TW201609865A - Polyimine, polylysine, resin composition, and substrate for flexible display - Google Patents

Abstract

A polyimine which is a polyimine obtained by reacting a tetracarboxylic acid component with a diamine component, characterized in that the tetracarboxylic acid component contains a compound represented by the following structural formula (1); The component contains 60 mol% or more of the compound represented by the following structural formula (2). □ □

Description

Polyimine, polylysine, resin composition, and substrate for flexible display

The present invention relates to polyimine and polylysine, and to a resin composition using the same, and a substrate for a flexible display.

Polyimine is known as an organic material having high heat resistance, flame retardancy, and electrical insulating properties (for example, see Patent Document 1).

Polyimine is widely used in the field of electrical and electronic materials due to its properties. Specifically, it is used as a base material of a flexible printed wiring board or a heat-resistant adhesive tape, and is used for an insulating film, a protective film, or the like of a semiconductor.

On the other hand, display devices such as an organic electroluminescence (EL) display and a liquid crystal display require high precision. In addition, in recent years, the use of display devices has expanded to information equipment. Therefore, in order to meet the requirements of ultra-thin, lightweight, and bendable, a flexible display using a plastic film as a substrate is attracting attention.

Polyimine is expected to be applied to the substrate of the flexible display.

The flexible display requires a correct coincidence position during the manufacturing process. In addition, at the time of manufacture, there is a case where high temperature treatment is required. Therefore, it is required that the substrate of the flexible display does not easily expand or contract (so-called dimensional stability) even if it is subjected to high-temperature treatment.

The dimensional stability of polyimine is generally evaluated by the coefficient of linear expansion. Therefore, attempts have been made to produce a polyimine having a low coefficient of linear expansion (for example, refer to Patent Document 2 and Patent Document 1). However, in the case where polyimide is used as the substrate of the flexible display, the film thickness is about 20 μm, and among the thicknesses of this grade, no polyimine having a linear expansion coefficient as low as that of the glass phase has been found. .

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-46054

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2007-99951

[Non-patent literature]

[Non-Patent Document 1] Youngsuk Jung et al., European Polymer Journal 49 (2013) 3642-3650

The present invention has been made in order to solve the above problems and achieve the following objects. That is, an object of the present invention is to provide a polyimine having a low coefficient of linear expansion and a polyphthalic acid as a precursor thereof, and to provide a resin composition using the same and a substrate for a flexible display.

The means for solving this problem is as follows. that is:

<1> Polyimine, which is a polyimine obtained by reacting a tetracarboxylic acid component with a diamine component, characterized in that the tetracarboxylic acid component contains the following structural formula (1). Compound The diamine component contains 60 mol% or more of the compound represented by the following structural formula (2).

<2> The polyimine of the above <1>, wherein the film has a linear expansion coefficient of 2.00 ppm/K to 7.00 ppmm/K when a film having an average thickness of 20 μm is formed.

The polyimine of any one of the above-mentioned <1> to <2>, wherein the film has a linear expansion coefficient of 3.00 ppm/K to 7.00 ppm/K when a film having an average thickness of 20 μm is formed.

The polyimine of any one of the above-mentioned <1> to <3>, wherein the diamine component contains 95% or more of the compound represented by the structural formula (2).

The polyimine of any one of the above-mentioned <1> to <4>, wherein the tetracarboxylic acid component contains 95% or more of the compound represented by the structural formula (1).

The polyimine of any one of the above-mentioned <1> to <5>, wherein the molar ratio of the tetracarboxylic acid component to the diamine component (tetracarboxylic acid component/diamine component) is 1.00/1.00. ~0.96/1.00.

The polyimine of any one of the above-mentioned <1> to <6>, wherein the molar ratio of the tetracarboxylic acid component to the diamine component (tetracarboxylic acid component/diamine component) is 1.00/1.00. ~0.98/1.00.

<8> A polyimine which is a polyimine having a repeating unit represented by the following structural formula (3), which is characterized by: When a film having an average thickness of 20 μm is formed, the film has a linear expansion coefficient of 2.00 ppm/K to 7.00 ppm/K.

<9> The polyimine of the above <8>, wherein the film has a linear expansion coefficient of 3.00 ppm/K to 7.00 ppm/K.

The polyimine of any one of the above-mentioned <8>, wherein the repeating unit represented by the structural formula (3) is 90 with respect to the total amount of the repeating unit of the polyimine. More than Mole.

The polyimine of any one of the above-mentioned <8>, which is obtained by reacting a tetracarboxylic acid component and a diamine component, wherein the tetracarboxylic acid component contains the following structural formula ( 1) A compound represented by the following structural formula (2) containing 60 mol% or more of the diamine component.

<12> A poly-proline acid obtained by reacting a tetracarboxylic acid component with a diamine component, wherein the tetracarboxylic acid component contains a compound represented by the following structural formula (1); The diamine component contains 60 mol% or more of the compound represented by the following structural formula (2).

<13> The polyaminic acid according to <12> above, wherein the diamine component contains 95% by mole or more of the compound represented by the structural formula (2).

The poly-proline in any one of the above-mentioned <12> to <13>, wherein the tetracarboxylic acid component contains 95% or more of the compound represented by the structural formula (1).

The poly-proline in any one of the above-mentioned <12> to <14> wherein the molar ratio of the tetracarboxylic acid component to the diamine component (tetracarboxylic acid component/diamine component) is 1.00/1.00. ~0.96/1.00.

The poly-proline in any one of the above-mentioned <12> to <15> wherein the molar ratio of the tetracarboxylic acid component to the diamine component (tetracarboxylic acid component/diamine component) is 1.00/1.00. ~0.98/1.00.

<17> The polylysine according to any one of the above <12> to <16> wherein the liquid containing 10% by mass of polyamic acid has a viscosity of 1 Pa after one month at 25 ° C. s above.

<18> A resin composition characterized by comprising: the polyimine of any one of <1> to <11> And any one of the polyamic acids of any one of <12> to <17>.

<19> A substrate for a flexible display, comprising: the polyimine of any one of <1> to <11>, and the polyamine of any one of <12> to <17> Any of the acids.

According to the present invention, the object of the prior art can be attained, and it is possible to provide a polyimine having a low coefficient of linear expansion, and a polylysine as a precursor thereof, and to provide a resin composition using the same. And substrates for flexible displays.

[Fig. 1] is a graph showing the relationship between temperature and CTE.

(polyimine)

<First polyimine>

The first polyimine of the present invention is a polyimine obtained by reacting a tetracarboxylic acid component with a diamine component.

<<tetracarboxylic acid component>>

The tetracarboxylic acid component contains a compound represented by the following structural formula (1), and further contains other compounds depending on the demand.

The tetracarboxylic acid component preferably contains 90 mol% or more of the compound represented by the structural formula (1), more preferably 95 mol% or more, and most preferably 100 mol%.

<<Diamine component>>

The diamine component contains 60 mol% or more of the compound represented by the following structural formula (2).

When the compound represented by the structural formula (1) is reacted with a compound represented by the following structural formula (A), a polyimine similar to the first polyimine can be obtained. However, this polyimine does not give a low coefficient of linear expansion.

The diamine component preferably contains 95 mol% or more of the compound represented by the structural formula (2), and more preferably contains 100 mol%.

In the first polyimine, the molar ratio (tetracarboxylic acid component/diamine component) of the tetracarboxylic acid component and the diamine component is not particularly limited and may be appropriately selected depending on the purpose, but 1.00/1.00 ~0.96/1.00 is better, and 1.00/1.00~0.98/1.00 is better.

Preferably, the first polyimine has valeric acid. The amount of the amic acid in the first polyimine is preferably 10 mol% or less of the quinone imine group in the first polyimine.

The first polyimine, when the film having an average thickness of 20 μm is formed, the film line The expansion coefficient is preferably from 2.00 ppm/K to 7.00 ppm/K, more preferably from 3.00 ppm/K to 7.00 ppm/K.

The coefficient of linear expansion can be obtained by thermomechanical analysis (TMA).

Specifically, a linear expansion coefficient was calculated using a thermomechanical measuring device (TMA/SS6100 manufactured by SII Corporation). First, a film is applied to a film of polyimine with a film thickness of 4.9 mN per 1 μm, and then treated at 30 ° C to 150 ° C (temperature rising rate of 10 ° C/min) in a nitrogen atmosphere to remove adsorption. Moisture. Next, after maintaining the tension, the mixture was cooled in a nitrogen atmosphere, and then measured at 50 ° C to 350 ° C (heating rate 5 ° C / min) to calculate a coefficient of linear expansion. The coefficient of linear expansion is calculated from the arithmetic mean value in the range of 100 ° C to 200 ° C.

The first polyimine may be obtained by reacting the tetracarboxylic acid component with the diamine component in the presence of a solvent to obtain a polyamic acid, and then subjecting the polyamic acid to ruthenium iodide. Get it.

The solvent is appropriately selected depending on the purpose, and is not particularly limited, and examples thereof include 1-methyl-2-pyrrolidone (NMP) and dimethylacetamide (DMAc).

The reaction temperature at the time of obtaining the polyamic acid is not particularly limited and may be appropriately selected depending on the intended purpose, and examples thereof include room temperature and the like. The normal temperature is a temperature of 20 ° C to 30 ° C.

The reaction time when the polyamic acid is obtained is not particularly limited and may be appropriately selected depending on the purpose, and may be, for example, from 1 day to 7 days.

The ruthenium imidization can be carried out, for example, by heating the polyamic acid (so-called hydrazine imidization).

The heating temperature is, for example, 200 ° C to 400 ° C or the like.

The heating time is, for example, 1 hour to 5 hours.

<Second polyimine>

The second polyimine of the present invention has a repeating unit represented by the following structural formula (3).

The second polyimine may also have a proline. In the second polyimine, the amount of the amic acid is preferably 10 mol% or less of the quinone imine group in the second polyimine.

In the second polyimide, when the film having an average thickness of 20 μm is formed, the film has a linear expansion coefficient of 2.00 ppm/K to 7.00 ppm/K, preferably 3.00 ppm/K to 7.00 ppm/K.

The coefficient of linear expansion can be obtained by thermomechanical analysis (TMA).

Specifically, a linear expansion coefficient was calculated using a thermomechanical measuring device (TMA/SS6100 manufactured by SII Corporation). First, a film is applied to a film of polyimine with a film thickness of 4.9 mN per 1 μm, and a treatment at 30 ° C to 150 ° C (temperature rising rate of 10 ° C/min) is performed under a nitrogen atmosphere to remove adsorbed moisture. . Subsequently, the film was cooled in a nitrogen atmosphere while maintaining the tension, and then measured at 50 ° C to 350 ° C (heating rate 5 ° C / min) to calculate a coefficient of linear expansion. The coefficient of linear expansion is calculated from the arithmetic mean value in the range of 100 ° C to 200 ° C.

In the second polyimine, the amount of the repeating unit represented by the structural formula (3) is appropriately selected depending on the purpose, but the total amount of the repeating unit relative to the second polyimine is not particularly limited. Preferably, it is 90% by mole, more preferably 95% by mole or more, and most preferably 100% by mole. Here, the repeating unit of the second polyimine refers to a repeating unit represented by the following formula (A).

In the formula (A), X represents a tetravalent group, and Y represents a divalent group.

The second polyimine is obtained, for example, by reacting a tetracarboxylic acid component with a diamine component.

The tetracarboxylic acid component contains a compound represented by the following structural formula (1).

In the diamine component, it is preferable to contain 60 mol% or more of the compound represented by the following structural formula (2) with respect to the diamine component.

The diamine component preferably contains 95 mol% or more of the compound represented by the structural formula (2), and more preferably contains 100 mol%.

The second polyimine can be obtained by reacting the tetracarboxylic acid component with the diamine component in the presence of a solvent to obtain polylysine, and then subjecting the polyamic acid to ruthenium imidization. It.

The solvent is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include 1-methyl-2-pyrrolidone (NMP) and dimethylacetamide (DMAc).

The reaction temperature in the case of obtaining the polyamic acid is not particularly limited and may be appropriately selected depending on the intended purpose, and examples thereof include room temperature and the like. The normal temperature is a temperature of 20 ° C to 30 ° C.

The reaction time when the polyamic acid is obtained is not particularly limited and may be appropriately selected depending on the purpose, and may be, for example, 1 day to 7 days.

The ruthenium imidization can be carried out, for example, by heating the polyamic acid (so-called hydrazine imidization).

The heating temperature is, for example, 200 ° C to 400 ° C or the like.

The heating time is, for example, 1 hour to 5 hours.

(polyglycine)

The polylysine of the present invention is a polyamic acid obtained by reacting a tetracarboxylic acid component with a diamine component.

<tetracarboxylic acid component>

The tetracarboxylic acid component contains a compound represented by the following structural formula (1), and further contains other compounds depending on the demand.

The tetracarboxylic acid component preferably contains 90 mol% or more of the compound represented by the structural formula (1), more preferably 95 mol% or more, and most preferably 100 mol%.

<<Diamine component>>

The diamine component contains 60 mol% or more of the compound represented by the following structural formula (2).

The diamine component preferably contains 95 mol% or more of the compound represented by the structural formula (2), and more preferably contains 100 mol%.

In the polyamic acid, the molar ratio (tetracarboxylic acid component/diamine component) of the tetracarboxylic acid component and the diamine component is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 1.00/1.00. ~0.96/1.00, more preferably 1.00/1.00~0.98/1.00.

The viscosity of the liquid containing 10% by mass of the polyaminic acid at 25 ° C for one month (30 days) is not particularly limited and may be appropriately selected depending on the purpose, but the coating property from the liquid is excellent. From a point of view, it is preferably 1 Pa. S or above.

In the liquid containing the polyamic acid, the concentration of the polyamic acid is preferably about 10% by mass. When the concentration is sufficiently less than 10% by mass, it is difficult to form a film thickly, and if it is more than 10% by mass, the polylysine becomes difficult to dissolve.

The solvent of the polyproline in the liquid is preferably 1-methyl-2-pyrrolidone (NMP).

For example, the polycarboxylic acid can be obtained by reacting the tetracarboxylic acid component with the diamine component in the presence of a solvent.

The solvent is not particularly limited and may be appropriately selected depending on the purpose, but may be exemplified For example, 1-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc), and the like.

The reaction temperature is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include room temperature and the like. The normal temperature is a temperature of 20 ° C to 30 ° C.

The reaction time is not particularly limited and may be appropriately selected depending on the purpose, and may be, for example, from 1 day to 7 days.

(resin composition)

The resin composition of the present invention contains any of the polyimine of the present invention and the polyamic acid of the present invention, and further contains other components such as a solvent depending on the demand.

When the resin composition contains the polyamic acid, the resin composition preferably contains a ruthenium-based catalyst.

<solvent>

The solvent may, for example, be m-cresol, 2-pyrrolidone, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1-vinyl-2-pyrrolidone, dimethylacetamide, N, N-dimethylformamide, γ-butyrolactone, ethyl lactate, propylene glycol-1-monomethyl ether-2-acetate (PGMEA), triglyme (Triglyme) and the like. These solvents may be used singly or in combination of two or more.

<醯imination catalyst>

Examples of the ruthenium-based catalyst include heterocyclic tertiary amines, aliphatic tertiary amines, aromatic tertiary amines, aliphatic acid anhydrides, and aromatic acid anhydrides.

Examples of the heterocyclic tertiary amines include pyridine, pyridyl, quinoline, and imidazole.

The aliphatic tertiary amine may, for example, be triethylamine or the like.

Examples of the aromatic tertiary amines include N,N-dimethylaniline and the like.

The aliphatic acid anhydride may, for example, be acetic anhydride or the like.

The aromatic acid anhydride may, for example, be phthalic anhydride or the like.

These compounds may be used alone or in combination of two or more.

<Other ingredients>

The other component may, for example, be a crosslinking agent or the like.

<<Crosslinker>>

The crosslinking agent may, for example, be an epoxy resin or a melamine resin.

- epoxy resin -

The epoxy resin may, for example, be a bisphenol A epoxy resin, a bisphenol F epoxy resin, a novolak epoxy resin, a cresol novolak epoxy resin, a naphthalene epoxy resin, or an alicyclic ring. Epoxy resin, etc.

(substrate for flexible display)

The substrate for a flexible display of the present invention contains the polyimine of the present invention and any of the polyamines of the present invention, and further contains other components as needed.

<Other ingredients>

Examples of the other component include a filler, a surface conditioner, a lubricant, and the like.

The average thickness of the substrate for a flexible display can be adjusted according to the average thickness. A suitable choice, but preferably 10 μm to 30 μm.

The substrate for a flexible display may have a single layer structure or a multilayer structure.

The method for producing the substrate for a flexible display is not particularly limited and may be appropriately selected depending on the purpose, and for example, the liquid resin composition of the present invention is applied onto a coating plate and dried, and then A method in which a coated plate is peeled off to form a film. However, a flexible resin sheet may be used as the coating sheet, and the film formed on the coating sheet may not be peeled off, and the coated sheet may be used as a substrate for a flexible display.

The coating plate may, for example, be a glass plate, a metal plate, a resin film or the like.

The coating method may, for example, be a roll coating method, a knife coating method, a die coating method, a dip coating method, a bar coating method, or the like.

When the resin composition contains the polyamic acid, it may be heated to be imidized by heating after application. The temperature and time of the hydrazine imidization may, for example, be the temperature and time of the hydrazine imidization in the production of the polyimine.

The flexible display having the substrate for a flexible display may, for example, be an organic EL display or an electronic paper.

An example of the organic EL display will be described. This organic EL device has a light-emitting layer between electrodes composed of a pair of anodes and cathodes which are transparent at least on one surface. Examples of such an organic EL device include the following organic EL devices.

(1) An organic EL element (anode/light-emitting layer/electron transport layer/cathode) in which an electron transport layer is provided between the cathode and the light-emitting layer ("/" means that each layer is adjacent and laminated)

(2) an organic EL element (anode/hole transport layer/light-emitting layer/cathode) having a hole transport layer between the anode and the light-emitting layer

(3) an organic EL element (anode/hole transport layer/light-emitting layer/electron transport layer) provided with an electron transport layer between the cathode and the light-emitting layer, and a hole transport layer between the anode and the light-emitting layer /cathode)

A flexible organic EL display having a layer structure (anode/hole transport layer/light emitting layer/electron transport layer/cathode) can be manufactured by, for example, a transparent or opaque flexibility An anode is formed on the substrate for display, and a cathode (where one surface is transparent) is formed on the transparent or opaque substrate for flexible display, and holes are sequentially formed on the substrate for flexible display forming the anode. The transport layer, the light-emitting layer, and the electron transport layer are finally stacked on the flexible display substrate in which the cathodes are formed so as to sandwich the respective layers, and the electrodes are formed to face the respective sides to seal the ends.

[Examples]

The embodiments of the present invention are described below, but the present invention is not limited by the embodiments.

In the following examples and comparative examples, compounds represented by the following structural formulas were used. For these compounds, the abbreviations below are used.

(Manufacturing Example 1)

<Synthesis of SBPDIDA>

SBPDIDA was synthesized according to the method described in Macromol. Chem. Phys. 200, 1879-1888 (1999). The method is as follows.

Under a nitrogen flow, in a 500 mL four-necked flask equipped with a mechanical stirring device and a cooling tube, 54.14 g (500.6 mmol) of p-phenylenediamine (PDA) and 280 g of 1-methyl-2-pyrrolidone (NMP) were added. Heat and stir at 60 °C. After confirming dissolution, 14.71 g (50.00 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was added in small portions. After heating and stirring at 60 ° C for 2 hours, heating and stirring were carried out at 190 ° C for 4 hours. After allowing to cool, the precipitated SBPDIDA was filtered and washed with 500 mL of ethanol. It was dried in a vacuum oven at 100 ° C for 12 hours to separate the red crystalline SBPDiDA. The yield was 20.93 g. The yield was 88.2%.

(1) ¹ H NMR (DMSO-d6, δ)

8.34 (d, J = 8.1 Hz, 2H), 8.32 (s, 2H), 8.04 (d, J = 7.8 Hz, 2H), 7.04 (d, J = 8.4 Hz, 4H), 6.64 (d, J = 8.7) Hz, 4H), 3.85 (Brs, 4H)

(2) IR (KBr, cm ^-1 ):

3438, 3328, 3215 (above is NH stretching), 1766, 1720 (above is yttrium carbonyl stretching), 1516, 1383 (above is aromatic ring stretching)

(3) m.p. (DSC)

405 ° C ~ 409 ° C

(Example 1)

<Preparation of polyamic acid varnish>

<<Diamine: SBPDiDA, tetracarboxylic acid component / diamine component = 1.00 / 1.00 (mole ratio), solid content 10% by mass>>

2.80 g of BPDA (6.80 mmol), 3.23 g of SBPDiDA (6.80 mmol), and 47.0 g of NMP were weighed and placed in a 100 mL glass vial. The mixture was stirred at room temperature for 3 days in a jar mill to obtain a polyamic acid varnish.

(Example 2)

<Preparation of polyamic acid varnish>

<<Diamine: SBPDiDA, tetracarboxylic acid component / diamine component = 0.98 / 1.00 (mole ratio), solid content 10% by mass>>

2.80 g of BPDA (6.80 mmol), 3.29 g of SBPIDDA (6.93 mmol), and 47.6 g of NMP were weighed and placed in a 100 mL glass vial. The mixture was stirred at room temperature for 3 days in a pot mill to obtain a polyamic acid varnish.

(Comparative Example 1)

<Preparation of polyamic acid varnish>

<<Diamine: PDA, tetracarboxylic acid component / diamine component = 1.00 / 1.00 (mole ratio), solid content 10% by mass>>

5.00 g of BPDA (16.99 mmol), 1.84 g of PDA (16.99 mmol), and 61.5 g of NMP were weighed and placed in a 100 mL glass vial. In a pot mill, stir at room temperature for 3 days to obtain polyfluorene Amino acid varnish.

(Comparative Example 2)

<Preparation of polyamic acid varnish>

<<Diamine: PDA, tetracarboxylic acid component / diamine component = 0.98 / 1.00 (mole ratio), solid content 10% by mass>>

5.00 g of BPDA (16.99 mmol), 1.88 g of PDA (17.38 mmol), and 61.9 g of NMP were weighed and placed in a 100 mL glass vial. The mixture was stirred at room temperature for 3 days in a pot mill to obtain a polyamic acid varnish.

(Comparative Example 3)

<Preparation of polyamic acid varnish>

<<Diamine: PDA/SBPDIDA (10/1 molar ratio), tetracarboxylic acid component/diamine component=0.98/1.00 (mole ratio), solid content 10% by mass>>

5.00 g of BPDA (16.99 mmol), 1.67 g of PDA (15.45 mmol), 0.73 g of SBPIDDA (1.54 mmol), and NMP 66.63 g were weighed and placed in a 100 mL glass vial. The mixture was stirred at room temperature for 3 days in a pot mill to obtain a polyamic acid varnish.

(Production of polyimine film)

The resulting polyamic acid varnish was cast on a glass plate provided with a gap. The glass plate was dried under predetermined drying conditions (described in Table 1-1 and Table 1-2). Next, hydrazylation was carried out at 250 ° C / 1 h + 350 ° C / 1 h. After cooling, the obtained polyimide film was peeled off from the glass to carry out separation. In order to release the stress remaining in the polyimide film, heat treatment at 360 ° C / 1 h was carried out without applying tension to obtain a polyimide film.

(TMA measurement: measurement of coefficient of linear expansion (CTE))

The coefficient of linear expansion was calculated using a thermomechanical measuring device (TMA/SS6100 manufactured by SII Corporation). First, the tension was applied so that the film thickness was 4.9 mN per 1 μm, and the treatment was carried out at 30 ° C to 150 ° C (temperature rising rate 10 ° C / min) in a nitrogen atmosphere to remove the adsorbed moisture. Then, after cooling in a nitrogen atmosphere while maintaining the tension, tension was applied so that the film thickness was 4.9 mN per 1 μm, and the measurement was performed at 50 ° C to 350 ° C (heating rate 5 ° C / min) to calculate Linear expansion coefficient. The results are shown in Table 1-1 and Table 1-2, and are shown in Figure 1. Further, the linear expansion coefficients in Tables 1-1 and 1-2 are arithmetic mean values of 100 ° C to 200 ° C.

Examples 3 and 4 are the case of using a varnish of BPDA/SBPDIDA having an acid/amine ratio of 1.00. Although it has a thickness of about 20 μm, it exhibits a linear expansion coefficient of 3.72 ppm/K and 3.47 ppm/K under drying at 60 °C.

Examples 5 to 9 were the case of using a varnish of BPDA/SBPDIDA having an acid/amine ratio of 0.98. Examples 5 and 6 had different thicknesses under the same drying conditions, but were low linear expansion coefficients of 3.05 ppm/K and 4.46 ppm/K, respectively.

In Example 7, the drying time in Example 6 was shortened, and the coefficient of linear expansion was 4.76 ppm/K, which was a low coefficient of linear expansion.

Examples 8 and 9 have different thicknesses under the same drying conditions, but are 6.75 ppm/K and 5.61 ppm/K, respectively, and have a low coefficient of linear expansion.

Since the drying time causes the coefficient of linear expansion to be different, this is considered to be the result of the difference in the cohesive force exhibited.

Comparative Examples 4 to 7 are comparative examples in which the drying conditions and the average thickness were changed.

When the average thickness of the polyamidene obtained from the polyamic acid varnish of Comparative Example 1 is about 10 μm, the low linear expansion coefficient is about 5 ppm/K, but if it is about 20 μm, the linear expansion coefficient becomes large. , more than 14ppm / K.

In Comparative Example 9, PDA was used as the majority of the diamine. In this case, the CTE cannot be made small, and a large value of 14.0 ppm/K is exhibited.

(viscosity measurement)

The viscosity at 25 ° C was measured using a rheometer (TA Instruments AR-G2). The results are shown in Table 2.

After storage for 53 days at 25 ° C, the viscosity of the polyamic acid varnish of Example 1 (polyammonic acid content 10% by mass) was 14.33 Pa. s, the viscosity of the polyamic acid varnish (polyglycine content 10% by mass) of Example 2 is 3.94 Pa. s. From this point of view, it can be clearly understood that the polyamic acid varnishes of Examples 1 and 2 have a sufficient viscosity and can be used for film formation even after 53 days. On the other hand, the viscosity of the polyamic acid varnish (polyglycine content: 10% by mass) of Comparative Example 1 and Comparative Example 2 in which SBPDIDA was not used was 0.3 Pa after 9 days. Below s, it can be understood that the viscosity is too low for film formation.

The polyimine films produced in Example 3 and Example 5 were evaluated as follows. The results are shown in Table 3.

(volume resistivity)

The polyimide film was sandwiched between a resistive cell having an electrode having a diameter of 50 mm, and a volume resistivity was calculated by applying a current value at 100 V using a high resistance meter (high resistance meter 4339B: Agilent). Further, the temperature at the time of measurement was 25 ° C or lower.

(1% weight reduction temperature)

The polyimide film was placed in an aluminum pan and measured using a thermogravimetric measuring apparatus (manufactured by TG/DTA6200 SII). The temperature range is from 30 ° C to 550 ° C (heating rate of 5 ° C / min) and is carried out under a nitrogen atmosphere.

(storage modulus E’)

The polyimide film was cut into a width of 1 cm and a length of 3 cm, and measured using a dynamic viscoelasticity measuring apparatus (manufactured by RSA3 TA Co., Ltd.). The temperature range was 25 ° C to 400 ° C (temperature up rate was 5 ° C / min), the applied frequency was 1 Hz, and the measurement was performed under the atmosphere.

(elongation at break and 5% tensile stress)

The polyimine film was cut into a width of 1 cm and a length of 10 cm, and a tensile test was performed at 20 mm/min using a universal testing machine (manufactured by Autocom AC-50 TSE Co., Ltd.) to obtain a stress-strain curve. Thereby, elongation at break (%) and 5% tensile stress (MPa) were obtained.

From the measurement results of the volume resistivity, it was confirmed that the polyimine of the present invention has the same molecular weight as the conventional polyimine, and has 10 ¹⁵ Ω. The insulation of the m station is sufficient.

From the results of the measurement of the 1% weight loss temperature, it was confirmed that the polyimine of the present invention did not decrease even at a temperature of 550 ° C, and it was confirmed that the heat resistance was sufficient. Further, the measurement temperature range of up to 550 ° C is limited by the melting point of the aluminum pan used.

From the measurement results of the storage modulus, the elongation at break, and the tensile stress of 5%, it was confirmed that the polyimide film of the present invention is a film having sufficient hardness and toughness.

[Industrial availability]

The polyimine of the present invention can be preferably applied as a substrate of a flexible display because it has a low coefficient of linear expansion.

Claims (19)

A polyimine which is a polyimine obtained by reacting a tetracarboxylic acid component with a diamine component, characterized in that the tetracarboxylic acid component contains a compound represented by the following structural formula (1); The component contains 60 mol% or more of the compound represented by the following structural formula (2); The polyimine according to claim 1, wherein the film has a linear expansion coefficient of 2.00 ppm/K to 7.00 ppm/K when a film having an average thickness of 20 μm is formed. The polyimine according to claim 1, wherein the film has a linear expansion coefficient of 3.00 ppm/K to 7.00 ppm/K when a film having an average thickness of 20 μm is formed. The polyimine according to claim 1, wherein the diamine component contains 95% by mole or more of the compound represented by the structural formula (2). The polyimine according to claim 1, wherein the tetracarboxylic acid component contains 95% by mole or more of the compound represented by the structural formula (1). The polyimine according to claim 1, wherein the molar ratio (tetracarboxylic acid component/diamine component) of the tetracarboxylic acid component to the diamine component is from 1.00/1.00 to 0.96/1.00. The polyimine according to claim 1, wherein the molar ratio (tetracarboxylic acid component/diamine component) of the tetracarboxylic acid component to the diamine component is from 1.00/1.00 to 0.98/1.00. A polyimine, which is a polyimine having a repeating unit represented by the following structural formula (3), characterized in that the linear expansion coefficient of the film is 2.00 ppm/K when a film having an average thickness of 20 μm is formed. ~7.00ppm/K; The polyimine according to claim 8, wherein the film has a linear expansion coefficient of 3.00 ppm/K to 7.00 ppm/K. The polyimine according to claim 8, wherein the repeating unit represented by the structural formula (3) is 90 mol% or more based on the total amount of the repeating unit of the polyimine. The polyimine according to claim 8, which is obtained by reacting a tetracarboxylic acid component and a diamine component, wherein the tetracarboxylic acid component contains a compound represented by the following structural formula (1). The diamine component contains 60 mol% or more of the compound represented by the following structural formula (2) with respect to the diamine component; [Chemical 4] A poly-proline acid obtained by reacting a tetracarboxylic acid component with a diamine component, wherein the tetracarboxylic acid component comprises a compound represented by the following structural formula (1); The component contains 60 mol% or more of the compound represented by the following structural formula (2); The polyaminic acid according to claim 12, wherein the diamine component contains 95% by mole or more of the compound represented by the structural formula (2). The polyamic acid according to claim 12, wherein the tetracarboxylic acid component contains 95% by mole or more of the compound represented by the structural formula (1). The poly-proline which is described in claim 12, wherein the molar ratio (tetracarboxylic acid component/diamine component) of the tetracarboxylic acid component to the diamine component is from 1.00/1.00 to 0.96/1.00. The poly-proline which is described in claim 12, wherein the molar ratio (tetracarboxylic acid component/diamine component) of the tetracarboxylic acid component to the diamine component is from 1.00/1.00 to 0.98/1.00. The polyamic acid according to claim 12, wherein the liquid containing 10% by mass of polyamic acid has a viscosity of 1 Pa after one month at 25 ° C. s above. A resin composition, comprising: the polyimine according to any one of claims 1 to 11 and the polyamic acid according to any one of claims 12 to 17; Either. A substrate for a flexible display, comprising: the polyimine according to any one of claims 1 to 11 and the polybenz according to any one of claims 12 to 17. Any of the amine acids.