appropriately set within the range from the melting point to the boiling point of the solvent used above. For example, an arbitrary temperature between -20 ° C and 150 ° C can be selected, and -5 ° C- 150 ° C, usually about 0 to 150 ° C, preferably about 0 to 140 ° C. The reaction time cannot be generalized depending on the reaction temperature or the reactivity of the raw materials, but it is usually about 1 to 100 hours. In addition, the reaction can be carried out at an arbitrary concentration. When the concentration is too low, it is difficult to obtain a polymer with a high molecular weight. When the concentration is too high, the viscosity of the reaction solution is too high, and it is difficult to perform uniform stirring. The total concentration of the acid dianhydride component and the diamine component in the reaction solution is preferably 1 to 50% by mass, and more preferably 5 to 40% by mass. Alternatively, the reaction may be performed at a high concentration in the initial stage, and thereafter, an organic solvent may be added.

<Polyimide-based imidization> 方法 A method for polyimide-based imidization, for example, heating a polyamic acid solution without heating, imidization, and a polyamic-acid solution The catalyst is added to the catalyst, such as imidization. The temperature at which the polyamidoacid is subjected to thermal hydrazone imidization in a solution is 100 ° C to 400 ° C, preferably 120 ° C to 250 ° C, and the water generated by the hydrazone imidization reaction is discharged to the reaction system It is better to do it in other ways.

Chemical (catalyst) / imidization of polyamic acid, can add alkaline catalyst and acid anhydride to polyamic acid solution, at -20 ～ 250 ℃, preferably 0 ～ 180 ℃ Next, the system is stirred in the reaction system. The amount of the alkaline catalyst is 0.5 to 30 mol times, preferably 1.5 to 20 mol times, of the phosphonium groups of the polyamic acid. The amount of the acid anhydride is 1 to 1 mol of the phosphonium groups of the polyamic acid. 50 mole times, preferably 2 to 30 mole times.

Basic catalysts, for example, pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and 1-ethylpiperidine. Among them, pyridine and 1-ethylpiperidine are used in the reaction. It is preferable to maintain moderate alkalinity. For example, acetic anhydride, such as acetic anhydride, trimellitic anhydride, and pyromellitic anhydride, and the like, when acetic anhydride is used, it is easy to purify after the reaction is completed, and it is more preferable. Catalyst 醯 Imidization rate can be controlled by adjusting the amount of catalyst and reaction temperature and reaction time.

In the polyfluorene imide resin used in the present invention, the dehydration ring closure rate (fluorine imidization rate) of the amino acid group is not necessarily 100%, and it can be arbitrarily adjusted according to the use or purpose. Usually, it is particularly preferably 50% or more.

In the present invention, after filtering the above reaction solution, the filtrate may be used without processing. Alternatively, the reaction solution may be diluted or concentrated as a composition for forming a peeling layer, or silicon dioxide described later may be added thereto. The formed resin film-forming composition may also be used. After the aforementioned filtration, not only the mixing of impurities that cause deterioration of the heat resistance, flexibility, or coefficient of linear expansion coefficient of the obtained resin film laminate can be reduced, but also an effective composition for forming a peeling layer can be obtained. Composition with resin film.

In addition, the polyimide used in the present invention is analyzed by gel permeation chromatography in consideration of the strength of the resin film laminate, workability when forming the resin film laminate, and the uniformity of the resin film laminate. The polystyrene-equivalent weight average molecular weight (Mw) of the GPC is preferably 5,000 to 200,000.

<Polymer Recovery> (1) When polymer components are recovered and used from the reaction solution of polyamic acid and polyimide, as long as the reaction solution is put into a poor solvent to precipitate it. Examples of the lean solvent used for the precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water. After filtering and recovering the polymer precipitated by the lean solvent, it can be dried at normal temperature or heating under normal pressure or reduced pressure. In addition, when the polymer recovered by precipitation is redissolved in an organic solvent, and the operation of reprecipitation recovery (reprecipitation recovery step) is repeated 2 to 10 times, impurities in the polymer can be reduced. The lean solvent at this time, for example, when three or more kinds of lean solvents such as alcohols, ketones, and hydrocarbons are used, the efficiency of purification can be further improved, which is better.

In the reprecipitation recovery step, the organic solvent that dissolves the resin component is not particularly limited. Specific examples are N, N-dimethylformamidine, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone , N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, dimethyl sulfene, tetramethyl urea, pyridine, dimethyl fluorene, hexamethyl fluorene, γ-butane Lactone, 1,3-dimethyl-imidazolinone, dipentene, ethylpentanone, methylnonanone, methyl ethyl ketone, methyl isopentanone, methyl isoacetone, cyclohexanone, ethylene carbonate, Propylene carbonate, glyme, and 4-hydroxy-4-methyl-2-pentanone. These solvents can be used by mixing two or more kinds.

[Silicon dioxide] 矽 The silicon dioxide (silicon dioxide) used in the composition for forming a resin film of the present invention is not particularly limited. The particle size of the silicon dioxide, for example, is 100 nm or less, for example, 5 nm to 100 nm, 5 nm to 60 nm, preferably 5 nm to 55 nm, etc. From the viewpoint of making the highly transparent film excellent in reproducibility, it is preferably 5 nm to 50 nm, more preferably 5 nm to 45 nm, most preferably 5 nm to 35 nm, and more. It is preferably 5 nm to 30 nm.的 The average particle diameter of the silicon dioxide particles in the present invention is an average particle diameter value calculated from a specific surface area value measured by a nitrogen adsorption method using the silicon dioxide particles.

In particular, in the present invention, it is preferable to use colloidal silica having the above-mentioned average particle diameter value. As the colloidal silica, a silica gel can be used. Silica dioxide gel can be obtained by using an aqueous solution of sodium silicate as a raw material, an aqueous silica gel prepared according to a known method, and water used as a dispersion medium of the aqueous silica gel being replaced by an organic solvent. Organic silica gel and so on. In addition, an alkoxysilane such as methyl silicate or ethyl silicate is present in the presence of an organic solvent such as an alcohol and a catalyst (for example, an alkali catalyst such as ammonia, an organic amine compound, or sodium hydroxide). A silica gel obtained by hydrolysis and condensation, or an organic silica gel obtained by replacing the silica gel with another organic solvent by a solvent. Among these, the present invention is preferably an organic silica gel using a dispersing medium as an organic solvent.

Examples of the organic solvent in the above-mentioned organic silica gel, for example, lower alcohols such as methanol, ethanol, and isopropanol; N, N-dimethylformamide, N, N-dimethylacetamide, and the like Linear amidines; cyclic amines such as N-methyl-2-pyrrolidone; ethers such as γ-butyrolactone; glycols such as ethyl cellosolve, ethylene glycol, Acetonitrile, etc. This substitution method can be performed by a general method such as a distillation method and an ultrafiltration method. The viscosity of the above-mentioned organic silica gel is about 0.6 mPa · s to 100 mPa · s at 20 ° C.

Examples of the commercially available organic silica gel mentioned above include, for example, the trade name MA-ST-S (methanol-dispersed silica gel, manufactured by Nissan Chemical Industries, Ltd.) and the trade name MT-ST (methanol-dispersed silica). Silica gel, manufactured by Nissan Chemical Industries, Ltd.), trade name MA-ST-UP (methanol-dispersed silica gel, manufactured by Nissan Chemical Industries, Ltd.), trade name MA-ST-M (methanol-dispersed silica gel) Silica gel, manufactured by Nissan Chemical Industries, Ltd.), trade name MA-ST-L (methanol-dispersed silica gel, manufactured by Nissan Chemical Industries, Ltd.), trade name IPA-ST-S (isopropanol Dispersed silica gel, manufactured by Nissan Chemical Industries, Ltd.), trade name IPA-ST (isopropanol dispersed silica gel, manufactured by Nissan Chemical Industries, Ltd.), trade name IPA-ST-UP (isolated Propanol-dispersed silica gel, manufactured by Nissan Chemical Industries, Ltd.), trade name IPA-ST-L (Isopropanol-dispersed silica gel, manufactured by Nissan Chemical Industries, Ltd.), trade name IPA-ST -ZL (isopropanol-dispersed silica gel, manufactured by Nissan Chemical Industries, Ltd.), trade name NPC-ST-30 (n-propyl cellosolve-dispersed silica gel, Nissan Chemical Industries, Ltd.) System), trade name PGM-ST (1-methoxy- 2-propanol dispersed silica gel, manufactured by Nissan Chemical Industries, Ltd.), trade name DMAC-ST (dimethylacetamide dispersed silica gel, manufactured by Nissan Chemical Industries, Ltd.), trade name XBA-ST (xylene / n-butanol mixed solvent dispersed silica gel, made by Nissan Chemical Industries, Ltd.), trade name EAC-ST (ethyl acetate dispersed silica gel, Nissan Chemical Industries (stocks) )), Trade name PMA-ST (propylene glycol monomethyl ether acetate dispersed silica gel, manufactured by Nissan Chemical Industry Co., Ltd.), trade name MEK-ST (methyl ethyl ketone dispersed silica gel, Nissan Chemical Industry (Trade name), trade name MEK-ST-UP (methyl ethyl ketone dispersed silica gel, made by Nissan Chemical Industries, Ltd.), trade name MEK-ST-L (methyl ethyl ketone dispersed silica gel, made by Nissan Chemical Industry) (Product) and MIBK-ST (methyl isobutyl ketone dispersed silica gel, Nissan Chemical Industry (product)), etc., but not limited to these contents.矽 The silicon dioxide in the present invention can be used as a mixture of two or more kinds of silicon dioxide, such as those listed in the above-mentioned products used as an organic silicon dioxide gel.

[Crosslinking Agent] The composition for forming a release layer and the composition for forming a resin film used in the present invention may further contain a crosslinking agent. When a crosslinking agent is used in the present invention, it is preferably used only in any one of a composition for forming a release layer or a composition for forming a resin film, and a crosslinking agent is further added only to a composition for forming a resin film. For the better. The cross-linking agent used here is a compound composed of only hydrogen atoms, carbon atoms, and oxygen atoms, or a compound composed of only these atoms and nitrogen atoms, and has two or more compounds composed of hydroxyl, epoxy, and A cross-linking agent formed by a compound selected from the group consisting of alkoxy groups having 1 to 5 carbon atoms and a compound having a ring structure. When these crosslinking agents are used, they not only have excellent solvent resistance, but also have excellent reproducibility for resin film laminates suitable for substrates for flexible devices, and can achieve peeling with improved storage stability. A composition for forming a layer and a composition for forming a resin film. Among them, the total number of hydroxyl groups, epoxy groups, and alkoxy groups having 1 to 5 carbon atoms of a compound in the crosslinking agent can fully realize the reproducibility of the solvent resistance of the obtained resin film laminate. The viewpoint is preferably 3 or more, and from the viewpoint that the reproducibility of the flexibility of the obtained resin film laminate can be sufficiently realized, it is preferably 10 or less, more preferably 8 or less, and most preferably 6 or less.

Specific examples of the ring structure contained in the crosslinking agent, for example, aryl rings such as benzene, pyridine, and pyridine , Pyrimidine, da , And 1,3,5-three Nitrogen-containing heteroaryl rings, cyclopentane, cyclohexane, and cycloheptane rings such as cycloheptane, piperidine, piperazine, hexahydropyrimidine, hexahydro , And hexahydro-1,3,5-tri And other cyclic amines.

The number of ring structures of one of the compounds in the cross-linking agent is not particularly limited as long as it is 1 or more, the solubility of the cross-linking agent in the solvent can be ensured, and a highly flat resin film can be laminated. In terms of things, 1 or 2 is preferred. When there are two or more ring structures, the ring structures may form condensation with each other, or the ring structures may have carbon atoms such as methyl, ethyl, trimethyl, and propane-2, 2-diyl groups. Linking groups such as alkane-diyl groups of 1 to 5 are linked.

The molecular weight of the cross-linking agent is not particularly limited as long as it has cross-linking ability and is soluble in the solvent used. The solvent resistance of the obtained resin film laminate and the effect of the cross-linking agent body on organic solvents are considered. In the case of solubility, availability, price, etc., it is preferably about 100 to 500, more preferably about 150 to 400.

The cross-linking agent may further have a group derived from a ketone group, an ester group (bond), etc., a hydrogen atom, a carbon atom, a nitrogen atom, and an oxygen atom.

Preferred examples of the crosslinking agent include, for example, compounds represented by the following formulae (K1) to (K5). Among them, one of the preferred aspects of the formula (K4) is represented by the formula (K4-1). The compound of formula (K5) is one of the preferred embodiments, such as the compound represented by formula (5-1).

In the above formula, each of A ¹ and A ² independently of each other represents an alkane-diyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a trimethyl group, and a propane-2,2-diyl group. Among them, A ¹ is preferably methyl and ethyl, more preferably methyl and A ² is preferably methyl and propane-2,2-diyl.

Each X, independently of each other, represents a hydroxy group, an epoxy group (oxe-cyclopropyl), or a methoxy group, an ethoxy group, a 1-propoxy group, an isopropoxy group, a 1-butoxy group, and a t-butyl group An alkoxy group having 1 to 5 carbon atoms such as an oxy group. Among them, when considering the availability, price, etc. of the cross-linking agent, X is preferably an epoxy group in the formulae (K1) and (K5), and the number of carbon atoms in the formulae (K2) and (K3) An alkoxy group of 1 to 5 is preferred, and in the formula (K4), a hydroxyl group is preferred.

In the formula (K4), each n represents the number of-(A ¹ -X) groups bonded to a benzene ring, which are integers of 1 to 5 independently of each other, preferably 2 to 3, and more preferably 3.

In each compound, it is preferable that all of A ¹ are all the same group, and each of X is preferably all the same group.

The compounds represented by the above formulae (K1) to (K5) may be a skeletal compound such as an aryl compound, a heteroaryl compound, or a cyclic amine, which has the same ring structure as the ring structure of each of these compounds, and the ring The oxyalkyl halide compound, alkoxy halide compound, etc. are prepared through a reaction such as a carbon-carbon coupling reaction or an N-alkylation reaction, or by hydrolyzing the alkoxy portion of the product.

As the cross-linking agent, a commercially available product may be used, or it may be synthesized by a known synthesis method. Commercial products, for example, CYMEL (registered trademark) 300, same 301, same 303LF, same 303ULF, same 304, same 350, same 3745, same XW3106, same MM-100, same 323, same 325, same 327, and 328 , The same 385, the same 370, the same 373, the same 380, the same 1116, the same 1130, the same 1133, the same 1141, the same 1161, the same 1168, the same 3020, the same 202, the 203, the same 1156, the same MB-94, the same MB -96, same as MB-98, same as 247-10, same as 651, same as 658, same as 683, same as 688, same as 1158, same as MB-14, same as MI-12-I, same as MI-97-IX, and same as U- 65. Same as UM-15, same as U-80, same as U-21-511, same as U-21-510, same as U-216-8, same as U-227-8, same as U-1050-10, and same as U- 1052-8, same as U-1054, same as U-610, same as U-640, same as UB-24-BX, same as UB-26-BX, same as UB-90-BX, same as UB-25-BE, and same as UB- 30-B, as U-662, as U-663, as U-1051, as UI-19-I, as UI-19-IE, as UI-21-E, as UI-27-EI, as U- 38-I, same UI-20-E, same 659, same 1123, same 1125, same 5010, same 1170, same 1172, same as NF3041, and same as NF2000 (above, made by Allnex); TEPIC (registered trademark) V, Same S, same HP, same L, same PAS, same VL, and same UC (above, Nissan Chemical Industry Co., Ltd.), TM-BIP-A (Asahi Machinery Industry Co., Ltd.), 1,3,4,6-Tetrakis (methoxymethyl) acetylene urea (hereinafter referred to as TMG) (Tokyo Chemical Industry Co., Ltd.), 4,4'-Methylene (N, N-diglycidylaniline) (manufactured by Aldrich), HP-4032D, HP-7200L, HP-7200, HP-7200H, HP-7200HH, HP-7200HHH, HP-4700, HP-4770, HP- 5000, HP-6000, HP-4710, EXA-4850-150, EXA-4850-1000, EXA-4816, and HP-820 (DIC (stock)), TG-G (Shikoku Chemical Industry (stock)), etc. .

Hereinafter, preferred specific examples of the cross-linking agent will be listed, but not limited to these.

The blending amount of the cross-linking agent cannot be generalized because the type of the cross-linking agent is appropriately determined. Generally, it is relative to the mass of the polyimide contained in the composition for forming a release layer, or The total mass of the polyimide and the silicon dioxide contained in the composition for forming a resin film is 50% by mass or less from the viewpoint of ensuring the flexibility of the obtained resin film laminate and suppressing fragility, and is preferably From 100 mass% or less, from the viewpoint of ensuring the solvent resistance of the obtained resin film laminate, it is 0.1 mass% or more, and preferably 1 mass% or more.

[Organic Solvent] The composition for forming a release layer and the composition for forming a resin film used in the present invention include an organic solvent. This organic solvent is not specifically limited, For example, the same solvent as the specific example of the reaction solvent used at the time of manufacture of the said polyamic acid and polyimide is mentioned. More specifically, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2- Imidazolinone, N-ethyl-2-pyrrolidone, γ-butyrolactone and the like. Moreover, an organic solvent may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, in consideration of the reproducibility of a resin film laminate that can sufficiently produce high flatness, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, Gamma-butyrolactone is preferred.

[Composition for forming peeling layer] The composition for forming a peeling layer used in the present invention is a composition containing the heat-resistant polymer and an organic solvent, and which can be expected to further contain a crosslinking agent, as described above. , Essentially those who do not contain silicon dioxide. The solid content and viscosity in this release layer-forming composition are based on the following composition for forming a resin film.

[Composition for Forming Resin Film] 组成 The composition for forming a resin film used in the present invention is a composition containing the aforementioned heat-resistant polymer, silicon dioxide, and an organic solvent, and a composition which can be expected to further contain a crosslinking agent. The composition for forming a resin film referred to herein is uniform, and no phase separation is observed. In the composition for forming a resin film, the addition ratio of the heat-resistant polymer to the silicon dioxide depends on the mass ratio, and the heat-resistant polymer: silica dioxide is preferably 10: 1 to 1:10, and more preferably It is 8: 2 to 2: 8, for example, 7: 3 to 3: 7. In addition, the solid content in the resin film-forming composition is usually about 0.5 to 30% by mass, and preferably about 5 to 25% by mass. When the solid content concentration is less than 0.5% by mass, in the production of the resin film, the film-forming efficiency will be reduced, and the viscosity of the resin film-forming composition will be reduced, and it will not be easy to obtain a coating film with a uniform surface. In addition, when the solid content concentration exceeds 30% by mass, the viscosity of the composition for forming a resin film is too high, which may cause deterioration of the film-forming efficiency or lack of surface uniformity of the coating film. The solid content (solid content concentration) referred to herein means the total mass of components other than the organic solvent, and is included in the weight of the solid content even when it is a liquid monomer or the like. The viscosity of the resin film-forming composition can be appropriately set in consideration of the thickness of the resin film to be produced, but in particular, the reproducibility of a resin film having a thickness of about 5 to 50 μm can be sufficiently obtained. For the purpose, it is usually about 500 to 50,000 mPa · s at 25 ° C, preferably about 1,000 to 20,000 mPa · s.

<Other components> In the composition for forming a release layer and the composition for forming a resin film, various other organic or inorganic low-molecular or high-molecular compounds may be added from the viewpoint of imparting processing characteristics or various functions. For example, a catalyst, an antifoaming agent, a leveling agent, a surfactant, a dye, a plasticizer, a fine particle, a coupling agent, a sensation agent, and the like can be used. For example, the catalyst may be added for the purpose of reducing the hysteresis or linear expansion coefficient of the resin film laminate.

The composition for forming a release layer, for example, a heat-resistant polymer, may include polyimide prepared according to the method described above, a cross-linking agent added if necessary, and other components (a variety of organics) added if necessary. Or inorganic low-molecular or high-molecular compounds) can be obtained by dissolving in the organic solvent.

The composition for forming a resin film, for example, a heat-resistant polymer, may include polyimide and silicon dioxide prepared according to the above-mentioned method, a cross-linking agent added if necessary, and other components (various formulas added when necessary). Various organic or inorganic low-molecular or high-molecular compounds) can be prepared by dissolving them in the organic solvent. Alternatively, silicon dioxide may be added to the reaction solution after the polyfluorene imide is obtained, and the organic solvent may be added in accordance with expectations. As described above, in the present invention, when a cross-linking agent is used, it can be used for either the composition for forming a release layer or the composition for forming a resin film.

In addition, in the present invention, the resin contained in the composition for forming a release layer and the resin contained in the composition for forming a resin film do not affect the characteristics and the like, as described above, they are mutually the same. Better. In addition, substantially only the composition for forming a resin film may further contain silica particles. When these preferable conditions are provided, the manufacturing method of each composition is not specifically limited. Therefore, in the method of the present invention, for example, after the composition for forming a release layer is first obtained, then a part of the composition for forming a release layer is added, and as described above, silicon dioxide particles are added, and then the desired Purpose By adding an organic solvent, the composition for forming a peeling layer and the composition for forming a resin film can be easily obtained, and these can be used in the method of the present invention.

<Manufacturing method of a resin film laminate> [Step of forming a release layer] This step is a step of forming a release layer on a supporting substrate by using the composition for forming a release layer described above. Specifically, in order to coat the above-mentioned composition for forming a release layer on a supporting substrate, and to dry and heat it to remove an organic solvent, a composition capable of maintaining excellent heat resistance, low hysteresis, and excellent flexibility can be obtained, and In addition to excellent properties such as excellent transparency, a flexible type of release layer that can be easily peeled off from a supporting substrate can also be used by at least one method selected from the group consisting of blade cutting, mechanical separation, and simultaneous stretching and peeling. Device substrate.

The above-mentioned supporting substrate is, for example, plastic (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy resin, melamine, triethyl cellulose, ABS, AS, norbornene-based resin) Etc.), metal, stainless steel (SUS), wood, paper, glass, silicon wafer, slate, etc. In particular, from the viewpoint of using existing equipment, the supporting substrate that can be used is preferably glass or silicon wafer, and from the viewpoint of making the obtained release layer exhibit good peelability, it is more preferable to use glass. Moreover, from a viewpoint of the warpage of the support base material after coating which is a linear expansion coefficient of the support base material used, it is preferably 40 ppm / ° C or less, and more preferably 30 ppm / ° C or less.

The method for applying the composition for forming a release layer to a supporting substrate is not particularly limited, and examples thereof include a mold coating method, a spin coating method, a panel coating method, a dip coating method, a roll coating method, Strip coating method, die coating method, inkjet method, printing method (letter plate, gravure, lithography, screen printing, etc.), etc., can be appropriately selected and used according to the purpose.

The heating temperature is preferably 500 ° C or lower, and more preferably 450 ° C or lower. However, when the temperature exceeds 300 ° C, problems such as yellowing may occur. In this case, the thickness ratio of the release layer in the entire thickness of the resin film laminate obtained by the production method of the present invention is extremely small as described below. , So the impact on characteristics is small. When the composition for forming a resin film is coated on the formed release layer, the higher the final sintering temperature, the less the proportion of the release layer dissolved in the composition for forming a resin film, for example, the sintering temperature is 400. At ℃, the release layer is difficult to dissolve. As a result, the boundary between the release layer and the resin film becomes clearer. At 300 ° C or lower, a part of the release layer is dissolved in the composition for forming a resin film. The boundary between the release layer and the resin film is formed into a layer, and in any case, the effect of the intended invention can be achieved. In addition, when considering the heat resistance and linear expansion coefficient characteristics of the obtained release layer, the composition for forming a release layer after coating may be heated at 40 ° C to 100 ° C for 5 minutes to 2 hours, and then During the processing, the heating temperature is increased stepwise, and it is better to heat the temperature in the range of more than 175 ° C to 450 ° C for 30 minutes to 2 hours. As described above, when heating is performed at a temperature of two or more stages, such as a step of drying a solvent and a stage of promoting molecular alignment, a low thermal expansion characteristic with better reproducibility can be produced. In particular, the composition for forming a release layer after coating is heated at a temperature of 40 ° C to 100 ° C for 5 minutes to 2 hours, and then heated at a temperature of more than 100 ° C to 175 ° C for 5 minutes to 2 hours, followed by more than 175 ° C. Heating at a temperature in the range of -450 ° C for 5 minutes to 2 hours is preferred.的 Appliances used for heating, such as hot plates, ovens, etc. The heating environment can be in the atmosphere or under an inert gas such as nitrogen, or under normal pressure, or under reduced pressure, and different pressures can be used in each stage of heating.

In this step, from the viewpoint of further improving the adhesion between the release layer and the resin film to be formed later, a coating structure can be used to form a fine structure (intermediate layer) on the surface of the release layer. In this case, specifically, it is preferable that a fine structure is formed on the surface of the release layer before the release layer is cured, for example, after the composition for forming the release layer is applied, or during the subsequent heating.

The thickness of the peeling layer is in the range of about 1 nm to 200 μm, and an appropriate decision may be made in consideration of the type of the flexible device. From the viewpoint of achieving the effect of the invention, it must be at least thicker than the diameter of the silicon dioxide particles. In particular, when a resin film laminate is intended to be used as a substrate for a flexible display, it is usually about 10 nm to 10 μm, preferably about 100 nm to 5 μm. The thickness of the coating film before heating can be adjusted to form a desired thickness. Of the release layer.

[Formation Step of Resin Film] This step is a step of forming a resin film on the release layer by using the composition for forming a resin film of the present invention. This step is also a step of forming a resin film laminate including a release layer and a resin film formed thereon on a supporting substrate. Specifically, in order to apply the composition for forming a thin film to a release layer formed on the support substrate, and to dry and heat the organic solvent to remove it, high heat resistance and high transparency can be obtained. Resin film with proper softness and proper coefficient of linear expansion, but also with low hysteresis. In addition, in this step, a part of the release layer is dissolved through an organic solvent contained in the composition for forming a resin film to make the resin film and the release layer adhere to each other, thereby enhancing the adhesion between the two.

The coating method of the composition for forming a resin film on the release layer, the heating temperature, the apparatus used for heating, and the thickness of the resin film are all based on the conditions described in the step of forming the release layer, and so on.

In the resin film laminate formed on the supporting substrate in this way, from the viewpoint of achieving easy peeling from the supporting substrate, the adhesion of the peeling layer to the resin film is greater than the adhesion of the peeling layer to the supporting substrate. The bigger one is better. Specifically, the adhesiveness between the release layer and the resin film is classified as 0 to 1 (0 to 5% peelability) by the CCJ series (JIS5400), and the adhesion between the support substrate and the release layer is as follows. It is better to classify CCJ series (JIS5400) as 5 (50% or more peelability). The CCJ series is defined by the classification of 0 to 5 stages. The classification of 0 is the meaning that 0% of the square area is stripped, the classification of 1 is 1 to 5% of the square area, and the classification of 2 is 6 to 10% of the square area, 11 to 25% of the square area classified as 3, 26 to 50% of the square area classified as 4 are intended to be stripped, and 5 to 50% of the square area The above is meant to be stripped. In other words, according to the cross cutting test conditions of JIS K5400, the square peeling number of the resin film is classified into 0 to 2 with respect to the peeling layer, and the peeling of the square of the peeling layer with respect to the supporting substrate is described. The number is better classified as 5.

[Step of Preparing Resin Film Laminate] (1) This step is a step of peeling the release layer together with the resin film from a supporting substrate to obtain a resin film laminate. The method of peeling the resin film laminate formed in this manner from the support substrate is not particularly limited. For example, the resin film laminate can be cooled on the support substrate and cut into the resin film laminate. The method of peeling the cutting hole, or the method of peeling by applying tension through a roller. In particular, in the method for peeling the resin film laminate from the supporting substrate in the present invention, at least one selected from the group consisting of cutting by a blade, mechanical separation, and stretching and peeling can be used.

In this way, in the method of the invention, since the adhesion between the release layer and the resin film is stronger than the adhesion between the release layer and the support substrate, the release layer and the resin film can be regarded as a single body, and it is easy to use The support substrate was peeled to obtain a resin film laminate. In the present invention, the thickness of the resin film laminate may be in a range of about 1 μm to 200 μm, and an appropriate decision may be made in consideration of the type of the flexible device. The thickness of the release layer is preferably 1 to 35% relative to the thickness (100%) of the resin film laminate.

The resin film laminate obtained in a preferred aspect of the present invention can achieve high transparency at a wavelength of 400 nm and a light transmittance of 75% or more. In addition, the resin film laminate may have, for example, a linear expansion coefficient between 50 ° C. and 200 ° C. of 60 ppm / ° C. or lower, particularly a low value of 10 ppm / ° C. to 35 ppm / ° C., for example, 200 ° C. to The linear expansion coefficient between 250 ° C is 80ppm / ° C or less, especially a low value of 15ppm / ° C to 55ppm / ° C, so it has excellent dimensional stability during heating. In particular, this resin film laminate has the product of birefringence (the difference between two refractive indices that crosses perpendicularly in the plane) and film thickness (thickness of the laminate) when the incident light wavelength is 590 nm. The in-plane hysteresis R ₀ and the two birefringences (the differences between the two refractive indices in the plane and the refractive index in the thickness direction) when viewed from the thickness section are multiplied by the film thickness (thickness of the laminate), respectively. The thickness direction retardation R _th of the average values of the two phase differences obtained is a feature of extremely small values. When the resin film laminate obtained by the manufacturing method of the present invention has an average film thickness (average thickness of the laminate) of 15 μm to 40 μm, the retardation R _{th in the} thickness direction has not reached 700 nm, for example, 660 nm or less, and 10 nm to At 660 nm, the in-plane hysteresis R ₀ has a value of less than 4, such as 0.3 to 3.9, and the birefringence Δn has an extremely low value of less than 0.02, such as 0.0003 to 0.019. As described above, in the resin film laminate obtained by the production method of the present invention, hysteresis can be reduced.

Since the resin film laminate obtained by using the manufacturing method of the present invention described above has the above-mentioned characteristics, it satisfies various conditions necessary as a base film for a flexible display substrate, and is particularly suitable for use as a flexible display substrate. Base film. That is, this invention is suitable for the manufacturing method of the board | substrate for flexible devices.

A manufacturing example of the flexible device using the manufacturing method of the present invention is shown in Fig. 1.内容 As shown in FIG. 1, first, a release layer is formed on a support substrate, and a resin film is formed on the release layer, and the resin film laminate is used. Thereafter, after a functional layer is formed on the resin film laminate, these are peeled together to obtain a flexible device. [Example]

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

The meanings of the abbreviations used in the following examples are as follows. <Acid dianhydride> DABODAxx: Bicyclo [2,2,2] octane-2,3,5,6-tetracarboxylic dianhydride CBDA: 1,2,3,4-cyclobutane tetracarboxylic dianhydride <Diamine> TFMB: 2,2'-bis (trifluoromethyl) benzidine <Organic solvents> GBL: γ-butyrolactone

In the examples, the equipment and conditions used for the manufacture of reagents and the analysis and evaluation of physical properties are as follows. 1) Measurement of number average molecular weight and weight average molecular weight The number average molecular weight of the polymer (hereinafter, abbreviated as Mn) and weight average molecular weight (hereinafter, abbreviated as Mw) are used: Showa Denko Corporation, Showdex GPC- 101. Column: KD803 and KD805, Column temperature: 50 ° C, Dissolution solvent: DMF, Flow rate: 1.5ml / min, Calibration line: Standard polystyrene. 2) Coefficient of linear expansion (CTE) Using TMA Q400 manufactured by TA Instruments, cut the film (or laminate) to a size of 5mm wide and 16mm long, first heat up to 50 to 350 ° C at 10 ° C / min and heat (First heating), and then cooled down to 50 ° C at 10 ° C / min and allowed to cool, and then heated at 50 ° C to 420 ° C at 10 ° C / min (second heating) to measure the second heating The linear expansion coefficient (CTE [ppm / ° C]) between 50 ° C and 200 ° C. In addition, a load of 0.05 N was applied between the first heating, the cooling, and the second heating. 3) The temperature at which the weight is reduced by 5% (Td _5% ) The temperature at which the weight is reduced by 5% (Td _5% [° C]) is the use of TGA Q500 manufactured by TA INSTRUMENTS, in nitrogen, the film (or laminate) is about 5 The measurement was performed until the temperature was increased to 10 mg, and the temperature was raised from 10 ° C / min to 800 ° C from 50 ° C. 4) Light transmittance (transparency) (T _308nm , T _400nm , T _550nm ) and CIE b value (CIE b ^* ) Light transmittance at wavelengths 308nm, 400nm, and 550nm (T _308nm , T _400nm , T _550nm [ %]) And CIE b value (CIE b ^* ) were measured using a SA4000 spectrometer manufactured by Nippon Denshoku Industries Co., Ltd. at room temperature using air as a reference. 5) Retardation (R _th , R ₀ ) The thickness direction retardation (R _th ) and the in-plane retardation (R ₀ ) are measured at room temperature using KOBURA 2100ADH, manufactured by Oji Instruments Co., Ltd. The thickness direction retardation (R _th ) and the in-plane retardation (R ₀ ) are calculated by the following calculation formulas. R ₀ = (Nx-Ny) × d = ΔNxy × d R _th = [(Nx + Ny) / 2-Nz] × d = [(ΔNxz × d) + (ΔNyz × d) / 2 Nx, Ny: in-plane vertical Crossed two refractive indices (Nx> Ny, Nx is also called hysteresis phase axis, and Ny is also called advancing phase axis) Nz: refractive index with respect to the thickness (vertical) direction of the surface d: film thickness (laminated Thickness) ΔNxy: Difference between two refractive indices in the plane (Nx-Ny) (birefringence) ΔNxz: Difference between refractive index Nx in the plane and refractive index Nz in the thickness direction (birefringence) ΔNyz: refractive index in the plane Difference between Ny and refractive index Nz in the thickness direction (birefringence) 6) Birefringence (Δn) The value of the thickness direction hysteresis (R _th ) obtained using the aforementioned <5) Hysteresis is calculated by the following calculation formula. Δn = [R _th / d (film thickness (thickness of laminate))] / 1000 7) film thickness (thickness of laminate) The thickness of the obtained resin film and the thickness of the resin film laminate are used ( ) TECLOCK thickness gauge measurement.

[1] Manufacturing Example Manufacturing Example 1: Production of Silicon Dioxide Gel (GBL-M) In a 1000 mL round-bottomed flask, a methanol-dispersed silica gel made by Nissan Chemical Industries, Ltd. was added: MA-ST-M 350 g (silica dioxide solid content concentration: 40.4% by mass) and 419 g of γ-butyrolactone. Subsequently, the flask was decompressed in a flask connected to a vacuum evaporator, and immersed in a warm water bath at about 35 ° C. for 20 to 50 minutes to obtain a solvent in which methanol was replaced with γ-butyrolactone. Silicon gel (GBL-M) was about 560.3 g (solid content of silicon dioxide: 25.25 mass%).

[2] Synthesis example Synthesis example 1: Synthesis of polyimide A (PI-A) In a 250-mL reaction three-necked flask equipped with a nitrogen injection port / exhaust port, a mechanical stirrer, and a cooler, TFMB 25.61 was added g (0.08 mol). Thereafter, 173.86 g of GBL was added, and stirring was started. After the diamine was completely dissolved in the solvent, immediately after stirring, 10 g (0.04 mol) of BODAxx, 7.84 g (0.04 mol) of CBDA and 43.4 g of GBL were added and heated to 140 ° C. under nitrogen. Thereafter, 0.348 g of 1-ethylpiperidine was added to the solution, and the solution was heated at 180 ° C. for 7 hours under nitrogen. Stop the last heating, dilute the reaction solution to 10%, and keep stirring overnight. The polyfluorene imide reaction solution was added to 2000 g of methanol and stirred for 30 minutes, and then the polyfluorine imide was filtered to purify the polyfluorene imide. Subsequently, the polyimide solid was stirred in 2000 g of methanol for 30 minutes, and the polyimide solid was filtered. The purification sequence of the polyimide solid was stirred and filtered three times. The methanol residue in polyimide was dried in a vacuum oven at 150 ° C. for 8 hours to remove it, and finally 31.16 g of polyimide A was dried. The yield of polyimide A (PI-A) was 74% (Mw = 169,802, Mn = 55,308).

[3] Production of a composition for forming a release layer and a composition for forming a resin film, and production of a resin film laminate (1) Example 1: Formation of a release layer at room temperature 1 g of imine (PI-A) was dissolved in a GBL solvent to form a solution of 8% by mass, and then gradually filtered under pressure through a 1 μm filter to obtain a composition for forming a peeling layer. Thereafter, the composition was coated on a glass supporting substrate, and sintered at 50 ° C for 30 minutes, 140 ° C for 30 minutes, and 200 ° C for 60 minutes in an air atmosphere, and then sintered at 300 ° C for 60 minutes. In this way, a transparent polyimide film is formed as a release layer on the glass supporting substrate. The optical and thermal characteristics are shown in Table 1.

Example 2: Formation of release layer Using the composition for forming a release layer prepared in Example 1, the composition was coated on a glass support substrate and subjected to a temperature of 50 ° C for 30 minutes and 140 ° C for 30 minutes in an air atmosphere. After sintering at 200 ° C for 60 minutes, and then sintering at 400 ° C for 60 minutes, the others were formed in the same manner as in Example 1 to form a transparent polyimide film as a release layer on a glass supporting substrate. The optical and thermal characteristics are shown in Table 1.

Example 3: Production of a composition for forming a resin film At room temperature, 1 g of polyimide (PI-A) of Synthesis Example 1 was dissolved in a GBL solvent to form a 10% by mass solution, and the solution was passed through A 5 μm filter was slowly pressurized. Thereafter, the filtrate was added to 9.241 g of silica dioxide gel (GBL-M) (18 to 23 nm SiO ₂ nanometer particles dispersed in GBL at 25.25%), and mixed for 30 minutes, and thereafter, in a stationary state The mixture was maintained for a while to obtain a composition for forming a resin film. The resin film-forming composition was coated on a glass support substrate, and sintered at 50 ° C for 30 minutes, 140 ° C for 30 minutes, and 200 ° C for 60 minutes in an air atmosphere, and a vacuum atmosphere of -99kpa Then, sintering was performed at 280 ° C for 60 minutes to obtain a resin film. The optical and thermal characteristics of the obtained resin film are shown in Table 1.

Example A: Production of resin film laminate A The composition for forming a resin film obtained in Example 3 was coated on the release layer obtained in Example 1 and subjected to a temperature of 50 ° C for 30 minutes in an air atmosphere. Sintering at 140 ° C for 30 minutes and 200 ° C for 60 minutes, and sintering at 280 ° C for 60 minutes in a vacuum atmosphere of -99 kpa, thereby producing a resin film (polyimide A / silica dioxide composite resin film). Thereafter, the release layer and the resin film formed on the glass support substrate were separated (peeled) from the glass support substrate by a mechanical cutting method to obtain a resin film laminate A. The optical and thermal characteristics of the fluorene resin film laminate A are shown in Table 1.

5 and 6 are cross-sectional views (part TEM inside the frame) of the resin film laminate A, and FIG. 7 is a (a) surface (resin film side) and (b) of the resin film laminate A The Raman IR spectrum of the interface between the release layer and the resin film, and (c) the back surface (side of the release layer). FIG. 6 (a) is an enlarged view showing the vicinity of the “mixing area” in FIG. 5, and FIG. 6 (b) is a diagram showing the component composition of each layer constituting the laminate, where [001] represents an intermediate layer, [002] indicates a resin film (polyimide + SiO ₂ ), and [003] indicates a release layer (DBL). According to the TEM part inside the frame of FIG. 5 and FIG. 6, it was confirmed that an intermediate layer was formed at the interface between the release layer and the resin film formed, and the thickness was about 300 nm. Moreover, as shown in the Raman IR spectrum of FIG. 7, the shape of the IR spectrum at the interface between (b) the peeling layer and the resin film is almost the same as the shape of the IR spectrum on the back of (c). It is confirmed that the interface is at least from the peeling layer. result.

Example B: Production of Resin Film Laminate B Except that the composition for forming a resin film obtained in Example 3 was applied to the release layer obtained in Example 2, everything else was prepared in the same order as in Example A. A resin film laminate B was obtained.

8 and 9 are respectively a cross-sectional view of the resin film laminate B (part inside the frame TEM), and FIG. 10 shows the surface of the resin film laminate B (a) (resin film side), (b) the release layer and The Raman IR spectrum of the interface of the resin film and (c) the back surface (side of the release layer). FIG. 9 (a) is an enlarged view showing the vicinity of the interface in FIG. 8, FIG. 9 (b) is a component composition of each layer constituting the laminate, [001] represents a release layer (DBL), and [002] represents a resin film (Polyimide + SiO ₂ ). According to the internal part TEM of FIG. 8 and FIG. 9, it was confirmed that the interface between the formed peeling layer and the resin film was more clearly separated than that of Example A, and the thickness of the intermediate layer at this time was about 1 nm or less. Thin person. As shown in the Raman IR spectrum of FIG. 10, the shape of the IR spectrum at the interface between (b) the peeling layer and the resin film was almost the same as the shape of the IR spectrum at the back of (c), and it was confirmed that the interface was the result from the peeling layer.

The sectional views of the resin film laminates A and B obtained in the above examples are shown in Figs. 2 and 3. As shown in FIG. 2, the resin film laminates A and B were confirmed to have a release layer (L II), an intermediate layer (L III), and a resin film (polyimide) in this order on the supporting substrate (G1), respectively. A / silica gel composite resin film) (LI) laminated structure. In addition, as shown in FIG. 3, after the laminated structures are separated (peeled) from the supporting substrate (G1), resin film laminates A and B can be obtained. In FIGS. 2 and 3, the electron layers such as electrodes are represented by L IV, respectively. Among them, the release layer (L II), the resin film (polyimide A / silica dioxide composite resin film) (LI), and the intermediate layer formed therebetween are presumably shown in FIG. 4 respectively. Polymer network construction. The network is composed of two polymers and nanometer silicon dioxide, which are bonded to each other by van der Waals or hydrogen bonding. In this way, the adhesion between the resin film and the release layer can be enhanced. The intermediate layer may be formed of not only a release layer but also a resin film. When the resin film is formed, the upper surface of the release layer is partially dissolved due to the solvent contained in the resin film-forming composition. Therefore, the intermediate layer can be formed by re-reacting (thermally imidizing) the resin film via the release layer.

Based on the contents shown in Table 1, it was confirmed that the resin film laminate A obtained by the production method of the present invention has a low linear expansion coefficient [ppm / ° C] (50 to 200 ° C), and after curing, has a temperature between 400 nm and 550 nm. High light transmittance [%]. In addition, the yellowness indicated by the CIE b * value is small, and the hysteresis can be suppressed to a lower value.

In addition, the resin film laminate A of the present invention obtained according to the above-mentioned embodiment does not break even when it is bent to an acute angle (about 30 degrees) under both hands, and has the high flexibility required for a flexible display substrate. Sex.

[4] Production of resin film laminate (2) Use the composition for forming a release layer obtained from the aforementioned <Example 1: Formation of a release layer> and <Example 3: Production of a composition for forming a resin film> The obtained resin film-forming composition is produced in the following order from a resin film laminate. (a) Production of a composition for forming a release layer containing a cross-linking agent is included in the composition for forming a release layer prepared in accordance with the above-mentioned <Example 1: Formation of a release layer> with respect to the amount contained in the composition. The mass of polyimide (PI-A) was 30 phr, and CYMEL (registered trademark) 303 (manufactured by Allnex Corporation) was mixed to obtain a composition for forming a release layer containing a cross-linking agent. (b) Production of a composition for forming a resin film containing a crosslinking agent is included in the composition for forming a resin film obtained in accordance with the above-mentioned "Example 3: Production of a composition for forming a resin film" so as to correspond to the composition. CYMEL303 was mixed so that the total mass of polyimide (PI-A) and silica gel (GBL-M) contained in the product was 30 phr, and a composition for forming a resin film containing a crosslinking agent was prepared. (I) After forming a release layer on a glass support substrate using the composition for forming a release layer, a resin film is formed on the release layer using the composition for forming a resin film. (Ii) After using the composition for forming a release layer to form a release layer on a glass supporting substrate, a resin film is formed on the release layer using the composition for forming a resin film containing a crosslinking agent. (Iii) Using the composition for forming a release layer containing the cross-linking agent, forming a release layer on a glass support substrate, and then forming a resin film on the release layer using the composition for forming a resin film. (iv) using the composition for forming a release layer incorporating the cross-linking agent, forming a release layer on a glass support substrate, and forming the resin film on the release layer using the composition for forming a resin film incorporating the cross-linking agent; .后 After the resin film is formed, the glass film is used to peel the release layer together with the resin film using a mechanical cutting method. The peelability is evaluated according to the following criteria. <Evaluation of Peelability> ◎: Can be completely separated (peeled off) from the glass supporting substrate (almost 100%) △: Not easily separated from the glass supporting substrate (5 to 50%) ×: Cannot be separated from the glass supporting substrate (<5 %)

In any of the examples, the sintering conditions were 120 ° C for 20 minutes, 140 ° C for 20 minutes, 200 ° C for 30 minutes, and 250 ° C for 60 minutes in an air atmosphere. The results obtained are shown in Table 2.

From the contents shown in Table 2, it was confirmed that in any of the composition for forming a release layer or the composition for forming a resin film, when a crosslinking agent is blended, the resin film laminate can be easily peeled off from the glass support substrate. .

[FIG. 1] Explanatory diagram of each stage of the manufacturing method of this invention. [Fig. 2] A schematic view (cross-sectional view) of a laminate prepared by the production method of the present invention. G1 is a supporting substrate, L II is a release layer, L I is a resin film, L IV is an electrode layer formed on the resin film, and the like. [Fig. 3] A schematic view of a method for peeling a laminate obtained by the manufacturing method of the present invention from a supporting substrate. [Fig. 4] A diagram showing the structure of a release layer, a resin film, and an intermediate layer in the laminate obtained by the production method of the present invention. [FIG. 5] A cross-section photograph (TEM inside the frame) of the laminate obtained in Example A. [FIG. 6] A cross-sectional photograph (TEM inside the frame) (a) of the laminate obtained in Example A and a diagram of the component composition (b) of each layer. [FIG. 7] Raman IR spectrum of the release layer, resin film, and interface in the laminate obtained in Example A. [Fig. 8] A cross-sectional photograph of the laminate obtained in Example B (inner frame part TEM). [FIG. 9] A cross-sectional photograph (TEM inside the frame) (a) of the laminate obtained in Example B and a diagram of the component composition (b) of each layer. [Fig. 10] Raman IR spectrum of the release layer, resin film, and its interface in the laminate obtained in Example B.

Claims (15)

A manufacturing method, which is a method for manufacturing a resin film laminate, comprising: (1) a step of forming a release layer on a supporting substrate, using a composition for forming a release layer containing a heat-resistant polymer (A) and an organic solvent; A composition for forming a resin film containing a heat-resistant polymer B and an organic solvent, a step of forming a resin film on the release layer, (i) peeling the release layer together with the resin film from a supporting substrate, and preparing a resin film laminate. Step: wherein the composition for forming a resin film further contains silica particles having an average particle diameter of 100 nm or less calculated from a specific surface area value measured by a nitrogen adsorption method, but the composition for forming a release layer does not contain Silicon oxide particles. The manufacturing method according to claim 1, wherein the heat-resistant polymer A and the heat-resistant polymer B are the same polymer. The method according to claim 1, wherein the heat-resistant polymer A and the heat-resistant polymer B are each independently composed of polyimide, polybenzoxazole, polybenzobisoxazole, and polybenzimidazole. And at least one polymer selected from polybenzothiazole. The method according to claim 1, wherein the heat-resistant polymer A and the heat-resistant polymer B are each independently composed of a tetracarboxylic dianhydride component containing an alicyclic tetracarboxylic dianhydride and a fluorine-containing aromatic The polyamidoacid obtained by reacting the diamine component of the amine is a polyamidoimide obtained by the imidization. The method according to claim 4, wherein the alicyclic tetracarboxylic dianhydride contains a tetracarboxylic dianhydride represented by formula (C1), [In the formula, B ¹ represents a 4-valent basis selected from the group consisting of formulas (X-1) to (X-12); (In the formula, plural R represents a hydrogen atom or a methyl group independently, and * represents a bonding bond)]. The method according to claim 4, wherein the fluorine-containing aromatic diamine includes a diamine represented by formula (A1), (In the formula, B ² represents a divalent base selected from the group consisting of formulas (Y-1) to (Y-34)) (In the formula, * represents a bond bond). The manufacturing method according to claim 4, wherein the polyimide comprises a monomer unit represented by formula (1), a monomer unit represented by formula (2), or a monomer unit of both, . The method according to claim 1, wherein the composition for forming a resin film contains the heat-resistant polymer B and the silica particles in a mass ratio of 7: 3 to 3: 7. The manufacturing method according to claim 1, wherein the silicon dioxide particles have an average particle diameter of 60 nm or less. The manufacturing method according to claim 1, wherein any one of the composition for forming a release layer or the composition for forming a resin film further contains a crosslinking agent. The manufacturing method as claimed in claim 1, which is hardened by heat or ultraviolet rays. The manufacturing method according to claim 1, wherein the adhesiveness between the release layer and the resin film can be peeled from 0 to 5% in the CCJ series (JIS5400) classification, and between the support substrate and the release layer The adhesiveness can be peeled off by more than 50% in the CCJ series (JIS5400) classification. The manufacturing method of claim 1, wherein the release layer has a thickness of 100 μm to 1 nm. The manufacturing method according to claim 1, wherein the step of preparing the aforementioned resin film laminate is performed by a method selected by cutting with a blade, mechanical separation, and tensile peeling. A flexible substrate characterized by being manufactured by the manufacturing method according to any one of claims 1 to 14.