TWI814769B - Polyimide precursor resin composition - Google Patents

Abstract

The present invention provides a resin composition, which contains the following formula (1): {In the formula, R ₁ independently represents a divalent organic group when there are a plurality of them, R ₂ independently represents a tetravalent organic group when there is a plurality of them, n is a positive integer} A polyimide precursor and a solvent, 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 further relates to a flexible device (such as a flexible display) and a laminate, as well as a method of manufacturing the same.

Polyimide resin is an insoluble and infusible super heat-resistant resin with excellent properties such as heat resistance (such as thermal oxidation resistance), radiation resistance, low temperature resistance, and chemical resistance. Therefore, polyimide resins are used in a wide range of fields including electronic materials. Examples of applications of polyimide resin in the field of electronic materials include insulating coating materials, insulating films, semiconductors, and electrode protective films for thin film transistor liquid crystal displays (TFT-LCDs). Recently, the industry has been studying the use of flexible substrates that take advantage of their lightweight and flexibility to replace the glass substrates previously used in the field of display materials.

For example, Patent Document 1 describes a resin precursor (weight average molecular weight 30,000 to 90,000) having a siloxane unit that is polymerized using bis(diaminodiphenyl)sulfane (hereinafter also referred to as DAS). It is also reported that the polyimide obtained by hardening the precursor has low residual stress between it and a support such as glass, has excellent chemical resistance, and is resistant to yellowness caused by the oxygen concentration during the curing step ( YI) value and total light transmittance have little impact. Furthermore, Patent Document 2 describes a A resin composition, characterized in that it contains a polyimide precursor with a specific absorbance and an alkoxysilane compound with a specific absorbance; and it is described that the resin obtained by hardening the resin composition achieves sufficient contact with the support at the same time Adhesion and peelability using laser peeling, etc.

[Prior technical literature] [Patent Document]

[Patent Document 1] International Publication No. 2014/148441

[Patent Document 2] 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, which is then heated and dried. , and then imidize the polyimide precursor to prepare a polyimide film. After forming a device on the film if necessary, the film is peeled off from a glass substrate or the like as a support to obtain the target object.

In recent years, as displays and the like used as flexible substrates have become larger in size, a slit coater has been sometimes used when applying a composition containing a polyimide precursor to a substrate such as glass. . When a slit coater is used to apply a composition to form a coating film, there is a coating gap (a setting value that specifies the distance between the glass substrate and the slit nozzle) as a parameter that affects the coating film. However, if If the coating gap is small, the slit nozzle may be damaged if the nozzle comes into contact with the substrate if the flatness of the glass substrate is poor. Especially with the recent increase in the size of displays, etc. etc., it is necessary to sufficiently increase the coating gap.

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

The present inventors conducted coating evaluation by slit coating using a polyimide precursor having the same molecular weight and skeleton as those described in Patent Documents 1 and 2, and found that the above characteristics were insufficient. Therefore, an object of one aspect of the present invention is to provide a polyimide precursor-containing polyimide precursor which is excellent in slit coating properties and is also excellent in mechanical properties and optical properties required for applications such as flexible substrates. Resin composition.

The present inventors conducted diligent research and found that using a polyimide precursor with a specific structure can achieve good coating characteristics of slit coating, as well as good mechanical characteristics and optical characteristics.

That is, the present invention includes the following aspects.

{式中，R₁於存在複數個之情形時分別獨立地表示二價有機基，R₂於存在複數個之情形時分別獨立地表示四價有機基，n為正整數}所表示之結構之聚醯亞胺前驅體與溶劑者，且 上述聚醯亞胺前驅體之重量平均分子量為110,000~250,000，上述樹脂組合物之固形物成分含量為10~25質量%。 [1] A resin composition containing the following formula (1):

{In the formula, R ₁ independently represents a divalent organic group when there are a plurality of them, R ₂ independently represents a tetravalent organic group when there is a plurality of them, n is a positive integer} A polyimide precursor and a solvent are used, and 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%.

[2] The resin composition according to the above aspect 1, wherein when the viscosity of the resin composition is measured at 23°C using a viscometer equipped with a temperature regulator, the shear rate dependence is represented by the following formula (TI) is 0.9~1.1. TI=ηa/ηb

{In the formula, eta (mPa.s) is the viscosity of the resin composition under the measured rotation speed a (rpm), etab (mPa.s) is the viscosity of the resin composition under the measured rotation speed b (rpm), where, a* 10=b}

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

所表示之基。 [4] The resin composition according to any one of the above aspects 1 to 3, wherein at least one of R ₁ in the above formula (1) is the following formula (2):

The basis represented.

{式中，R₃及R₄之各者於存在複數個之情形時分別獨立地表示碳數1~5之一價脂肪族烴基、或碳數6~10之一價芳香族基，並且m為1~200之整數} 所表示之結構。 [5] The resin composition according to any one of aspects 1 to 4 above, wherein the polyimide precursor has the following formula (3):

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

[6] The resin composition according to any one of aspects 1 to 5 above, wherein the polyimide precursor system includes a copolymer of pyromellitic dianhydride, tetracarboxylic dianhydride and diamine.

[7] The resin composition according to any one of aspects 1 to 6 above, wherein the polyimide precursor system contains tetracarboxylic acid of 3,3',4,4'-biphenyltetracarboxylic dianhydride. Copolymer of acid dianhydride and diamine.

[8] The resin composition according to any one of the above aspects 1 to 7, wherein the polyimide precursor is a copolymer of tetracarboxylic dianhydride and diamine, and the tetracarboxylic dianhydride is The molar ratio of the above-mentioned pyromellitic dianhydride and the above-mentioned 3,3',4,4'-biphenyltetracarboxylic dianhydride is 20:80~80:20, including pyromellitic dianhydride and 3,3', 4,4'-Biphenyltetracarboxylic dianhydride.

[9] The resin composition according to any one of the above aspects 1 to 8, wherein the polyimide precursor is tetracarboxylic dianhydride, and a 4,4'-diaminodiphenyl group selected from the group consisting of Among the group consisting of sulfate, 3,3'-diaminodiphenyl sulfide, 2,2'-bis(trifluoromethyl)benzidine and 9,9-bis(4-aminophenyl)benzidine Copolymer of more than one diamine.

[10] The resin composition according to any one of aspects 1 to 9 above, 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 aspects 1 to 10 above, wherein the resin composition is a resin composition for a flexible device.

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

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

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

[15] A flexible device including the polyimide film described in aspect 13 or 14 above.

[16] A flexible display including the polyimide film described in aspect 13 or 14 above.

[17] The flexible display according to aspect 16 above, wherein the polyimide film is disposed at a portion that is visible when the flexible display is viewed from the outside.

[18] A method for manufacturing a polyimide film, which includes the following steps: a coating step of coating the resin composition as described in any one of the above aspects 1 to 12 on the surface of the support; a film forming step of heating the resin composition to form a polyimide film; and 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.

所表示之基。 [20] The method for producing a polyimide film as described in aspect 19 above, wherein at least one of R ₁ in the above formula (1) is the following formula (2):

The basis represented.

{式中，R₃及R₄之各者於存在複數個之情形時分別獨立地表示碳數1~5之一價脂肪族烴基、或碳數6~10之一價芳香族基，並且m為1~200之整數}所表示之結構。 [21] The method for producing a polyimide film as described in aspect 19 or 20, wherein the polyimide precursor has the following formula (3):

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

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

[23] A method for manufacturing a display, which includes the following steps: a coating step of coating the resin composition as described in any one of the above aspects 1 to 12 on the surface of the support; a film forming step, The step of heating the resin composition to form a polyimide film; the element forming step of forming an element on the polyimide film; and the peeling step of removing the polyimide film on which the element is formed from the support. Body peeling.

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

[25] The method of manufacturing a display according to aspect 23 or 24, wherein the polyimide film is disposed at a portion that is visible when the display is viewed from the outside.

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

2a: Lower base plate

2b: Sealing substrate

25:Organic EL Structure Department

250a: Organic EL element that emits red light

250b: Organic EL element that emits green light

250c: Organic EL element that emits blue light

251:Partition wall(touch row)

252: Lower electrode (anode)

253: Hole transport layer

254: Luminous layer

255: Upper electrode (cathode)

256:TFT

257:Contact hole

258:Interlayer insulation film

259:Lower electrode

261: Hollow part

FIG. 1 is a diagram illustrating the structure of a top-emission flexible organic EL display as an example of a display provided in one aspect of the present invention, above a polyimide substrate.

Hereinafter, exemplary embodiments of the present invention (hereinafter simply referred to as “embodiments”) will be described in detail. In addition, the present invention is not limited to the following embodiments, and can be implemented with various changes within the scope of the spirit. In addition, unless otherwise specified, the characteristic values described in the present invention mean values measured by the method described in the section [Examples] or a method understood by those skilled in the art to be equivalent.

{式中，R₁於存在複數個之情形時分別獨立地表示二價有機基，R₂於存在複數個之情形時分別獨立地表示四價有機基，n為正整數} This embodiment provides a resin composition containing the following formula (1):

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

Polyimide precursor of the structure represented. In one aspect, the resin composition includes the polyimide precursor and a solvent.

所表示之基。 In a preferred aspect, at least one of R ₁ in formula (1) is the following formula (2): [Chemical 7]

The basis represented.

At least one of R ₁ in the formula (1) is a structure represented by the formula (2), which contributes to the good optical properties (especially Rth) of the polyimide as a cured product of the polyimide precursor and Heat resistance. In one aspect, all n R ₁ 's in formula (1) have the structure represented by formula (2). Furthermore, 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 may be 100 % or less, or 90% or less.

Furthermore, this embodiment also provides a resin composition containing a polyimide precursor having a structure represented by the above formula (1), and the polyimide as a cured product of the resin composition has a thickness direction Retardation (Rth) below 300 and/or yellowness (YI) below 20. The above-mentioned lower thickness direction retardation (Rth) indicates that the polyimide has low birefringence, and the above-mentioned lower yellowness (YI) indicates that the polyimide has a good hue (that is, it is approximately colorless).

The resin composition of this embodiment forms a polyimide film that has excellent slit coating performance and excellent mechanical and optical properties, so it is preferably used as a flexible device (such as a flexible substrate). ) is more useful, especially as a flexible display.

(weight average molecular weight of polyimide precursor)

In one aspect, the weight average molecular weight of the polyimide precursor is between 110,000 and 250,000. The inventors found that when the resin composition of this embodiment is used for slot coating, the weight average molecular weight of the polyimide precursor greatly affects the coating performance, and repeatedly Do diligent research. As a result, it was found that when the weight average molecular weight of the polyimide precursor is 110,000 or more, the solid component content of the resin composition can be adjusted to achieve good slit coating, and on the other hand, the weight average molecular weight can be easily produced. Polyimide precursor with molecular weight below 250,000. That is, in this 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 from the viewpoint of production ease.

The ideal weight average molecular weight of the polyimide precursor depends on the desired use, the type of polyimide precursor, the solid content of the resin composition, the type of solvent that the resin composition can contain, etc. different.

For example, preferred examples of the lower limit of the weight average molecular weight are 111,000, 112,000, 113,000, 114,000, 115,000, 116,000, 117,000, 118,000, 119,000, 120,000, 121,000, 122,000, 123,000, 124, 000, 125,000, 126,000, 127,000, 128,000, 129,000, 130,000, 131,000, 132,000, 133,000, 134,000, 135,000, 136,000, 137,000, 138,000, 139,000, 140,000, 141,000, 142,000, 143,000, 144,000, 1 45,000, 146,000, 147,000, 148,000, 149,000, 150,000, 151,000, 152,000, 153,000, 154,000, 155,000, 156,000, 157,000, 158,000, 159,000, 160,000, 161,000, 162,000, 163,000, 164,000, 165,000, 166,000, 167,000, 168,000, 169,000, 1 70,000, 171,000, 172,000, 173,000, 174,000, 175,000, 176,000, 177,000, 178,000, 179,000, 180,000, 181,000, 182,000, 183,000, 184,000, 185,000, 186,000, 187,000, 188,000, 189,000, 190,000, 191,000, 192,000, 193,000, 194,000, 195,000, 196,000, 197,000, 198,000, 199,000, 200,000, 201,000, 202,000, 203,000, 204,000, 2 05,000, 206,000, 207,000, 208,000, 209,000, 210,000, 211,000, 212,000, 213,000, 214,000, 215,000, 216,000, 217,000, 218,000, 219,000, 220,000, 221,000, 222,000, 223,000, 224,000, 225,000, 226,000, 227,000, 228,000, 229,000, 2 30,000, 231,000, 232,000, 233,000, 234,000, 235,000, 236,000, 237,000, 238,000, 239,000, 240,000, 241,000, 242,000, 243,000, 244,000, 245,000, 246,000, 247,000, 248,000, or 249,000.

Furthermore, preferred upper limits of the weight average molecular weight are 249,000, 248,000, 247,000, 246,000, 245,000, 244,000, 243,000, 242,000, 241,000, 240,000, 239,000, 238,000, 237,000, 236 ,000, 235,000, 234,000, 233,000, 232,000, 231,000, 230,000, 229,000, 228,000, 227,000, 226,000, 225,000, 224,000, 223,000, 222,000, 221,000, 220,000, 219,000, 218,000, 217,000, 216,000, 2 15,000, 214,000, 213,000, 212,000, 211,000, 210,000, 209,000, 208,000, 207,000, 206,000, 205,000,204,000,203,000,202,000,201,000,200,000,199,000,198,000,197,000,196,000,195,000,194,000,193,000,192,000,191,000,1 90,000, 189,000, 188,000, 187,000, 186,000, 185,000, 184,000, 183,000, 182,000, 181,000, 180,000, 179,000, 178,000, 177,000, 176,000, 175,000, 174,000, 173,000, 172,000, 171,000, 170,000, 169,000, 168,000, 167,000, 166,000, 1 65,000, 164,000, 163,000, 162,000, 161,000, 160,000, 159,000, 158,000, 157,000, 156,000, 155,000, 154,000, 153,000, 152,000, 151,000, 150,000, 149,000, 1 48,000, 147,000, 146,000, 145,000, 144,000, 143,000, 142,000, 141,000, 140,000, 139,000, 138,000, 137,000, 136,000, 135,000, 134,000, 133,000, 132,000, 131,000, 130,000, 129,000, 128,000, 127,000, 126,000, 125,000, 124,000, 1 23,000, 122,000, 121,000, 120,000, 119,000, 118,000, 117,000, 116,000, 115,000, 114,000, 113,000, 112,000, or 111,000.

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

(Thickness direction retardation (Rth) of polyimide film)

When producing a polyimide film that is a cured product (i.e., an imide compound) of a polyimide precursor, the thickness direction retardation (Rth) of the polyimide film at a film thickness of 10 μm is based on the polyimide The monomer skeleton of the precursor is different. If the monomer skeleton is the same, the greater the weight average molecular weight of the polyimide precursor, the smaller the Rth will tend to be. If DAS is used as the polymer backbone, Rth tends to decrease. Although the mechanism of the above-mentioned relationship between the weight average molecular weight of the polyimide precursor and the Rth of the polyimide film is not yet clear, it is believed to be related to the alignment of the molecules of the polyimide film. and related to crystallinity.

In a specific aspect, from the viewpoint of obtaining a polyimide film with low birefringence, Rth is 300 nm or less. Especially when a polyimide film is used as a display material, Rth is preferably 200 nm or less, more preferably 100 nm or less, more preferably 80 nm or less, more preferably 50 nm or less, and particularly preferably 30 nm. If Rth is 300 nm or less, it is easier to accurately capture an image. In particular, if Rth is 200 nm or less, the color reproducibility of the image is good.

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

(Yellowness (YI) of polyimide film)

In a specific aspect, when producing a polyimide film that is a cured product of a polyimide precursor (i.e., an imide compound), from the viewpoint of obtaining good optical properties, the polyimide is The yellowness (YI) of the film at a film thickness of 10 μm is 20 or less, preferably 18 or less, more preferably 16 or less, further preferably 14 or less, further preferably 13 or less, still more preferably 10 or less, especially The best value is below 7. The YI of the polyimide film at a film thickness of 10 μm varies depending on the monomer skeleton of the polyimide precursor. If it is the same monomer skeleton, the weight average molecular weight of the polyimide precursor will be higher. Large, YI tends to be smaller.

(Other better properties of polyimide film)

When producing a polyimide film that is a cured product of a polyimide precursor (i.e., an imide compound) on an inorganic support substrate such as a glass substrate, the polyimide film has a film thickness of 10 μm. The residual stress generated between glass substrates, for example, in the manufacture of displays, is preferably 25 MPa or less, more preferably 23 MPa or less, and further preferably less than 25 MPa from the viewpoint of reducing the amount of warpage of the glass substrate with polyimide. It is preferably 20 MPa or less, more preferably 18 MPa or less, and particularly preferably 16 MPa or less.

In addition, the tensile elongation of the polyimide film at a film thickness of 10 μm is preferably 15% or more. Regarding the tensile elongation, from the viewpoint of the mechanical strength of the flexible display, it is more preferably 20% or more, further preferably 25% or more, further preferably 30% or more, and still more preferably 35% or more. Especially preferably, it is above 40%. The tensile elongation of the polyimide film varies depending on the monomer skeleton of the polyimide precursor. If the monomer skeleton is the same, the weight average molecular weight of the polyimide precursor will be larger. Tensile elongation tends to be larger.

Regarding the glass transition temperature Tg of the polyimide film, it is necessary to further increase the process temperature when forming an inorganic film such as silicon nitride on polyimide in the CVD (Chemical Vapor Deposition) step. Specifically, it is preferably 360°C or higher, more preferably 400°C or higher, and still more preferably 470°C or higher.

The polyimide film is preferably more uniform in film thickness. Especially when a polyimide film is used as a material for a screen of a flexible display or the like, since the wavelength of visible light is from about 380 nm to about 700 nm, it is difficult to obtain good display performance and manufacturing steps for the display. In other words, particularly high film thickness uniformity is required. Film thickness uniformity of polyimide film (plural points of film thickness standard deviation) is preferably 10 μm or less, preferably 8 μm or less, preferably 5 μm or less, preferably 3 μm or less, preferably 2 μm or less, especially 1 μm or less, especially 500 nm or less, especially 300 nm the following. The smaller the film thickness uniformity, the better. However, from the viewpoint of improving the productivity of display manufacturing, it may be, for example, 50 nm or more, or 100 nm or more. In addition, the above-mentioned film thickness uniformity means, for example, the value of 3σ calculated based on the film thickness at multiple points measured by the method described in the section "Examples" of the present invention.

(Shear speed dependence of resin composition)

The shear rate dependence (TI) (hereinafter, also abbreviated as TI) of the resin composition of this embodiment is preferably 0.9 or more and 1.1 or less. In the present invention, TI is measured based on the viscosity at the rotation number a (rpm) when measuring the viscosity of the resin composition using a viscometer with a temperature regulator (TVE-35H manufactured by Toki Industrial Machinery Co., Ltd.) at 23°C. ηa (mPa.s), and the viscosity ηb (mPa.s) measured at rotation speed b (rpm) (where, a* 10=b), and based on the following formula: TI=ηa/ηb

Find the value. Details of the measurement conditions are described in the examples.

The shear rate dependence (TI) is preferably 0.9 or more, or 0.95 or more, or 1.0 or more, and is preferably 1.1 or less, or 1.05 or less, or 1.0 or less. If TI is within this range, the resin composition is called a Newtonian fluid, and the film thickness uniformity is good when the resin composition is slit-coated, so it is preferable. The polyimide film obtained by hardening a resin composition with good film thickness uniformity has good film thickness uniformity, and therefore can be suitably used as a screen material for a flexible display or the like.

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 not yet clear, but it is considered as follows.

In slit coating, a small shearing speed is given to the resin composition just after the coating is started, and a large shearing speed is given to the resin composition when coating is continued. When the shear rate dependence is small (specifically, TI is 0.9 or more and 1.1 or less), the viscosity difference of the resin composition immediately after the coating is started and when the coating is continued is small, so the coating direction (MD (Machine direction, longitudinal)) film thickness unevenness is small (that is, the film thickness uniformity in the coating direction is good). In addition, when the slit coating nozzle has a specification for injecting the resin composition only from either end in the width direction (TD (Transverse direction)), during slit coating, the resin composition near the injection port The shearing speed is large, but the shearing speed of the resin composition decreases on the side opposite to the injection port (that is, the deadlock side of the nozzle). In this case, since the shear speed dependence is small (specifically, TI is 0.9 or more and 1.1 or less), the film thickness unevenness in the width direction can be reduced. In this way, the shear speed dependence is small (specifically, TI is 0.9 or more and 1.1 or less), which can provide the following advantages: the impact on viscosity caused by shear is reduced, and the film thickness in both directions of MD and TD is reduced. The unevenness is small (that is, the film thickness uniformity is good).

It is considered that there is a correlation between the shear speed dependence of the resin composition and the synthesis method of the resin composition.

For example, if all the acid dianhydride, diamine, and polysiloxane oil that may become acid dianhydride or diamine depending on the structure are added to the reaction vessel and then heated to react, and if the diamine is added to the diamine, Spend time at room temperature and gradually add the acid dianhydride dissolved in the solvent and the polysiloxane oil dissolved in the solvent in small amounts at room temperature to compare the gradual reactions. In the former case, from the single Whichever is more reactive (acidic or alkaline) (i.e. acid dianhydride, diamine and polysiloxane oil) Higher, less steric hindrance, etc.) begins to react, and the polyimide precursor tends to become a block polymer. On the other hand, in the latter case, the acid dianhydride and polysiloxane oil are dissolved in the solvent and gradually added dropwise in small amounts. Therefore, each monomer can react regardless of its reactivity. The polyimide precursor There is a tendency to become random polymers. It is considered that the polymer composition of the product is different in the former and the latter. Furthermore, it is thought that in the case of block polymers (the former), specific monomers in the polymer aggregate, so intermolecular interactions easily occur between polymer chains, or the flexibility of the polymer is impaired, so the polymer becomes Chains stack easily on top of each other. As a result, it is thought that the shear rate dependence of the resin composition increases. On the other hand, in the latter case, it is considered that since each monomer is bonded in sequence, intermolecular interactions are less likely to occur, and therefore the shear rate dependence is smaller.

Moreover, in the former case, it is thought that since all the monomers are added and heated, especially a part of the acid dianhydride is thermally opened by heat before reacting with the polymer chain. It is considered that when the acid dianhydride group is ring-opened and becomes a dicarboxylic group, the reactivity is lowered compared to the acid dianhydride group, and therefore the molecular weight of the polyimide precursor is reduced. On the other hand, in the latter case, it is considered that by dissolving the acid dianhydride in the solvent and gradually adding it dropwise in small amounts at room temperature, the acid dianhydride group can interact with the polymer chain without ring opening. reaction, the molecular weight increases.

(Slit coating characteristics of resin composition)

The coating characteristics (slit coating characteristics) of a resin composition containing a polyimide precursor using a slit nozzle are correlated 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 the resin composition has a low solid content, leakage is likely to occur from the nozzle. On the other hand, On the other hand, when the polyimide precursor has a high molecular weight and/or the resin composition has a high solid content, clogging of the varnish is likely to occur at the front end of the nozzle. Therefore, the weight average molecular weight of the polyimide precursor is preferably controlled within a range such that desired slit coating characteristics 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, the polyimide precursor has a low molecular weight and/or the resin composition has a low solid content. When the content is high, edge dripping is likely to occur. On the other hand, when the polyimide precursor has a high molecular weight and/or the resin composition has a high solid content, edge liquid is likely to occur. Drop (that is, the bulge of the edge). Therefore, the weight average molecular weight of the polyimide precursor is preferably controlled within a range such that desired edge characteristics are obtained by controlling the solid content.

In one aspect, the solid content of the resin composition is 10% by mass to 25% by mass. The settable coating gap (i.e., the gap between the front end of the slit coating nozzle and the substrate) when slit-coating a resin composition is related to the solid content of the resin composition. As long as the resin composition contains If the solid content of the resin composition is the same, the coating gap will tend to increase as the solid content of the resin composition decreases. From the perspective of good coating, it is preferable that the coating gap is larger. For example, if the coating gap is 50 μm or more, collision between the slit nozzle and the substrate can be avoided when the substrate size is relatively large. When the solid content of the resin composition is 10% to 25% by mass, the type and molecular weight of the polyimide precursor can be selected to achieve the target coating gap. The preferred solid content of the resin composition depends on the desired use, The type and molecular weight of the polyimide precursor, the type of solvent that can be included in the resin composition, etc. vary.

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

Preferred upper limits of the solid component content are 24% by mass, 23% by mass, 22% by mass, 21% by mass, 20% by mass, 19% by mass, 18% by mass, 17% by mass, 16% by mass, and 15% by mass. , 14% by mass, 13% by mass, 12% by mass, or 11% by mass.

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

{式中，R₃及R₄之各者於存在複數個之情形時分別獨立地表示碳數1~5之一價脂肪族烴基、或碳數6~10之一價芳香族基，並且m為1~200之整數}所表示之結構。 In a preferred aspect, the polyimide precursor has formula (3):

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

R ₃ and R ₄ are a monovalent aliphatic hydrocarbon group with 1 to 5 carbon atoms or a monovalent aromatic group with 6 to 10 carbon atoms to obtain a polyimide that can reduce the residual stress and Rth generated between the support and the support. It is more favorable from this point of view. Preferred structures of R ₃ and R ₄ include methyl, ethyl, propyl, butyl, phenyl, etc.

From the viewpoint of obtaining a polyimide that can reduce the residual stress and Rth generated between the support and the support, m is 1 to 200, preferably 1 or more, or 3 or more, or 5 or more, and more preferably Below 200, or below 180, or below 160.

The polyimide precursor can have the structure of formula (3) at any position in the molecule, but from the perspective of the type and cost of the siloxane monomer, the structure of formula (3) is preferably derived from two Amine components. The proportion of the structural part represented by relation (3) in the total mass of the polyimide precursor is preferably 5 mass % from the viewpoint of reducing the residual stress and Rth generated between the support and the support. Above, more preferably 6% by mass or more, still more preferably 7% by mass or more, and from the viewpoint of transparency and heat resistance of the obtained cured product (for example, polyimide film), 40% by mass is more preferred. % or less, more preferably 30 mass% or less, still more preferably 25 mass% or less.

In a typical aspect, the polyimide precursor system of the structure represented by the above formula (1) includes a diamine component of R ₁ group and a polymer containing an acid dianhydride component of R ₂ group.

Examples of the acid dianhydride containing R ₂ group include: pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and 2,2',3,3'-biphenyl Tetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 5-(2,5-dioxatetrahydro-3-furyl)-3-methyl- Cyclohexene-1,2 dicarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 2, 2',3,3'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenyltetracarboxylic dianhydride, methylene-4,4'-diphthalene Dicarboxylic dianhydride, 1,1-ethylene-4,4'-diphthalic dianhydride, 2,2-propylene-4,4'-diphthalic dianhydride, 1,2 -Ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4,4' -Diphthalic dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, p-phenylene bis (Trimellitic acid anhydride), thio-4,4'-diphthalic dianhydride, sulfonyl-4,4'-diphthalic dianhydride, 1,3-bis(3, 4-Dicarboxyphenyl)phthalic anhydride, 1,3-bis(3,4-dicarboxyphenoxy)phthalic anhydride, 1,4-bis(3,4-dicarboxyphenoxy)phthalic anhydride , 1,3-bis[2-(3,4-dicarboxyphenyl)-2-propyl]phthalic anhydride, 1,4-bis[2-(3,4-dicarboxyphenyl)-2- Propyl]phthalic anhydride, bis[3-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, bis[4-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride , 2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane Dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane dianhydride, 1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldi Siloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride , 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, etc.

Among them, pyromellitic dianhydride (PMDA) and biphenyltetracarboxylic dianhydride (BPDA) are used to control the solid content of the resin composition within a specific weight average molecular weight range of the polyimide precursor. In this case, it is better from the viewpoint of easily obtaining good slit coating performance, as well as good mechanical properties, optical properties, and high glass transition temperature of the cured product (such as a polyimide film). In one aspect, the polyimide precursor having the structure represented by formula (1) is a copolymer of tetracarboxylic dianhydride and diamine. In one aspect, the polyimide precursor system includes a copolymer of pyromellitic dianhydride (PMDA), a tetracarboxylic dianhydride and a diamine. Furthermore, in one aspect, the polyimide precursor system includes a copolymer of 3,3',4,4'-biphenyl tetracarboxylic dianhydride, tetracarboxylic dianhydride and diamine.

In a specific aspect, regarding the total content of pyromellitic dianhydride (PMDA) and biphenyltetracarboxylic dianhydride (BPDA) in all acid dianhydrides, good slit coating performance and hardening are obtained. From the viewpoint of good thickness direction retardation (Rth), yellowness (YI), glass transition temperature Tg, and elongation of the material (such as polyimide film), it is preferably 60 mol% or more, and more preferably More than 80 mol%, preferably 100 mol%.

In a specific aspect, regarding the content of pyromellitic dianhydride (PMDA) in the total acid dianhydride, good slit coating properties and good curing properties (such as polyimide films) can be obtained. From the viewpoint of the glass transition temperature Tg, it is preferably 0 mol% or more, preferably 10 mol% or more, preferably 20 mol% or more, and preferably 100 mol% or less, and preferably 90 Mol% or less.

In a specific aspect, with regard to the content of biphenyltetracarboxylic dianhydride (BPDA) in the total acid dianhydride, good slit coating performance and good hardened material (such as polyimide film) can be obtained. From the viewpoint of thickness direction retardation (Rth), yellowness (YI), and elongation, it is preferably 0 mol% or more, preferably 10 mol% or more, and preferably 20 mol% or more, and Preferably it is 100 mol% or less, More preferably, it is 90 mol% or less.

In a specific aspect, regarding the content ratio of pyromellitic dianhydride (PMDA): biphenyltetracarboxylic dianhydride (BPDA) in the acid dianhydride, a hardened product (such as a polyimide film) can be realized at the same time From the viewpoint of good thickness direction retardation (Rth), yellowness (YI) and heat resistance represented by glass transition temperature, 20:80~80:20 is preferred, and 30:70~70: is more preferred. 30. to a specific In this aspect, the polyimide precursor is a copolymer of tetracarboxylic dianhydride and diamine. The tetracarboxylic dianhydride is based on pyromellitic dianhydride: 3,3',4,4'-biphenyl. The molar ratio of tetracarboxylic dianhydride is 20:80~80:20, more preferably 30:70~70:3, including pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic acid dianhydride.

Examples of the diamine containing the R ₁ group in the formula (1) include: diaminodiphenyl sulfide (for example, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide) base), p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide Sulfide, 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]terine, 4,4-bis(4-aminophenoxy)biphenyl, 4,4-bis( 3-Aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl] ether, bis[4-(3-aminophenoxy)phenyl] ether, 1,4 -Bis(4-aminophenyl)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, 1,4-bis(3-aminopropyldimethylsilyl)benzene, etc.

The diamine used to form the polyimide precursor having the structure represented by formula (1) preferably contains diaminodiphenyl sulfide (such as 4,4'-diaminodiphenyl sulfide and/or 3,3'-Diaminodiphenylsine).

The content of diaminodiphenyl terine in all diamines is preferably 50 mol% or more, more preferably 70 mol% or more, more preferably 90 mol% or more, and may be 95 mol% or more. From the viewpoint of the yellowness (YI), glass transition temperature Tg, and thickness direction retardation Rth of the cured product (eg, polyimide film), the larger the amount of diaminodiphenyl sulfide, the better. As the diaminodiphenyl sulfide, from the viewpoint of low yellowness (YI), 4,4'-diaminodiphenyl sulfide is particularly preferred.

In a preferred aspect, from the viewpoint of the heat resistance and yellowness (YI) of the cured product (for example, a polyimide film), the diamine to be copolymerized with diaminodiphenyl sulfide is: Preferably, it contains diamide biphenyl, and more preferably, it contains diamino bis (trifluoromethyl) biphenyl (TFMB). Regarding the content of diamine bis(trifluoromethyl)biphenyl (TFMB) in all diamines, from the viewpoint of the yellowness (YI) of the cured product (for example, polyimide film), it is preferably 20 Mol% or more, more preferably 30 mol% or more. From the viewpoint that the diamine can contain other beneficial components such as diaminodiphenyl terine, it is preferably 80 mol% or less, more preferably 70 mol%. Mol% or less.

{式中，R₅表示二價烴基，分別可相同亦可不同，複數個R₃及R₄之各者與式(3)中所定義者同樣，並且l表示1~200之整數}所表示之二胺基(聚)矽氧烷。 In a preferred aspect, the diamine includes a silicon-containing diamine. In a more preferred aspect, the diamine includes a silicon-containing diamine having a structure represented by the above formula (3). As the silicon-containing diamine, for example, the following formula (3a) can be suitably used:

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

Preferable structures of R ₅ in the general formula (3a) include methylene, ethylene, propylene, butylene, phenylene, and the like. In addition, preferred structures of R ₃ and R ₄ in formula (3a) include methyl, ethyl, propyl, butyl, phenyl and the like.

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

Specific examples of the compound represented by the above formula (3a) include: both terminal amine-modified methylphenyl polysiloxane oil (manufactured by Shin-Etsu Chemical Co., Ltd.: X22-1660B-3 (number average molecular weight 4400), X22 -9409 (number average molecular weight 1300)), both terminal amine modified dimethyl polysiloxane (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), Dow Corning Toray manufacturer: BY16-835U (number average molecular weight 900), Chisso company manufacturer: Silaplane FM3311 (number average molecular weight 1000)), etc. Among these, from the viewpoint of improving chemical resistance and increasing Tg, both terminal amine-modified methylphenyl polysiloxane oil is preferred.

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 %, and still more preferably 1.5 mass % based on the mass of the entire polyimide precursor. %~20% by mass. In the case of more than 0.5% by mass, it will occur between the support and the The stress reduction effect is good. In addition, when the content is 30% by mass or less, the transparency (especially low haze) of the obtained cured product (such as a polyimide film) is good, thereby achieving high total light transmittance and preventing a decrease in Tg. Better.

As the acid component used to form the polyimide precursor in this embodiment, in addition to the acid dianhydride (such as the tetracarboxylic dianhydride exemplified above) within the range that does not impair its performance, there are also Dicarboxylic acids can be used. That is, the polyamide imine precursor of the present invention may also be a polyamide imine precursor. The film obtained by using this polyimide precursor has good mechanical elongation, glass transition temperature Tg, yellowness (YI) and other properties. Examples of the dicarboxylic acid used include dicarboxylic acids having an aromatic ring and alicyclic dicarboxylic acids. Particularly preferred is at least one compound selected from the group consisting of aromatic dicarboxylic acids having 8 to 36 carbon atoms and alicyclic dicarboxylic acids having 6 to 34 carbon atoms. The number of carbon atoms referred to here also includes the number of carbon atoms contained in the carboxyl group. Among these, dicarboxylic acids having an aromatic ring are preferred.

Specific examples include isophthalic acid, terephthalic acid, 4,4'-biphenyldicarboxylic acid, 3,4'-biphenyldicarboxylic acid, and 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'-oxybisphenyl Formic 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)fluorine, 9,9-bis(4-(3-carboxyphenoxy)phenyl)fluorine, 4,4'-bis(4-carboxyphenoxy)biphenyl, 4 ,4'-bis(3-carboxyphenoxy)biphenyl, 3,4'-bis(4-carboxyphenoxy)biphenyl, 3,4'-bis(3-carboxyphenoxy)biphenyl, 3,3'-bis(4-carboxyphenoxy base)biphenyl, 3,3'-bis(3-carboxyphenoxy)biphenyl, 4,4'-bis(4-carboxyphenoxy)-p-triphenyl, 4,4'-bis(4- Carboxyphenoxy)-p-triphenyl, 3,4'-bis(4-carboxyphenoxy)-p-triphenyl, 3,3'-bis(4-carboxyphenoxy)-p-triphenyl, 3 ,4'-bis(4-carboxyphenoxy)-m-terphenyl, 3,3'-bis(4-carboxyphenoxy)-m-terphenyl, 4,4'-bis(3-carboxybenzene) oxy)-p-triphenyl, 4,4'-bis(3-carboxyphenoxy)-p-triphenyl, 3,4'-bis(3-carboxyphenoxy)-p-triphenyl, 3,3 '-Bis(3-carboxyphenoxy)-p-terphenyl, 3,4'-bis(3-carboxyphenoxy)-p-terphenyl, 3,3'-bis(3-carboxyphenoxy) -Triphenyl, 1,1-cyclobutanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4,4'-benzophenonedicarboxylic acid acid, 1,3-phenylene diacetic acid, 1,4-phenylene diacetic acid, etc.; and 5-aminoisophthalic acid derivatives described in International Publication No. 2005/068535. When the dicarboxylic acid is actually copolymerized with a polymer, it can be used in the form of a chloride form derived from thionyl chloride or the like, an active ester form, or the like.

In a preferred aspect, the polyimide precursor is tetracarboxylic dianhydride and a compound selected from the group consisting of 4,4'-diaminodiphenylthione, 3,3'-diaminodiphenylthione, and 2, A copolymer of more than one diamine from the group consisting of 2'-bis(trifluoromethyl)benzidine and 9,9-bis(4-aminophenyl)fluoride.

Particularly preferred polyimide precursors include the following.

(1) The acid dianhydride component is pyromellitic dianhydride (PMDA) and biphenyltetracarboxylic dianhydride (BPDA), and the diamine component is the condensation polymer of the material component of diaminodiphenyl sulfone (DAS) (More preferably, the weight average molecular weight is 110,000~130,000, and the solid content is 12~25% by mass)

(2) The acid dianhydride components are pyromellitic dianhydride (PMDA) and biphenyltetracarboxylic dianhydride (BPDA), and the diamine components are diaminodiphenyl sulfone (DAS) and silicon-containing diamine. Condensation polymer of material components (preferably weight average molecular weight 110,000~210,000, solid component content 10 ~25 mass%)

(3) The acid dianhydride components are pyromellitic dianhydride (PMDA) and biphenyltetracarboxylic dianhydride (BPDA), and the diamine components are diaminodiphenylsine (DAS), diaminobis( Condensation polymer of trifluoromethyl)biphenyl (TFMB) and silicon-containing diamine (preferably weight average molecular weight 110,000~250,000, solid content 10~25% by mass)

(4) The acid dianhydride component is pyromellitic dianhydride (PMDA) and the diamine component is a condensation polymer of the material component (more preferably, the weight average molecular weight is 110,000~140,000, Solid content: 10~25% by mass)

(5) The acid dianhydride component is pyromellitic dianhydride (PMDA), and the diamine component is a condensation polymer of the material components of diaminodiphenyl sulfone (DAS) and silicon-containing diamine (preferably the weight Average molecular weight 110,000~230,000, solid content 10~25 mass%)

(6) The acid dianhydride component is pyromellitic dianhydride (PMDA), and the diamine component is diaminodiphenylsulfone (DAS), diaminobis(trifluoromethyl)biphenyl (TFMB) and Condensation polymer of silicon-containing diamine material component (preferably weight average molecular weight 110,000~250,000, solid content 10~25 mass%)

(7) The acid dianhydride component is biphenyltetracarboxylic dianhydride (BPDA), and the diamine component is diaminodiphenyl sulfone (DAS). The condensation polymer of the material component (more preferably, the weight average molecular weight is 110,000~120,000 , solid content content 20~25 mass%)

(8) The acid dianhydride component is biphenyltetracarboxylic dianhydride (BPDA), and the diamine component is a condensation polymer of the material components of diaminodiphenyl sulfone (DAS) and silicon-containing diamine (more preferably Weight average molecular weight 110,000~160,000, solid content 10~25 mass%)

(9) The acid dianhydride component is biphenyltetracarboxylic dianhydride (BPDA), and the diamine component is diaminodiphenylsulfane (DAS), diaminobis(trifluoromethyl)biphenyl (TFMB) And the condensation polymer of silicon-containing diamine material components (preferably a weight average molecular weight of 110,000~240,000, and a solid content of 10~25% by mass)

Among the material components of the above-mentioned condensation polymers (1) to (9), the silicon-containing diamine is preferably a diamine (poly)siloxane represented by the above formula (3a) (preferably a number average molecular weight of 500 ~12,000), preferably two-terminal amine-modified methylphenyl polysiloxane oil.

[Manufacture of polyimide precursor]

The polyimide precursor of this embodiment can be synthesized by subjecting a polycondensation component including an acid dianhydride component and a diamine component to a polycondensation reaction. In a preferred aspect, the polycondensation component includes an acid dianhydride component and a diamine component. The polycondensation reaction is preferably carried out in an appropriate solvent. Specifically, for example, a method may be mentioned in which a specific amount of an acid dianhydride is added to the obtained diamine solution after dissolving a specific amount of the diamine component in a solvent and stirred.

Regarding the molar ratio of the acid dianhydride component and the diamine component when synthesizing the polyimide precursor, from the viewpoint of the high molecular weight of the polyimide precursor resin and the slit coating characteristics of the resin composition, It is preferable to set it to the range of acid dianhydride:diamine=100:90~100:110 (diamine is 0.90~1.10 mole part with respect to 1 mole part of acid dianhydride), and further preferably 100 :95~100:105 (0.95~1.05 mole part of diamine relative to 1 mole part of acid dianhydride).

The molecular weight of the polyimide precursor can be determined by the type of acid dianhydride component and diamine component, acid Control is carried out by adjusting the ratio of the dianhydride component to the diamine component, adding the terminal blocking agent, adjusting the reaction conditions, etc. The closer the ratio of the acid dianhydride component to the diamine component is to 1:1, and the smaller the amount of terminal blocking agent used, the higher the molecular weight of the polyimide precursor can be achieved. As the acid dianhydride component and diamine component, it is recommended to use high-purity products. The purity is preferably 98 mass% or more, more preferably 99 mass% or more, and still more preferably 99.5 mass% or more. In addition, by reducing the moisture content in the acid dianhydride component and the diamine component, high purification can also be achieved. When a plurality of acid dianhydride components or diamine components are used together, it is sufficient as long as the acid dianhydride component or diamine component as a whole has the above-mentioned purity, and preferably all types of acid dianhydride components and diamines used are used. The ingredients respectively have the purity stated above.

式中，R₁₂=甲基所表示之Equamide M100(商品名：出光興產公司製造)、及R₁₂=正丁基所表示之Equamide B100(商品名：出光興產公司製造)等醯胺系溶劑；γ-丁內酯、γ-戊內酯等內酯系溶劑；六甲基磷醯胺、六 甲基膦三醯胺等含磷系醯胺系溶劑；二甲基碸、二甲基亞碸、環丁碸等含硫系溶劑；環己酮、甲基環己酮等酮系溶劑；甲基吡啶、吡啶等三級胺系溶劑；乙酸(2-甲氧基-1-甲基乙基)酯等酯系溶劑等；作為上述酚系溶劑，例如可列舉：苯酚、鄰甲酚、間甲酚、對甲酚、2,3-二甲苯酚、2,4-二甲苯酚、2,5-二甲苯酚、2,6-二甲苯酚、3,4-二甲苯酚、3,5-二甲苯酚等；作為上述醚及二醇系溶劑，例如可列舉：1,2-二甲氧基乙烷、雙(2-甲氧基乙基)醚、1,2-雙(2-甲氧基乙氧基)乙烷、雙[2-(2-甲氧基乙氧基)乙基]醚、四氫呋喃、1,4-二

烷等。該等溶劑可單獨使用或混合兩種以上而使用。 The reaction solvent is not particularly limited as long as it can dissolve the acid dianhydride component and the diamine component, as well as the produced polyimide precursor, and can obtain a high molecular weight polymer. Specific examples of such solvents include aprotic solvents, phenol solvents, ether and glycol solvents, and the like. Specific examples of the aprotic solvent include N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methyl -2-pyrrolidinone (NMP), N-methylcaprolactam, 1,3-dimethylimidazolidinone, tetramethylurea, the following general formula (4):

In the formula, R ₁₂ = Equamide M100 (trade name: manufactured by Idemitsu Kosan Co., Ltd.) represented by methyl group, and R ₁₂ = Equamide B100 (trade name: manufactured by Idemitsu Kosan Co., Ltd.) represented by n-butyl group, etc. Solvents; lactone solvents such as γ-butyrolactone and γ-valerolactone; phosphorus-containing amide solvents such as hexamethylphosphonamide and hexamethylphosphine triamide; dimethyl ester, dimethyl Sulfur-containing solvents such as sulfur dioxide and cyclobutane; ketone solvents such as cyclohexanone and methylcyclohexanone; tertiary amine solvents such as picoline and pyridine; acetic acid (2-methoxy-1-methyl Ester solvents such as ethyl ester; examples of the phenolic solvent include: phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, etc.; examples of the above-mentioned ether and glycol solvents include: 1,2- Dimethoxyethane, bis(2-methoxyethyl) ether, 1,2-bis(2-methoxyethoxy)ethane, bis[2-(2-methoxyethoxy) )ethyl] ether, tetrahydrofuran, 1,4-bis

Alkane etc. These solvents can be used individually or in mixture of two or more types.

The boiling point of the solvent used in the synthesis of the polyimide precursor under normal pressure is preferably 60~300°C, more preferably 140~280°C, and particularly preferably 170~270°C. If the boiling point of the solvent is higher than 300°C, the drying step will take a long time. On the other hand, if the boiling point of the solvent is lower than 60° C., the surface of the resin film may be roughened during the drying step, bubbles may be mixed into the resin film, etc., and a uniform film may not be obtained. From the viewpoint of solubility and edge depression during coating, it is particularly preferable to use a solvent with a boiling point of 170~270°C and/or a vapor pressure of 250Pa or less at 20°C. More specifically, it is preferably one selected from the group consisting of N-methyl-2-pyrrolidinone (NMP), γ-butyrolactone (GBL), and the compound represented by the above general formula (4) More than 1 species.

The moisture content in the solvent is preferably 3,000 mass ppm or less, for example, from the viewpoint of favorable progress of the polycondensation reaction. Moreover, in the resin composition in this embodiment, it is preferable that the content of molecules having a molecular weight of less than 1,000 is less than 5% by mass. The reason is thought to be the presence of molecules with a molecular weight of less than 1,000 in the resin composition and the solvent or raw materials (acid) used in the synthesis. dianhydride, diamine) is related to the moisture content. That is, it is considered that the reason is that some of the acid anhydride groups of the acid dianhydride monomer are hydrolyzed by moisture and become carboxyl groups, and remain in a low-molecular state without being increased in molecular weight. Therefore, the smaller the moisture content of the solvent used in the above-mentioned polycondensation reaction, the better. The water content of the solvent is preferably 3,000 mass ppm or less, more preferably 1,000 mass ppm or less. Similarly, the moisture content contained in the raw material is preferably 3,000 mass ppm or less, more preferably 1,000 mass ppm or less.

The water content of the solvent is considered to be related to the solvent grade used (dehydration grade, general grade, etc.), the solvent container (bottle, 18L can, canister, etc.), the storage state of the solvent (whether rare gas is enclosed, etc.), and the self-opening seal. It depends on the time until use (use immediately after opening, use after opening, etc.). In addition, it is considered that it is also related to the replacement of rare gases in the reactor before synthesis and the presence or absence of circulation of rare gases during synthesis. Therefore, when synthesizing the polyimide precursor, it is recommended to take measures such as using high-purity products as raw materials, using solvents with less moisture, and not mixing moisture from the environment into the system before and during the reaction. .

When dissolving each polycondensation component in the solvent, heating may be performed if necessary. From the perspective of obtaining a polyimide precursor with a higher degree of polymerization, the preferred reaction temperature when synthesizing the polyimide precursor is as follows: 0°C to 120°C, or 40°C to 100°C, Or 60 to 100°C. As a preferred polymerization time, 1 to 100 hours, or 2 to 10 hours can be exemplified. By setting the polymerization time to 1 hour or more, a polyimide precursor with a uniform degree of polymerization can be obtained, and by setting the polymerization time to 100 hours or less, a polyimide precursor with a higher degree of polymerization can be obtained.

The resin composition of this embodiment may be a polyimide precursor having a structure represented by formula (1). The combination of the precursor and other additional polyimide precursors, regarding the mass ratio of the additional polyimide precursor, reduces the yellowness (YI) and total light transmittance of the hardened product (such as polyimide film) From the viewpoint of oxygen dependence of the ratio, it is preferably 30 mass% or less, more preferably 10 mass% or less based on the total amount of the polyimide precursor in the resin composition.

In a preferred aspect of this embodiment, part of the polyimide precursor may be imidized. According to the partially imidized polyimide precursor, the viscosity stability of the resin composition when stored at room temperature can be improved. In this case, the imidization rate is preferably 5% or more, more preferably, from the viewpoint of achieving a balance between the solubility of the polyimide precursor in the resin composition and the storage stability of the solution. It is 8% or more, and preferably 80% or less, more preferably 70% or less, and still more preferably 50% or less. This partial imidization can be obtained by heating the polyimide precursor to perform dehydration and ring closure. The heating can be performed at a temperature of preferably 120 to 200°C, more preferably 150 to 180°C, preferably 15 minutes to 20 hours, and more preferably 30 minutes to 10 hours. Furthermore, by adding N,N-dimethylformamide dimethyl acetal or N,N-dimethylformamide diethyl acetal to the polyamic acid obtained by the above reaction. It is also heated to esterify part or all of the carboxylic acid, and then used as the polyimide precursor in this embodiment, thereby obtaining a resin composition with improved viscosity stability when stored at room temperature. These ester-modified polyamic acids can also be obtained by the following method: the above-mentioned acid dianhydride component is mixed with 1 equivalent of a monohydric alcohol relative to the acid anhydride group, and thionite chloride, dicyclohexylcarbodiamide After the dehydration condensation agent such as amine is reacted in sequence, it is subjected to condensation reaction with the diamine component.

In one aspect, the resin composition includes a solvent. As a solvent, it is preferable that the polyimide precursor has good solubility and can appropriately control the solution viscosity of the resin composition. The above-mentioned solvents can be used. The reaction solvent of the polyimide precursor serves as the solvent of the composition. Among them, N-methyl-2-pyrrolidone (NMP), γ-butyrolactone (GBL), the compound represented by the above general formula (4), and the like are preferred. Specific examples of the solvent composition include N-methyl-2-pyrrolidone (NMP) alone or a mixture of N-methyl-2-pyrrolidone (NMP) and γ-butyrolactone (GBL). Solvent (for example, NMP: GBL (mass ratio) = 10:90~90:10), etc.

[Additional ingredients]

The resin composition of this embodiment may contain additional components in addition to (a) the polyimide precursor and (b) the solvent. Examples of additional components include (c) surfactant, (d) alkoxysilane compound, and the like.

((c) Surfactant)

By adding a surfactant to the resin composition of this embodiment, the coating properties of the resin composition can be improved. Specifically, it can prevent the occurrence of streaks in the coating film.

Examples of such surfactants include polysiloxane-based surfactants, fluorine-based surfactants, and nonionic surfactants other than these. Examples of the polysiloxane surfactant include organosiloxane polymer KF-640, 642, 643, KP341, X-70-092, X-70-093, (above, Trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), SH-28PA, SH-190, SH-193, SZ-6032, SF-8428, DC-57, DC-190 (above, trade name, manufactured by Dow Corning Toray Silicone Co., Ltd. ), SILWET L-77, L-7001, FZ-2105, FZ-2120, FZ-2154, FZ-2164, FZ-2166, L-7604 (above, trade name, manufactured by Nippon Unicar Corporation), DBE-814, DBE-224, DBE-621, CMS-626, CMS-222, KF-352A, KF-3541, KF-355A, KF- 6020, DBE-821, DBE-712 (Gelest), BYK-307, BYK-310, BYK-378, BYK-333 (above, trade name, manufactured by BYK-Chemie Japan), Glanol (trade name, Kyoeisha Chemical Co., Ltd. Co., Ltd.), etc.; examples of fluorine-based surfactants include: MEGAFAC F171, F173, R-08 (trade name, manufactured by Dainippon Ink Chemical Industries, Ltd.), Fluorad FC4430, FC4432 (Sumitomo 3M Co., Ltd., Trade name), etc.; examples of nonionic surfactants other than these include: polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oil ether, polyoxyethylene octylphenol ether, etc.

Among these surfactants, from the viewpoint of coating properties (streak suppression) of the resin composition, polysiloxane-based surfactants and fluorine-based surfactants are preferred, in terms of resistance to oxygen during the curing step. From the perspective of the influence of concentration on the yellowness (YI) value and total light transmittance, polysiloxane surfactants are preferred. When (c) surfactant is used, its compounding amount is preferably 0.001 to 5 parts by mass, and more preferably 0.01 to 3 parts by mass relative to 100 parts by mass of (a) polyimide precursor in the resin composition. parts by mass.

(d) Alkoxysilane compound

When the polyimide film obtained using the resin composition of this embodiment is used in a flexible substrate or the like, good adhesion between the support and the polyimide film in the manufacturing process is obtained. Specifically, the resin composition may contain 0.01 to 20 parts by mass of the alkoxysilane compound relative to 100 parts by mass of (a) the polyimide precursor. When the content of the alkoxysilane compound is 0.01 parts by mass or more relative to 100 parts by mass of the polyimide precursor, good adhesion can be obtained between the support and the polyimide film. Moreover, from the viewpoint of storage stability of the resin composition, the content of the alkoxysilane compound is preferably 20 parts by mass or less. About alkoxysilane compounds The content is preferably 0.02 to 15 parts by mass relative to 100 parts by mass of the polyimide precursor, further preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 8 parts by mass.

Furthermore, by using an alkoxysilane compound as an additive to the resin composition of this embodiment, in addition to improving the above-mentioned adhesiveness, the coating properties of the resin composition (suppression of stripe unevenness) can also be improved, and the resulting The yellowness (YI) value of the obtained cured film depends on the oxygen concentration during curing.

Examples of the alkoxysilane compound include 3-ureidopropyltriethoxysilane, bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, and 3-glycidoxysilane. Propyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltripropoxysilane, γ-aminopropyltributoxysilane, γ-aminoethyltriethyl Oxysilane, γ-aminoethyltripropoxysilane, γ-aminoethyltributoxysilane, γ-aminobutyltriethoxysilane, γ-aminobutyltrimethoxysilane , γ-aminobutyl tripropoxysilane, γ-aminobutyltributoxysilane, phenylsilanetriol, trimethoxyphenylsilane, trimethoxy(p-tolyl)silane, diphenyl Silicone diol, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxydiphenylsilane, triphenylsilanol and alkoxysilane represented by the following structures respectively compounds, etc., it is preferred to use one or more types selected from these compounds.

[Chemical 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 in (a) synthesizing the polyimide precursor is the same as the solvent contained in (b) the resin composition, the synthesized polyimide precursor solution can be directly used as the resin composition. things. In addition, if necessary, (b) solvent and one or more additional components can be added to (a) the polyimide precursor in the temperature range of room temperature (25°C) to 80°C, and stirred. After mixing, it is used as a resin composition. Appropriate devices such as a Sany motor (manufactured by Shinto Chemical Co., Ltd.) equipped with stirring wings and a rotational and revolving mixer can be used for the stirring and mixing. In addition, heat of 40~100℃ can also be applied if necessary.

On the other hand, when (a) the solvent used in synthesizing the polyimide precursor is different from (b) the solvent contained in the resin composition, it may also be appropriately removed by reprecipitation, solvent distillation, etc. The method removes the solvent in the synthesized polyimide precursor solution, isolates (a) the polyimide precursor, and then adds (b) solvent in the temperature range of room temperature to 80°C, and Chase as necessary The ingredients are added and mixed with stirring to prepare a resin composition.

After preparing the resin composition as described above, the composition can be heated, for example, at 130 to 200° C. for 5 minutes to 2 hours, so that part of the polyimide precursor is dehydrated and imidized to the point where polymerization will not occur. The extent of material precipitation. Here, by controlling the heating temperature and heating time, the acyl imidization rate can be controlled. As mentioned above, the partially imidized polyimide precursor can improve the viscosity stability of the resin composition when stored at room temperature.

Regarding the solution viscosity of the resin composition, in terms of slot coating performance, it is preferably 500 to 100,000 mPa. s, preferably 1,000~50,000mPa. s, preferably 3,000~20,000mPa. s. Specifically, in terms of preventing liquid leakage from the slit nozzle, 500 mPa is preferred. s or more, preferably 1,000mPa. s or more, and more preferably 3,000mPa. s or above. In addition, in terms of making the slit nozzle less likely to be clogged, 100,000 mPa is preferred. s or less, preferably 50,000mPa. s or less, and more preferably 20,000mPa. s or less. Also, from the perspective of viscosity during synthesis, if the solution viscosity of the resin composition is higher than 200,000 mPa. s, there is a risk that it will be difficult to stir during synthesis. Among them, even if the solution becomes highly viscous during synthesis, a resin composition with good viscosity can be obtained by adding a solvent after the reaction and stirring. The solution viscosity of the resin composition in the present invention is a value measured at 23°C using an E-type viscometer (such as VISCONICE HD, manufactured by Toki Sangyo).

The water content of the resin composition of this embodiment is preferably 3,000 ppm by mass or less. The moisture content of the resin composition is preferably 2,500 mass ppm or less, more preferably 2,000 mass ppm or less, and more preferably 1,500 mass ppm from the viewpoint of viscosity stability when the resin composition is stored. ppm or less, more preferably 1,000 mass ppm or less, further preferably 500 mass ppm or less, preferably 300 mass ppm or less, more preferably 100 mass ppm or less.

<Manufacturing method of polyimide film>

This embodiment provides a method for manufacturing a polyimide film, which is characterized by including the following steps: a coating step, which coats the resin composition of this embodiment on the surface of a support; and a film forming step, which heats the resin composition. to form a polyimide film; and a peeling step, which peels off the polyimide film from the support.

[Coating step]

In the coating step, the resin composition is coated on the surface of the support. The support is not particularly limited as long as the support has heat resistance at the heating temperature of the subsequent film formation step (heating step) and the peelability in the peeling step is good. For example, glass (such as alkali-free glass) substrates; silicon wafers; PET (polyethylene terephthalate), OPP (extended polypropylene), polyethylene terephthalate, polyethylene glycol naphthalene can be used Resin substrates such as dicarboxylate, polycarbonate, polyimide, polyamideimide, polyetherimide, polyetheretherketone, polyethersulfone, polyphenylenesulfide, polyphenylene sulfide; Stainless steel, alumina, copper, nickel and other metal substrates, etc.

When forming a thin film-like polyimide molded body, for example, a glass substrate, a silicon wafer, etc. is preferred, and when forming a thick film-like polyimide molded body (such as a thick film, a sheet, etc.) In this case, for example, a support containing PET (polyethylene terephthalate), OPP (stretched polypropylene), etc. is preferred.

As a coating method, a knife coater, an air knife coater, a roll coater, a rotary coater, a flow coater, a die coater, a rod coater, etc. are generally mentioned. Coating methods, spin coating, spray coating, dip coating and other coating methods; printing technologies represented by screen printing and gravure printing, etc., the resin composition of the present embodiment is particularly suitable for slit coating Cloth (i.e. coating using a slit coater) is more useful. The coating thickness should be appropriately adjusted according to the required thickness of the polyimide film and the content of the polyimide precursor in the resin composition, and is preferably about 1 to 1,000 μm. Regarding the coating step, it is sufficient to perform it at room temperature. However, in order to reduce the viscosity and improve the workability, the resin composition can be heated in the range of 40 to 80° C., for example.

[optional drying step]

Following the coating step, a drying step may be performed, or the drying step may be omitted and the following film forming step (heating step) may be performed directly. The above drying step is performed to remove the organic solvent in the resin composition. When performing the drying step, suitable devices such as a heating plate, a box dryer, and a conveyor belt dryer may be used. The drying step is preferably carried out at 80~200°C, more preferably at 100~150°C. The implementation time of the drying step is preferably set to 1 minute to 10 hours, and more preferably set to 3 minutes to 1 hour. A coating film containing the polyimide precursor is formed on the support by the above method.

[Film formation step]

Next, a film forming step (heating step) is performed. The heating step is to remove the organic solvent remaining in the coating film in the above-mentioned drying step, and to remove the polyimide precursor in the coating film. chemical reaction to obtain a polyimide film. This heating step can be performed using, for example, an inert gas oven, a hot plate, a box dryer, a conveyor belt dryer, or the like. This step can be performed simultaneously with the above-mentioned drying step, or the two steps can be performed one after another.

The heating step can be carried out in an air environment, but from the viewpoint of safety and obtaining good transparency, lower thickness direction retardation (Rth) and lower yellowness (YI) of the polyimide film obtained For this purpose, it is recommended to perform it in an inert gas environment. Examples of the inert gas include nitrogen gas, argon gas, and the like. The heating temperature can be appropriately set according to the type of polyimide precursor and the type of solvent in the resin composition, and is preferably 250°C to 550°C, more preferably 300°C to 450°C. If it is 250°C or higher, imidization proceeds favorably, and if it is 550°C or lower, disadvantages such as a decrease in transparency and deterioration of heat resistance of the polyimide film obtained can be avoided. The heating time is preferably set to about 0.1 to 10 hours.

In this embodiment, the oxygen concentration of the surrounding environment in the above-mentioned heating step is preferably 2,000 mass ppm or less from the viewpoint of the transparency and yellowness (YI) value of the polyimide film obtained. More preferably, it is 100 mass ppm or less, and still more preferably, it is 10 mass ppm or less. By heating in an environment with an oxygen concentration of 2,000 mass ppm or less, the yellowness (YI) value of the obtained polyimide film can be set to 30 or less.

[Peel-off step]

Then, in the peeling step, the polyimide film on the support is cooled to about room temperature to 50° C. and then peeled off. Examples of the peeling step include the following aspects (1) to (4).

(1) By the above method, a structure including a polyimide film/support is produced, and then a laser is irradiated from the support side of the structure to ablate the interface between the support and the polyimide film. , a method of peeling off polyimide resin. Examples of types of laser include solid (YAG) laser, gas (UV (Ultra Violet, ultraviolet) excimer) laser, and the like. It is preferable to use a spectrum such as a wavelength of 308 nm (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 coating the resin composition on the support, and then obtaining a structure including the polyimide film/release layer/support, and peeling off the polyimide film. . Examples of the release layer include methods using Parylene (registered trademark, manufactured by Parylene Japan LLC) and tungsten oxide; methods using vegetable oil-based, silicone-based, fluorine-based, alkyd-based release agents, etc. (see Japanese patent Japanese Patent Application Publication No. 2010-67957, Japanese Patent Application Publication No. 2013-179306, etc.).

This method (2) can be used in combination with the laser irradiation of (1) above.

(3) A method of using an etchable metal substrate as a support to obtain a structure including a polyimide film/support, and then etching the metal with an etchant to obtain a polyimide film. As the metal, for example, copper (as a specific example, electrolytic copper foil "DFF" manufactured by Mitsui Metal Mining Co., Ltd.), aluminum, etc. can be used. As an etchant, ferric chloride can be used for copper, and dilute hydrochloric acid can be used for aluminum.

(4) Through the above method, a structure including a polyimide film/support is obtained, and then an adhesive film is attached to the surface of the polyimide film, and the adhesive film/polyimide film is separated from the support. A method to separate the polyimide film from the adhesive film.

Among these peeling methods, method (1) or (2) is suitable from the viewpoint of the refractive index difference, yellowness (YI) value, and elongation of the front and back surfaces of the polyimide film obtained. , from the viewpoint of the difference in refractive index between the front and back surfaces of the obtained polyimide film, method (1) is more suitable, that is, before the peeling step, the self-supporting side side is irradiated with laser irradiation step.

Furthermore, in the method (3), when copper is used as a support, the yellowness (YI) value of the obtained polyimide film tends to increase and the elongation tends to decrease. It is thought 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, and more preferably 5 to 100 μm.

<Applications of polyimide membrane>

The polyimide film obtained by using the polyimide precursor of this embodiment can be used, for example, as a semiconductor insulating film, a TFT-LCD insulating film, an electrode protective film, etc. In addition, it can be particularly used in the manufacture of flexible devices. Suitable for use as TFT substrates, color filter substrates, and touch panel substrates. Here, examples of flexible devices to which the polyimide film of this embodiment can be applied include TFT devices for flexible displays, flexible solar cells, flexible touch panels, and flexible lighting. , flexible batteries, flexible printed circuit boards, flexible color filters, surface housing lenses for smartphones, etc.

The step of forming a TFT on a flexible substrate using a polyimide film is typically performed at a temperature within 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 usually required. Since this embodiment The polyimide film must be able to withstand this temperature, so specifically, a polymer structure with a glass transition temperature and a thermal decomposition onset temperature above the process temperature must be appropriately selected.

When manufacturing TFT devices using metal oxide semiconductors (IGZO, etc.), a process temperature of 320°C to 400°C is usually required. Since the polyimide film of this embodiment must be able to withstand this temperature, it must be appropriately selected. It has a polymer structure with a glass transition temperature and thermal decomposition onset temperature above the maximum temperature of the TFT manufacturing process.

When manufacturing TFT devices using low-temperature polycrystalline silicon (LTPS), a process temperature of 380°C to 520°C is usually required. Since the polyimide film of this embodiment must be able to withstand this temperature, the TFT manufacturing process must be appropriately selected. Glass transition temperature and thermal decomposition onset temperature above the maximum temperature.

On the other hand, due to such thermal history, the optical properties of the polyimide film (especially light transmittance, retardation characteristics and yellowness) tend to decrease as the film is exposed to high-temperature processes. However, the polyimide obtained by using the polyimide precursor of this embodiment has good optical properties even after thermal history.

Hereinafter, as application examples of the resin composition and the polyimide film of this embodiment, a display, a laminated body, and a manufacturing method thereof will be described.

[Display and manufacturing method thereof]

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

This embodiment also provides a method for manufacturing a display, which includes the following steps: a coating step of coating (preferably slit coating) the resin composition of this embodiment on the surface of a support such as a glass substrate; a film forming step, which heats the resin composition to form a polyimide film; an element forming step, which forms an element on the polyimide film; and a peeling step, which peels off the support to form a polyimide film with an element .

[Manufacturing method of flexible organic EL display]

FIG. 1 is a diagram illustrating the structure of a top-emission flexible organic EL display as an example of a display provided in one aspect of the present invention, above a polyimide substrate. If the organic EL structure part 25 of FIG. 1 is explained, for example, the organic EL element 250a that emits red light, the organic EL element 250b that emits green light, and the organic EL element 250c that emits blue light are used as one unit in a matrix shape. Arrange, and use partition walls (bars) 251 to demarcate the light-emitting range of each organic EL element. 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. In addition, on the lower layer 2a representing a CVD multilayer film (multi-barrier layer) containing silicon nitride (SiN) or silicon oxide (SiO), a plurality of TFTs 256 (selected from low-temperature polycrystalline silicon) for driving organic EL elements are provided. (LTPS), metal oxide semiconductor (IGZO, etc.)), an interlayer insulating film 258 having a contact hole 257, and a lower electrode 259. The organic EL elements are sealed with the sealing substrate 2b, and a hollow is formed between each organic EL element and the sealing substrate 2b. Department 261.

The flexible organic EL display manufacturing step includes the following steps: making a polyimide film on a glass substrate support, and manufacturing the organic EL substrate shown in Figure 1 on top of it; a sealing substrate manufacturing step; The assembly step of bonding the two substrates together; and the peeling step of the organic EL display produced by peeling off the glass substrate support on the polyimide film.

Well-known manufacturing steps can be applied to the organic EL substrate manufacturing step, the sealing substrate manufacturing step, and the assembly step. An example is given below, but it is not limited to this. In addition, the peeling step may be the same as the peeling step of the above-mentioned polyimide film.

Referring to Figure 1, for example, first, the polyimide film of the present invention is produced on a glass substrate support by the above method, and a film containing silicon nitride (SiN) and silicon oxide is produced on the upper part by a CVD method or a sputtering method. A multi-layer structure of (SiO) multi-barrier layer (lower substrate 2a in Figure 1), and a photoresist is used on the upper part to make a metal wiring layer for driving the TFT. On the upper part, the CVD method is used to make an active buffer layer such as SiO, and on the upper part, TFT devices such as metal oxide semiconductor (IGZO) and low-temperature polycrystalline silicon (LTPS) are made (TFT256 in Figure 1). After the TFT substrate for a flexible display is produced, an interlayer insulating film 258 having contact holes 257 is formed using photosensitive acrylic resin or the like. An ITO (Indium Tin Oxide) film is formed by sputtering or the like, and the lower electrode 259 is formed to be paired with the TFT.

Next, after forming the partitions (bars) 251 using photosensitive polyimide or the like, the hole transport layer 253 and the light-emitting layer 254 are formed in each space divided by the partitions. Furthermore, an upper electrode (cathode) 255 is formed so as to cover the light-emitting layer 254 and the partition wall (bar) 251. Afterwards, the semen A fine metal mask is used as a mask, and an organic EL material that emits red light (corresponding to the organic EL element 250a that emits red light in FIG. 1) and an organic EL material that emits green light (corresponding to the organic EL element 250a that emits red light) are evaporated by a known method. The organic EL element 250b that emits green light in Figure 1 corresponds to the organic EL material that emits blue light (corresponds to the organic EL element 250c that emits blue light in Figure 1), thereby making an organic EL substrate, and After sealing with a sealing film (sealing substrate 2b in Figure 1), the device above the polyimide substrate is peeled off from the glass substrate support by a known peeling method such as laser peeling, thereby producing a top-emitting device. Flexible organic EL display. When the polyimide of this embodiment is used, a see-through type flexible organic EL display is produced. In addition, a bottom-emitting flexible organic EL display can also be produced by known methods.

[Manufacturing method of flexible liquid crystal display]

A flexible liquid crystal display can be produced using the polyimide film of this embodiment. As a specific production method, the polyimide film containing the present invention is produced on a glass substrate support by the above method, and the above method is used to produce, for example, amorphous silicon, metal oxide semiconductor (IGZO, etc.), or low temperature Polycrystalline silicon TFT substrate. In addition, according to the coating step and film forming step of this embodiment, a polyimide film is produced on a glass substrate support, and a color photoresist is used according to a known method to produce a color filter having a polyimide film. Light sheet glass substrate (CF substrate). On either the TFT substrate or the CF substrate, a sealing material containing thermosetting epoxy resin or the like is applied to a frame-shaped pattern on the part lacking the liquid crystal injection port by screen printing, and a frame-shaped pattern equivalent to the liquid crystal layer is formed. diameter, and the spherical spaces containing plastic or silicon dioxide are spread on another substrate.

Then, the TFT substrate and the CF substrate are bonded together, and the sealing material is hardened.

Finally, after injecting the liquid crystal material into the space surrounded by the TFT substrate, the CF substrate and the sealing material by a pressure reduction method, a thermosetting resin is applied to the liquid crystal injection port, and the liquid crystal material is sealed by heating, thereby forming a liquid crystal layer. Finally, the glass substrate on the CF side and the glass substrate on the TFT side are peeled off at the interface between the polyimide film and the glass substrate, thereby making a flexible liquid crystal display.

[Manufacturing method of laminated body]

This embodiment also provides a method for manufacturing a laminated body, which includes the following steps: a coating step, which coats the resin composition of this embodiment on the surface of a support; and a film forming step, which heats the resin composition to form a polyimide film; and an element forming step of forming an element on the polyimide film.

Examples of elements in the laminated body include those exemplified as the above-mentioned flexible device (for example, a flexible display). For example, a glass substrate is used as a support. In the preferable specific order of the coating step and the film forming step, the manufacturing method of the above-mentioned polyimide film is the same as the above-mentioned one. Furthermore, in the element forming step, the above-mentioned element is formed on a polyimide film as a flexible substrate formed on a support. Thereafter, the polyimide film and the element can be peeled off from the support in a peeling step.

[Example]

Hereinafter, the present invention will be further described in detail based on examples. However, these are described for the purpose of explanation, and the scope of the present invention is not limited to the following examples. Various evaluations in Examples and Comparative Examples were performed as follows.

<Weight average molecular weight>

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

Using NMP (for high-speed liquid chromatography manufactured by Wako Pure Chemical Industries, Ltd.), 24.8 mmol/L of lithium bromide monohydrate (99.5% purity manufactured by Wako Pure Chemical Industries, Ltd.) and 63.2 mmol/L of lithium bromide monohydrate were added immediately before measurement. Phosphoric acid (for high-speed liquid chromatography manufactured by Wako Pure Chemical Industries, Ltd.) is used as a solvent. The calibration curve used to calculate the weight average molecular weight was prepared using standard polystyrene (manufactured by Tosoh Corporation).

Pipe string: Shodex KD-806M (manufactured by Showa Denko Co., Ltd.)

Flow rate: 1.0mL/min

Tube string temperature: 40℃

Pump: PU-2080Plus (manufactured by JASCO Corporation)

Detector: RI-2031Plus (RI (Refractive Index, refractive index): differential refractometer, manufactured by JASCO Corporation) and UV-2075Plus (UV-VIS: ultraviolet-visible absorbance meter, manufactured by JASCO Corporation)

<Evaluation of shear speed dependence (TI)>

At 23°C, use a viscometer with a temperature regulator (TVE-35H manufactured by Toki Industrial Machinery Co., Ltd.), a rotation speed that can measure the viscosity of the resin composition to be measured, and a cone-plate viscometer. The viscosity of the resin composition prepared in Examples and Comparative Examples was evaluated for shear rate dependence.

Specifically, the viscosity eta (mPa.s) at the measurement rotation number a (rpm) and the viscosity eta (mPa.s) at the measurement rotation number b (rpm) are measured (here, a*10=b ), and find TI represented by the following formula.

TI=ηa/ηb

Specific examples of the measurable rotation speed are 0.5, 1, 2.5, 5, 10, 20, 50, and 100 rpm.

Specific examples of the cone and plate viscometer that can be measured are 1°34' (angle of the cone and plate viscometer) × R24 (diameter of the cone and plate viscometer), 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>

Use a slit coater (manufactured by SCREEN Finetech Solutions Co., Ltd.) to apply the resin composition prepared in the examples and comparative examples on a 300mm*300mm glass substrate with a coating area of 295mm*295mm, and conduct Coating evaluation.

(Slit nozzle evaluation)

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

The spray of varnish starts from the nozzle, and after the spray stops, the varnish drips from the slit nozzle: liquid leakage

Varnish does not come out of the nozzle: clogged

Coating can be performed without leakage or clogging: no problem

(coating gap)

After imidizing the resin composition (varnish) prepared in the Examples and Comparative Examples (heating at 100°C for 1 hour and then at 400°C for 30 minutes at an oxygen concentration of 10 ppm by mass or less) It was applied on the glass substrate so that the film thickness became 10 μm (coating speed: 100 mm/sec). Record the coating gap setting value of the slit coater at this time in the table.

(marginal review)

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

Furthermore, a stylus type step meter (P-15: manufactured by KLA Tencor) was used to measure the edge droplets of the coating film (ridges at the edge), and the evaluation was performed based on the following standards.

Drooping of liquid droplets with a width of 0.5mm or more observed through a microscope at the edge: dripping

The thickness of the droplet measured by the film thickness of the edge part is more than 30% of the thickness of the coating film: droplet

There are no dripping or edge abnormalities: no problem

(Can slit coating be performed)

The above (slit nozzle evaluation), (coating gap), and (edge evaluation) were evaluated based on the following standards and listed in the table.

In the composition using the polyimide precursor with a specific weight average molecular weight in each of the examples and comparative examples, the content of at least one solid component in the range of 7 to 28 mass % satisfies all of the following evaluation results: Yes

In the compositions using polyimide precursors with specific polymerization average molecular weights in each of the Examples and Comparative Examples, there was no case where all of the following evaluation results were satisfied within the solid content content range of 7 to 28% by mass. : No

Slit nozzle evaluation: no problem

Coating gap: 50μm or more

Marginal rating: No problem

<Cure film thickness uniformity (standard deviation)>

In the above <Coating Evaluation> (coating gap), the polyimide films of Examples and Comparative Examples produced on glass substrates (that is, polyimide films formed at 295mm*295mm on a 300mm*300mm glass substrate were used) imine film). Using a glass substrate with a polyimide film formed on it, measure the film position at intervals of 20 mm from the center of the coating surface toward each end surface of MD (i.e., the direction of slit coating) and TD (direction at right angles to MD). Thick (therefore, the endmost side is 7.5mm away from the end surface) (MD15 points, TD15 points, 30 points in total). The film thickness is measured using a contact step meter. Based on the results, the film thickness uniformity of the polyimide film (standard deviation of the film thickness at 30 points) was calculated and evaluated based on the following standards.

Good: In-plane film thickness uniformity (3Sigma) is 1.0 μm or less

Possible: In-facial film thickness uniformity (3Sigma) exceeds 1.0μm and is less than 2.0μm

Defective: In-facial film thickness uniformity (3Sigma) exceeds 2.0μm

<Cured film elongation>

The resin composition prepared in the Examples and Comparative Examples was spin-coated on a 6-inch silicon wafer substrate with an aluminum evaporation layer on the surface in such a way that the film thickness after hardening became 10 μm, and heated at 100°C. Pre-bake for 6 minutes. Thereafter, a vertical curing furnace (model name VF-2000B manufactured by Koyo Lindberg Co., Ltd.) was used to adjust the oxygen concentration in the chamber so that it became 10 mass ppm or less, and a heat hardening process was performed at 400° C. for 30 minutes. A wafer formed with a polyimide film is produced. Next, a wafer dicing saw (DAD 3350 manufactured by DISCO Co., Ltd.) was used to place a 3 mm wide slit on the polyimide film of the wafer, and then the film was peeled off by immersing it in a dilute hydrochloric acid aqueous solution overnight. , and dry. Cut it to a length of 50mm and set it as a sample.

For the above-mentioned sample, TENSILON (UTM-II-20 manufactured by Orientec) was used to measure the elongation at a test speed of 40 mm/min and an initial load of 0.5 fs. Evaluation was performed based on the following criteria and listed in the table.

Excellent: above 40%

Good: more than 20% but less than 40%

Yes: less than 20%

<Cured film Haze>

In the above <Coating Evaluation> (coating gap), the polyimide films of Examples and Comparative Examples produced on a glass substrate were used.

The haze (film thickness equivalent to 10 μm) of the obtained sample was measured based on the JIS K7105 transparency test method using an SC-3H haze meter manufactured by Suga Testing Machine Co., Ltd. The measurement results were evaluated based on the following standards and are listed in the table.

Excellent: Haze is less than 0.5

Good: Haze is greater than 0.5 and less than 1.5

Yes: haze greater than 1.5

<Cure film yellowness (YI))>

In the above <Coating Evaluation> (coating gap), the polyimide films of Examples and Comparative Examples produced on a glass substrate were used. The obtained sample was measured for yellowness (YI) value (film thickness: 10 μm conversion) using a D65 light source manufactured by Nippon Denshoku Industries Co., Ltd. (Spectrophotometer: SE600). Record the results in the table.

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

In the above <Coating Evaluation> (coating gap), the polyimide films of Examples and Comparative Examples produced on a glass substrate were used. For the obtained sample, Rth (film thickness: 10 μm conversion) was measured using a phase difference birefringence measuring device (KOBRA-WR manufactured by Oji Instruments Co., Ltd.). The wavelength of the measurement light was set to 589nm. Record the results in the table.

<Comparative Example 1-1>

To a 3L separable flask with a stirring rod, NMP (812g) was added while introducing nitrogen gas, and 4,4'-DAS (4,4'-diaminodiphenyl sulfide) as the diamine was added while stirring. ) (14.2g), TFMB (12.2g), both terminal amine modified methylphenyl polysiloxane oil (10.56g), and then add PMDA (15.3g) and BPDA (8.8g) as acid dianhydride (acid The molar ratio of dianhydride and diamine (100:98)). Next, use an oil bath to raise the temperature to 80° C. and stir for 4 hours. Then, remove the oil bath and return to room temperature to obtain a transparent NMP solution of polyamide (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer (set at -20° C., the same below), and was thawed before use during evaluation.

<Comparative Examples 1-2~1-6>

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

<Example 1-1>

To a 3L separable flask with a stirring rod, 4,4'-DAS (15.3g) and TFMB (12.4g) as diamines were added while introducing nitrogen gas, and 2 times the total mass of these diamines. Polymerization solvent (NMP).

Next, a dropping funnel was installed in the above-mentioned separable flask. While introducing nitrogen gas into the dropping funnel, PMDA (15.3g) and BPDA (8.8g) as acid dianhydrides and 2 of these acid dianhydrides were added. times the mass of polymerization solvent (NMP). Then, stir at room temperature using a small stirring blade.

Then, another dropping funnel was installed in the above-mentioned separable flask, and nitrogen gas was introduced into the dropping funnel while adding both terminal amine-modified methylphenyl polysiloxane oil X-22-1660B-3 as the diamine. (10.56g) and 2 times the mass of polymerization solvent (NMP) of the polysiloxane oil. Then, stir at room temperature using a small stirring blade.

Then, while stirring the diamine solution in the separable flask, at room temperature, while stirring the small stirring blade of the dropping funnel, the dropwise addition of the acid dianhydride solution and the polysiloxane oil was started at the same time. The dripping was performed at low speed and lasted for more than 30 minutes. After the dropwise addition, the mixture was washed with a cleaning solvent (NMP), and the residue (molar ratio of acid dianhydride and diamine (100:99)) was added dropwise.

Thereafter, an additional solvent (NMP) was added to finally achieve the solid content content shown in Table 1. Mode. The mixture was then 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 a transparent NMP solution of polyamide (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer (set at -20° C., the same below), and was thawed before use during evaluation.

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

The compositions of the acid dianhydride and diamine are as shown in Tables 1 to 4, and the usage amount of the polymerization solvent is changed accordingly (that is, the amount is adjusted so that it becomes twice the mass of the acid dianhydride or diamine). , and further for Examples 1-5 to 1-8, 2-5 to 2-14, 3-3 to 3-16, and 4-5 to 4-12, "raise the temperature to 70°C and stir for 4 hours" to "Raise the temperature to 40°C and stir for 12 hours." For Examples 1-9, 2-9, 3-9, and 4-9, change "Additional solvent (NMP)" to "Additional solvent (NMP and GBL) (with Adjustment was made so that NMP/GBL after addition becomes 100/100 (w/w)", except for this, it was the same as Example 1-1. The solid content amounts shown in Tables 1 to 4 were adjusted to the values shown in the tables by changing the amount of the additional solvent. Furthermore, in Examples 1-16, 2-12, 2-13, 3-14, 3-15, 4-10, and 4-11, the reaction time was further measured after "stirring for 12 hours". The weight average molecular weight did not increase compared with that after stirring for 12 hours.

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

Comparative Examples 2-1, 3-1, and 4-1 respectively changed the NMP amount of Comparative Example 1-1 to 745g (Comparative Example 2-1), 799g (Comparative Example 3-1), and 850g (Comparative Example 4-1). ), except that the compositions of the acid dianhydride and diamine were as shown in Table 2, the procedure was carried out in the same manner as Comparative Example 1-1. In addition, Comparative Examples 2-2 to 2-6 were performed in the same manner as Comparative Example 2-1, except that the NMP amount was changed to the solid content content in Tables 2 to 4. Comparative Examples 3-2 to 3- Series 6 was carried out in the same manner as Comparative Example 3-1, Comparative Examples 4-2~4- Series 7 was performed in the same manner as in Comparative Example 4-1.

<Comparative Example 5-1>

Into a 3L separable flask with a stirring rod, NMP (620g) was added while introducing nitrogen gas, and 4,4'-DAS (24.8g) as the diamine was added while stirring, and then PMDA as the acid dianhydride was added (21.8g) (molar ratio of acid dianhydride and diamine (100:100)). Next, use an oil bath to raise the temperature to 80° C. and stir for 4 hours. Then, remove the oil bath and return to room temperature to obtain a transparent NMP solution of polyamide (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer and thawed before use during evaluation.

<Comparative Examples 5-2~5-6>

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

<Example 5-1>

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

Next, a dropping funnel was installed in the above-mentioned separable flask. While introducing nitrogen into the dropping funnel, PMDA (10.9g) and BPDA (14.7g) as acid dianhydrides and 2 times of these acid dianhydrides were added. Quality of NMP. Then, stir at room temperature using a small stirring blade.

Then, while stirring the diamine solution in the separable flask, the acid dianhydride solution was started to be dripped while stirring the small stirring blade of the dropping funnel at room temperature. The dropwise addition was performed at a low speed and lasted for more than 30 minutes. After adding dropwise, use the cleaning solvent (NMP) was washed, and the residue (molar ratio of acid dianhydride and diamine (100:98)) was added dropwise.

Thereafter, an additional solvent (NMP) was added so that the solid content content in Table 5 would finally be obtained. The mixture was then 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 a transparent NMP solution of polyamide (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer (set at -20° C., the same below), and was thawed before use during evaluation.

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

The compositions of the acid dianhydride and diamine are as shown in Tables 5 to 9, and the usage amount of the polymerization solvent is changed accordingly (that is, the amount is adjusted to become twice the mass of the acid dianhydride or diamine). , and further for Examples 5-3 to 5-9, 6-5 to 6-9, 7-4, 8-1, and 8-2, the above "heat to 70°C and stir for 4 hours" was changed to "heat to 70°C and stir for 4 hours." 40°C and stir for 12 hours." For Examples 5-7, 6-4, and 7-4, change "Additional solvent (NMP)" to "Additional solvent (NMP and GBL) (NMP/GBL after addition becomes 100/100 (w/w) method)", except that it is the same as Example 5-1. The solid content amounts shown in Tables 5 to 9 were adjusted to the values shown in the tables by changing the amount of the additional solvent. Furthermore, in Examples 5-8, 5-9, 6-6~6-9, the weight average molecular weight of the reaction time extended after "stirring for 12 hours" was further measured, and the results were compared with those after stirring for 12 hours. has not increased.

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

Comparative Examples 6-1, 7-1, and 8-1~8-2 change the NMP amount of Comparative Example 5-1 to 664g (Comparative Example 6-1), 718g (Comparative Example 7-1), and 401g ( Comparative Example 8-1), 344g (Comparative Example 8-2), except that the compositions of the acid dianhydride and diamine are as shown in Tables 6 to 8, and Comparative Example 5-1 Proceed similarly. Comparative Examples 6-2 to 6-6 were performed in the same manner as Comparative Example 6-1 except that the NMP amount was changed to the solid content content in Table 6. Comparative Examples 7-2 to 7-6 were changed. Except that the NMP amount was set to the solid content content in Table 7, the same procedure as Comparative Example 7-1 was performed. Comparative Examples 7-7 and 7-8 change the NMP amount from 718g to 215g (Comparative Example 7-7) and 163g (Comparative Example 7-8) respectively, and set the compositions of acid dianhydride and diamine as shown in Table 7 Except that "stirring for 4 hours" was changed to "stirring for 3 hours", the same procedure as Comparative Example 7-1 was performed.

<Comparative Example 9-1>

Into a 3L separable flask with a stirring rod, NMP (495g) was added while introducing nitrogen gas, and TFMB (30.9g) as the diamine was added while stirring, and then BPAF (9,9-) was added as the acid dianhydride. Bis(3,4-dicarboxyphenyl)azidic anhydride) (45.8g) and both terminal amine modified methylphenyl polysiloxane oil were added to X-22-1660B-3 (10.56g) (acid dianhydride , molar ratio of diamine (100:99)). Next, use an oil bath to raise the temperature to 80° C. and stir for 4 hours. Then, remove the oil bath and return to room temperature to obtain a transparent NMP solution of polyamide (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer and thawed before use during evaluation.

<Comparative Examples 9-2~9-3>

The amounts of NMP were changed from 495g to 438g (Comparative Example 9-2) and 374g (Comparative Example 9-3) respectively, and the compositions of acid dianhydrides and diamines were as shown in Table 9. 9-1 proceeds similarly.

<Example 9-1>

Into a 3L detachable flask with a stirring rod, add the diamine while introducing nitrogen gas. TFMB (31.3g), and NMP (63g) which is twice the total mass of the diamine.

Next, a dropping funnel was installed in the separable flask, and while nitrogen gas was introduced into the dropping funnel, BPAF (45.8 g) as an acid dianhydride and NMP (92 g), which was twice the mass of the acid dianhydride, were added. Then, stir at room temperature using a small stirring blade.

Then, another dropping funnel was installed in the above-mentioned separable flask, and nitrogen gas was introduced into the dropping funnel while adding both terminal amine modified methylphenyl polysiloxane oil X-22-1660B-3 (10.56g). NMP (21g) with twice the mass of the polysiloxane oil. Then, stir at room temperature using a small stirring blade.

Then, while stirring the diamine solution in the separable flask, the acid dianhydride solution was started to be dripped while stirring the small stirring blade of the dropping funnel at room temperature. The dropwise addition was performed at a low speed and lasted for more than 30 minutes. After the dropwise addition, the mixture was washed with a cleaning solvent (NMP), and the residue (molar ratio of acid dianhydride and diamine (100:100)) was added dropwise.

Thereafter, an additional solvent (NMP) was added so that the solid content content in Table 9 would finally be obtained. The mixture was then 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 a transparent NMP solution of polyamide (hereinafter also referred to as varnish). The obtained varnish was stored in a freezer (set at -20° C., the same below), and was thawed before use during evaluation.

<Examples 9-2, 9-3>

The compositions of the acid dianhydride and diamine were as shown in Table 9, and the usage amount of the polymerization solvent was changed accordingly (that is, adjusted so that the amount becomes twice the mass of the acid dianhydride or diamine), except that Otherwise, it was carried out in the same manner as in Example 9-1. The solid content 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 3L separable flask with a stirring rod, NMP (246g) was added while introducing nitrogen gas, and while stirring, 4,4'-DAS (14.4g), TFMB (12.4g), and both ends of the diamine were added. Amine-modified methylphenyl polysiloxane oil (10.56g), and then add PMDA (15.3g) and BPDA (8.8g) as acid dianhydride (molar ratio of acid dianhydride and diamine (100:99) ). Next, use an oil bath to raise the temperature to 70°C and stir for 8 hours. Then remove the oil bath and return to room temperature to obtain a transparent NMP solution of polyamide. The obtained varnish was stored in a freezer (set at -20° C., the same below), and was thawed before use during evaluation.

<Examples 10-2~10-5>

The amount of NMP was changed from 246g to 225g (Example 10-2), 242g (Example 10-3), 185g (Example 10-4), and 201g (Example 10-5). Except that the composition of the amine was as shown in Table 10, it was carried out in the same manner as in Example 10-1.

Table 10 shows the evaluation results.

[Industrial availability]

The resin composition of the present invention can be suitably used for flexible devices (such as flexible substrates), especially flexible displays. For example, the resin composition of the present invention can be suitably used to form transparent substrates for display devices such as liquid crystal displays, organic electroluminescent displays, field emission displays, and electronic paper. More specifically, the resin composition of the present invention can be used to form substrates for thin film transistors (TFTs), color filter substrates, transparent conductive films (ITO, Indium Thin Oxide) substrates, etc.

2a‧‧‧Lower base plate

2b‧‧‧Sealing substrate

25‧‧‧Organic EL Structure Department

250a‧‧‧Organic EL element that emits red light

250b‧‧‧Organic EL element that emits green light

250c‧‧‧Organic EL device that emits blue light

251‧‧‧Partition Wall (Tower)

252‧‧‧Lower electrode (anode)

253‧‧‧hole transport layer

254‧‧‧Light-emitting layer

255‧‧‧Upper electrode (cathode)

256‧‧‧TFT

257‧‧‧Contact hole

258‧‧‧Interlayer insulation film

259‧‧‧Lower electrode

261‧‧‧Hollow part

Claims (21)

A resin composition comprising the following formula (1):

{In the formula, R ₁ independently represents a divalent organic group when there are a plurality of R 1 s, and at least one of R _1s is the following formula (2):

The group represented, R ₂ independently represents a tetravalent organic group when there are plural, n is a positive integer, the polyimide precursor and solvent of the structure represented by }, and the above-mentioned polyimide precursor The weight average molecular weight of the body is 110,000~250,000, the solid component content of the above-mentioned resin composition is 10~25% by mass, and the above-mentioned polyimide precursor is tetracarboxylic dianhydride and 4,4'-diamine. A copolymer of one or more diamines in the group consisting of diphenyl terine and 3,3'-diaminodiphenyl terine, the above resin is measured using a viscometer with a temperature regulator at 23°C When the viscosity of the composition is determined, the shear rate dependence (TI) expressed by the following formula is 0.9 to 1.1, TI = ηa/ηb{where, eta (mPa.s) is the rotation speed a ( The viscosity at rpm), etab (mPa.s) is the viscosity of the resin composition at the measured rotation speed b (rpm), where a* 10=b}. A resin composition comprising the following formula (1):

{In the formula, R ₁ independently represents a divalent organic group when there are a plurality of them, R ₂ independently represents a tetravalent organic group when there is a plurality of them, and n is a positive integer} represents the structure, And the following formula (3):

{In the formula, each of R ₃ and R ₄ independently represents a monovalent aliphatic hydrocarbon group with 1 to 5 carbon atoms or a monovalent aromatic group with 6 to 10 carbon atoms when there are plural, and m It is a polyimide precursor and a solvent having a structure represented by an integer from 1 to 200, and the weight average molecular weight of the polyimide precursor is 160,000 to 250,000, and the solid content of the resin composition is 10 ~25 mass%, when the viscosity of the above-mentioned resin composition is measured at 23°C using a viscometer equipped with a temperature regulator, the shear rate dependence (TI) represented by the following formula is 0.9~1.1, TI=ηa/ ηb{In the formula, ηa (mPa.s) is the viscosity of the resin composition under the measured rotation speed a (rpm), etab (mPa.s) is the viscosity of the resin composition under the measured rotation speed b (rpm), where , a* 10=b}. The resin composition of claim 1 or 2, wherein the resin composition is a resin composition for slot coating. The resin composition of claim 1 or 2, wherein the polyimide precursor system includes a copolymer of pyromellitic dianhydride, tetracarboxylic dianhydride and diamine. The resin composition of claim 1 or 2, wherein the polyimide precursor system includes a copolymer of 3,3',4,4'-biphenyl tetracarboxylic dianhydride, tetracarboxylic dianhydride and diamine. The resin composition of claim 1 or 2, wherein the polyimide precursor is a copolymer of tetracarboxylic dianhydride and diamine, and the above tetracarboxylic dianhydride is composed of pyromellitic dianhydride and 3,3 The molar ratio of ',4,4'-biphenyltetracarboxylic dianhydride 20:80~80:20 includes the above-mentioned pyromellitic dianhydride and the above-mentioned 3,3',4,4'-biphenyltetracarboxylic acid dianhydride. The resin composition of claim 2, wherein the polyimide precursor is tetracarboxylic dianhydride, and is selected from the group consisting of 4,4'-diaminodiphenylsulfone and 3,3'-diaminodiphenyl A copolymer of one or more diamines from the group consisting of benzene, 2,2'-bis(trifluoromethyl)benzidine and 9,9-bis(4-aminophenyl)benzidine. The resin composition of claim 1, wherein the weight average molecular weight of the polyimide precursor is 160,000~220,000. The resin composition of claim 1 or 2, wherein the resin composition is for flexible devices resin composition. The resin composition of claim 1 or 2, wherein the resin composition is a resin composition for flexible displays. A polyimide film, which is a cured product of the resin composition according to any one of claims 1 to 10. For example, the polyimide film of claim 11, wherein the thickness direction retardation (Rth) calculated as a film thickness of 10 μm is 300 or less, and/or the yellowness (YI) calculated as a film thickness of 10 μm is less than 20. A flexible device comprising the polyimide film of claim 11 or 12. A flexible display comprising the polyimide film of claim 11 or 12. The flexible display according to claim 14, wherein the polyimide film is disposed at a portion that is visible when the flexible display is viewed from the outside. A method for manufacturing a polyimide film, which includes the following steps: a coating step, which coats the resin composition of any one of claims 1 to 10 on the surface of the support; a film forming step, which heats The resin composition is used to form a polyimide film; and a peeling step is performed to peel the polyimide film from the support. The method for manufacturing a polyimide film according to claim 16, wherein the coating step includes a slit coating operation on the resin composition. The method for manufacturing a polyimide film according to claim 16 or 17, which further includes an irradiation step of irradiating the polyimide film with laser from the support side before the peeling step. A method for manufacturing a display, which includes the following steps: a coating step, which coats the resin composition according to any one of claims 1 to 10 on the surface of the support; a film forming step, which heats the above resin composition and forming a polyimide film; an element forming step of forming an element on the polyimide film; and a peeling step of peeling off the polyimide film on which the element is formed from the support. The manufacturing method of a display according to claim 19, wherein the coating step includes a slit coating operation on the resin composition. The method of manufacturing a display according to claim 19 or 20, wherein the polyimide film is disposed at a portion that is visually recognized when the display is viewed from the outside.