KR20200044950A - Polyimide precursor resin composition - Google Patents

Abstract

{식 중, R₁ 은, 복수 있는 경우 각각 독립적으로 2 가의 유기기를 나타내고, R₂ 는, 복수 있는 경우 각각 독립적으로 4 가의 유기기를 나타내고, n 은 양의 정수이다.} 로 나타내는 구조를 갖는 폴리이미드 전구체와, 용매를 포함하는 수지 조성물로서, 상기 폴리이미드 전구체의 중량 평균 분자량이 110,000 ∼ 250,000 이고, 상기 수지 조성물의 고형분 함유량이 10 ∼ 25 질량％ 인, 수지 조성물이 제공된다.Equation (1) below:

{In the formula, R ₁ represents a divalent organic group each independently if there are plural, R ₂ represents a tetravalent organic group each if it is plural, and n is a positive integer. As a resin composition containing a mid precursor and a solvent, a resin composition is provided in which the weight average molecular weight of the polyimide precursor is 110,000 to 250,000, and the solid content of the resin composition is 10 to 25 mass%.

Description

Polyimide precursor resin composition

The present invention relates to a resin composition containing a polyimide precursor, and a polyimide film. The present invention also relates to flexible devices (eg flexible displays) and laminates and methods of making them.

The polyimide resin is an insoluble and infusible super heat resistant resin, and has excellent properties such as heat resistance (for example, heat oxidation resistance), radiation resistance, low temperature resistance, and chemical resistance. For this reason, polyimide resins are used in a wide range of fields including electronic materials. Examples of the application of the polyimide resin in the field of electronic materials include, for example, insulating coating materials, insulating films, semiconductors, electrode protective films of thin film transistor liquid crystal displays (TFT-LCDs), and the like. In recent years, in the field of display materials, adoption of a flexible substrate utilizing its lightness and flexibility has been considered instead of a glass substrate conventionally used.

For example, Patent Document 1 describes a resin precursor (weight average molecular weight of 30,000 to 90,000) polymerized from bis (diaminodiphenyl) sulfone (hereinafter also referred to as DAS) and having a siloxane unit, The polyimide obtained by curing has low residual stress generated between a support such as glass, has excellent chemical resistance, and has a small effect on the yellowness (YI) value and total light transmittance due to oxygen concentration during the curing process. It is described. In addition, Patent Document 2 describes a resin composition characterized by containing a polyimide precursor having a specific absorbance and an alkoxysilane compound having a specific absorbance, and the resin obtained by curing the resin composition has sufficient adhesiveness with a support. , It is described that the peelability by laser peeling is compatible.

International Publication No. 2014/148441 International Publication No. 2016/167296

When a transparent polyimide resin is to be applied to a flexible substrate, a resin composition containing a polyimide precursor is coated on a substrate such as glass to form a coating film, followed by heating and drying, and further imidizing the polyimide precursor. Then, a polyimide film was formed, and if necessary, a device was formed on the film, and then the film was peeled off from a glass substrate or the like as a support to obtain a target product.

In recent years, when a composition containing a polyimide precursor is applied to a substrate such as glass, along with the enlargement of a display, which is a use of a flexible substrate, a slit coater may be used. When a coating film is formed by applying a composition with a slit coater, there is a coater gap (a setting value that defines a distance between the glass substrate and the slit nozzle) as a parameter that affects the coating film. If the coater gap is small, the flatness of the glass substrate In this bad case, there is a possibility that the nozzle contacts the substrate and the slit nozzle is broken. In particular, with the recent enlargement of displays and the like, it is necessary to make this coater gap sufficiently large.

Moreover, when a polyimide film is used as a material for a screen such as a flexible display, since the wavelength of visible light is about 380 nm to about 700 nm, particularly high film thickness uniformity is required to obtain good optical performance.

As a result of coating evaluation of the slit coat using the polyimide precursors having the same molecular weight and skeleton as those described in Patent Documents 1 and 2, the present inventors found that the above properties were insufficient. Accordingly, one aspect of the present invention is to provide a polyimide precursor-containing resin composition having excellent coating properties of a slit coat and excellent mechanical and optical properties required for applications such as flexible substrates.

As a result of intensive examination, the present inventors have found that the use of a polyimide precursor having a specific structure results in good coating properties in a slit coat, and realization of good mechanical and optical properties.

That is, the present invention includes the following aspects.

[1] The following formula (1):

[Formula 1]

{In the formula, R ₁ represents a divalent organic group each independently if there are plural, R ₂ represents a tetravalent organic group each if it is plural, and n is a positive integer. As a resin composition containing a mid precursor and a solvent,

The weight average molecular weight of the polyimide precursor is 110,000 to 250,000,

The resin composition whose solid content of the said resin composition is 10-25 mass%.

[2] The resin composition according to the above aspect 1, wherein the shear rate dependency (TI) represented by the following formula when the viscosity of the resin composition is measured at 23 ° C with a viscometer with a temperature controller is 0.9 to 1.1.

TI = ηa / ηb

{In the formula, ηa (mPa · s) is the viscosity at the measured rotational speed a (rpm) of the resin composition, ηb (mPa · s) is the viscosity at the measured rotational speed b (rpm) of the resin composition, However, a * 10 = b.}

[3] The resin composition according to the aspect 1 or 2, wherein the resin composition is a resin composition for slit coat.

[4] At least one of R ₁ in the formula (1) is represented by the following formula (2):

[Formula 2]

The resin composition as described in any one of said aspect 1-3, which is a group represented by.

[5] The polyimide precursor is represented by the following formula (3):

[Formula 3]

{In the formula, each of R ₃ and R ₄ , when plural, each independently represents a monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms or a monovalent aromatic group having 6 to 10 carbon atoms, and m is 1 to 200 The resin composition according to any one of the above aspects 1 to 4, having a structure represented by}.

[6] The resin composition according to any one of the above aspects 1 to 5, wherein the polyimide precursor is a copolymer of dicarboxylic acid and tetracarboxylic dianhydride containing pyromellitic dianhydride.

[7] Any one of the above aspects 1 to 6, wherein the polyimide precursor is a copolymer of diamine and tetracarboxylic dianhydride containing 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride. The resin composition described in.

[8] The polyimide precursor is a copolymer of tetracarboxylic dianhydride and diamine, and the tetracarboxylic dianhydride is pyromellitic dianhydride and 3,3 ', 4,4'-biphenyltetra The above aspect 1 to 1, wherein the carboxylic acid 2 anhydride contains the pyromellitic acid 2 anhydride and the 3,3 ', 4,4'-biphenyltetracarboxylic acid 2 anhydride in a molar ratio of 20:80 to 80:20. The resin composition according to any one of 7.

[9] The polyimide precursor is tetracarboxylic dianhydride, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 2,2'-bis (trifluoromethyl ) A resin composition according to any one of the above aspects 1 to 8, which is a copolymer of at least one diamine selected from the group consisting of benzidine and 9,9-bis (4-aminophenyl) fluorene.

[10] The resin composition according to any one of the above aspects 1 to 9, wherein the weight average molecular weight of the polyimide precursor is 160,000 to 220,000.

[11] The resin composition according to any one of the above aspects 1 to 10, wherein the resin composition is a resin composition for a flexible device.

[12] The resin composition according to any one of the above aspects 1 to 11, wherein the resin composition is a resin composition for a flexible display.

[13] A polyimide film that is a cured product of the resin composition according to any one of embodiments 1 to 12 above.

[14] The polyimide film according to aspect 13, wherein the thickness direction retardation (Rth) in terms of the film thickness of 10 μm is 300 or less, and / or the yellowness (YI) in terms of the film thickness of 10 μm is 20 or less. .

[15] A flexible device comprising the polyimide film according to aspect 13 or 14 above.

[16] A flexible display comprising the polyimide film according to aspect 13 or 14 above.

[17] The flexible display according to the aspect 16, wherein the polyimide film is disposed at a point visually observed when the flexible display is observed from the outside.

[18] a coating step of applying the resin composition according to any one of the above aspects 1 to 12 on the surface of the support;

A film forming process of heating the resin composition to form a polyimide film,

A method for producing a polyimide film comprising a peeling step of peeling the polyimide film from the support.

[19] The method for producing a polyimide film according to aspect 18, wherein the coating step includes slit coating the resin composition.

[20] At least one of R ₁ in the formula (1) is represented by the following formula (2):

[Formula 4]

The polyimide film production method according to the aspect 19, which is a group represented by.

[21] The polyimide precursor is represented by the following formula (3):

[Formula 5]

{In the formula, each of R ₃ and R ₄ , when plural, each independently represents a monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms or a monovalent aromatic group having 6 to 10 carbon atoms, and m is 1 to 200 The method for producing a polyimide film according to the aspect 19 or 20, which has a structure represented by}.

[22] The method for producing a polyimide film according to any one of the aspects 18 to 21, further comprising an irradiation step of irradiating a laser to the polyimide film from the support side prior to the peeling step.

[23] a coating step of applying the resin composition according to any one of the above aspects 1 to 12 on the surface of the support;

A film forming process of heating the resin composition to form a polyimide film,

An element forming process for forming an element on the polyimide film,

A method of manufacturing a display comprising a peeling step of peeling the polyimide film on which the device is formed from the support.

[24] The method for producing a display according to aspect 23, wherein the coating step includes slit coating the resin composition.

[25] The method for producing a display according to the aspect 23 or 24, wherein the polyimide film is disposed at a point visually observed when the display is viewed from the outside.

According to one aspect of the present invention, it is possible to provide a polyimide precursor-containing resin composition having excellent coating properties in a slit coat and excellent mechanical and optical properties required for applications such as flexible substrates.

1 is a view showing a structure above the polyimide substrate of a top emission type flexible organic EL display as an example of a display provided in one aspect of the present invention.

Hereinafter, exemplary embodiments of the present invention (hereinafter abbreviated as "embodiments") will be described in detail. In addition, this invention is not limited to the following embodiment, It can be implemented by carrying out various modifications within the range of the summary. The characteristic values described in the present disclosure are intended to be values measured in a manner understood by those skilled in the art or the methods described in the section of [Example] or equivalents thereof unless otherwise specified.

This embodiment,

Equation (1) below:

[Formula 6]

{In the formula, R ₁ each independently represents a divalent organic group when there are plural, R ₂ each independently represents a tetravalent organic group when plural, and n is a positive integer.}

It provides a resin composition comprising a polyimide precursor having a structure represented by. In one aspect, the resin composition includes the polyimide precursor and a solvent.

In a preferred aspect, at least one of R ₁ in formula (1) is represented by the following formula (2):

[Formula 7]

It is a group represented by.

When at least one of R ₁ in formula (1) is a structure represented by formula (2), it contributes to good optical properties (particularly Rth) and heat resistance of polyimide, which is a cured product of the polyimide precursor. In one aspect, all of n n R ₁ in Formula (1) has a structure represented by Formula (2). Moreover, in one aspect, the ratio of the structure represented by Formula (2) among n R ₁ in Formula (1) may be 0% or more, or 10% or more, or 20% or more, and 100% or less, or 90 % Or less.

This embodiment is also a resin composition comprising a polyimide precursor having a structure represented by the formula (1), wherein the cured polyimide of the resin composition has a thickness direction retardation (Rth) of 300 or less and / or yellowness. (YI) A resin composition having 20 or less is also provided. The low thickness direction retardation (Rth) indicates that the polyimide is low birefringent, and the low yellowness (YI) above indicates that the polyimide has a good color tone (ie, almost colorless). .

The resin composition of the present embodiment has excellent slit coat performance and provides a polyimide film having excellent mechanical and optical properties, and is preferably for a flexible device (for example, for a flexible substrate). It is preferably useful for flexible displays.

(Weight average molecular weight of polyimide precursor)

In one embodiment, the weight average molecular weight of the polyimide precursor is 110,000 or more and 250,000 or less. The inventor found out that when the resin composition of the present embodiment is used for a slit coat, the weight average molecular weight of the polyimide precursor greatly affects the coating performance, and repeated examinations. As a result, when the weight average molecular weight of the polyimide precursor was 110,000 or more, it was found that the solid content of the resin composition was adjusted to realize good slit coat, while the polyimide precursor having a weight average molecular weight of 250,000 or less was easy to manufacture. . That is, in the present embodiment, the weight average molecular weight of the polyimide precursor is 110,000 or more from the viewpoint of coating performance, and 250,000 or less in terms of ease of manufacture.

The preferable weight average molecular weight of the polyimide precursor may be different depending on the desired application, the type of the polyimide precursor, the solid content of the resin composition, and the type of solvent the resin composition may contain.

For example, a preferable example of the lower limit of the weight average molecular weight,

Moreover, a preferable example of the upper limit of the weight average molecular weight is,

For example, from the viewpoint of elongation and yellowness (YI) of a cured product of a resin composition containing a polyimide precursor (for example, a polyimide film (also referred to as a cure film in the present disclosure)), the weight average molecular weight is 120,000 or more. This is preferable, 130,000 or more is more preferable, and 160,000 or more is particularly preferable. Moreover, from the viewpoint of the haze of the cured product (for example, a polyimide film), 220,000 or less is preferable, and 200,000 or less is more preferable. In one preferred aspect, the weight average molecular weight of the polyimide precursor is 160,000 or more and 220,000 or less.

(Polyimide film thickness direction retardation (Rth))

When a polyimide film is produced as a cured product of polyimide precursor (i.e., an imide), the thickness direction retardation (Rth) at a film thickness of 10 µm of the polyimide film varies depending on the monomer skeleton of the polyimide precursor. However, if the same monomer skeleton, the larger the weight average molecular weight of the polyimide precursor, the smaller the Rth tends to be. As the polymer backbone, when DAS is used, Rth tends to be small. Although the mechanism of the above relationship between the weight average molecular weight of the polyimide precursor and Rth of the polyimide film is unclear, it is believed that the orientation and crystallinity of the molecules of the polyimide film are related.

In a specific aspect, Rth is 300 nm or less from the viewpoint of obtaining a low-birefringent polyimide film. In particular, when a polyimide film is used as a display material, as Rth, 200 nm or less is preferable, 100 nm or less is more preferable, 80 nm or less is more preferable, 50 nm or less is more preferable, and 30 nm is particularly desirable. When Rth is 300 nm or less, it is easy to accurately capture an image image. Particularly, when Rth is 200 nm or less, color reproducibility of the image is good.

In one aspect, the polyimide film has a thickness direction retardation (Rth) in terms of 10 μm film thickness of 300 nm or less, and / or a yellowness (YI) in terms of 10 μm film thickness of 20 μm or less. . In one aspect, in the polyimide film, the thickness direction retardation (Rth) in terms of 10 µm film thickness is 300 nm or less, and the yellowness (YI) in terms of 10 µm film thickness is 20 or less.

(Yellow degree of polyimide film (YI))

In a specific aspect, when a polyimide film is produced as a cured product (i.e., an imide) of a polyimide precursor, the yellowness (YI) at a film thickness of 10 µm of the polyimide film obtains good optical properties. From a viewpoint, it is 20 or less, Preferably it is 18 or less, More preferably, it is 16 or less, More preferably, it is 14 or less, More preferably, it is 13 or less, More preferably, it is 10 or less, Especially preferably, it is 7 or less. Although the YI at the film thickness of 10 µm of the polyimide film differs depending on the monomer skeleton of the polyimide precursor, if the same monomer skeleton, the larger the weight average molecular weight of the polyimide precursor, the smaller the YI tends to be.

(Other desirable properties of polyimide film)

When a polyimide film is produced on an inorganic support substrate such as a glass substrate as a cured product (i.e., an imide) of a polyimide precursor, the polyimide film is formed between the glass substrate at a thickness of 10 µm. Residual stress is preferably 25 MPa or less, more preferably 23 MPa or less, even more preferably 20 MPa or less, from the viewpoint of reducing the amount of warpage of the glass substrate with polyimide, for example, in display applications. It is more preferably 18 MPa or less, and particularly preferably 16 MPa or less.

Moreover, it is preferable that the tensile elongation in the film thickness of 10 micrometers of the said polyimide film is 15% or more. The tensile elongation is more preferably 20% or more, more preferably 25% or more, still more preferably 30% or more, still more preferably 35% or more, particularly preferably from the viewpoint of the dynamic strength of the flexible display. It is 40% or more. The tensile elongation of the polyimide film differs depending on the monomer skeleton of the polyimide precursor, but if it is the same monomer skeleton, the larger the weight average molecular weight of the polyimide precursor, the higher the tensile elongation.

The glass transition temperature Tg of the polyimide film is preferably 360 ° C. or higher, more preferably 400 ° C. or higher, and more preferably 400 ° C. or higher, from the viewpoint of a higher process temperature when producing an inorganic film such as silicon nitride on the polyimide by a CVD process. The above is more preferable.

It is preferable that the polyimide film has a uniform film thickness. In particular, when a polyimide film is used as a material for a screen such as a flexible display, since the wavelength of visible light is about 380 nm to about 700 nm, it is a particularly high film from the viewpoint of obtaining good display performance and from the viewpoint of the manufacturing process of the display. Thickness uniformity is required. The film thickness uniformity of the polyimide film (standard deviation of multiple points in the film thickness) is preferably 10 μm or less, preferably 8 μm or less, preferably 5 μm or less, preferably 3 μm or less, and 2 μm or less Is preferred, 1 μm or less is particularly preferred, 500 nm or less is particularly preferred, and 300 nm or less is particularly preferred. The smaller the film thickness uniformity is, the more preferable it is, from the viewpoint of improving the yield of display production, for example, may be 50 nm or more, or 100 nm or more. In addition, the said film thickness uniformity means the value of 3σ calculated from the film thickness of several points measured by the method of the term of the [Example] of this indication, for example.

(Depending on the shear rate of the resin composition)

The shear rate dependence (TI) (hereinafter, simply referred to as TI) of the resin composition of the present embodiment is preferably 0.9 or more and 1.1 or less. In the present disclosure, TI measured the viscosity of the resin composition at 23 ° C with a viscometer with a thermostat (TVE-35H manufactured by Toki Sangyo), and the viscosity ηa (mPa · s) at the measured rotational speed a (rpm). , From the viscosity ηb (mPa · s) at the measured rotational speed b (rpm) (however, a * 10 = b), the following formula:

TI = ηa / ηb

It is a value obtained according to. The details of the measurement conditions are described in the description in Examples.

The shear rate dependence (TI) is preferably 0.9 or more, or 0.95 or more, or 1.0 or more, and preferably 1.1 or less, or 1.05 or less, or 1.0 or less. When TI is in this range, the resin composition is referred to as Newtonian fluid, and is preferable because the film thickness uniformity when the resin composition is slit coated is good. The polyimide film obtained by curing a resin composition having good film thickness uniformity has good film thickness uniformity, and therefore can be preferably used as a material for a screen such as a flexible display.

The detailed reason why the film thickness uniformity becomes good when the shear rate dependence of the resin composition is 0.9 or more and 1.1 or less is unclear, but is considered as follows.

In the slit coat, the shear rate applied to the resin composition immediately after the start of application is small, and the shear rate applied to the resin composition when application is continued. When the shear rate dependence is small (specifically, TI is 0.9 or more and 1.1 or less), since the difference in viscosity of the resin composition immediately after the start of coating and when the coating is continued is small, the film thickness variation in the MD (Machine direction) Is small (that is, the film thickness uniformity in the coating direction is good). Moreover, when the slit coat nozzle is a specification in which the resin composition is injected from only one end in the transverse direction (TD), the shear rate of the resin composition is large in the vicinity of the injection port during slit coating, but opposite to the injection port. In the (ie, the deadlock side of the nozzle), the shear rate of the resin composition becomes small. Even in such a case, since the shear rate dependence is small (specifically, TI is 0.9 or more and 1.1 or less), it is possible to reduce the film thickness variation in the width direction. Thus, a small shear rate dependence (specifically, TI is 0.9 or more and 1.1 or less) reduces the influence on the viscosity due to shear, and thus the film thickness variation is small in both MD and TD (ie, film thickness uniformity) It is good).

It is considered that the shear rate dependence of the resin composition is correlated with the method for synthesizing the resin composition.

For example, when the reaction vessel is reacted by adding acid 2 anhydride, diamine, and silicone oil, which may be acid 2 anhydride or diamine by structure, and reacting by heating, the diamine dissolved in a solvent When comparing the case where the acid 2 anhydride and the silicone oil dissolved in a solvent are dripped little by little over a period of time at room temperature, and reacted little by little, in the former case, among the monomers (ie, acid 2 anhydride, diamine and silicone oil), It reacts from a more reactive one (higher acidity or basicity, smaller steric hindrance, etc.), and the polyimide precursor tends to become a block polymer. On the other hand, in the latter case, since acid 2 anhydride and silicone oil are dissolved in a solvent and added in small portions, each monomer can react regardless of reactivity or the like, and the polyimide precursor tends to be a random polymer. Thus, in the former and the latter, it is considered that the polymer structure of the product is different. In the case of block polymers (electrons), since specific monomers are clustered among polymers, it is thought that intermolecular interactions are likely to occur between polymer chains, or because polymer flexibility is impaired, stacking between polymer chains is likely to occur. As a result, it is thought that the shear rate dependence of the resin composition becomes large. On the other hand, in the latter case, it is considered that the dependence on the shear rate is small because each monomer is bound in sequence and interaction between molecules is unlikely to occur.

Moreover, in the former case, since all monomers are added and heated, it is considered that, in particular, some acid 2 anhydride groups are opened by heat before reacting with the polymer chain. When the acid 2 anhydride group is opened and becomes a dicarboxyl group, the reactivity is lower than that of the acid 2 anhydride group, and it is considered that the molecular weight of the polyimide precursor is reduced. On the other hand, in the latter case, since the acid 2 anhydride is dissolved in a solvent and added dropwise at room temperature, it is considered that the acid 2 anhydride group can react with the polymer chain without ring opening, and the molecular weight is considered to be large.

(Slit coat properties of resin composition)

The coat characteristic (slit coat characteristic) of the resin composition containing the polyimide precursor by the slit nozzle correlates with the weight average molecular weight of the polyimide precursor and the solid content of the resin composition. When the polyimide precursor has a low molecular weight, and / or when the resin composition has a low solid content, liquid leakage is likely to occur from the nozzle, while the polyimide precursor has a high molecular weight, and / or the resin composition has a high In the case of solid content, clogging of the varnish tends to occur at the tip of the nozzle. Therefore, it is preferable to control the weight average molecular weight of the polyimide precursor to a range in which desired slit coat properties are obtained by controlling the solid content.

(Edge characteristics of coating film)

When the resin composition containing the polyimide precursor is slit-coated to form a dry coating film, when the polyimide precursor has a low molecular weight, and / or the resin composition has a low solid content, edge sagging is likely to occur. , When the polyimide precursor has a high molecular weight, and / or when the resin composition has a high solid content, edge beads (ie, edge ridges) are likely to occur. Therefore, it is preferable to control the weight average molecular weight of the polyimide precursor to a range in which desired edge characteristics are obtained by controlling the solid content.

In one aspect, the solid content of the resin composition is 10 mass% to 25 mass%. The settable coat gap (i.e., the gap between the tip of the slit coat nozzle and the substrate) when slit-coating the resin composition correlates with the solid content of the resin composition, and if the kind of solid content contained in the resin composition is the same, the The smaller the solid content, the larger the coat gap tends to be. From the viewpoint of good coating, it is preferable that the coat gap is large, and for example, if the coat gap is 50 µm or more, collision between the slit nozzle and the substrate can be avoided even when the substrate size is relatively large. When the solid content of the resin composition is 10% by mass to 25% by mass, the desired coat gap can be realized by selecting the type and molecular weight of the polyimide precursor. The preferable solid content of the resin composition may be different depending on the desired use, the type and molecular weight of the polyimide precursor, and the type of solvent the resin composition may contain.

Preferable examples of the lower limit of the solid content are 11 mass%, 12 mass%, 13 mass%, 14 mass%, 15 mass%, 16 mass%, 17 mass%, 18 mass%, 19 mass%, 20 mass%, 21 Mass%, 22 mass%, 23 mass%, or 24 mass%.

Preferable examples of the upper limit of the solid content are 24 mass%, 23 mass%, 22 mass%, 21 mass%, 20 mass%, 19 mass%, 18 mass%, 17 mass%, 16 mass%, 15 mass%, 14 It is mass%, 13 mass%, 12 mass%, or 11 mass%.

In a preferable aspect, the solid content concentration is 10 to 20 mass%, and more preferably 10 to 15 mass%.

In a preferred embodiment, the polyimide precursor is represented by formula (3):

[Formula 8]

{In the formula, each of R ₃ and R ₄ , when plural, each independently represents a monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms or a monovalent aromatic group having 6 to 10 carbon atoms, and m is 1 to 200 It is an integer of}.

When R ₃ and R ₄ are a monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms or a monovalent aromatic group having 6 to 10 carbon atoms, from the viewpoint of obtaining a polyimide capable of reducing residual stress and Rth generated between the supports, It is advantageous. Preferable structures of R ₃ and R ₄ include methyl group, ethyl group, propyl group, butyl group and phenyl group.

m is 1 to 200, preferably 1 or more, or 3 or more, or 5 or more, preferably from the viewpoint of obtaining a polyimide capable of reducing residual stress and Rth generated between the supports 200 or less, or 180 or less, or 160 or less.

The polyimide precursor may have the structure of formula (3) at any site in the molecule, but it is preferable that the structure of formula (3) is derived from the diamine component from the viewpoint of the type and cost of the siloxane monomer. The proportion of the structural site represented by the formula (3), which occupies the total mass of the polyimide precursor, is preferably 5 mass% or more, more preferably 6 from the viewpoint of reducing residual stress and Rth generated between the support body It is mass% or more, more preferably 7 mass% or more, and from the viewpoint of transparency and heat resistance of the resulting cured product (for example, polyimide film), preferably 40 mass% or less, more preferably 30 mass% or less , More preferably 25% by mass or less.

In a typical embodiment, the polyimide precursor having a structure represented by the formula (1) is a polymer of a diamine component containing an R ₁ group and an acid 2 anhydride component containing an R ₂ group.

As the acid 2 anhydride containing the R ₂ group, pyromellitic acid 2 anhydride, 3,3 ', 4,4'-biphenyltetracarboxylic acid 2 anhydride, 2,2', 3,3'-biphenyltetracar Carboxylic acid anhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-cyclohexene-1,2 Dicarboxylic acid anhydride, 1,2,3,4-benzenetetracarboxylic acid anhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic acid anhydride, 2,2', 3,3 ' -Benzophenonetetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylsulfonetetracarboxylic dianhydride, methylene-4,4'-diphthalic acid 2 anhydride, 1,1-ethylidene-4 , 4'-Diphthalic acid 2 anhydride, 2,2-propylidene-4,4'-diphthalic acid 2 anhydride, 1,2-ethylene-4,4'-diphthalic acid 2 anhydride, 1,3-trimethylene-4 , 4'-Diphthalic acid 2 anhydride, 1,4-tetramethylene-4,4'-diphthalic acid 2 anhydride, 1,5-pentamethylene-4,4'-diphthalic acid 2 anhydride, 4,4'-oxydi Phthalic anhydride, p-phenylene ratio (Trimellitate anhydride), thio-4,4'-diphthalic acid 2 anhydride, sulfonyl-4,4'-diphthalic acid 2 anhydride, 1,3-bis (3,4-dicarboxyphenyl) benzene 2 anhydride , 1,3-bis (3,4-dicarboxyphenoxy) benzene 2 anhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene 2 anhydride, 1,3-bis [2- (3, 4-dicarboxyphenyl) -2-propyl] benzene 2 anhydride, 1,4-bis [2- (3,4-dicarboxyphenyl) -2-propyl] benzene 2 anhydride, bis [3- (3,4- Dicarboxyphenoxy) phenyl] methane 2 anhydride, bis [4- (3,4-dicarboxyphenoxy) phenyl] methane 2 anhydride, 2,2-bis [3- (3,4-dicarboxyphenoxy) phenyl ] Propane 2 anhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane 2 anhydride, bis (3,4-dicarboxyphenoxy) dimethylsilane 2 anhydride, 1,3-bis (3,4-dicarboxyphenyl) -1,1,3,3-tetramethyldisiloxane 2 anhydride, 2,3,6,7-naphthalenetetracarboxylic acid anhydride, 1,4,5,8-naphthalene Tetracarboxylic acid anhydride, 1,2,5,6-na Tallentetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenane Trentetracarboxylic dianhydride etc. can be illustrated.

Especially, pyromellitic dianhydride (PMDA) and biphenyltetracarboxylic dianhydride (BPDA) are preferable when the solid content of the resin composition is controlled within the range of the predetermined weight average molecular weight of the polyimide precursor. Slit coat performance and good mechanical properties, optical properties, and high glass transition temperature of a cured product (for example, a polyimide film) are preferred from the viewpoint of being easily obtained. In one aspect, the polyimide precursor having a structure represented by formula (1) is a copolymer of tetracarboxylic dianhydride and diamine. In one aspect, the polyimide precursor is a copolymer of dicarboxylic acid and tetracarboxylic dianhydride containing pyromellitic dianhydride (PMDA). In one aspect, the polyimide precursor is a copolymer of dicarboxylic acid and tetracarboxylic dianhydride containing 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride.

In a specific embodiment, the total content of pyromellitic dianhydride (PMDA) and biphenyltetracarboxylic dianhydride (BPDA) in the total acid 2 anhydride has good slit coat performance and a cured product (eg poly From the viewpoint of obtaining good thickness direction retardation (Rth), yellowness (YI), glass transition temperature Tg, and elongation of the mid film), preferably 60 mol% or more, more preferably 80 mol% or more, particularly preferably It is 100 mol%.

In a specific aspect, the content of pyromellitic acid 2 anhydride (PMDA) in the total acid 2 anhydride is from the viewpoint of obtaining good slit coat performance and good glass transition temperature Tg of the cured product (for example, polyimide film). , 0 mol% or more is preferable, 10 mol% or more is preferable, 20 mol% or more is preferable, 100 mol% or less is preferable, and 90 mol% or less is preferable.

In a specific aspect, the content of biphenyltetracarboxylic dianhydride (BPDA) in the total acid 2 anhydride has good slit coat performance, and good retardation in the thickness direction of the cured product (for example, a polyimide film). From the viewpoint of obtaining (Rth), yellowness (YI), and elongation, 0 mol% or more is preferable, 10 mol% or more is preferable, 20 mol% or more is preferable, 100 mol% or less is preferable, 90 Molar% or less is preferred.

In a specific embodiment, the content ratio of pyromellitic acid anhydride (PMDA) to biphenyltetracarboxylic acid anhydride (BPDA) in acid 2 anhydride is a good thickness direction of the cured product (for example, a polyimide film). From the viewpoint of achieving the heat resistance represented by the partition (Rth), the yellowness (YI) and the glass transition temperature, 20:80 to 80:20 is preferable, and 30:70 to 70:30 is more preferable. In a specific aspect, the polyimide precursor is a copolymer of tetracarboxylic dianhydride and diamine, and the tetracarboxylic dianhydride is pyromellitic dianhydride and 3,3 ', 4,4'-biphenyl The molar ratio of tetracarboxylic dianhydride to pyromellitic dianhydride: 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride 20: 80 to 80: 20, more preferably 30: 70 to 70: 30.

As the diamine containing the R ₁ group in formula (1), diaminodiphenylsulfone (for example, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone), p- Phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylsulfide, 3,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfide, 4,4 ' -Diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3 ' -Diaminobenzophenone, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 1,4-bis (4-aminophenoxy ) Benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, 4,4- Bis (4-aminophenoxy) biphenyl, 4,4-bis (3-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) Si) phenyl] ether, 1,4-bis (4-aminophen ) Benzene, 1,3-bis (4-aminophenyl) benzene, 9,10-bis (4-aminophenyl) anthracene, 2,2-bis (4-aminophenyl) propane, 2,2-bis (4- Aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl) propane, 2,2-bis [4- (4-aminophenoxy) phenyl) hexafluoropropane, 1 And 4-bis (3-aminopropyldimethylsilyl) benzene.

The diamine used to form the polyimide precursor having the structure represented by formula (1) is diaminodiphenylsulfone (for example, 4,4'-diaminodiphenylsulfone and / or 3,3'-dia It is preferred to include minodiphenylsulfone).

The content of diaminodiphenylsulfone in all diamines is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more, and may be 95 mol% or more. The larger the amount of diaminodiphenylsulfone, the more preferable it is from the viewpoints of yellowness (YI) of the cured product (for example, polyimide film), glass transition temperature Tg, and thickness direction retardation Rth. As diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone is particularly preferable from the viewpoint of low yellowness (YI).

In a preferred aspect, the diamine of the counterpart copolymerized with diaminodiphenylsulfone is preferably a diamide biphenyl from the viewpoints of heat resistance of the cured product (for example, polyimide film) and yellowness (YI). , More preferably diaminobis (trifluoromethyl) biphenyl (TFMB). The content of diaminobis (trifluoromethyl) biphenyl (TFMB) in all diamines is preferably 20 mol% or more, from the viewpoint of yellowness (YI) of the cured product (for example, polyimide film). It is preferably 30 mol% or more, and preferably 80 mol% or less, more preferably 70 mol% or less, from the viewpoint of allowing diamine to contain other advantageous components such as diaminodiphenylsulfone.

In a preferred aspect, the diamine includes silicon-containing diamine. In a more preferable aspect, the diamine contains silicon-containing diamine containing a structure represented by the formula (3) described above. As the silicon-containing diamine, for example, the following formula (3a):

[Formula 9]

{In the formula, R ₅ represents a divalent hydrocarbon group, each may be the same or different, and each of the plurality of R ₃ and R ₄ is the same as defined in Formula (3), and l is an integer from 1 to 200 Diamino (poly) siloxane represented by} can be preferably used.

As a preferable structure of R <_5> in said general formula (3a), a methylene group, an ethylene group, a propylene group, a butylene group, a phenylene group, etc. are mentioned. In addition, as R _3, and a preferred structure of R ₄ in the formula (3a) is a methyl group, it may be mentioned an ethyl group, a propyl group, a butyl group, a phenyl group and the like.

The number average molecular weight of the compound represented by the formula (3a) is preferably 500 or more, more preferably from the viewpoint of reducing the residual stress generated between the obtained cured product (for example, polyimide film) and the support. 1,000 or more, more preferably 2,000 or more, from the viewpoint of transparency (especially low HAZE) of the resulting cured product (for example, polyimide film), preferably 12,000 or less, more preferably 10,000 or less, further preferably 8,000 or less.

As the compound represented by the formula (3a), specifically, sock-end amine-modified methylphenylsilicone oil (manufactured by Shin-Etsu Chemical Co., Ltd .: X22-1660B-3 (number average molecular weight 4400), X22-9409 (number average molecular weight 1300)), Socks short amino-modified dimethylsilicone (manufactured by Shin-Etsu Chemical Co., Ltd .: X22-161A (number average molecular weight 1600), X22-161B (number average molecular weight 3000), KF8012 (number average molecular weight 4400), manufactured by Toray Dow Corning: BY16-835U (number average Molecular weight 900) manufactured by Chisso Corporation: Cyrapin FM3311 (number average molecular weight 1000)). Of these, the sock-end amine-modified methylphenylsilicone oil is preferred from the viewpoint of improving chemical resistance and improving Tg.

The copolymerization ratio of the silicon-containing diamine is preferably in the range of 0.5 to 30 mass%, more preferably 1.0 to 25 mass%, still more preferably 1.5 to 20 mass%, relative to the mass of the total polyimide precursor. % to be. When it is 0.5 mass% or more, the effect of reducing the stress generated between the supports is good. Moreover, when it is 30 mass% or less, transparency (especially low HAZE) of the hardened | cured material obtained (for example, polyimide film) is favorable, and it is preferable from the viewpoint of realizing high total light transmittance and preventing Tg from falling.

As an acid component for forming the polyimide precursor in the present embodiment, in addition to the acid 2 anhydride (for example, the tetracarboxylic dianhydride exemplified above), in the range that does not impair its performance, dicar You may use carboxylic acid. That is, the polyimide precursor of the present disclosure may be a polyamideimide precursor. The film obtained from such a polyimide precursor may have various performances such as mechanical elongation, glass transition temperature Tg, and yellowness (YI). Examples of the dicarboxylic acid to be used include dicarboxylic acids having an aromatic ring and alicyclic dicarboxylic acids. It is particularly preferable that it is at least one compound selected from the group consisting of an aromatic dicarboxylic acid having 8 to 36 carbon atoms and an alicyclic dicarboxylic acid having 6 to 34 carbon atoms. The number of carbons referred to herein includes the number of carbons contained in the carboxyl group. Of these, dicarboxylic acids having aromatic rings are preferred.

Specifically, for example, isophthalic acid, terephthalic acid, 4,4'-biphenyldicarboxylic acid, 3,4'-biphenyldicarboxylic acid, 3,3'-biphenyldicarboxylic acid, 1, 4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-sulfonylbisbenzoic acid, 3, 4'-sulfonylbisbenzoic acid, 3,3'-sulfonylbisbenzoic acid, 4,4'-oxybisbenzoic acid, 3,4'-oxybisbenzoic acid, 3,3'-oxybisbenzoic acid, 2,2-bis (4-carboxyphenyl) propane, 2,2-bis (3-carboxyphenyl) propane, 2,2'-dimethyl-4,4'-biphenyldicarboxylic acid, 3,3'-dimethyl-4,4 '-Biphenyldicarboxylic acid, 2,2'-dimethyl-3,3'-biphenyldicarboxylic acid, 9,9-bis (4- (4-carboxyphenoxy) phenyl) fluorene, 9, 9-bis (4- (3-carboxyphenoxy) phenyl) fluorene, 4,4'-bis (4-carboxyphenoxy) biphenyl, 4,4'-bis (3-carboxyphenoxy) biphenyl, 3,4'-bis (4-carboxyphenoxy) biphenyl, 3,4'-bis (3-car Leboxoxyphenoxy) biphenyl, 3,3'-bis (4-carboxyphenoxy) biphenyl, 3,3'-bis (3-carboxyphenoxy) biphenyl, 4,4'-bis (4-carboxy Phenoxy) -p-terphenyl, 4,4'-bis (4-carboxyphenoxy) -m-terphenyl, 3,4'-bis (4-carboxyphenoxy) -p-terphenyl, 3,3 '-Bis (4-carboxyphenoxy) -p-terphenyl, 3,4'-bis (4-carboxyphenoxy) -m-terphenyl, 3,3'-bis (4-carboxyphenoxy) -m -Terphenyl, 4,4'-bis (3-carboxyphenoxy) -p-terphenyl, 4,4'-bis (3-carboxyphenoxy) -m-terphenyl, 3,4'-bis (3 -Carboxyphenoxy) -p-terphenyl, 3,3'-bis (3-carboxyphenoxy) -p-terphenyl, 3,4'-bis (3-carboxyphenoxy) -m-terphenyl, 3 , 3'-bis (3-carboxyphenoxy) -m-terphenyl, 1,1-cyclobutanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid , 4,4'-benzophenone dicarboxylic acid, 1,3-phenylene diacetic acid, 1,4-phenylene diacetic acid, etc .; And 5-aminoisophthalic acid derivatives described in the international publication 2005/068535 pamphlet. When these dicarboxylic acids are actually copolymerized with the polymer, they may be used in the form of acid chlorides derived from thionyl chloride or the like, and active esters.

In a preferred embodiment, the polyimide precursor is tetracarboxylic dianhydride, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 2,2'-bis (trifluoro It is a copolymer of at least one diamine selected from the group consisting of methyl) benzidine and 9,9-bis (4-aminophenyl) fluorene.

The following are mentioned as a particularly preferable polyimide precursor.

(1) Polycondensates of material components wherein the acid 2 anhydride component is pyromellitic acid 2 anhydride (PMDA) and biphenyltetracarboxylic acid anhydride (BPDA), and the diamine component is diaminodiphenylsulfone (DAS) (more preferably Is, weight average molecular weight 110,000 to 130,000, solid content 12 to 25 mass%)

(2) Polycondensates of material components wherein the acid 2 anhydride component is pyromellitic acid 2 anhydride (PMDA) and biphenyltetracarboxylic acid anhydride (BPDA), the diamine component is diaminodiphenylsulfone (DAS) and silicon-containing diamine. (More preferably, weight average molecular weight 110,000 to 210,000, solid content 10 to 25 mass%)

(3) Acid 2 anhydride component pyromellitic acid 2 anhydride (PMDA) and biphenyltetracarboxylic acid anhydride (BPDA), diamine component diaminodiphenylsulfone (DAS), diaminobis (trifluoromethyl) Biphenyl (TFMB) and a polycondensate of a material component that is a silicon-containing diamine (more preferably, weight average molecular weight 110,000 to 250,000, solid content 10 to 25 mass%)

(4) Polycondensate of a material component in which the acid 2 anhydride component is pyromellitic acid 2 anhydride (PMDA) and the diamine component is diaminodiphenylsulfone (DAS) (more preferably, a weight average molecular weight of 110,000 to 140,000, solid content 10 ∼ 25 mass%)

(5) Polycondensates of material components wherein the acid 2 anhydride component is pyromellitic acid 2 anhydride (PMDA), the diamine component is diaminodiphenylsulfone (DAS) and silicon-containing diamine (more preferably, a weight average molecular weight of 110,000 to 230,000 , Solid content 10 to 25 mass%)

(6) Material components wherein the acid 2 anhydride component is pyromellitic acid 2 anhydride (PMDA), the diamine component is diaminodiphenylsulfone (DAS), diaminobis (trifluoromethyl) biphenyl (TFMB) and silicon-containing diamine Polycondensate (more preferably, weight average molecular weight 110,000 to 250,000, solid content 10 to 25 mass%)

(7) A polycondensate of a material component in which the acid 2 anhydride component is biphenyltetracarboxylic acid 2 anhydride (BPDA) and the diamine component is diaminodiphenylsulfone (DAS) (more preferably, a weight average molecular weight of 110,000 to 120,000, Solid content 20-25 mass%)

(8) Polycondensates of material components wherein the acid 2 anhydride component is biphenyltetracarboxylic acid anhydride (BPDA), the diamine component is diaminodiphenylsulfone (DAS), and silicon-containing diamine (more preferably, a weight average molecular weight 110,000 to 160,000, solid content 10 to 25 mass%)

(9) The acid 2 anhydride component is biphenyltetracarboxylic acid 2 anhydride (BPDA), the diamine component is diaminodiphenylsulfone (DAS), diaminobis (trifluoromethyl) biphenyl (TFMB) and silicon-containing diamine Polycondensate of phosphorus material component (more preferably, weight average molecular weight 110,000 to 240,000, solid content 10 to 25 mass%)

In the material component of the polycondensate of the above (1) to (9), the silicon-containing diamine is preferably a diamino (poly) siloxane represented by the formula (3a) described above (preferably having a number average molecular weight of 500 to 12,000). Is), more preferably, a sock-end amine-modified methylphenylsilicone oil.

[Preparation of polyimide precursor]

The polyimide precursor of the present embodiment can be synthesized by subjecting a polycondensation component comprising an acid 2 anhydride component and a diamine component to a polycondensation reaction. In a preferable aspect, a polycondensation component consists of an acid 2 anhydride component and a diamine component. It is preferable to perform polycondensation reaction in a suitable solvent. Specifically, for example, after dissolving a predetermined amount of diamine component in a solvent, a predetermined amount of acid 2 anhydride is added to the obtained diamine solution and stirred.

The molar ratio of the acid 2 anhydride component to the diamine component when synthesizing the polyimide precursor is from the viewpoint of high molecular weight polyimide precursor resin and slit coating properties of the resin composition, acid 2 anhydride: diamine = 100: 90 to 100: It is preferable to be in the range of 110 (0.90 to 1.10 mol parts of diamine with respect to 1 mol part of acid anhydride), more preferably in the range of 100: 95 to 100: 105 (0.95 to 1.05 mol parts of diamine with respect to 1 mol part of acid 2 anhydride). desirable.

The molecular weight of the polyimide precursor can be controlled by adjusting the type of the acid 2 anhydride component and the diamine component, adjusting the ratio of the acid 2 anhydride component and the diamine component, adding a terminal sealant, and adjusting the reaction conditions. The closer the ratio of the acid 2 anhydride component to the diamine component is close to 1: 1, and the less the amount of the terminal blocker is used, the higher the polyimide precursor can be. It is recommended to use high purity products as acid 2 anhydride component and diamine component. The purity is preferably 98% by mass or more, more preferably 99% by mass or more, and even more preferably 99.5% by mass or more. Moreover, it can also make high purity by reducing the water content in an acid 2 anhydride component and a diamine component. In the case where a plurality of types of acid 2 anhydride components or diamine components are used in combination, it is sufficient to have the above-mentioned purity as a whole of acid 2 anhydride components or diamine components, but all kinds of acid 2 anhydride components and diamine components used are It is desirable to have the above purity.

As a solvent for the reaction, an acid 2 anhydride component, a diamine component, and a generated polyimide precursor can be dissolved, and a solvent having a high molecular weight polymer is not particularly limited. Specific examples of such a solvent include aprotic solvents, phenolic solvents, ether and glycol solvents, and the like. As specific examples of these, as the aprotic solvent, for example, N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP) ), N-methylcaprolactam, 1,3-dimethylimidazolidinone, tetramethylurea, the following general formula (4):

[Formula 10]

In the formula, R ₁₂ = amide solvents such as acamide M100 represented by a methyl group (trade name: manufactured by Idemitsu Heungsan Co.), and R ₁₂ = ecamide B100 represented by n-butyl group (trade name: manufactured by Idemitsu Heungsan Co., Ltd.); lactone solvents such as γ-butyrolactone and γ-valerolactone; Phosphorus-based amide solvents such as hexamethylphosphoricamide and hexamethylphosphine triamide; Sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide and sulfolane; Ketone solvents such as cyclohexanone and methylcyclohexanone; Tertiary amine solvents such as picoline and pyridine; Ester-based solvents such as acetic acid (2-methoxy-1-methylethyl): Examples of the phenol-based solvent include phenol, o-cresol, m-cresol, p-cresol, and 2,3-xylenol. , 2,4-Xylenol, 2,5-Xylenol, 2,6-Xylenol, 3,4-Xylenol, 3,5-Xylenol and the like: as the ether and glycol solvent For example, 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, bis [2- (2-methoxyethoxy) ethyl ] Ether, tetrahydrofuran, 1,4-dioxane, etc. are mentioned, respectively. You may use these solvents individually or in mixture of 2 or more types.

The boiling point at normal pressure of the solvent used for the synthesis of the polyimide precursor is preferably 60 to 300 ° C, more preferably 140 to 280 ° C, and particularly preferably 170 to 270 ° C. If the boiling point of the solvent is higher than 300 ° C, a drying process is required for a long time. On the other hand, if the boiling point of the solvent is lower than 60 ° C., during the drying step, roughness on the surface of the resin film, mixing of bubbles into the resin film, etc. may occur, and a uniform film may not be obtained. In particular, it is preferable from the viewpoint of solubility and edge cratering during coating to use a solvent having a boiling point of 170 to 270 ° C and / or a vapor pressure of 250 Pa or less at 20 ° C. More specifically, one or more selected from the group consisting of N-methyl-2-pyrrolidone (NMP), γ-butyrolactone (GBL), and the compound represented by the general formula (4) is preferable.

It is preferable that the water content in the solvent is, for example, 3,000 ppm by mass or less from the viewpoint of the progress of a good polycondensation reaction. Moreover, it is preferable that content of the molecule | numerator of molecular weight less than 1,000 in resin composition in this embodiment is less than 5 mass%. It is considered that the presence of a molecule having a molecular weight of less than 1,000 in the resin composition is due to the fact that the amount of water in the solvent or raw material (acid 2 anhydride, diamine) used in synthesis is involved. That is, it is considered that the acid anhydride group of some of the acid anhydride monomers is hydrolyzed by moisture to become a carboxyl group, and remains in a low molecular state without high molecular weight. Therefore, the smaller the water content of the solvent used in the polycondensation reaction, the more preferable. The water content of the solvent is preferably 3,000 mass ppm or less, and more preferably 1,000 mass ppm or less. Similarly, the amount of water contained in the raw material is also preferably 3,000 ppm by mass or less, and more preferably 1,000 ppm by mass or less.

The amount of water in the solvent is the grade of the solvent used (dehydration grade, general purpose grade, etc.), solvent container (bottle, 18 L can, canister can, etc.), storage condition of the solvent (with or without rare gas encapsulation), from opening to use. It is considered that the time (whether it is used immediately after opening, whether it is used after a lapse of time after opening, etc.) is involved. In addition, it is considered that the replacement of the rare gas in the reactor before synthesis and the presence or absence of the distribution of the rare gas during synthesis are also involved. Therefore, when synthesizing the polyimide precursor, it is recommended to use a high-purity product as a raw material, use a solvent with a small amount of moisture, and take measures to prevent moisture from entering the system from entering the system before and during the reaction.

When dissolving each polycondensation component in a solvent, you may heat as needed. From the viewpoint of obtaining a polyimide precursor having a high degree of polymerization, preferred reaction temperature for synthesizing the polyimide precursor is 0 ° C to 120 ° C, or 40 ° C to 100 ° C, or 60 to 100 ° C, and preferred polymerization As time, 1 to 100 hours, or 2 to 10 hours can be illustrated. By setting the polymerization time to 1 hour or more, a polyimide precursor having a uniform polymerization degree is obtained, and by setting it to 100 hours or less, a polyimide precursor having a high polymerization degree can be obtained.

The resin composition of the present embodiment may be a combination of a polyimide precursor having a structure represented by formula (1) and another additional polyimide precursor, but the mass ratio of the additional polyimide precursor is a cured product (for example, polyimide). From the viewpoint of reducing the yellowness (YI) of the mid film) and the oxygen dependence of the total light transmittance, the total amount of the polyimide precursor in the resin composition is preferably 30% by mass or less, more preferably 10% by mass or less.

In a preferable aspect of this embodiment, a part of the polyimide precursor may be imidized. According to the partially imidized polyimide precursor, the viscosity stability at the time of storage of the resin composition at room temperature can be improved. The imidation rate in this case is preferably 5% or more, more preferably 8% or more, and preferably 80% from the viewpoint of balancing the solubility of the polyimide precursor in the resin composition and storage stability of the solution. Hereinafter, it is more preferably 70% or less, and still more preferably 50% or less. This partial imidization is obtained by heating the polyimide precursor and dehydrating the ring. The heating is preferably carried out at a temperature of 120 to 200 ° C, more preferably 150 to 180 ° C, preferably 15 minutes to 20 hours, more preferably 30 minutes to 10 hours. Further, N, N-dimethylformamidedimethylacetal or N, N-dimethylformamidediethylacetal is added to the polyamic acid obtained by the reaction described above and heated to esterify a part or all of the carboxylic acid. After that, by using as the polyimide precursor in the present embodiment, a resin composition with improved viscosity stability at room temperature can also be obtained. In addition to these ester-modified polyamic acids, the above-mentioned acid 2 anhydride component is sequentially reacted with an equivalent of a monohydric alcohol with respect to the acid anhydride group and a dehydration condensing agent such as thionyl chloride and dicyclohexylcarbodiimide. It can also be obtained by a condensation reaction with a diamine component after being prepared.

In one aspect, the resin composition includes a solvent. As a solvent, it is preferable that the solubility of the polyimide precursor is good, and that the solution viscosity of the resin composition can be appropriately controlled, and the reaction solvent of the polyimide precursor can be used as a solvent of the composition. Especially, N-methyl-2-pyrrolidone (NMP), γ-butyrolactone (GBL), the compound represented by the said general formula (4), etc. are preferable. As a specific example of the solvent composition, N-methyl-2-pyrrolidone (NMP) alone or a mixed solvent of N-methyl-2-pyrrolidone (NMP) and γ-butyrolactone (GBL) (eg For example, NMP: GBL (mass ratio) = 10: 90-90: 10) etc. are mentioned.

[Additional ingredients]

The resin composition of this embodiment may contain further components in addition to (a) a polyimide precursor and (b) a solvent. (C) surfactant, (d) alkoxysilane compound, etc. are mentioned as an additional component.

((c) surfactant)

By adding surfactant to the resin composition of this embodiment, the coating property of the resin composition can be improved. Specifically, generation of streaks in the coated film can be prevented.

Examples of such surfactants include silicone-based surfactants, fluorine-based surfactants, and nonionic surfactants other than these. Examples of these are silicone-based surfactants, for example, organosiloxane polymers KF-640, 642, 643, KP341, X-70-092, X-70-093 (above, trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), SH -28PA, SH-190, SH-193, SZ-6032, SF-8428, DC-57, DC-190 (above, trade names, manufactured by Toray, Dow Corning and Silicon), SILWET L-77, L-7001, FZ-2105, FZ-2120, FZ-2154, FZ-2164, FZ-2166, L-7604 (above, trade names, manufactured by Nihon Unika), DBE-814, DBE-224, DBE-621, CMS-626, CMS-222, KF-352A, KF-354L, KF-355A, KF-6020, DBE-821, DBE-712 (Gelest), BYK-307, BYK-310, BYK-378, BYK-333 (above, trade name , Big Chemical, Japan), Granol (trade name, manufactured by Kyoeisha Chemical Co., Ltd.); Examples of the fluorine-based surfactant include Megapak F171, F173, R-08 (manufactured by Dainippon Ink Chemical Industry Co., Ltd.), Florad FC4430, FC4432 (Sumitomo 3M Co., Ltd.); Examples of nonionic surfactants other than these include polyoxyethylene uraryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenol ether, and the like.

Among these surfactants, silicone surfactants and fluorine surfactants are preferred from the viewpoint of coatability (stripes suppression) of the resin composition, and the effect on the yellowness (YI) value and total light transmittance by oxygen concentration during the curing process is preferred. From the viewpoint, silicone-based surfactants are preferred. (c) When a surfactant is used, the blending amount is preferably 0.001 to 5 parts by mass, more preferably 0.01 to 3 parts by mass relative to 100 parts by mass of the polyimide precursor (a) in the resin composition.

(d) alkoxysilane compounds

When the polyimide film obtained from the resin composition according to the present embodiment is used for a flexible substrate or the like, from the viewpoint of obtaining good adhesion between the support and the polyimide film in the manufacturing process, the resin composition is (a) polyimide precursor 100 The alkoxysilane compound may be contained in an amount of 0.01 to 20 parts by mass based on parts by mass. When the content of the alkoxysilane compound to 100 parts by mass of the polyimide precursor is 0.01 parts by mass or more, good adhesion between the support and the polyimide film can be obtained. Moreover, it is preferable from a viewpoint of storage stability of a resin composition that content of an alkoxysilane compound is 20 mass parts or less. The content of the alkoxysilane compound is more preferably 0.02 to 15 parts by mass, more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 8 parts by mass, relative to 100 parts by mass of the polyimide precursor.

In addition, by using the alkoxysilane compound as an additive to the resin composition according to the present embodiment, in addition to the above-mentioned adhesion improvement, the coating property of the resin composition (suppression of unevenness of stripes) and the yellowness of the resulting cured film (YI) It is also possible to reduce the dependence of oxygen concentration upon curing of the value.

Examples of the alkoxysilane compound include 3-ureidopropyltriethoxysilane, bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, γ -Aminopropyltrimethoxysilane, γ-aminopropyltripropoxysilane, γ-aminopropyltributoxysilane, γ-aminoethyltriethoxysilane, γ-aminoethyltripropoxysilane, γ-aminoethyltribu Methoxysilane, γ-aminobutyltriethoxysilane, γ-aminobutyltrimethoxysilane, γ-aminobutyltripropoxysilane, γ-aminobutyltributoxysilane, phenylsilanetriol, trimethoxyphenylsilane, Trimethoxy (p-tolyl) silane, diphenylsilanediol, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxydi-p-tolylsilane, triphenylsilanol, and alkoxysilane compounds represented by the following structures And the like, and one selected from these It is preferred to use a phase.

[Formula 11]

The manufacturing method of the resin composition in this embodiment is not specifically limited, For example, it can be based on the following method.

When the solvent used when (a) the polyimide precursor is synthesized and the solvent contained in the resin composition (b) are the same, the synthesized polyimide precursor solution can be used as the resin composition. Moreover, as needed, in the temperature range of room temperature (25 degreeC)-80 degreeC, after adding (a) 1 type or more of a solvent and additional components to a polyimide precursor, and stirring and mixing, resin composition You may use it as For this stirring and mixing, an appropriate device such as a three-one motor (manufactured by Shinto Chemical Co., Ltd.) equipped with a stirring blade, or a rotating revolution mixer can be used. Moreover, you may apply heat of 40-100 degreeC as needed.

On the other hand, when the solvent used when (a) the polyimide precursor is synthesized and the solvent contained in the resin composition (b) are different, the solvent in the synthesized polyimide precursor solution, for example, reprecipitation, solvent distillation removal, etc. After removing by a suitable method of (a) isolating the polyimide precursor, the resin composition is prepared by adding (b) a solvent and, if necessary, additional components in a temperature range of room temperature to 80 ° C. and stirring and mixing. You may prepare.

After preparing the resin composition as described above, a part of the polyimide precursor is dehydrated imide to the extent that the polymer does not cause precipitation by heating the composition at, for example, 130 to 200 ° C for 5 minutes to 2 hours. You may be angry. Here, the imidation rate can be controlled by controlling the heating temperature and the heating time. As described above, according to the partially imidized polyimide precursor, viscosity stability during storage of the resin composition at room temperature can be improved.

From the viewpoint of slit coat performance, the solution viscosity of the resin composition is preferably 500 to 100,000 mPa · s, more preferably 1,000 to 50,000 mPa · s, and particularly preferably 3,000 to 20,000 mPa · s. Specifically, it is preferably 500 mPa · s or more, more preferably 1,000 mPa · s or more, and still more preferably 3,000 mPa · s or more, because it is difficult to leak liquid from the slit nozzle. Moreover, from the point that a slit nozzle is difficult to block, it is preferably 100,000 mPa · s or less, more preferably 50,000 mPa · s or less, still more preferably 20,000 mPa · s or less. Moreover, from the viewpoint of the viscosity at the time of synthesis, if the solution viscosity of the resin composition is higher than 200,000 mPa · s, there is a concern that the problem of agitation during synthesis becomes difficult. However, even when the solution has a high viscosity at the time of synthesis, it is possible to obtain a resin composition having a good handleability by adding a solvent and stirring after completion of the reaction. The solution viscosity of the resin composition in the present disclosure is a value measured at 23 ° C using an E-type viscometer (for example, VISCONICEHD, manufactured by Toki Sangyo).

It is preferable that the moisture content of the resin composition which concerns on this embodiment is 3,000 mass ppm or less. The moisture content of the resin composition is preferably 2,500 mass ppm or less, preferably 2,000 mass ppm or less, preferably 1,500 mass ppm or less, and more preferably 1,000 mass ppm or less from the viewpoint of viscosity stability when the resin composition is stored. It is preferable, it is more preferable that it is 500 mass ppm or less, 300 mass ppm or less is preferable, and 100 mass ppm or less is preferable.

<Method for producing polyimide film>

This embodiment,

A coating step of applying the resin composition of the present embodiment on the surface of the support;

A film forming process of heating the resin composition to form a polyimide film,

It provides a method for producing a polyimide film, characterized in that it comprises a peeling step of peeling the polyimide film from the support.

[Application process]

In the application step, a resin composition is applied on the surface of the support. The support is not particularly limited as long as it has heat resistance at a heating temperature in the subsequent film forming step (heating step) and has good peelability in the peeling step. For example, a glass (eg, alkali-free glass) substrate; Silicon wafers; PET (polyethylene terephthalate), OPP (stretched polypropylene), polyethylene glycol terephthalate, polyethylene glycol naphthalate, polycarbonate, polyimide, polyamideimide, polyetherimide, polyetheretherketone, polyethersulfone, polyphenylene Resin substrates such as sulfone and polyphenylene sulfide; Metal substrates such as stainless steel, alumina, copper, and nickel are used.

In the case of forming a thin-film polyimide molded body, for example, a glass substrate, a silicon wafer, etc. are preferable, and when forming a thick-film polyimide molded body (for example, a thick film, sheet, etc.), for example , PET (polyethylene terephthalate), OPP (stretched polypropylene) and the like.

As a coating method, generally, a coating method, such as a doctor blade knife coater, an air knife coater, a roll coater, a rotary coater, a flow coater, a die coater, a bar coater, a spin coat, a spray coat, a dip coat, etc .; Although printing techniques, such as screen printing and gravure printing, etc. are mentioned, the resin composition of this embodiment is especially useful for a slit coat (namely, application | coating with a slit coater). The coating thickness should be appropriately adjusted depending on the desired thickness of the polyimide film and the content of the polyimide precursor in the resin composition, but is preferably about 1 to 1,000 μm. Although the coating process is sufficient at room temperature, for the purpose of lowering the viscosity and improving workability, the resin composition may be heated, for example, in a range of 40 to 80 ° C.

[Random drying process]

After the coating step, a drying step may be performed, or the drying step may be omitted and the film formation step (heating step) may be directly performed. The said drying process is performed for the purpose of removing the organic solvent in a resin composition. When performing a drying process, suitable apparatus, such as a hot plate, a box dryer, and a conveyor dryer, can be used, for example. It is preferable to perform a drying process at 80-200 degreeC, and it is more preferable to carry out at 100-150 degreeC. The drying time is preferably 1 minute to 10 hours, and more preferably 3 minutes to 1 hour. As described above, a coating film containing a polyimide precursor is formed on the support.

[Film formation process]

Subsequently, a film forming process (heating process) is performed. The heating step is a step of obtaining an polyimide film by performing an imidization reaction of the polyimide precursor in the coating film while removing the organic solvent remaining in the coating film in the drying step described above. This heating process can be performed, for example, using an apparatus such as an inert gas oven, a hot plate, a box dryer, or a conveyor dryer. This step may be carried out simultaneously with the drying step, or both steps may be performed sequentially.

Although the heating step may be performed under an air atmosphere, it is recommended to perform under an inert gas atmosphere from the viewpoint of safety and good transparency of the resulting polyimide film, low thickness direction retardation (Rth), and low yellowness (YI). do. As an inert gas, nitrogen, argon, etc. are mentioned, for example. Although the heating temperature may be appropriately set depending on the type of the polyimide precursor and the type of the solvent in the resin composition, 250 ° C to 550 ° C is preferable, and 300 to 450 ° C is more preferable. If the temperature is 250 ° C or higher, imidization proceeds satisfactorily, and if it is 550 ° C or lower, problems such as deterioration in transparency and deterioration in heat resistance of the resulting polyimide film can be avoided. It is preferable to set heating time to about 0.1 to 10 hours.

In the present embodiment, the oxygen concentration of the ambient atmosphere in the heating step is preferably 2,000 mass ppm or less, and more preferably 100 mass ppm or less, from the viewpoint of the transparency and yellowness (YI) value of the polyimide film obtained. It is preferable, and 10 mass ppm or less is more preferable. By heating in an atmosphere having an oxygen concentration of 2,000 mass ppm or less, the yellowness (YI) value of the resulting polyimide film can be made 30 or less.

[Peeling process]

Subsequently, in the peeling step, the polyimide film on the support is peeled after cooling to room temperature to about 50 ° C, for example. As this peeling process, the following aspect (1)-(4) is mentioned, for example.

(1) A polyimide resin is produced by producing a structure comprising a polyimide film / support by the above method, and then irradiating a laser from the support side of the structure to ablation the interface between the support and the polyimide film. How to peel. As a type of laser, a solid (YAG) laser, a gas (UV excimer) laser, etc. are mentioned. It is preferable to use a spectrum having a wavelength of 308 nm or the like (see Japanese Patent Publication No. 2007-512568, Japanese Patent Publication No. 2012-511173, etc.).

(2) A method of forming a release layer on the support before applying the resin composition to the support, and then obtaining a construct comprising a polyimide film / peeling layer / support and peeling the polyimide film. As the release layer, a method using parylene (registered trademark, manufactured by Nippon Parylene Co., Ltd.) and tungsten oxide; And a method of using a release agent such as vegetable oil-based, silicone-based, fluorine-based, alkyd-based, and the like (see Japanese Unexamined Patent Publication No. 2010-67957, Japanese Unexamined Patent Publication No. 2013-179306, etc.).

You may use together the laser irradiation of this method (2) and said (1).

(3) A method of obtaining a polyimide film by etching a metal with an etchant after obtaining a construct comprising a polyimide film / support using a metal substrate that can be etched as a support. As a metal, copper (for example, Mitsui Metal Mining Co., Ltd. electrolytic copper foil "DFF"), aluminum, etc. can be used, for example. As the etchant, ferric chloride or the like can be used for copper, and dilute hydrochloric acid or the like can be used for aluminum.

(4) After obtaining a construct comprising a polyimide film / support by the above method, a pressure-sensitive adhesive film is attached to the surface of the polyimide film, the pressure-sensitive adhesive film / polyimide film is separated from the support, and thereafter the polyimide from the pressure-sensitive adhesive film How to separate the mid film.

Among these peeling methods, from the viewpoints of the difference in refractive index between the front and back of the polyimide film obtained, the yellowness (YI) value, and elongation, the method (1) or (2) is appropriate, and the difference in refractive index between the front and back of the resulting polyimide film is obtained. From the viewpoint, it is more appropriate to perform the irradiation step of irradiating the laser from the support side before the method (1), that is, the separation step.

In addition, in the method (3), when copper is used as the support, the yellowness (YI) value of the resulting polyimide film is increased, and the elongation tends to be small. This is considered to be the influence of copper ions.

The thickness of the polyimide film obtained by the above method is not particularly limited, but is preferably in the range of 1 to 200 μm, more preferably 5 to 100 μm.

<Use of polyimide film>

The polyimide film obtained from the polyimide precursor according to the present embodiment can be applied, for example, as a semiconductor insulating film, a TFT-LCD insulating film, an electrode protective film, or the like, particularly in the production of a flexible device, particularly a TFT substrate or a color. It can be preferably used as a filter substrate or a touch panel substrate. Here, as a flexible device to which the polyimide film according to the present embodiment can be applied, for example, a TFT device for a flexible display, a flexible solar cell, a flexible touch panel, flexible lighting, a flexible battery, a flexible printed circuit board, a flexible color filter, And a surface cover lens for smartphones.

The process of forming a TFT on a flexible substrate using a polyimide film is typically performed at a temperature in a wide range of 150 to 650 ° C. Specifically, when manufacturing a TFT device using amorphous silicon, a process temperature of 250 ° C to 350 ° C is generally required, and the polyimide film of the present embodiment needs to be able to withstand the temperature. It is necessary to appropriately select a polymer structure having a glass transition temperature equal to or higher than the process temperature and a thermal decomposition initiation temperature.

In the case of manufacturing a TFT device using a metal oxide semiconductor (IGZO, etc.), a process temperature of 320 ° C to 400 ° C is generally required, and the polyimide film of this embodiment needs to be able to withstand the temperature. It is necessary to appropriately select a polymer structure having a glass transition temperature or a thermal decomposition initiation temperature equal to or higher than the TFT manufacturing process maximum temperature.

In the case of manufacturing a TFT device using low-temperature polysilicon (LTPS), a process temperature of 380 ° C to 520 ° C is generally required, and the polyimide film of this embodiment needs to be able to withstand that temperature. It is necessary to appropriately select the glass transition temperature or the thermal decomposition initiation temperature that is higher than or equal to the maximum manufacturing process temperature.

On the one hand, by these thermal histories, the optical properties (especially light transmittance, retardation properties and yellowness) of the polyimide film tend to decrease as exposed to high temperature processes. However, the polyimide obtained from the polyimide precursor of the present embodiment has good optical properties even through a thermal history.

Below, as a use example of the resin composition of this embodiment and a polyimide film, a display, a laminated body, and its manufacturing method are demonstrated.

[Display and its manufacturing method]

The present embodiment also provides a flexible device comprising a polyimide film that is a cured product of the resin composition of the present embodiment. A suitable example of the flexible device is a flexible display. In one aspect, the polyimide film has excellent optical properties (eg Rth and / or yellowness). Therefore, in a preferred aspect, the polyimide film is disposed at a point (specifically, a screen portion of the flexible display) viewed when the display is viewed from the outside.

This embodiment,

A coating step of applying (preferably a slit coat) the resin composition of the present embodiment on the surface of a support such as a glass substrate,

A film forming process of heating the resin composition to form a polyimide film,

A device forming process for forming a device on a polyimide film,

A method of manufacturing a display including a peeling step of peeling a polyimide film on which a device is formed from a support is also provided.

[Method of manufacturing flexible organic EL display]

1 is a view showing a structure above the polyimide substrate of a top emission type flexible organic EL display as an example of a display provided in one aspect of the present invention. Referring to the organic EL structure portion 25 of Fig. 1, for example, an organic EL element 250a that emits red light, an organic EL element 250b that emits green light, and an organic EL element 250c that emits blue light are described. As one unit, they are arranged in a matrix, and the light-emitting regions of each organic EL element are defined by the partition walls (banks) 251. Each organic EL element is composed of a lower electrode (anode) 252, a hole transport layer 253, a light emitting layer 254, and an upper electrode (cathode) 255. Further, on the lower layer 2a showing a CVD multilayer film (multi-barrier layer) made of silicon nitride (SiN) or silicon oxide (SiO), a TFT 256 for driving an organic EL element (low temperature polysilicon (LTPS), metal A plurality of oxide semiconductors (selected from IGZO or the like), an interlayer insulating film 258 having a contact hole 257, and a lower electrode 259 are formed. The organic EL element is sealed with a sealing substrate 2b, and a hollow portion 261 is formed between each organic EL element and the sealing substrate 2b.

In the flexible organic EL display manufacturing process, a polyimide film is produced on a glass substrate support, and the organic EL substrate shown in FIG. 1 is formed thereon, an encapsulation substrate manufacturing process, an assembly process for bonding both substrates, and , A peeling step of peeling the organic EL display produced on the polyimide film from the glass substrate support is included.

A well-known manufacturing process can be applied to the organic EL substrate manufacturing process, the sealing substrate manufacturing process, and the assembly process. Below, although an example is given, it is not limited to this. Moreover, the peeling process may be the same as the peeling process of the polyimide film mentioned above.

Referring to FIG. 1, for example, first, a polyimide film of the present disclosure is produced on a glass substrate support by the above-described method, and silicon nitride (SiN) and silicon oxide are deposited thereon by CVD or sputtering. A multi-barrier layer (a lower substrate 2a in Fig. 1) made of a (SiO) multi-layer structure is produced, and a metal wiring layer for driving a TFT thereon is produced using a photoresist or the like. An active buffer layer such as SiO is fabricated on the upper portion using a CVD method, and a TFT device such as a metal oxide semiconductor (IGZO) or low-temperature polysilicon (LTPS) (TFT 256 in FIG. 1) is fabricated on the active buffer layer. After manufacturing the TFT substrate for the flexible display, an interlayer insulating film 258 having a contact hole 257 is formed of a photosensitive acrylic resin or the like. An ITO film is formed by a sputtering method or the like, and a lower electrode 259 is formed so as to be paired with a TFT.

Next, after forming a partition wall (bank) 251 with a photosensitive polyimide or the like, a hole transport layer 253 and a light emitting layer 254 are formed in each space partitioned by the partition wall. Further, an upper electrode (cathode) 255 is formed to cover the light emitting layer 254 and the partition wall (bank) 251. Thereafter, using a fine metal mask or the like as a mask, an organic EL material emitting red light (corresponding to the organic EL element 250a emitting red light in FIG. 1), an organic EL material emitting green light (in FIG. 1, The organic EL substrate is obtained by depositing a green light emitting organic EL element 250b and an organic EL material emitting blue light (corresponding to the organic EL element 250c emitting blue light in FIG. 1) by a known method. This is produced, and after sealing with a sealing film or the like (the sealing substrate 2b in FIG. 1), the device above the polyimide substrate is peeled from the glass substrate support by a known peeling method such as laser peeling, and the top emission type is flexible. An organic EL display is produced. When the polyimide of the present embodiment is used, a see-through flexible organic EL display is produced. Further, a bottom emission type flexible organic EL display may be produced by a known method.

[Method of manufacturing flexible liquid crystal display]

A flexible liquid crystal display can be produced using the polyimide film of this embodiment. As a specific manufacturing method, a polyimide film made of the present invention is produced on a glass substrate support by the method described above, and for example, amorphous silicon, metal oxide semiconductor (IGZO, etc.), using the method described above, Alternatively, a TFT substrate made of low-temperature polysilicon is produced. Separately, according to the coating process and the film forming process of the present embodiment, a polyimide film is produced on a glass substrate support, and a color filter glass substrate provided with a polyimide film is prepared using a color resist or the like according to a known method. (CF substrate) is produced. On one of the TFT substrate and the CF substrate, by screen printing, a seal material composed of a thermosetting epoxy resin or the like is applied in a frame-like pattern lacking a portion of the liquid crystal injection port, and corresponds to the thickness of the liquid crystal layer on the other substrate. A spherical spacer composed of plastic or silica is dispersed.

Subsequently, the TFT substrate and the CF substrate are bonded, and the seal material is cured.

Finally, after the liquid crystal material is injected into the space surrounded by the TFT substrate, the CF substrate, and the seal material by a decompression method, a thermosetting resin is applied to the liquid crystal injection port, and the liquid crystal material is sealed by heating to form a liquid crystal layer. do. Finally, a flexible liquid crystal display can be produced by peeling the glass substrate on the CF side and the glass substrate on the TFT side at the interface between the polyimide film and the glass substrate by a laser peeling method or the like.

[Manufacturing Method of Laminate]

This embodiment,

A coating step of applying the resin composition of the present embodiment on the surface of the support;

A film forming process of heating the resin composition to form a polyimide film,

Also provided is a method of manufacturing a laminate comprising a device forming process for forming a device on a polyimide film.

What was illustrated as said flexible device (for example, flexible display) as an element in a laminated body is mentioned. As a support, a glass substrate is used, for example. Preferred specific steps of the coating process and the film forming process are the same as those described above with respect to the method for producing the polyimide film described above. In addition, in the element forming step, the element is formed on a polyimide film as a flexible substrate formed on a support. Thereafter, in the peeling step, the polyimide film and the element may be peeled off from the support.

Example

Hereinafter, the present invention will be described in more detail based on Examples, but these are described for explanation, and the scope of the present invention is not limited to the following Examples. Various evaluations in Examples and Comparative Examples were carried out as follows.

<Weight average molecular weight>

The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) under the following conditions.

As a solvent, NMP (manufactured by Wako Pure Chemical Industries, for high-speed liquid chromatography, 24.8 mmol / L lithium bromide monohydrate (manufactured by Wako Pure Chemical Industries, purity 99.5%) and 63.2 mmol / L phosphoric acid (manufactured by Wako Pure Chemical Industries) just before measurement , For high-speed liquid chromatography). The calibration curve for calculating the weight average molecular weight was prepared using standard polystyrene (manufactured by Tosoh Corporation).

Column: Shodex KD-806M (manufactured by Showa Electric Works)

Flow rate: 1.0 ml / min

Column temperature: 40 ℃

Pump: PU-2080Plus (manufactured by JASCO)

Detector: RI-2031Plus (RI: differential refractometer, manufactured by JASCO) and UV-2075Plus (UV-VIS: ultraviolet visible absorbometer, manufactured by JASCO)

<Evaluation of shear rate dependence (TI)>

The viscosity of the resin composition prepared in Examples and Comparative Examples was measured at 23 ° C using a viscometer with a temperature controller (TVE-35H manufactured by Toki Sangyo) to measure the rotational speed and cone rotor at which the viscosity of the resin composition to be measured can be measured. Measurement was carried out, and shear rate dependence was evaluated.

Specifically, the viscosity ηa (mPa · s) at the measured rotational speed a (rpm) and the viscosity ηb (mPa · s) at the measured rotational speed b (rpm) are measured (where a * 10 = b Is), TI represented by the following formula was obtained.

TI = ηa / ηb

Specific examples of the measurable rotational speed are, for example, 0.5, 1, 2.5, 5, 10, 20, 50, 100 rpm.

Specific examples of the measurable cone rotor are, for example, 1 ° 34 '(angle of the cone rotor) × R24 (diameter of the cone rotor), 1 ° 34' × R12, 0.8 ° × R24, 0.8 ° × R12, 3 ° × R24, 3 ° × R12, 3 ° × R17.65, 3 ° × R14, 3 ° × R12, 3 ° × R9.7.

<Coating evaluation>

The resin composition prepared in Examples and Comparative Examples was applied to a 300 mm * 300 mm glass substrate using a slit coater (manufactured by SCREEN Finetech Solutions Co., Ltd.) with an application area of 295 mm * 295 mm, and coating evaluation. Was conducted.

(Slit nozzle evaluation)

The resin composition (varnish) prepared in Examples and Comparative Examples was filled into a nozzle of a slit coater, evaluated based on the following criteria, and listed in the table.

The discharge of the varnish from the nozzle starts, and after the discharge is stopped, the varnish flows out of the slit nozzle: liquid leakage

No varnish is ejected from the nozzle: clogged

Can coat without leaking or clogging: no problem

(Coat gap)

The film thickness after imidization (heating at 100 ° C for 1 hour and heating at 400 ° C for 30 minutes) after imidizing the resin composition (varnish) prepared in Examples and Comparative Examples was 10 μm. It was coated on a glass substrate (coating speed of 100 mm / sec) as much as possible. The coat gap setting value of the slit coater at that time is shown in the table.

(Edge evaluation)

The resin composition prepared in Examples and Comparative Examples was coated on a glass substrate, transferred to a drying furnace, heated at 100 ° C. for 1 hour, and then the edge portion of the coating film was observed 10 times using an optical microscope and evaluated according to the following criteria. .

Moreover, the edge bead (elevation of the edge part) of the coating film was measured using the stylus step difference meter (P-15: manufactured by KLA Tencor), and evaluated based on the following criteria.

In the microscopic observation of the edge portion, a liquid flow of width of 0.5 mm or more was observed: sag

The bead thickness is 30% or more of the applied film thickness in the film thickness measurement of the edge portion: the bead

No sagging, no edge abnormality: no problem

(Slit coat availability)

The (slit nozzle evaluation), (coat gap), and (edge evaluation) were evaluated according to the following criteria, and listed in the table.

In the composition using the polyimide precursor of the predetermined weight average molecular weight of each Example and the comparative example, all the following evaluation results are satisfy | filled with content of at least one solid content in the range of 7-28 mass%:

In the composition using the polyimide precursor having a predetermined polymerization average molecular weight in each of Examples and Comparative Examples, in the range of 7 to 28% by mass of the solid content, all of the following evaluation results are not satisfied:

Slit nozzle evaluation: no problem

Coat gap: 50 μm or more

Edge evaluation: no problem

<Film thickness uniformity (standard deviation)>

In the <coating evaluation> (coat gap), a polyimide film formed on a glass substrate of 295 mm * 295 mm on a glass substrate of 300 mm * 300 mm according to Examples and Comparative Examples prepared on a glass substrate ) Was used. Using a glass substrate on which a polyimide film was formed, a film thickness at a position of 20 mm apart from the center of the application surface toward the end faces of each of MD (i.e., slit coat direction) and TD (direction perpendicular to MD). Was measured (therefore, the tip is a position of 7.5 mm from the end face) (15 points for MD and 30 points for TD). For the measurement of the film thickness, a contact step difference meter was used. From the results, the film thickness uniformity (standard deviation of the film thickness of 30 points) of the polyimide film was calculated and evaluated based on the following criteria.

Amount: In-plane film thickness uniformity (3 sigma) is 1.0 μm or less

A: In-plane film thickness uniformity (3 sigma) greater than 1.0 μm and less than 2.0 μm

Poor: In-plane film thickness uniformity (3 sigma) exceeds 2.0 μm

＜ Curable film Shinto ＞

The resin composition prepared in Examples and Comparative Examples was spin-coated on a 6-inch silicon wafer substrate having an aluminum vapor-deposited layer formed on its surface so that the film thickness after curing was 10 µm, and pre-baked at 100 ° C. for 6 minutes. Thereafter, a vertical curing furnace (manufactured by Koyo Lindberg, model name VF-2000B) was used, the oxygen concentration in the high was adjusted to be 10 mass ppm or less, and heat curing treatment was performed at 400 ° C for 30 minutes. Thus, a wafer on which a polyimide film was formed was produced. Next, a dicing saw (DAD 3350 manufactured by Disco Co., Ltd.) was used to insert a 3 mm-wide incision mark on the polyimide film of the wafer, immersed in a dilute hydrochloric acid aqueous solution overnight, the film piece was peeled off, and dried. This was cut to a length of 50 mm and used as a sample.

For the above sample, elongation was measured at a test speed of 40 mm / min and an initial load of 0.5 fs using TENSILON (UTM-II-20 manufactured by Orien Tech). It evaluated by the following criteria, and was described in the table.

Right: 40% or more

Amount: 20% or more, less than 40%

A: Less than 20%

<Hardened Film Haze>

In <coating evaluation> (coat gap), polyimide films related to Examples and Comparative Examples prepared on a glass substrate were used.

About the obtained sample, the haze (film thickness 10 micrometer conversion) was measured according to the JIS K7105 transparency test method using the SC-3H hazemeter manufactured by Suga Test Instruments. The measurement results were evaluated based on the following criteria, and are listed in the table.

Right: Haze is 0.5 or less

Amount: Haze is greater than 0.5 and less than 1.5

A: Haze is greater than 1.5

<Yellowness of cured film (YI)>

In <coating evaluation> (coat gap), polyimide films related to Examples and Comparative Examples prepared on a glass substrate were used. About the obtained sample, the yellowness (YI) value (film thickness conversion of 10 micrometers) was measured using the D65 light source by Nippon Color Industries Co., Ltd. (spectrophotometer: SE600). The results are listed in the table.

<Cured film Rth (retardation, thickness direction retardation)>

In <coating evaluation> (coat gap), polyimide films related to Examples and Comparative Examples prepared on a glass substrate were used. About the obtained sample, Rth (film thickness 10 micrometer conversion) was measured using the phase difference birefringence measuring apparatus (KOBRA-WR manufactured by Oji Scientific Instruments). The wavelength of the measured light was 589 nm. The results are listed in the table.

<Comparative Example 1-1>

To a 3 L separable flask with a stirring rod, NMP (812 g) was added while introducing nitrogen gas, and 4,4'-DAS (4,4'-diaminodiphenylsulfone) (14.2 g) as diamine, TFMB (12.2 g), sockdan amine-modified methylphenylsilicone oil (10.56 g) was added with stirring, followed by addition of PMDA (15.3 g) and BPDA (8.8 g) as acid 2 anhydride (molar ratio of acid 2 anhydride, diamine) (100: 98)). Next, using an oil bath, the temperature was raised to 80 ° C and stirred for 4 hours, and then the oil bath was removed and returned to room temperature to obtain an NMP solution of transparent polyamic acid (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer (set at -20 ° C, hereinafter the same.) And used for thawing when evaluating.

<Comparative Examples 1-2 to 1-6>

It was carried out in the same manner as in Comparative Example 1-1, except that the amount of NMP was changed to a solid content of Table 1.

<Example 1-1>

4,4'-DAS (15.3 g) and TFMB (12.4 g) as diamine while introducing nitrogen gas into a 3 L separable flask with a stirring rod, and a polymerization solvent of twice the mass of the total mass of these diamines ( NMP).

Next, a dropping funnel was set in the separable flask, and PMDA (15.3 g) and BPDA (8.8 g) as acid 2 anhydrides and polymerization of twice the mass of these acid 2 anhydrides were introduced while introducing nitrogen gas into the dropping funnel. Solvent (NMP) was added. Then, the mixture was stirred with a small stirring blade at room temperature.

Subsequently, another dropping funnel was set in the separable flask, and nitrogen gas was introduced into the dropping funnel, so as to diamine, sonic-end amine-modified methylphenylsilicone oil X-22-1660B-3 (10.56 g) and 2 of the silicone oil. A pear mass of polymerization solvent (NMP) was added. Then, the mixture was stirred with a small stirring blade at room temperature.

Then, while stirring the diamine solution in the separable flask, the dropping of the acid 2 anhydride solution and silicone oil was simultaneously started while stirring the small stirring blade of the dropping funnel at room temperature. All the dropping was performed at a low speed, and dropping was performed over 30 minutes. After dropping, it was washed with a washing solvent (NMP), and the residue was added dropwise (molar ratio of acid 2 anhydride and diamine (100: 99)).

Thereafter, an additional solvent (NMP) was added to finally achieve a solid content of Table 1. Then, the mixture was stirred at room temperature for 30 minutes, then heated to 70 ° C using an oil bath and stirred for 4 hours. Thereafter, the oil bath was removed and returned to room temperature to obtain an NMP solution of transparent polyamic acid (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer (set at -20 ° C, hereinafter the same.) And used for thawing when evaluating.

<Examples 1-2 to 1-17, 2-1 to 2-14, 3-1 to 3-16, 4-1 to 4-12>

The combination of acid 2 anhydride and diamine is as shown in Tables 1 to 4, and accordingly, the amount of the polymerization solvent used is changed (i.e., adjusted to an amount twice the mass of the acid 2 anhydride or diamine), and further carried out. For Examples 1-5 to 1-8, 2-5 to 2-14, 3-3 to 3-16, and 4-5 to 4-12, "heated to 70 ° C and stirred for 4 hours" was heated to "40 ° C" And stirred for 12 hours. ”For Examples 1-9, 2-9, 3-9, and 4-9,“ additional solvent (NMP) ”was added to“ additional solvent (NMP and GBL) (NMP / GBL after addition) It was made similar to Example 1-1 except having changed to 100/100 (adjusted so that it may be 100 / w (w / w)). The amount of solids shown in Tables 1 to 4 was adjusted to the value shown in the table by changing the amount of the additional solvent. In addition, in Example 1-16, 2-12, 2-13, 3-14, 3-15, 4-10, and 4-11, the weight average molecular weight of the thing which further extended the reaction time after "12 hours stirring" As a result of measuring, there was no case that it became large compared with that after stirring for 12 hours.

<Comparative Examples 2-1 to 2-6, 3-1 to 3-6, 4-1 to 4-7>

In Comparative Examples 2-1, 3-1, and 4-1, the NMP amount of Comparative Example 1-1 was 745 g (Comparative Example 2-1), 799 g (Comparative Example 3-1), and 850 g (Comparative Example 4). Each was changed to -1), and it was carried out in the same manner as in Comparative Example 1-1, except that the combination of acid 2 anhydride and diamine was shown in Table 2. In addition, Comparative Examples 2-2 to 2-6 are Comparative Examples 2-1 and Comparative Examples 3-2 to 3-6 are Comparative Examples 3, except that the amount of NMP is changed to have a solid content of Tables 2 to 4, respectively. -1 and Comparative Examples 4-2 to 4-7 were conducted in the same manner as Comparative Example 4-1.

<Comparative Example 5-1>

To a 3 L separable flask with a stirring rod, NMP (620 g) was added while introducing nitrogen gas, 4,4'-DAS (24.8 g) was added as diamine while stirring, and PMDA (as an acid 2 anhydride was subsequently added). 21.8 g) was added (molar ratio of acid 2 anhydride and diamine (100: 100)). Next, using an oil bath, the temperature was raised to 80 ° C and stirred for 4 hours, and then the oil bath was removed and returned to room temperature to obtain an NMP solution of transparent polyamic acid (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer, and used for thawing when evaluating.

<Comparative Examples 5-2 to 5-6>

It was carried out in the same manner as in Comparative Example 5-1, except that the amount of NMP was changed to a solid content of Table 5.

<Example 5-1>

To a 3 L separable flask with a stirring rod, 4,4'-DAS (24.3 g) as diamine and NMP twice as large as the total mass of diamine were added while introducing nitrogen gas.

Next, a dropping funnel was set in the separable flask, and nitrogen gas was introduced into the dropping funnel, and PMDA (10.9 g), BPDA (14.7 g) as acid 2 anhydride and NMP of twice the mass of these acid 2 anhydrides were added. Was added. Then, the mixture was stirred with a small stirring blade at room temperature.

Then, while stirring the diamine solution in the separable flask, the dropping of the acid 2 anhydride solution was started at room temperature while stirring the small stirring blade of the dropping funnel. Dropping was performed at a low speed, and dropping was performed over 30 minutes. After dropping, it was washed with a washing solvent (NMP), and the residue was added dropwise (molar ratio of acid 2 anhydride and diamine (100: 98)).

Thereafter, an additional solvent (NMP) was added to finally achieve a solid content of Table 5. Then, the mixture was stirred at room temperature for 30 minutes, then heated to 70 ° C using an oil bath and stirred for 4 hours. Thereafter, the oil bath was removed and returned to room temperature to obtain an NMP solution of transparent polyamic acid (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer (set at -20 ° C, hereinafter the same.) And used for thawing when evaluating.

<Examples 5-2 to 5-9, 6-1 to 6-9, 7-1 to 7-4, 8-1, 8-2>

The combination of acid 2 anhydride and diamine is as shown in Tables 5 to 9, and accordingly, the amount of the polymerization solvent used is changed (i.e., adjusted to an amount twice the mass of the acid 2 anhydride or diamine), and further carried out. For Examples 5-3 to 5-9, 6-5 to 6-9, 7-4, 8-1, and 8-2, the above "heating to 70 ° C and stirring for 4 hours" was "heating to 40 ° C for 12 hours" Stirring, and for Examples 5-7, 6-4, and 7-4, "Additional solvent (NMP)" was added to "Additional solvent (NMP and GBL) (NMP / GBL after addition was 100/100 (w / w), and the same as in Example 5-1. The amount of solids shown in Tables 5 to 9 was adjusted to the value shown in the table by changing the amount of the additional solvent. In addition, in Examples 5-8, 5-9, and 6-6 to 6-9, the weight average molecular weight of the extended reaction time after "12 hours of stirring" was measured, and compared with that after 12 hours of stirring. It never grew.

<Comparative Examples 6-1 to 6-6, 7-1 to 7-8, 8-1 to 8-2>

In Comparative Examples 6-1, 7-1, and 8-1 to 8-2, the amount of NMP in Comparative Example 5-1 was 664 g (Comparative Example 6-1), 718 g (Comparative Example 7-1), and 401 g. (Comparative Example 8-1), and changed to 344 g (Comparative Example 8-2), respectively, and the composition of acid 2 anhydride and diamine was as in Comparative Examples 5-1, except that as shown in Tables 6-8. It was carried out. Comparative Examples 6-2 to 6-6 were carried out in the same manner as in Comparative Example 6-1, except that the amount of NMP was changed to change the amount of NMP, and Comparative Examples 7-2 to 7-6 changed the amount of NMP. Then, it was carried out in the same manner as in Comparative Example 7-1 except that the solid content of Table 7 was used. In Comparative Examples 7-7 and 7-8, the amount of NMP was changed from 718 g to 215 g (Comparative Example 7-7) and 163 g (Comparative Example 7-8), respectively, and the combination of acid 2 anhydride and diamine is shown. It carried out similarly to the comparative example 7-1 except having changed as shown in 7, and changing "4 hours stirring" to "3 hours stirring".

<Comparative Example 9-1>

To a 3 L separable flask with a stirring rod, NMP (495 g) was added while introducing nitrogen gas, TFMB (30.9 g) was added as a diamine while stirring, and BPAF (9,9-bis) was subsequently added as acid 2 anhydride. (3,4-dicarboxyphenyl) fluorene 2 anhydride) (45.8 g), sock-end amine-modified methylphenylsilicone oil was added X-22-1660B-3 (10.56 g) (molar ratio of acid 2 anhydride, diamine ( 100: 99)). Next, using an oil bath, the temperature was raised to 80 ° C and stirred for 4 hours, and then the oil bath was removed and returned to room temperature to obtain an NMP solution of transparent polyamic acid (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer, and used for thawing when evaluating.

<Comparative Examples 9-2 to 9-3>

The amount of NMP was changed from 495 g to 438 g (Comparative Example 9-2) and 374 g (Comparative Example 9-3), respectively, except that the combination of acid 2 anhydride and diamine was shown in Table 9, and compared. It carried out similarly to Example 9-1.

<Example 9-1>

To a 3 L separable flask with a stirring rod, TFMB (31.3 g) as diamine and NMP (63 g) twice as large as the total mass of diamine were added while introducing nitrogen gas.

Next, a dropping funnel was set in the separable flask, and nitrogen gas was introduced into the dropping funnel, and BPAF (45.8 g) as an acid 2 anhydride and NMP (92 g) of twice the mass of this acid 2 anhydride were added. . Then, the mixture was stirred with a small stirring blade at room temperature.

Subsequently, another dropping funnel was set in the separable flask, and nitrogen gas was introduced into the dropping funnel, so as to double the amine-modified methylphenylsilicone oil X-22-1660B-3 (10.56 g) and the silicone oil. Mass of NMP (21 g) was added. Then, the mixture was stirred with a small stirring blade at room temperature.

Then, while stirring the diamine solution in the separable flask, the dropping of the acid 2 anhydride solution was started at room temperature while stirring the small stirring blade of the dropping funnel. Dropping was performed at a low speed, and dropping was performed over 30 minutes. After dropping, it was washed with a washing solvent (NMP), and the residue was added dropwise (molar ratio of acid 2 anhydride and diamine (100: 100)).

Thereafter, an additional solvent (NMP) was added to finally achieve a solid content of Table 9.

Then, the mixture was stirred at room temperature for 30 minutes, then heated to 40 ° C using an oil bath and stirred for 12 hours. Thereafter, the oil bath was removed and returned to room temperature to obtain an NMP solution of transparent polyamic acid (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer (set at -20 ° C, hereinafter the same.) And used for thawing when evaluating.

<Examples 9-2 and 9-3>

Example 9-1 except that the compounding of the acid 2 anhydride and diamine was as shown in Table 9, and the amount of the polymerization solvent was changed accordingly (i.e., adjusted to an amount twice the mass of the acid 2 anhydride or diamine). It was carried out in the same manner as. The solid content shown in Table 9 was adjusted to the value shown in the table by changing the amount of the additional solvent.

<Example 10-1>

To a 3 L separable flask with a stirring rod, NMP (246 g) was added while introducing nitrogen gas, and 4,4'-DAS (14.4 g), TFMB (12.4 g) as diamine, amine-modified methylphenylsilicone oil (10.56 g) was added with stirring, followed by addition of PMDA (15.3 g) and BPDA (8.8 g) as acid 2 anhydride (molar ratio of acid 2 anhydride and diamine (100: 99)). Next, using an oil bath, the temperature was raised to 70 ° C. and stirred for 8 hours, then the oil bath was removed and returned to room temperature to obtain a clear polyamic acid NMP solution. The obtained varnish was stored in a freezer (set at -20 ° C, hereinafter the same.) And used for thawing when evaluating.

<Examples 10-2 to 10-5>

The amount of NMP was changed from 246 g to 225 g (Example 10-2), 242 g (Example 10-3), 185 g (Example 10-4), and 201 g (Example 10-5), respectively. It was carried out in the same manner as in Example 10-1, except that the combination of acid 2 anhydride and diamine was as shown in Table 10.

Table 10 shows the results of the evaluation.

Industrial availability

The resin composition of the present disclosure can be preferably applied to applications such as flexible devices (eg, flexible substrates), particularly flexible displays. For example, the resin composition of the present disclosure can be preferably used to form a transparent substrate of a display device such as a liquid crystal display, an organic electroluminescence display, a field emission display, or electronic paper. More specifically, the resin composition of the present disclosure can be used to form a substrate of a thin film transistor (TFT), a substrate of a color filter, a substrate of a transparent conductive film (ITO, IndiumTinOxide), or the like.

2a: lower substrate
2b: sealing substrate
25: organic EL structure
250a: Organic EL device emitting red light
250b: organic EL device emitting green light
250c: Organic EL device emitting blue light
251: bulkhead (bank)
252: lower electrode (anode)
253: hole transport layer
254: light emitting layer
255: upper electrode (cathode)
256: TFT
257: contact hole
258: interlayer insulating film
259: lower electrode
261: Hollow Department

Claims (25)

Equation (1) below:

{In the formula, R ₁ represents a divalent organic group each independently if there are plural, R ₂ represents a tetravalent organic group each if it is plural, and n is a positive integer. As a resin composition containing a mid precursor and a solvent,
The weight average molecular weight of the polyimide precursor is 110,000 to 250,000,
The resin composition whose solid content of the said resin composition is 10-25 mass%. According to claim 1,
A resin composition having a shear rate dependency (TI) represented by the following formula when the viscosity of the resin composition is measured at 23 ° C. using a viscometer with a temperature controller, 0.9 to 1.1.
TI = ηa / ηb
{In the formula, ηa (mPa · s) is the viscosity at the measured rotational speed a (rpm) of the resin composition, ηb (mPa · s) is the viscosity at the measured rotational speed b (rpm) of the resin composition, However, a * 10 = b.} The method of claim 1 or 2,
The resin composition is a resin composition for a slit coat. The method according to any one of claims 1 to 3,
At least one of R ₁ in the formula (1) is represented by the following formula (2):

The resin composition. The method according to any one of claims 1 to 4,
The polyimide precursor is represented by the following formula (3):

{In the formula, each of R ₃ and R ₄ , when plural, each independently represents a monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms or a monovalent aromatic group having 6 to 10 carbon atoms, and m is 1 to 200 A resin composition having a structure represented by}. The method according to any one of claims 1 to 5,
The resin composition, wherein the polyimide precursor is a copolymer of tetracarboxylic dianhydride and diamine containing pyromellitic dianhydride. The method according to any one of claims 1 to 6,
The resin composition, wherein the polyimide precursor is a copolymer of diamine and tetracarboxylic dianhydride containing 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride. The method according to any one of claims 1 to 7,
The polyimide precursor is a copolymer of tetracarboxylic dianhydride and diamine, and the tetracarboxylic dianhydride is pyromellitic dianhydride and 3,3 ', 4,4'-biphenyltetracarboxylic acid A resin composition comprising 2 anhydrides in a molar ratio of 20:80 to 80:20 of the pyromellitic acid 2 anhydride and the 3,3 ', 4,4'-biphenyltetracarboxylic acid 2 anhydride. The method according to any one of claims 1 to 8,
The polyimide precursor is tetracarboxylic dianhydride, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 2,2'-bis (trifluoromethyl) benzidine, and A resin composition, which is a copolymer of one or more diamines selected from the group consisting of 9,9-bis (4-aminophenyl) fluorene. The method according to any one of claims 1 to 9,
The resin composition having a weight average molecular weight of the polyimide precursor is 160,000 to 220,000. The method according to any one of claims 1 to 10,
The resin composition is a resin composition for a flexible device. The method according to any one of claims 1 to 11,
The resin composition is a resin composition for a flexible display. The polyimide film which is a hardened | cured material of the resin composition in any one of Claims 1-12. The method of claim 13,
A polyimide film in which the thickness direction retardation (Rth) in terms of a film thickness of 10 µm is 300 or less, and / or the yellowness (YI) in terms of a film thickness of 10 µm is 20 or less. A flexible device comprising the polyimide film according to claim 13 or 14. A flexible display comprising the polyimide film according to claim 13 or 14. The method of claim 16,
The said polyimide film is arrange | positioned at the point visually recognized when the said flexible display was observed from the outside. A coating step of applying the resin composition according to any one of claims 1 to 12 on a surface of a support,
A film forming process of heating the resin composition to form a polyimide film,
A method for producing a polyimide film comprising a peeling step of peeling the polyimide film from the support. The method of claim 18,
The coating step includes a slit coat of the resin composition, a method for producing a polyimide film. The method of claim 19,
At least one of R ₁ in the formula (1) is represented by the following formula (2):

The group represented by the method for producing a polyimide film. The method of claim 19 or 20,
The polyimide precursor is represented by the following formula (3):

{In the formula, each of R ₃ and R ₄ , when plural, each independently represents a monovalent aliphatic hydrocarbon group having 1 to 5 carbon atoms or a monovalent aromatic group having 6 to 10 carbon atoms, and m is 1 to 200 A method for producing a polyimide film having a structure represented by}. The method according to any one of claims 18 to 21,
Prior to the peeling step, a method of manufacturing a polyimide film further comprising an irradiation step of irradiating a laser to the polyimide film from the support side. A coating step of applying the resin composition according to any one of claims 1 to 12 on a surface of a support,
A film forming process of heating the resin composition to form a polyimide film,
An element forming process for forming an element on the polyimide film,
A method of manufacturing a display comprising a peeling step of peeling the polyimide film on which the device is formed from the support. The method of claim 23,
The coating step includes a slit coat of the resin composition, a method of manufacturing a display. The method of claim 23 or 24,
A method for manufacturing a display, wherein the polyimide film is disposed at a point where the display is viewed when viewed from the outside.

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