WO2021106627A1 - Polyimide, polyimide resin film, multilayer body and flexible device - Google Patents

Abstract

The present invention provides a polyimide which contains a specific structural unit, and which is characterized in that with respect to the IR spectrum of a resin film formed of this polyimide and having a thickness of 10 μm, if Y is the maximum peak intensity present within the range of from 1,450 to 1,550 cm-1 and Z is the maximum peak intensity present within the range of from 3,400 to 3,700 cm-1, Y and Z satisfy formula 0.1 ≤ Z/Y ≤ 0.4; and this polyimide has good transparency, oxidation resistance and laser releasability from a supporting substrate, while having low in-plane/out-of-plane birefringence, and enables the achievement of a polyimide resin film having excellent flexibility and a flexible device.

Description

Polyimide, polyimide resin film, laminate and flexible device

The present invention relates to polyimides, polyimide resin films, laminates and flexible devices.

Organic film is more flexible than glass, is hard to break, and is lightweight. Recently, there has been an active movement to make flat panel displays flexible by replacing the substrate of flat panel displays with organic films.

Examples of the resin used for the organic film include polyester, polyamide, polyimide, polycarbonate, polyether sulfone, acrylic, epoxy, cycloolefin polymer and the like. Of these, polyimide is a highly heat-resistant resin and is therefore suitable as a display substrate. However, general polyimide resins are colored brown or yellow due to high aromatic ring density, have low transmittance in the visible light region, and are difficult to use in fields where transparency is required.

In response to the problem of improving the transparency of such a polyimide resin, Patent Document 1 states that a polyimide obtained from an alicyclic acid dianhydride and various aromatic diamines or alicyclic diamines has high transparency. , Has low birefringence.

Further, Patent Document 2 discloses a method for obtaining a flexible touch panel by using a transparent polyimide resin film obtained by firing in air.

Japanese Unexamined Patent Publication No. 11-080350 International Publication No. 2018/84067

However, the polyimide described in Patent Document 1 has a low oxidation resistance, and has a problem that it easily turns yellow due to thermal oxidation when heated in an air atmosphere. Further, when a display is manufactured on an organic film, a process in which an organic film is formed on a support substrate, an electronic device is formed on the organic film, and then the organic film is peeled off from the support substrate is common. In this peeling process, the polyimide described in Patent Document 1 has a problem that the irradiation energy required for peeling is high and the laser peeling property is poor.

Further, Patent Document 2 discloses that a transparent polyimide resin film can be obtained by firing in air for 30 minutes. However, since the transparent polyimide resin film described in Patent Document 2 has a slightly low mechanical strength, there is a problem that the polyimide resin film is easily broken in the above-mentioned peeling process. Further, there is a problem that the bending resistance of the polyimide resin film is small.

An object of the present invention is to provide a polyimide and a polyimide resin film having good transparency, oxidation resistance, laser peeling property from a support substrate, low in-plane / out-of-plane birefringence, and excellent flexibility. ..

In order to solve the above-mentioned problems and achieve the object, the present invention presents the polyimide structural unit A represented by the following formula (1), the polyimide structural unit B represented by the following formula (2), and the following formula. It is a polyimide containing the polyimide structural unit C represented by (3), and the maximum peak intensity existing in the range of ^{1450 to 1550 cm -1} in the IR spectrum when the polyimide is made into a resin film having a thickness of 10 μm. Y is a polyimide characterized by satisfying the following formula, where Z is the maximum peak intensity existing in the range of 3400 to 3700 cm ^-1.
Equation) 0.1 ≤ Z / Y ≤ 0.4

(X ¹ represents a direct bond or an oxygen atom. X ² represents an oxygen atom, -C (CF ₃ ) _2- , -C (CH ₃ ) _2- or -Si (CH ₃ ) _2-. ³ represents direct binding, -SO _2- , -C (CH ₃ ) _2- or -C (CF ₃ ) _2- ).

According to the present invention, it is possible to provide a polyimide and a polyimide resin film having good transparency, oxidation resistance, laser peeling property from a support substrate, low in-plane / out-of-plane birefringence, and excellent flexibility. .. The polyimide and polyimide resin film of the present invention can be used for flexible devices such as liquid crystal displays, organic EL displays, touch panels, color filters, electronic paper, micro LED displays and other display devices, solar cells, CMOS and other light receiving devices, transparent antennas and the like. It can be suitably used as a flexible substrate for a communication device or the like. By using such a flexible substrate, it is possible to manufacture a highly reliable flexible device.

IR spectrum of the polyimide resin film of Example 3 (2000-4000 cm ^-1 ) IR spectrum of the polyimide resin film of Example 3 (1480-1510 cm ^-1 ) IR spectrum of the polyimide resin film of Comparative Example 1 (2000 to 4000 cm ^-1 ) IR spectrum of the polyimide resin film of Comparative Example 1 (1480-1510 cm ^-1 ) IR spectrum of the polyimide resin film of Comparative Example 2 (2000 to 4000 cm ^-1 ) IR spectrum of the polyimide resin film of Comparative Example 2 (1480-1510 cm ^-1 )

Hereinafter, embodiments of the polyimide, the polyimide resin film, the laminate, and the flexible device according to the present invention will be described in detail together with drawings. The present invention is not limited to the following embodiments.

<Polyimide>
The polyimide according to the embodiment of the present invention is represented by the polyimide structural unit A represented by the following formula (1), the polyimide structural unit B represented by the following formula (2), and the following formula (3). It is a polyimide containing a polyimide structural unit C, and in the IR spectrum when the polyimide is used as a resin film having a thickness of 10 μm, the maximum peak intensity existing in the range of ^{1480 to 1510 cm -1 is Y, 3400 to 3700 cm -1.} When the maximum peak intensity existing in the range of is Z, the following equation is satisfied.

Formula) 0.1 ≤ Z / Y ≤ 0.4

X ¹ represents a direct bond or an oxygen atom. X ² represents an oxygen atom, -C (CF ₃ ) _2- , -C (CH ₃ ) _2- or -Si (CH ₃ ) _2- . X ³ represents direct binding, -SO _2- , -C (CH ₃ ) _2- or -C (CF ₃ ) _2- .

In IR spectrum, in the region of 1480 ~ 1510 cm ^-1 ring carbon of a monocyclic aromatic hydrocarbon - appeared absorption by skeletal vibration due to the carbon stretching, the intermolecular hydrogen bonds in the region of 3400 ~ 3700 cm ^-1 It is considered that absorption due to the formed OH expansion and contraction appears. Therefore, Z / Y represents the intensity ratio of the peak derived from the intermolecular hydrogen bond to the peak intensity derived from the monocyclic aromatic hydrocarbon.

When Z / Y is less than 0.1, the intermolecular hydrogen bond is weak, so that the polyimide resin film is easily broken when stress is applied from the outside. If it is larger than 0.4, the intermolecular hydrogen bond is too strong, and it is considered that the stress cannot be relaxed inside the polyimide resin film when stress is applied to the polyimide resin film from the outside, and the film becomes brittle. When Z / Y is 0.1 or more and 0.4 or less, a polyimide having good flexibility can be obtained.

The polyimide according to the embodiment of the present invention contains, for example, 5 mol% or more and 95 mol% or less of a diamine having a sulfonyl group in all the diamine residues contained in the polyimide, and the curing conditions for imidization are satisfied. When the heating temperature is higher than 230 ° C. and the heating time is 1 hour or more, the Z / Y tends to be 0.1 or more and 0.4 or less.

Since the sulfonyl group has properties as a hydrogen bond acceptor, it forms a hydrogen bond with a hydrogen bond donor such as an amino group or a hydroxyl group existing in a polyimide molecule, for example. Therefore, Z increases according to the content of the diamine having a sulfonyl group.

On the other hand, since the peak intensity of Y is determined by the content of the monocyclic aromatic ring, the maximum peak intensity of general aromatic polyimide is almost determined. Therefore, by adjusting Z, it is possible to adjust Z / Y to 0.1 or more and 0.4 or less.

Further, when the curing conditions for imidization are the above conditions, the solvent contained in the polyimide film is sufficiently removed and the imidization reaction proceeds sufficiently, so that the polyimide molecules are packed together. .. It is believed that this will result in the formation of more hydrogen bonds between the polyimide molecules.

The polyimide according to the embodiment of the present invention is excellent in mechanical strength and flexibility by containing the polyimide structural unit A, and can improve chemical resistance and lower the birefringence by containing the polyimide structural unit B. By including the polyimide structural unit C, transparency and laser peelability can be improved without deteriorating mechanical properties. The polyimide structural unit A is preferably a structural unit A'represented by the following formula (4), and the polyimide structural unit B is preferably a structural unit B'represented by the following formula (5), and has a polyimide structure. The unit C is preferably the structural unit C'represented by the following formula (6). In formula (4), X ¹ represents a direct bond or an oxygen atom.

Further, since the polyimide structural units A, B, and C all have a structure having excellent oxidation resistance, yellowing due to thermal oxidation is unlikely to occur even when heated in an atmospheric atmosphere. Therefore, by including all of the polyimide structural units A, B, and C, transparency, oxidation resistance, laser peelability from the support substrate are good, in-plane / out-of-plane birefringence is low, and flexibility is excellent. Polyimide can be obtained.

From the viewpoint of further enhancing the oxidation resistance, the total amount of the polyimide structural units A, B and C is preferably 80 mol% or more, more preferably 90 mol% or more of the total polyimide structural units. The total polyimide structural unit is all the structural units constituting the polyimide. When the polyimide contains a structural unit other than the structural units A, B and C, the total amount (molar basis) of the structural units A, B and C and the other structural units is the total polyimide structural unit.

Further, when the ratios (molar standard) of each of the polyimide structural units A, B, and C are (i), (ii), and (iii), preferably (i) :( ii) :( iii) = 5 to 80. 1 to 70: 1 to 70, more preferably (i) :( ii) :( iii) = 10 to 70: 5 to 60: 5 to 60, and particularly preferably (i) :( ii). : (Iii) = 15-60: 15-50: 15-55.

The polyimide of the present invention may contain other structural units as long as the effects of the present invention are not impaired. Examples of other structural units include polyimide (a structural unit other than structural units A, B and C) which is a dehydrated ring-closed body of polyamic acid, polybenzoxazole which is a dehydrated ring-closed body of polyhydroxyamide, and the like. As an example of another structural unit, a polyimide structural unit represented by the general formula (7) (however, a structural unit other than the structural units A, B and C) can be mentioned.

R ¹ indicates a tetravalent tetracarboxylic acid residue, and R ² indicates a divalent diamine residue.

Examples of the acid dianhydride used for R ¹ include aromatic dianhydrides, alicyclic acid dianhydrides, and aliphatic dianhydrides described in International Publication No. 2017/099183. Of these, an acid dianhydride giving the structure represented by the formula (8) and an acid dianhydride giving the structure represented by the formula (9) are preferable. By including the structure represented by the general formula (8) in R ^{1, a polyimide having a high glass transition temperature can be obtained.} Further, since R ¹ includes a structure represented by the general formula (9), it is possible to obtain a polyimide having high transparency, small in-plane / out-of-plane birefringence, and a high glass transition temperature. These other acid dianhydrides can be used alone or in combination of two or more.

Examples of the diamine compound used for R ² include aromatic diamine compounds, alicyclic diamine compounds, and aliphatic diamine compounds described in International Publication No. 2017/099183. Among them, a diamine having a structure represented by any of the formulas (10) to (15) is preferable because it is possible to achieve both transparency and heat resistance. These aromatic diamine compounds, alicyclic diamine compounds, or aliphatic diamine compounds can be used alone or in combination of two or more.

Further, the polyimide of the present invention may contain a triamine skeleton. Triamine has three amino groups and forms a branched molecular chain by binding with three tetracarboxylic dianhydride components, so that a polyimide resin film having excellent mechanical strength can be obtained. Is. A polyimide precursor having such a triamine skeleton can be obtained by using a triamine compound as one of the polymerization components.

Among specific examples of triamine compounds, those having no aliphatic group include 2,4,4'-triaminodiphenyl ether (TAPE) and 1,3,5-tris (4-aminophenoxy) benzene (1,3). , 5-TAPOB), 1,2,3-tris (4-aminophenoxy) benzene (1,2,3-TAPOB), tris (4-aminophenyl) amine, 1,3,5-tris (4-amino) Phenyl) benzene, 3,4,4'-triaminodiphenyl ether and the like can be mentioned. Specific examples of the triamine compound having an aliphatic group include tris (2-aminoethyl) amine (TAEA) and tris (3-aminopropyl) amine. Of these, it is preferable to use a component that does not have an aliphatic group and is not easily thermally decomposed. That is, 2,4,4'-triaminodiphenyl ether (TAPE), 1,3,5-tris (4-aminophenoxy) benzene (1,3,5-TAPOB), 1,2,3-tris (4-) It is preferable to use aminophenoxy) benzene (1,2,3-TAPOB) or the like.

Further, the polyimide of the present invention may have a structure represented by the general formula (16) in ^{R 1} and / or R ^2. Since the polyimide has a structure represented by the general formula (16), the residual stress generated between the polyimide resin film obtained by using the polyimide resin film and the support substrate can be reduced. Therefore, it is possible to suppress the warp of the substrate when the polyimide resin film is formed on the support substrate.

In formula (16), R ³ and R ⁴ each independently represent a monovalent organic group having 1 to 20 carbon atoms. x represents an integer from 3 to 200.

Examples of the monovalent organic group having 1 to 20 carbon atoms in R ³ and R ⁴ include a hydrocarbon group, an amino group, an alkoxy group, an epoxy group and the like. Examples of the hydrocarbon group in R ³ and R ⁴ include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms.

The alkyl group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 10 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, t-. Examples thereof include a butyl group, a pentyl group, and a hexyl group. The cycloalkyl group having 3 to 20 carbon atoms is preferably a cycloalkyl group having 3 to 10 carbon atoms, and specific examples thereof include a cyclopentyl group and a cyclohexyl group. The aryl group having 6 to 20 carbon atoms is preferably an aryl group having 6 to 12 carbon atoms, and specific examples thereof include a phenyl group, a tolyl group, and a naphthyl group.

Examples ^{of the alkoxy group in R 3} and R ⁴ include a methoxy group, an ethoxy group, a propoxy group, an isopropyloxy group, a butoxy group, a phenoxy group, a propenyloxy group and a cyclohexyloxy group.

^{R 3} and R ⁴ in the general formula (16) are preferably a monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms or an aromatic group having 6 to 10 carbon atoms. This is because the obtained polyimide film has both high heat resistance and low residual stress. Here, the monovalent aliphatic hydrocarbon having 1 to 3 carbon atoms is preferably a methyl group, and the aromatic group having 6 to 10 carbon atoms is preferably a phenyl group.

X in the general formula (16) is an integer of 3 to 200, preferably an integer of 5 to 100, more preferably 5 to 70, and even more preferably an integer of 8 to 50. When x is within the above range, the residual stress of the polyimide can be reduced and the warpage of the substrate can be reduced. In addition, it is possible to prevent the polyimide film from becoming cloudy and the mechanical strength of the polyimide film from being lowered.

The polyimide precursor resin having the structure represented by the general formula (16) can be obtained by using the silicone compound represented by the following general formula (17) as a monomer component.

In the formula (17), the plurality of R ^5s are independently single-bonded or divalent organic groups having 1 to 20 carbon atoms, and the plurality of R ⁶ , R ⁷ and R ⁸ are independently carbons. It is a monovalent organic group of numbers 1 to 20, and L ¹ , L ² and L ³ are independently amino groups, acid anhydride groups, carboxyl groups, hydroxy groups, epoxy groups, mercapto groups, and R ^{10 respectively.} It is one group selected from the group consisting of. R ¹⁰ is a monovalent organic group having 1 to 20 carbon atoms. y is an integer of 3 to 200, and z is an integer of 0 to 197.

In the above, "single bond" is synonymous with "direct bond". That is, it is a state in which ^{L 1} or L ^{2 and Si are directly bonded.}

The polyimide of the present invention can be obtained by imide ring closure of a polyimide precursor containing a structural unit represented by the following formula (18), a structural unit represented by (19) and a structural unit represented by (20). ..

In formulas (18) to (20), Y ¹ to Y ⁶ independently represent a hydrogen atom, a monovalent organic group having 1 to 10 carbon atoms, or a monovalent alkylsilyl group having 1 to 10 carbon atoms. .. R ⁹ represents a tetravalent tetracarboxylic dian residue represented by the formula (21), and X ² in the formula (21) is an oxygen atom, -C (CF ₃ ) _2- , -C (CH ₃ ). ₂ - or -Si _{(CH 3) 2} - represents a. R ¹⁰ represents a divalent diamine residue represented by the formula (22), and X ¹ in the formula (22) represents a direct bond or an oxygen atom. R ¹¹ represents a divalent diamine residue represented by the formula (23), and X ³ in the formula (23) is a direct bond, -SO _2- , -C (CH ₃ ) _2- or -C ( CF ₃ ) Represents _2-. R ¹² represents a divalent diamine residue represented by the formula (24).

The imidization method is not particularly limited, and examples thereof include thermal imidization and chemical imidization. Above all, thermal imidization is preferable from the viewpoint of heat resistance of the polyimide resin film and transparency in the visible light region.

Polyimide precursor resins such as polyamic acid, polyamic acid ester, and polyamic acid silyl ester can be synthesized by reacting a diamine compound with an acid dianhydride or a derivative thereof. Examples of the derivative include tetracarboxylic acid of the acid dianhydride, mono, di, tri, tetraester, and acid chloride of the tetracarboxylic acid, and specific examples thereof include methyl group, ethyl group, and n-propyl. Examples thereof include structures esterified with a group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group and the like. The reaction method of the polymerization reaction is not particularly limited as long as the desired polyimide precursor resin can be produced, and a known reaction method can be used.

As a specific reaction method, a predetermined amount of all diamine components and a solvent are charged into a reactor and dissolved, and then a predetermined amount of an acid dianhydride component is charged, and the temperature at room temperature (25 ° C.) to 80 ° C. is 0. Examples thereof include a method of stirring for 5 to 30 hours.

The solvent used is not particularly limited, and known solvents can be used. For example, as this solvent, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-dimethylisobutylamide, 3-methoxy-N, N-dimethylpropionamide, 3- Butoxy-N, N-dimethylpropionamide, γ-butyrolactone, ethyl lactate, 1,3-dimethyl-2-imidazolidinone, N, N'-dimethylpropylene urea, 1,1,3,3-tetramethylurea, Examples thereof include dimethylsulfoxide, sulfolane, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, water, and the solvent described in International Publication No. 2017/099183. These can be used alone or in combination of two or more. Among these, γ-butyrolactone is preferable from the viewpoint of the transparency of the obtained polyimide film.

The weight average molecular weight (Mw) of the polyimide precursor is preferably 10,000 to 1,000,000, more preferably 30,000 to 500,000, still more preferably 65,000 to 300,000. is there.

When the weight average molecular weight of the polyimide precursor is within the above range, it is possible to increase the strength of the obtained polyimide without deteriorating the flatness of the obtained coating film.

The weight average molecular weight, number average molecular weight and molecular weight distribution are determined by TOSOH DP-8020 type GPC device (guard column: TSK guard column ALPHA column: TSK-GEL α-M, developing solvent: N, N'-dimethylacetamide ( DMAc), 0.05M-LiCl, 0.05% phosphoric acid addition).

Both ends of the polyimide precursor may be sealed with an end sealant in order to adjust the molecular weight to a preferable range. Examples of the terminal encapsulant that reacts with the acid dianhydride include monoamines and monohydric alcohols. Examples of the terminal encapsulant that reacts with the diamine compound include acid anhydrides, monocarboxylic acids, monoacid chloride compounds, monoactive ester compounds, dicarbonates, vinyl ethers and the like. In addition, various organic groups can be introduced as terminal groups by reacting the terminal encapsulant.

The introduction ratio of the encapsulant at the end of the acid anhydride group is preferably in the range of 0.1 to 60 mol%, particularly preferably 0.5 to 50 mol% with respect to the acid dianhydride component. The introduction ratio of the encapsulant at the terminal of the amino group is preferably in the range of 0.1 to 100 mol%, particularly preferably 0.5 to 70 mol% with respect to the diamine component. A plurality of different end groups may be introduced by reacting a plurality of end sealants.

The end-capping agent introduced into the polyimide precursor can be easily detected by the following method. For example, a polymer into which an end-capping agent has been introduced is dissolved in an acidic solution, decomposed into an amine component and an acid anhydride component, which are constituent units of the polymer, and this is measured by gas chromatography (GC) or NMR. The end sealant can be easily detected. In addition, the polymer into which the terminal encapsulant has been introduced ^{can be easily detected by direct thermal decomposition gas chromatography (PGC), infrared spectrum, 1} H-NMR spectrum measurement and ¹³ C-NMR spectrum measurement.

The method for producing the polyimide by imidizing the polyimide precursor obtained by the above method is not particularly limited, and a known reaction method can be used. Specific examples of the reaction method include a method of stirring the polyamide precursor solution obtained as described above at 100 to 200 ° C. for 0.5 to 30 hours.

<Polyimide resin composition>
The polyimide according to the embodiment of the present invention can be mixed with an appropriate component to obtain a polyimide resin composition. The components that may be contained in the polyimide resin composition are not particularly limited, and examples thereof include a solvent, an ultraviolet absorber, a heat crosslinker, an inorganic filler, a surfactant, an internal release agent, and a colorant.

(solvent)
The polyimide resin composition according to the embodiment of the present invention may contain a solvent. As the solvent, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-dimethylisobutylamide, 3-methoxy-N, N-dimethylpropionamide, 3-butoxy- N, N-dimethylpropionamide, γ-butyrolactone, ethyl lactate, 1,3-dimethyl-2-imidazolidinone, N, N'-dimethylpropylene urea, 1,1,3,3-tetramethylurea, dimethylsulfoxide , Sulfolane, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, water, and the solvent described in International Publication No. 2017/099183. The solvent contained in the polyimide resin composition according to the embodiment of the present invention may be one kind or a plurality of kinds. Among these, γ-butyrolactone is preferably contained, and an amide solvent is preferably not contained, from the viewpoint of obtaining the above-mentioned effect with the transparency of the obtained polyimide and the inclusion of a small amount of the polyimide.

(UV absorber)
The polyimide resin composition according to the embodiment of the present invention may contain an ultraviolet absorber. Since the polyimide resin composition contains an ultraviolet absorber, it is greatly suppressed that physical properties such as transparency and mechanical properties of the polyimide are deteriorated when exposed to sunlight for a long period of time.

The ultraviolet absorber is not particularly limited and a known one can be used. Benzotriazole-based compounds, benzophenone-based compounds, and triazine-based compounds are preferably used from the viewpoint of transparency and non-coloring property.

The ultraviolet absorber is preferably a compound having a molecular weight of 1000 or less. When the ultraviolet absorber is a low molecular weight compound having a molecular weight of 1000 or less, the light resistance of the resin film can be improved without increasing the haze of the polyimide resin film.

The content of the ultraviolet absorber in the polyimide resin composition is preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the polyimide resin. When the polyimide resin composition contains an ultraviolet absorber within the above range, the light resistance (resistance to light, particularly ultraviolet light) can be improved without impairing the transparency of the resin.

(Thermal crosslinker)
The polyimide resin composition according to the embodiment of the present invention may contain a thermal cross-linking agent. As the thermal cross-linking agent, an epoxy compound or a compound having at least two alkoxymethyl groups or methylol groups is preferable. By having at least two of these groups, a crosslinked structure is formed by a condensation reaction with a resin and a homologous molecule, and the mechanical strength and chemical resistance of the cured film after heat treatment can be improved.

The content of the heat-crosslinking agent in the polyimide resin composition is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the polyimide resin. When the polyimide resin composition contains a thermal cross-linking agent within the above range, it is possible to improve the mechanical properties and chemical resistance of the resin without impairing the transparency of the resin.

(Coupling agent)
To the polyimide resin composition according to the embodiment of the present invention, a coupling agent such as a silane coupling agent or a titanium coupling agent can be added in order to improve the adhesiveness with the base material. The content of the coupling agent in the polyimide resin composition is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the polyimide resin.

(Inorganic filler)
The polyimide resin composition according to the embodiment of the present invention may contain an inorganic filler. Examples of the inorganic filler include silica fine particles, alumina fine particles, titania fine particles, and zirconia fine particles. The shape of the inorganic filler is not particularly limited, and examples thereof include a spherical shape, an elliptical shape, a flat shape, a rod shape, and a fibrous shape.

The inorganic filler preferably has a small particle size in order to prevent light scattering. Specifically, the average particle size of the inorganic filler is preferably 0.5 to 100 nm, more preferably 0.5 to 30 nm.

The content of the inorganic filler in the polyimide resin composition is preferably 1 to 100 parts by weight with respect to 100 parts by weight of the polyimide resin. By containing the inorganic filler within the above range, the polyimide resin composition can reduce the CTE and birefringence of the polyimide resin without impairing the flexibility.

(Surfactant)
The polyimide resin composition according to the embodiment of the present invention can contain a surfactant. When the polyimide resin composition contains a surfactant, the film thickness uniformity when the polyimide resin composition is applied can be improved. Examples of the surfactant include fluorosurfactants such as Florard (trade name, manufactured by Sumitomo 3M Ltd.), Megafuck (trade name, manufactured by DIC Corporation), and Sulflon (trade name, manufactured by Asahi Glass Co., Ltd.). .. In addition, KP341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), DBE (trade name, manufactured by Chisso Co., Ltd.), Polyflow, Granol (trade name, manufactured by Kyoeisha Chemical Co., Ltd.), BYK (manufactured by BIC Chemie Co., Ltd.), etc. Includes organic siloxane surfactants. Further, acrylic polymer surfactants such as Polyflow (trade name, manufactured by Kyoeisha Chemical Co., Ltd.) can be mentioned.

The content of the surfactant in the polyimide resin composition is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the polyimide resin.

(Internal mold release agent)
The polyimide resin composition according to the embodiment of the present invention can contain an internal mold release agent. When the polyimide resin composition contains an internal mold release agent, the peelability of the polyimide resin film from the support substrate can be improved. Examples of the internal release agent include long-chain fatty acids. The content of the internal mold release agent in the polyimide resin composition is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the polyimide resin.

(Colorant)
The polyimide resin composition according to the embodiment of the present invention can contain a colorant. By adding a colorant to the polyimide resin composition, the color of the polyimide resin film can be adjusted.

As the colorant, dyes, organic pigments, inorganic pigments and the like can be used, but organic pigments are preferable from the viewpoint of heat resistance and transparency. Among them, those having high transparency and excellent light resistance, heat resistance, and chemical resistance are preferable.

<Polyimide resin film>
The polyimide resin film according to the embodiment of the present invention contains the above-mentioned polyimide. This can be obtained by molding the polyimide or polyimide resin composition into a film.

The polyimide resin film according to the embodiment of the present invention preferably contains γ-butyrolactone at 1 ppm or more and 1000 ppm or less, more preferably 5 ppm or more and 500 ppm or less, and 10 ppm or more and 300 ppm or more with respect to the weight of the polyimide resin film. Is even more preferable. When the polyimide resin film contains γ-butyrolactone in the above ratio, the mechanical peelability from the support substrate can be improved without deteriorating the characteristics of the circuit or element formed on the polyimide resin film. In addition, the stress generated at the interface between the polyimide resin film and the circuit or element formed on the polyimide resin film can be relaxed. Therefore, it is possible to improve the crack resistance when the laminated body in which the circuit or the element is laminated on the polyimide resin film is bent.

As a method for obtaining a polyimide resin film containing 1 ppm or more and 1000 ppm or less of γ-butyrolactone with respect to the weight of the polyimide resin film, for example, a polyimide precursor resin solution is prepared using γ-butyrolactone as a solvent and applied to a supporting base material. Then, a method of thermally imidizing by heating in the range of 240 ° C. to 290 ° C. for 45 to 180 minutes can be mentioned.

Further, it is preferable that the polyimide resin film according to the embodiment of the present invention does not contain an amide solvent. Since the polyimide resin film does not contain an amide solvent, it is possible to suppress yellowing during thermal imidization and improve transparency. Examples of amide-based solvents preferably not contained include N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-dimethylisobutyramide, 3-methoxy-N, N-dimethyl. Propionamide, 3-butoxy-N, N-dimethylpropionamide, 1,3-dimethyl-2-imidazolidinone, N, N'-dimethylpropyleneurea, 1,1,3,3-tetramethylurea, etc. Be done.

In the present invention, the content of the solvent contained in the polyimide resin film is a value measured by heat-desorbing GC / MS of the collected gas by putting the polyimide resin film cut into strips into a heating container and heating it. Is. The polyimide resin film according to the embodiment of the present invention preferably has a γ-butyrolactone content of 1 ppm or more and 1000 ppm or less as measured by the above measuring method, and the content of the amide solvent is not more than the detection limit (polyimide resin). It is preferably less than 1 ppm based on the weight of the film).

The glass transition temperature (Tg) of the polyimide resin film according to the embodiment of the present invention is preferably 220 ° C. or higher and 250 ° C. or lower, and more preferably 225 ° C. or higher and 245 ° C. or lower. When the Tg of the polyimide resin film is 220 ° C. or higher, deformation at the time of device production can be suppressed. Further, when the Tg of the polyimide resin film is 250 ° C. or lower, the residual stress can be reduced and the warp can be suppressed. The term "warp" as used herein refers to the degree of rounding of a laminate composed of a film and a support substrate, which is visually determined. "Residual stress" refers to the stress remaining inside the film after the resin composition is applied onto a substrate such as a glass substrate to form the film, and is a measure of the "warp" that can occur in the film. .. Specifically, it can be measured by the method described in the following examples.

Hereinafter, a method for producing a polyimide resin film using the polyimide or the composition thereof according to the embodiment of the present invention will be described.

By applying the above-mentioned resin composition of the polyimide precursor or the polyimide resin composition on the substrate, a coating film of the polyimide precursor or the polyimide resin is formed. As a method of applying the polyimide precursor or the resin composition of the polyimide resin on the substrate to form a coating film, it is applied by using a roll coating method, a spin coating method, a slit coating method, a doctor blade, a coater, or the like. The method of doing this can be mentioned. In the coating film forming step, the thickness and surface smoothness of the coating film may be controlled by repeating the coating. Above all, the slit die coating method is preferable from the viewpoint of surface smoothness and film thickness uniformity of the coating film.

The thickness of the coating film is appropriately selected according to the desired application and is not particularly limited, but is, for example, 1 to 500 μm, preferably 2 to 250 μm, and particularly preferably 5 to 125 μm. Examples of the substrate include polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, polybutylene terephthalate (PBT) film, silicon wafer, glass wafer, oxide wafer, glass substrate, Cu substrate and SUS plate. Of these, a glass substrate is preferable from the viewpoint of surface smoothness and dimensional stability during heating. As the glass constituting the glass substrate, non-alkali glass is particularly preferable from the viewpoint of dimensional stability.

Then, the coating film is dried by evaporating the solvent from the coating film on the substrate. Specifically, in this drying step, the coating film may be vacuum-dried or heat-dried, but in consideration of the transparency of the obtained polyimide resin film, it is preferable to evaporate the solvent without white turbidity. A hot plate, an oven, infrared rays, a vacuum chamber, or the like is used to dry the coating film in the drying step.

The heating temperature for drying varies depending on the type and purpose of the object to be heated such as a coating film, and it is preferable to carry out the heating in the range of room temperature to 170 ° C. for 1 minute to several hours. Room temperature is usually 20 to 30 ° C, but is preferably 25 ° C. Further, the drying step may be performed a plurality of times under the same conditions or different conditions.

In the case of the polyimide precursor resin, the polyimide precursor is imidized by performing a heating step thereafter, and a polyimide resin film is formed on the substrate. In the case of the polyimide resin, since it is already imidized, it is not necessary to perform the heating step, but by performing the heating step, the mechanical strength and heat resistance of the obtained polyimide resin film can be improved, so that the heating step is performed. Is preferable. The atmosphere of the heating step is not particularly limited, and may be air (oxygen concentration: about 21% by volume) or an inert gas such as nitrogen or argon. In particular, by heating in an air atmosphere, the surface of the polyimide resin film is partially oxidized to improve the adhesion between the polyimide resin film and the circuits and elements formed on the polyimide resin film, and the polyimide resin film and elements The atmosphere of the heating step is preferably air because the crack resistance when the laminate is bent can be improved.

Further, the time required to reach the heating temperature for the heating step is not particularly limited, and a heating method can be selected according to the heating type of the production line. For example, in an oven, a polyimide precursor or a polyimide resin coating film formed on a substrate is heated from room temperature to a heating temperature of 180 ° C. or higher and 550 ° C. or lower over 5 to 120 minutes while raising the temperature. You may. Alternatively, the polyimide precursor or the polyimide resin coating film formed on the substrate may be directly put into an oven whose temperature has been raised to 180 ° C. or higher and 550 ° C. or lower in advance and heated. Further, the polyimide precursor or the polyimide resin coating film may be heated under reduced pressure, if necessary.

In order to obtain the polyimide resin film according to the embodiment of the present invention, it is preferable to heat the polyimide precursor or the polyimide resin coating film in the range of 240 ° C. or higher and 290 ° C. or lower for 60 minutes or longer. By heating under the above conditions, it is possible to obtain a polyimide resin film having good transparency and mechanical strength.

The polyimide resin film obtained through each of the above steps can be used by peeling from the substrate, or can be used as it is without peeling. The peeling method is not particularly limited and a known method can be used. For example, a method of immersing in a chemical solution such as hydrofluoric acid or a method of irradiating the interface between the polyimide resin film and the substrate with a laser (laser peeling). There is a method of making a notch in the end with a single blade and lifting it from the end to peel it (mechanical peeling). Since the polyimide resin film of the present invention is excellent in both laser peeling property and mechanical peeling property, it is preferable to perform peeling by either laser peeling method or mechanical peeling method.

The thickness of the polyimide resin film obtained as described above is appropriately selected depending on the desired application, but is preferably 1 to 100 μm, more preferably 2 to 30 μm, and particularly preferably 3 to 20 μm. is there.

<Laminated body>
The laminate according to the embodiment of the present invention includes an insulating layer and / or a wiring layer on the polyimide resin film.

(Insulation layer)
The insulating layer preferably contains an alkali-soluble resin. Alkali-soluble in the present invention means that 0.1 g or more is dissolved at 25 ° C. in a 0.045 mass% potassium hydroxide aqueous solution (100 g). The insulating layer formed from the alkali-soluble resin is preferable because it can be patterned by photolithography, thereby forming an opening for conduction of the conductive layer. Further, the laminate according to the embodiment of the present invention preferably has an insulating layer formed of an alkali-soluble resin containing a (meth) acrylic copolymer. This is because the (meth) acrylic copolymer in the alkali-soluble resin enhances the flexibility of the insulating layer. Further, the film with a conductive layer according to the embodiment of the present invention is formed on the conductive layer from an alkali-soluble resin containing a cardo-based resin having two or more structures represented by the following structural formula (25). It is preferable to have an insulating layer. This is because the cardo-based resin enhances the hydrophobicity of the insulating layer, whereby the insulating property of the insulating layer can be improved.

Further, as the cardo-based resin having two or more structures represented by the structural formula (25), a commercially available product can be preferably used. Examples of commercially available products of this cardo-based resin include "WR-301 (trade name)" (manufactured by ADEKA), "V-259ME (trade name)" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), and "Oxol CR-TR1 (manufactured by Nippon Steel & Sumitomo Metal Corporation). "Product name", "Ogsol CR-TR2 (product name)", "Ogsol CR-TR3 (product name)", "Ogsol CR-TR4 (product name)", "Ogsol CR-TR5 (product name)", " Exol CR-TR6 (trade name) ”(above, manufactured by Osaka Gas Chemical Co., Ltd.) and the like can be mentioned.

The weight average molecular weights of the (meth) acrylic copolymer and the cardo-based resin are preferably 2,000 or more from the viewpoint of improving the coating characteristics. Further, each of these weight average molecular weights is preferably 200,000 or less from the viewpoint of improving the solubility of the insulating layer in the developing solution in the pattern formation of the insulating layer. Here, the weight average molecular weight refers to a polystyrene-equivalent value measured by GPC.

When the insulating layer contains both the (meth) acrylic copolymer and the cardo-based resin, the weight average molecular weight of the (meth) acrylic copolymer (Mw (A1)) and the weight average molecular weight of the cardo-based resin The ratio (Mw (A2) / Mw (A1)) to (Mw (A2)) is preferably 0.14 or more from the viewpoint of suppressing layer separation and forming a uniform cured film. On the other hand, this ratio (Mw (A2) / Mw (A1)) is preferably 1.5 or less, preferably 1.0 or less, from the viewpoint of suppressing layer separation and forming a uniform cured film. Is more preferable.

The insulating layer in the present invention can be formed by using an insulating composition containing an alkali-soluble resin. The content of the alkali-soluble resin contained in this insulating composition can be arbitrarily selected depending on the desired film thickness and application, but is 10% by mass or more and 70% by mass with respect to 100% by mass of the solid content. It is common to do the following.

The above insulating composition may contain an antioxidant. When the above-mentioned insulating composition contains an antioxidant, the coloring of the insulating layer can be further reduced and the weather resistance of the insulating layer can be improved. Examples of the type of antioxidant include benzotriazole, organic phosphorus, a compound having a hindered phenol structure, a compound having a hindered amine structure, and the like. Among these, by containing a compound having a phenolic hydroxyl group and / or a compound having an amino group, the adhesion between the insulating layer and the underlying layer is improved, and peeling at the time of bending is suppressed, which is preferable.

Specific examples of the compound having a benzotriazole, an organic phosphorus, and a hindered phenol structure include, but are not limited to, those described in JP-A-2019-101440. Specific examples of the compound having a hindered amine structure include, but are not limited to, those described in International Publication No. 2015/012228.

The antioxidant can be contained alone or in combination of two or more. The content of the antioxidant in the insulating layer is preferably 0.1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the solid content.

The above insulating composition further comprises a polyfunctional monomer, a curing agent, an ultraviolet absorber, a polymerization inhibitor, an adhesion improver, a solvent, a surfactant, a dissolution inhibitor, a stabilizer, a defoaming agent, and the like. It can also contain additives such as colorants.

(Conductive layer)
The conductive layer preferably has a network structure having a line width of 0.1 to 9 μm. When the conductive layer has a network structure having a line width of 0.1 to 9 μm, the conductivity and visibility of the conductive layer can be improved. The line width of the network structure of the conductive layer is more preferably 0.5 μm or more, and further preferably 1 μm or more. On the other hand, the line width of the network structure of the conductive layer is more preferably 7 μm or less, and further preferably 6 μm or less.

Further, the film thickness of the conductive layer is preferably 0.1 μm or more, more preferably 0.2 μm or more, and further preferably 0.3 μm or more. On the other hand, the film thickness of the conductive layer is preferably 5 μm or less, more preferably 3 μm or less, and further preferably 1 μm or less.

Examples of the conductive particles contained in the conductive layer include those described in International Publication No. 2018/084067, and silver particles are more preferable.

The primary particle size of the conductive particles is preferably 10 to 200 nm, more preferably 10 to 60 nm in order to form a fine conductive pattern having desired conductivity. Here, as for the primary particle size of the conductive particles, 100 particles are randomly selected by observing the cross section of the conductive layer with a scanning electron microscope, and the primary particle size of each particle is measured to obtain them. It is calculated by taking the arithmetic average value of. The particle size of the primary particles of each particle is the arithmetic mean value of the part having the longest diameter and the part having the shortest diameter in the primary particles.

The content of the conductive particles in the conductive layer is preferably 20% by mass or more from the viewpoint of improving conductivity, and preferably 95% by mass or less from the viewpoint of improving pattern processability. ..

Further, the conductive layer preferably contains 0.1 to 80% by mass of an organic compound. When the conductive layer contains 0.1% by mass or more of the organic compound, it is possible to impart flexibility to the conductive layer and further improve the bending resistance of the conductive layer. On the other hand, when the conductive layer contains 80% by mass or less of the organic compound, the conductivity can be improved.

As the organic compound contained in the conductive layer, an alkali-soluble resin is preferable. As the alkali-soluble resin, a (meth) acrylic copolymer having a carboxyl group is preferable. Here, the (meth) acrylic copolymer means a copolymer of a (meth) acrylic monomer and another monomer.

Specific examples of the (meth) acrylic monomer and other monomers include, but are not limited to, those described in International Publication No. 2018/084067.

In order to introduce a carboxyl group that imparts alkali solubility to an alkali-soluble resin, for example, (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, acid anhydrides thereof and the like can be used as described above (meth). ) A method of copolymerizing with an acrylic monomer can be mentioned.

The (meth) acrylic copolymer preferably has a carbon-carbon double bond at the side chain or the molecular terminal from the viewpoint of increasing the rate of the curing reaction. Examples of the functional group having a carbon-carbon double bond include a vinyl group, an allyl group, a (meth) acrylic group and the like.

The carboxylic acid equivalent of the alkali-soluble resin is preferably 400 to 1,000 g / mol. The carboxylic acid equivalent of the acrylic soluble resin can be calculated by measuring the acid value. Further, the double bond equivalent of the alkali-soluble resin is preferably 150 to 10,000 g / mol because both hardness and crack resistance can be compatible at a high level. The double bond equivalent of the acrylic soluble resin can be calculated by measuring the iodine value.

The weight average molecular weight (Mw) of the alkali-soluble resin is preferably 1,000 to 100,000. By setting the weight average molecular weight within the above range, good coating characteristics of the alkali-soluble resin can be obtained, and the solubility of the alkali-soluble resin in the developing solution when forming the pattern of the conductive layer is also good. Here, the weight average molecular weight of the alkali-soluble resin refers to a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

Further, the conductive layer may contain at least one of an organotin compound and a metal chelate compound. When the conductive layer contains at least one of the organotin compound and the metal chelate compound, the adhesion between the conductive layer and the gas barrier layer can be further improved. In particular, the metal chelate compound is more preferable than the organic tin compound because the effect of improving the adhesion can be obtained without imposing an environmental load. Known compounds can be used as the organotin compound and the metal chelate compound.

Further, the conductive layer may contain an antioxidant. Since the conductive layer contains an antioxidant, the weather resistance of the conductive layer can be improved. Examples of the type of antioxidant include the same types that can be contained in the above-mentioned insulating layer. Among these, by containing a compound having a phenolic hydroxyl group and / or a compound having an amino group, the adhesion between the conductive layer and the underlying layer is improved, and peeling at the time of bending is suppressed, which is preferable.

The antioxidant can be contained alone or in combination of two or more. The content of the antioxidant in the conductive layer is preferably 0.1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the solid content.

The conductive layer also has at least one of a dispersant, a photopolymerization initiator, a monomer, a photoacid generator, a thermoacid generator, a solvent, a sensitizer, a pigment and a dye having absorption in visible light, and improved adhesion. It preferably contains an agent, a surfactant, a polymerization inhibitor, an antioxidant and the like.

Further, the conductive layer in the present invention can be formed by using a conductive composition. Examples of the components contained in this conductive composition include conductive particles, alkali-soluble resins, organic tin compounds, metal chelate compounds, dispersants, photopolymerization initiators, monomers, photoacid generators, and thermoacid generators. Examples include at least one of a solvent, a sensitizer, a pigment and a dye having absorption in visible light, an adhesion improver, a surfactant, an antioxidant, a polymerization inhibitor and the like.

The conductive particles contained in the conductive composition preferably have a coating layer on at least a part of the particle surface. Thereby, the surface activity of the conductive particles can be lowered, at least one of the reaction between the conductive particles and the reaction between the conductive particles and the organic component can be suppressed, and the dispersibility of the conductive particles can be improved. .. Further, even when photolithography is used for processing the conductive layer, scattering of exposure light can be suppressed and the conductive layer can be patterned with high accuracy. On the other hand, the coating layer on the surface of the conductive particles can be easily removed by heating at a high temperature of about 150 to 350 ° C. in the presence of oxygen. As a result, the conductive particles in the conductive composition can exhibit sufficient conductivity of the conductive layer.

The coating layer on the surface of the conductive particles preferably contains at least one of carbon and a carbon compound. When the coating layer contains at least one of carbon and a carbon compound, the dispersibility of the conductive particles in the conductive composition can be further improved.

As a method of forming a coating layer containing at least one of carbon and a carbon compound on the surface of the conductive particles, for example, a reactive gas having carbon such as methane gas is brought into contact with the conductive particles by a thermal plasma method. (Method described in Japanese Patent Application Laid-Open No. 2007-138287) and the like.

<Use>
The polyimide and polyimide resin films according to the embodiment of the present invention are display devices such as liquid crystal displays, organic EL displays, touch panels, electronic papers, color filters and micro LED displays, solar cells, light receiving devices such as CMOS, transparent antennas and the like. It can be used as a flexible substrate in a flexible device such as a communication device. In particular, since the polyimide resin described in the present application has excellent oxidation resistance and good transparency, high light resistance reliability and transparency are required for flexible touch panels, flexible solar cells, and flexible transparent antennas. It can be suitably used in each application.

The manufacturing process of the flexible device includes a process of forming circuits and elements necessary for a display device and a light receiving device on a polyimide resin film formed on a substrate. For example, a circuit or element required for a device can be formed on a polyimide resin film by a known method. As described above, the solid polyimide resin film on which the circuit or the element is formed on the surface can be peeled off from the substrate by using a known method such as laser peeling or mechanical peeling to obtain a flexible device.

Hereinafter, the present invention will be described with reference to examples and the like, but the present invention is not limited to these examples.

<Material>
(Acid dianhydride)
ODPA: 4,4'-oxydiphthalic anhydride 6FDA: 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride PMDA: pyromellitic dianhydride BPDA: 3,3', 4, 4'-Biphenyltetracarboxylic dianhydride (diamine compound)
3,3'-DDS: 3,3'-diaminodiphenyl sulfone BAPS-m: Bis [4- (3-aminophenoxy) phenyl] sulfone TFMB: 2,2'-bis (trifluoromethyl) benzidine 6FODA: 2, 2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl ether HFBAPP: 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane 4,4'-DDS: 4,4'- Diaminodiphenyl sulfone (triamine compound)
TAPOB: 1,3,5-tris (4-aminophenoxy) benzene (solvent)
GBL: γ-Butyrolactone NMP: N-methyl-2-pyrrolidone (alkali-soluble resin)
Alkali-soluble resin (A): A copolymer obtained by adding 0.4 equivalents of glycidyl methacrylate to the carboxyl group of a copolymer composed of methacrylic acid / methyl methacrylate / styrene = 54/23/23 (mol%). (Weight average molecular weight (Mw): 29,000)
(Conductive particles)
A-1: Silver particles having an average thickness of 1 nm on the surface carbon coating layer and a primary particle size of 40 nm (manufactured by Nisshin Engineering Co., Ltd.).

<Evaluation>
(1) Measurement of Weight Average Molecular Weight of Polyimide Precursor Resin The weight average molecular weight (Mw) was measured by gel permeation chromatography (GPC) under the following conditions. The calibration curve for calculating the weight average molecular weight was prepared using standard polystyrene (manufactured by Tosoh Corporation).

Equipment Equipment: DP-8020 (manufactured by Tosoh Corporation)
Developing solvent: N, N'-dimethylacetamide (DMAc), 0.05M-LiCl, 0.05% phosphoric acid addition Guard column: TSK guard colon ALPHA (manufactured by Tosoh Corporation)
Column: TSK-GEL α-M (manufactured by Tosoh Corporation)
Flow velocity: 0.8 mL / min Column temperature: 23 ° C
Detector: RI-8020 (manufactured by Tosoh Corporation).

(2) Preparation of Polyimide Resin Film (on Glass Substrate) The polyimide precursor resin composition prepared in each Example and Comparative Example was placed on a 125 mm □, 0.5 mm thick non-alkali glass substrate (AN100, manufactured by AGC Inc.). After spin-coating with a spin coater (“1H-360S (trade name)” manufactured by Mikasa Co., Ltd.) so that the film thickness after curing becomes 10 ± 0.5 μm, a hot plate (Dainippon Screen Mfg. Co., Ltd.) A prebaked film was prepared by prebaking at 120 ° C. for 5 minutes using "SCW-636 (trade name)" manufactured by Co., Ltd. The prepared substrate was cured under the following conditions to prepare a polyimide resin film (on a glass substrate).

Examples 1 to 14, 16 to 21, Comparative Examples 1 to 4: Using an oven (“IHPS-222”; manufactured by ESPEC CORPORATION), cure in air at the temperature and time shown in Table 1. To prepare a film-like material (on a glass substrate) of the polyimide resin composition. The curing was performed by putting the substrate into an oven adjusted to the temperature described in each of the examples and comparative examples.

Example 15: Using an inert oven (INH-21CD manufactured by Koyo Thermo System Co., Ltd.), the temperature is raised to 250 ° C. over 40 minutes under a nitrogen stream (oxygen concentration less than 100 ppm), held for 60 minutes, and held for 5 to 5 to A polyimide resin film (on a glass substrate) was prepared by cooling to 50 ° C. at 8 ° C./min.

The film thickness of the obtained polyimide resin film was measured using a surface roughness / contour shape measuring machine (SURFCOM1400D; manufactured by Tokyo Precision Co., Ltd.) at a measurement magnification of 10,000 times, a measurement length of 1.0 mm, and a measurement speed. Was measured at 0.30 mm / s.

(3) Preparation of polyimide resin film (peeling film) The polyimide resin film (on the glass substrate) prepared in (2) is peeled by making a notch in the part 1 cm from the four sides with a single blade and lifting it from the edge. A polyimide resin film (release film) was obtained.

(4) Measurement of peak intensity ratio of IR spectrum The peak intensity ratio of the IR spectrum of the polyimide resin film obtained in (2) was measured by the following method.
Analytical method: FTIR-ATR device: FTS-55A (manufactured by Bio-Rad)
Condition: ATR attachment (Ge45 °)
Light source: Special ceramics detector: MCT
Resolution: 4 cm ^-1
Number of integrations: 32 times Measurement range: 400-4000 cm ^-1
Spectrum vertical axis: Absorbance procedure 1) Draw a baseline based on ^{2000 to 4000 cm -1} 2) Normalize with the maximum peak existing in the range of ^{1480 to 1510 cm -1} 3) In the range of ^{3400 to 3700 cm -1} Procedure for reading the height of the existing maximum peak from the baseline 4) The maximum peak intensity existing in the range ^{of 1480 to 1510 cm -1} of the IR spectrum is Y, and the maximum peak intensity existing in the range of ^{3400 to 3700 cm -1 is Z.} The peak intensity ratio is calculated from the following formula) Peak intensity ratio = Z / Y.

(5) Measurement of GBL and NMP Amount in Polyimide Resin Film The amount of GBL contained in the polyimide resin composition was measured by the following procedure.
Procedure 1) Collection of desorbed gas The polyimide resin film (peeling film) obtained in (3) was cut into strips and collected in a heating container. Subsequently, the entire heating container was heated under the following conditions, and the generated gas was collected in an adsorption tube. A sample obtained by performing the same operation without using a sample was used as a blank.
・ Heating temperature: 400 ℃
・ Heating time: 60 min
・ Atmosphere: Nitrogen 50 mL / min
Step 2) Thermal desorption GC / MS
The gas collected in the adsorption tube by the method of step 1 was measured by thermal desorption GC / MS. The conditions for thermal desorption GC / MS are shown below.
・ Thermal desorption device: TD-100 (Markes)
・ Primary heat desorption conditions: Desorption temperature 260 ℃, trap temperature -27 ℃, 15 min
・ Secondary heat desorption conditions: 320 ℃, 5 min
・ GC device: 7890A (Agilent)
-Column: DB-5MS 30 m x 0.25 mm ID film thickness 1 μm (Agilent J & W)
-Column temperature: 40 ° C (4 min) to 280 ° C (22 min) Heating rate 10 ° C / min
・ MS device: 5975C (Agilent)
・ Ionization method: Electron ionization (EI)
・ Monitor ion: m / z 29-600
・ GBL quantitative ion: m / z 86
・ NMP quantitative ion: m / z 98
・ Ion source temperature: 230 ℃
-Standard products: GBL (special grade manufactured by Wako Pure Chemical Industries, Ltd.), NMP (special grade manufactured by Wako Pure Chemical Industries, Ltd.)
The standard product was dissolved in methanol to prepare a standard solution. After collecting 1 μL of this solution from a standard solution prepared by appropriately diluting it and injecting it into an adsorption tube, measurement was performed under the same conditions as the sample, and a calibration curve was prepared for quantification.

(6) Measurement of glass transition temperature Using a thermomechanical analyzer (EXSTAR6000TMA / SS6000 manufactured by SII Nanotechnology), the glass transition temperature was measured under a nitrogen stream with a tensile load of 30 mN. The temperature raising method was carried out under the following conditions. In the first step, the temperature was raised to 150 ° C. at a temperature rising rate of 5 ° C./min to remove the adsorbed water of the polyimide resin film sample, and in the second step, the temperature was cooled to room temperature at a temperature lowering rate of 5 ° C./min. In the third step, the main measurement was performed at a temperature rising rate of 5 ° C./min, and the glass transition temperature of this sample was determined. The polyimide resin film (release film) shown in (3) was used for this measurement, and the width of the film used for the measurement was 5 mm and the distance between the chucks was 20 mm.

(7) Measurement of Warpage The glass substrate with the polyimide resin film prepared in (2) was placed on a stone surface plate and allowed to stand for 30 minutes, and then the amount of warpage was measured for evaluation. The amount of warpage was defined as the average value of the floating of the four corners, and the measurement was carried out in a room adjusted to a room temperature of 23 ± 2 ° C. and a humidity of 50 ± 5%.

(8) Measurement of yellowness The yellowness was measured using a color meter (SM-T45, manufactured by Suga Test Instruments Co., Ltd.). A C light source was used as the light source, and the measurement was performed in the transmitted light mode. For the measurement, the polyimide resin film (on the glass substrate) prepared in (2) and the polyimide resin film (on the glass substrate) prepared in (2) were placed in an oven (“IHPS-222”; manufactured by Espec Co., Ltd.). ) Was used in an air atmosphere (oxygen concentration: 21% by volume), and the mixture was additionally heated at 250 ° C. for 1 hour. In Table 1, "after curing" and "after additional heating" are shown, respectively.

(9) Measurement of in-plane / out-of-plane birefringence The TE refractive index (n (TE)) and TM refractive index (n (TM)) at a wavelength of 632.8 nm are measured using a prism coupler (manufactured by METRICON, PC2010). did. n (TE) and n (TM) are refractive indexes in the parallel and vertical directions with respect to the polyimide film surface, respectively. The in-plane / out-of-plane birefringence was calculated as the difference between n (TE) and n (TM) (n (TE) -n (TM)). The polyimide resin film (release film) obtained in (3) was used for the measurement.

(10) Folding resistance test of polyimide resin film (MIT test)
The test was carried out under the following conditions using the polyimide resin film (release film) obtained in (3). The number of measurements was set to n = 3, and the average value was taken as the number of folding resistances.
Test method: JIS P 8115 (2001) compliant Test piece: Strip 110 mm x 10 mm
Test conditions: Test load; 1.0 kgf
Bending angle; 135 °
R of bent surface; 0.38 mm
Bending speed; 175 measurements per minute; n = 3
Test environment: (23 ± 2) ° C, (50 ± 5)% RH
Measuring device: MIT testing machine Model DA (manufactured by Toyo Seiki Seisakusho Co., Ltd.).

(11) Measurement of substrate adhesion (90 ° peel test)
The polyimide resin film (on the glass substrate) obtained in (2) was cut out to a width of 10 mm and a length of 100 mm, dehydrated and baked at 120 ° C. for 6 minutes using a hot plate, and then pulled at a tensile speed of 50 mm / min. A 90 ° peel test was performed under the conditions. Here, in the 90 ° peel test, a 90 ° peel strength (N) using an adhesion tester (manufactured by Yamamoto Plating Tester Co., Ltd.) conforming to JIS C6481 (1996, copper-clad laminate test method for printed wiring boards). / Cm) was measured, and the judgment was made by the following evaluation method.
Excellent (A): 0.3 N / cm or less Good (B): 0.3 N / cm or more and less than 0.5 N / cm Possible (C): 0.5 N / cm or more and less than 0.8 N / cm Defective (D): 0.8 N / cm or more.

(12) Laser peeling test The polyimide resin film (on the glass substrate) obtained in (2) is irradiated with an excimer laser (shape: 21 mm × 1.0 mm) of 308 nm from the glass substrate side to perform a laser peeling test. Was done. The laser was irradiated while shifting by 0.25 mm in the minor axis direction. The energy at which the film was peeled off when a cut was made along the edge of the irradiation region was defined as the irradiation energy (peeling energy) required for peeling, and evaluation was performed according to the following criteria.
Excellent (A): Peeling energy is 230 mJ / cm ² or less.
Good (B): irradiation energy exceeds ^{230mJ / cm 2, 260mJ / cm} 2 or less.
Yes (C): irradiation energy exceeds ^{260mJ / cm 2, 300mJ / cm} 2 or less.
Defective (D): Irradiation energy exceeds ^{300 mJ / cm 2.}

(13) Conductivity Evaluation of Conductive Composition A laminate is produced using the conductive composition and the insulating composition prepared in advance by the following method, and then the conductivity evaluation using the laminate is performed. Was done.

(Production Example 1: Preparation of Conductive Composition)
In Production Example 1, a conductive composition (AE-1) was prepared. Specifically, 80 g of conductive particles (A-1), 4.06 g of a surfactant (“DISPERBYK” (registered trademark) 21116: manufactured by DIC Corporation), 98.07 g of PGMEA, and 98.07 g of DPM are mixed. The mixture was treated with a homogenizer at 1200 rpm for 30 minutes. Further, the mixture was dispersed using a high-pressure wet medialess atomizer Nanomizer (manufactured by Nanomizer) to obtain a silver dispersion having a silver content of 40% by mass.

20 g of alkali-soluble resin (AR) as an organic compound, 0.6 g of ethylacetacetate aluminum diisopropylate (ALCH: manufactured by Kawaken Fine Chemicals) as a metal chelate compound, photopolymerization initiator (NCI-831: manufactured by ADEKA) To a mixture of 2.4 g of PGMEA and 12.0 g of PE-3A, 132.6 g of PGMEA and 52.6 g of DPM were added, and the mixture was stirred to obtain an organic I solution for a conductive composition. .. The silver dispersion liquid and the organic I liquid were mixed at a mass ratio of 72.6 / 27.4 to obtain a conductive composition (AE-1).

(Production Example 2: Preparation of Conductive Composition)
A conductive composition (AE-2) was obtained in the same manner as in Production Example 1 except that 0.24 g of Irganox 1010 (manufactured by BASF Japan Ltd.), which is a hindered phenolic antioxidant, was further added to the organic I solution. ..

(Production Example 3: Preparation of Conductive Composition)
A conductive composition (AE-3) was obtained in the same manner as in Production Example 1 except that 0.24 g of ADEKA STUB LA-87 (manufactured by ADEKA), which is a hindered amine-based antioxidant, was further added to the organic I solution. ..

(Production Example 4: Preparation of Conductive Composition)
The conductive composition (AE-4) was prepared in the same manner as in Production Example 1 except that 0.24 g of ADEKA STUB AO-20 (manufactured by ADEKA), which is a hindered phenolic antioxidant, was further added to the organic I solution. Obtained.

(Production Example 5: Preparation of Insulating Composition)
In Production Example 5, an insulating composition (OA-1) was prepared. Specifically, in a clean bottle, 50.0 g of a cardo resin (V-259ME: manufactured by Nippon Steel Sumitomo Chemical Co., Ltd.), 18.0 g of a crosslinkable monomer (TAIC: manufactured by Nippon Kasei Co., Ltd.), and a crosslinkable monomer (M-315). : 10.0 g of Toa Synthetic Co., Ltd.), 20.0 g of epoxy compound (PG-100: manufactured by Osaka Gas Chemical Co., Ltd.), 0.2 g of photopolymerization initiator (OXE-01: manufactured by BASF Co., Ltd.) were added. Stirring for 1 hour gave an insulating composition (OA-1).

(Production Example 6: Preparation of Insulating Composition)
Further, an insulating composition (OA-2) was obtained in the same manner as in Production Example 5 except that 0.2 g of Irganox 1010 (manufactured by BASF Japan Ltd.), which is a hindered phenolic antioxidant, was added.

(Production Example 7: Preparation of Insulating Composition)
Further, an insulating composition (OA-3) was obtained in the same manner as in Production Example 5 except that 0.2 g of ADEKA STUB LA-87 (manufactured by ADEKA), which is a hindered amine-based antioxidant, was added.

(Production Example 8: Preparation of Insulating Composition)
Further, an insulating composition (OA-4) was obtained in the same manner as in Production Example 5 except that 0.2 g of ADEKA STUB AO-20 (manufactured by ADEKA), which is a hindered phenolic antioxidant, was added.

(Evaluation of conductivity)
Step 1: Formation of Insulating Layer On the polyimide resin film (on the glass substrate) prepared in (2), the insulating compositions (OA-1 to 4) prepared in Production Examples 5 to 8 are subjected to 1000 rpm using a spin coater. After spin-coating for 5 seconds with, prebaking was performed at 100 ° C. for 2 minutes using a hot plate to prepare a prebaked film. The prebake film was exposed through a desired mask using an ultra-high pressure mercury lamp as a light source using a parallel light mask aligner. Then, using an automatic developing apparatus, shower development was performed with a 0.045 mass% potassium hydroxide aqueous solution for 60 seconds, and then rinse with water for 30 seconds to perform pattern processing. The patterned substrate was cured in air at 230 ° C. for 60 minutes using an oven to form an insulating layer having a thickness of 1.0 μm to obtain a laminated substrate.

Step 2: Formation of wiring layer On the laminated substrate prepared in step 1, the conductive compositions (AE-1 to 4) prepared in Production Examples 1 to 4 were applied to a spin coater (Mikasa Co., Ltd. "1H-360S (1H-360S). Spin-coat the substrate using a hot plate (“SCW-636 (trade name)” manufactured by Dainippon Screen Mfg. Co., Ltd.) for 10 seconds at 300 rpm and 2 seconds at 500 rpm. Prebaking was performed at 100 ° C. for 2 minutes to obtain a prebaked film having a film thickness of 0.9 μm. A parallel light mask aligner (“PLA-501F (trade name)” manufactured by Canon Inc.) was used as a light source, and a prebake film was exposed through a desired mask. After that, using an automatic developing device (“AD-2000 (trade name)” manufactured by Takizawa Sangyo Co., Ltd.), shower-develop with 0.045 mass% potassium hydroxide aqueous solution for 60 seconds, and then rinse with water for 30 seconds. , Pattern processing was performed. Then, using an oven (“IHPS-222”; manufactured by ESPEC CORPORATION), post-baking was performed in air at 230 ° C. for 30 minutes to obtain a volume resistivity evaluation pattern.

For the obtained volume resistivity evaluation pattern, the surface resistivity value ρs (Ω / □) was measured by a surface resistivity measuring machine (“Loresta” (registered trademark) -FP; manufactured by Mitsubishi Yuka Co., Ltd.), and the surface roughness shape was measured. The film film resistivity (μΩ · cm) is calculated by measuring the film thickness t (cm) with a machine (“Surfcom” (registered trademark) 1400D; manufactured by Tokyo Precision Co., Ltd.) and multiplying both values. Conductivity was evaluated according to the evaluation criteria of.
Excellent (A): 60 μΩ ・ cm or less Good (B): 60 μΩ ・ cm or more and less than 80 μΩ ・ cm possible (C): 80 μΩ ・ cm or more and less than 100 μΩ ・ cm Defective (D): 100 μΩ ・ cm or more.

(14) Evaluation of Bending Tolerance The same substrate prepared in (13) above was cut out to a width of 1 cm, and a 180-degree bending test was performed using a metal rod having a diameter of 1 cm, 5 mm, 1 mm, and 0.8 mm. The number of tests was one, and the presence or absence of cracks was observed using an optical microscope, and the bending resistance was evaluated according to the following evaluation criteria.
Excellent (S): No cracks at 0.8 mm in diameter Excellent (A): No cracks at 1 mm in diameter Good (B): No cracks at 5 mm in diameter, cracks can occur at 1 mm in diameter (C): 1 cm in diameter No cracks, no cracks with a diameter of 5 mm (D): Cracks with a diameter of 1 cm.

Synthesis example 1
A thermometer and a stirring rod with a stirring blade were set in a 300 mL four-necked flask. Next, 110 g of GBL was charged under a dry nitrogen air flow, and the temperature was raised to 30 ° C. After raising the temperature, the diamine compound 3,3'-DDS was 7.00 g (28.2 mmol), BAPS-m was 8.87 g (20.5 mmol), and TFMB was 0.82 g (2.56 mmol) with stirring. It was put in and washed with 20 g of GBL. After confirming that the diamine compound was dissolved, 16.2 g (52.3 mmol) of ODPA, which is an acid dianhydride, was added and washed with 20 g of GBL. Then, the mixture was heated to 50 ° C. and reacted for 4 hours, cooled, 0.02 g of a surfactant (“F-477” manufactured by DIC Corporation) was added, and the mixture was stirred for 1 hour. The obtained solution was filtered through a polyethylene filter (filter pore size 0.2 μm) to obtain a polyimide precursor composition. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 85,000.

Synthesis example 2
5.01 g (20.2 mmol) of 3,3'-DDS, 8.72 g (20.2 mmol) of BAPS-m, 3.23 g (10.1 mmol) of TFMB, 16.0 g (51.5 mmol) of ODPA. A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 1 except that the composition was changed to. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 94000.

Synthesis example 3
5.08 g (20.5 mmol) of 3,3'-DDS, 8.39 g (20.5 mmol) of HFBAPP instead of BAPS-m, 3.27 g (10.2 mmol) of TFMB, 16.2 g of ODPA (16.2 mmol). A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 1 except that the composition was changed to 52.2 mmol). The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 97,000.

Synthesis example 4
3.87 g (19.6 mmol) of 3,3'-DDS, 8.70 g (20.1 mmol) of BAPS-m, 3.22 g (10.1 mmol) of TFMB, 15.9 g (51.4 mmol) of ODPA. Polyimide precursor in the same manner as in Synthesis Example 1 except that 0.201 g (0.50 mmol) of TAPOB was further added at the same timing as when 3,3'-DDS, BAPS-m, and TFMB were added. A resin composition was obtained. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 125,000.

Synthesis example 5
3.76 g (19.2 mmol) of 3,3'-DDS, 8.29 g (19.2 mmol) of BAPS-m, 3.07 g (9.59 mmol) of TFMB, 11.4 g (36.7 mmol) of ODPA. A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 1 except that 5.43 g (12.2 mmol) of 6FDA was added at the same timing as ODPA. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 92000.

Synthesis example 6
5.20 g (20.9 mmol) of 3,3'-DDS, 9.04 g (20.9 mmol) of BAPS-m, 3.35 g (10.5 mmol) of TFMB, 12.4 g (40.1 mmol) of ODPA. A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 1 except that 2.91 g (13.4 mmol) of PMDA was added at the same timing as ODPA. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 101000.

Synthesis example 7
2.45 g (9.87 mmol) of 3,3'-DDS, 8.53 g (19.7 mmol) of BAPS-m, 6.32 g (19.7 mmol) of TFMB, 15.6 g (50.4 mmol) of ODPA. A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 1 except that the composition was changed to. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 98,000.

Synthesis example 8
2.54 g (10.2 mmol) of 3,3'-DDS, 4.41 g (10.2 mmol) of BAPS-m, 9.81 g (30.6 mmol) of TFMB, 16.2 g (52.1 mmol) of ODPA. A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 1 except that the composition was changed to. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 102000.

Synthesis example 9
A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 4 except that the solvent used was changed from GBL to NMP. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 120,000.

Synthesis example 10
2.50 g (10.1 mmol) of 3,3'-DDS, 4.35 g (10.1 mmol) of BAPS-m, 10.15 g (30.2 mmol) of 6FODA and 15.9 g (15.9 mmol) of ODPA by changing to TFMB. A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 1 except that the composition was changed to 51.3 mmol). The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 107,000.

Synthesis example 11
1.28 g (5.14 mmol) of 3,3'-DDS, 2.22 g (5.14 mmol) of BAPS-m, 13.2 g (41.1 mmol) of TFMB, 16.3 g (52.4 mmol) of ODPA. A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 1 except that the composition was changed to. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 107,000.

Synthesis example 12
0.64 g (2.58 mmol) of 3,3'-DDS, 1.11 g (2.58 mmol) of BAPS-m, 14.9 g (46.4 mmol) of TFMB, 16.3 g (52.6 mmol) of ODPA. A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 1 except that the composition was changed to. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 110,000.

Synthesis example 13
2.55 g (10.3 mmol) of 3,3'-DDS, 4.44 g (10.3 mmol) of BAPS-m, 9.88 g (30.8 mmol) of TFMB, 12.2 g (39.3 mmol) of ODPA. A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 1 except that 3.86 g (13.1 mmol) of BPDA was added at the same timing as ODPA. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 116000.

Synthesis example 14
Other than changing 3,3'-DDS to 6.22 g (25.1 mmol), BAPS-m to 10.8 g (25.1 mmol), ODPA to 15.9 g (51.2 mmol), and not using TFMB. Obtained a polyimide precursor resin composition in the same manner as in Synthesis Example 1. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 64,000.

Synthesis example 15
A polyimide precursor resin composition was obtained in the same manner as in Synthesis Example 4 except that 3,3'-DDS was changed to 4,4'-DDS. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 81000.

Synthesis example 16
Other than changing 3,3'-DDS to 5.38 g (21.7 mmol), TFMB to 10.4 g (32.5 mmol), ODPA to 17.1 g (55.3 mmol), and not using BAPS-m. Obtained a polyimide precursor resin composition in the same manner as in Synthesis Example 1. The weight average molecular weight (Mw) of the polyimide precursor in the obtained composition was 90000.

Examples 1 to 21 and Comparative Examples 1 to 4
A polyimide resin film was prepared by using the polyimide precursor resin composition shown in Table 1 and setting the curing conditions as shown in Table 1 by the method described in (2) above. The test results of the obtained polyimide resin film are shown in Table 2 below.

It was confirmed that Examples 1 to 21 had good mechanical properties, laser peeling properties, optical properties, and heat-resistant oxidizing properties. Further, as an example of the circuit, when an insulating layer and a conductive wiring were formed on the polyimide resin film and the volume resistance and the bending resistance were evaluated, good characteristics were confirmed.

It is probable that in Comparative Example 1, since the cure was not sufficiently advanced, the intermolecular interaction was weak and the mechanical properties were inferior. Further, it is considered that a large amount of GBL remaining in the film acts on the conductive wiring in the curing process to deteriorate the conductivity.

Since the structural unit represented by the formula (1) is not included in Comparative Example 2, it is considered that the mechanical strength of the obtained polyimide film is lowered. In Comparative Example 3, since 4,4'-DDS was used instead of 3,3'-DDS, it is considered that the yellowness of the obtained polyimide resin film was increased and the mechanical strength was further decreased. Since BAPS-m is not contained in Comparative Example 4, it is considered that the chemical resistance of the polyimide film is lowered. Further, since cracks were generated when the insulating composition was applied, the conductivity and bending test could not be performed.

1 Baseline 2 Intensity of maximum peak in the range of 3400 to 3700 cm ^-1 Intensity of maximum peak in the range of ^{1480 to 1510 cm -1}

Claims (14)

1. A polyimide containing a polyimide structural unit A represented by the formula (1), a polyimide structural unit B represented by the formula (2), and a polyimide structural unit C represented by the formula (3). In the IR spectrum when a resin film having a thickness of 10 μm is used, when the maximum peak intensity existing in the range of ^{1480 to 1510 cm -1} is Y and the maximum peak intensity existing in the range of ^{3400 to 3700 cm -1 is Z,} A polyimide characterized by satisfying the following formula.
   Equation) 0.1 ≤ Z / Y ≤ 0.4
   

   

   (X ¹ represents a direct bond or an oxygen atom. X ² represents an oxygen atom, -C (CF ₃ ) _2- , -C (CH ₃ ) _2- or -Si (CH ₃ ) _2-. ³ represents direct binding, -SO _2- , -C (CH ₃ ) _2- or -C (CF ₃ ) _2- ).
2. The polyimide according to claim 1, wherein the total amount of the polyimide structural unit A, the polyimide structural unit B, and the polyimide structural unit C is 80 mol% or more of the total polyimide structural units.
3. The polyimide according to claim 1 or 2, wherein the polyimide structural unit A is a structural unit represented by the following formula (4).
   

   

   (X ¹ represents a direct bond or an oxygen atom.)
4. The polyimide according to any one of claims 1 to 3, wherein the polyimide structural unit B is a structural unit represented by the following formula (5).
   

   
5. The polyimide according to any one of claims 1 to 4, wherein the polyimide structural unit C is a structural unit represented by the following formula (6).
   

   
6. A polyimide resin film containing the polyimide according to any one of claims 1 to 5.
7. The polyimide resin film according to claim 6, wherein the glass transition temperature is 220 ° C. or higher and 250 ° C. or lower.
8. The polyimide resin film according to claim 6 or 7, which contains γ-butyrolactone in a range of 1 ppm or more and 1000 ppm or less with respect to the weight of the polyimide resin film.
9. The polyimide resin film according to any one of claims 6 to 8, which does not contain an amide solvent.
10. A laminate comprising an insulating layer and / or a conductive layer on the polyimide resin film according to any one of claims 6 to 9.
11. A laminate having an insulating layer and a conductive layer on the polyimide resin film according to any one of claims 6 to 9, wherein both the insulating layer and the conductive layer contain an antioxidant.
12. The laminate according to claim 11, wherein the antioxidant is a compound containing an amino group or a phenolic hydroxyl group.
13. A flexible device comprising the polyimide resin film according to any one of claims 6 to 9 or the laminate according to any one of claims 10 to 12.
14. The flexible device according to claim 13, wherein the flexible device is a flexible touch panel, a flexible solar cell, or a flexible transparent antenna.

Images