KR20160081613A - Planarization film for the substrate of flexible organic light emitting diodes devices and flexible organic light emitting diodes devices containing the same - Google Patents

Abstract

The present invention relates to a planarization film for a substrate of a flexible OTFT device, and a flexible OTFT device comprising the same. More particularly, provided is a flexible OTFT device securing physical properties of low voltage, high efficiency, high color purity by introducing a planarization film having a particular material and structure to an upper surface of a substrate of the flexible OTFT device as a planarization layer to prevent and/or minimize degradation of electronic characteristics of the OTFT device caused by introducing a paper material as the OTFT substrate material. The planarization film comprises at least one type selected among: PMF, PVP, PGMEA, PEGDMA, PPGDMA, PPGDA, PDEGDA, a POSS-based compound represented by chemical formula 1, a silazane-based compound represented by chemical formula 2, a polysilazane-based compound, and a polymer represented by chemical formula 3.

Description

TECHNICAL FIELD [0001] The present invention relates to a planarizing film for a substrate of a flexible OTFT device and a flexible OTFT device including the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a flattening film for substrate of a flexible OTFT device and a flexible OTFT device including the flattening film. When a polyamide paper is introduced into a base layer to realize flexible, To a flattening film capable of minimizing and / or preventing deterioration of characteristics, and a flexible OTFT device including the flattening film.

In recent years, interest and research on smart wear have been increasing. Smart apparel means functional clothing capable of embodying digital functions by combining electric and electronic materials while maintaining the properties of textiles and clothing, It has been developed for military use, and is currently undergoing research and investment to expand its application to the clothing and medical fields. For example, clothing electronics can be used to combine clothing with wearable computers.

In addition, with regard to display in recent years, development of a flexible display capable of folding, bending, and speaking is demanded because people desire a larger screen with ease of portability. Flat panel displays such as OLEDs and LCDs require an active matrix drive method for high resolution and low power operation. Inorganic thin film transistors, such as silicon currently used, have a high manufacturing temperature and break easily when bent or bent. There is a limit to apply.

As described above, in order to provide flexible electric and electronic products such as smart clothes and flexible displays, researches on organic thin film transistors (OTFTs) and OLED devices that can withstand bending or bending have been actively conducted .

As an organic thin film transistor (OTFT) or an organic light emitting diode (OLED) device, an organic semiconducting material is dissolved in a solvent to form a thin film by a variety of coating methods. Organic semiconductors that can not dissolve in a solvent and form a thin film by sublimating organic semiconductors by applying heat in a high vacuum device. The method that can apply the organic semiconductor thin film by the solution process has a lower manufacturing cost than the vacuum evaporation method and has recently been actively studied because it is possible to perform a roll to roll continuous process on a flexible substrate by various coating methods.

In the roll-to-roll process, the flexible organic thin film transistor can be mass-produced at a lower cost. However, for this purpose, it is necessary to use substrates such as plastic or stainless steel which can be rolled up to a temperature of 300 ° C. or less, or a material excellent in flexibility and electrical properties There is a problem in that it is necessary to introduce the system. Conventionally, PET films and fibers have been introduced as organic thin film transistors (OTFTs) and / or substrates for OLED devices. However, there is a limit in that heat resistance is insufficient.

U.S. Registration No. US 6,107,117 (published on August 22, 2000) Korea Open Patent KR 2012-0021023 (public date March 23, 2012)

The present inventors have studied to solve the heat resistance limitations of conventional flexible OTFT devices, and as a result, found that the polyamide paper introduced for improving the heat resistance and flexibility minimizes and / or prevents deterioration of the electrical characteristics of the flexible OTFT device A planarizing film for a substrate of a flexible OTFT device and a flexible OTFT device using the same, which can secure heat resistance and excellent electrical and optical characteristics when a two-layer planarization layer composed of a specific material is formed.

The present invention relates to a flattening film for substrate of a flexible OTFT device, and more particularly, to a flattening film for a substrate of a flexible OTFT device, which is made of PMF (polyamine-co-formaldehyde), poly (4-vinylphenol), PGMEA (propylene glycol monomethyl ether acetate ), PEGDMA (Polyethylene glycol dimethacrylate), PPGDMA (Polypropylene glycol dimethacrylate), PPGDA (Polypropylene glycol diacrylate), PDEGDA (Polyethylene glycol diacrylate), POSS compounds represented by the following formula A silazane-based compound, a polysilazane-based compound, and a polymer represented by the following formula (3).

[Chemical Formula 1]

,

또는

이고, R¹, R³ 및 R⁴는 각각은 독립적인 것으로서, 탄소수 2 ~ 5의 알킬렌기이며, R²는 수소원자 또는 탄소수 1 ~ 5의 알킬기이고, X는 -NHR⁵이고, 상기 R⁵는 수소원자 또는 탄소수 1 ~ 5의 알킬기이다.In Formula 1, E is

,

or

And, R ^1, R ³ And Each of R ⁴ is independently an alkylene group having 2 to 5 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, X is -NHR ⁵ , R ⁵ is a hydrogen atom, Lt; / RTI >

(2)

In Formula 2, R < ^{1 >} To R ⁹ Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, B is -NHR ¹⁰ , and R ¹⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

(3)

In the general formula (3), R &^lt; ¹ > Each R ⁸ is independently a hydrogen atom, a halogen atom, a carboxyl group, an amide group, -CF ₃ , -Si (OR) _m H _3-m , a formyl group or N is an rational number satisfying a weight average molecular weight of 50,000 to 200,000, and m is an integer of 0 to 3.

In one preferred embodiment of the present invention, the polysilazane based compound is a polymer of a monomer represented by the following formula 4-1; A copolymer comprising a compound represented by the following formula (4-1) and a compound represented by the following formula (4-2); And a polymer represented by the following formula (4-3).

[Formula 4-1]

In Formula 4-1, R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms,

[Formula 4-2]

In Formula 4-2, R ¹ is an alkyl group having 1 to 3 carbon atoms,

[Formula 4-3]

In Formula 4-3, R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ² is an alkylene group having 2 to 5 carbon atoms, R ³ and R ⁴ are independently a hydrogen atom, An alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, and R ⁵ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

In one preferred embodiment of the present invention, as the polysilazane compound, the copolymer is characterized by copolymerizing the monomer represented by the formula (4-1) and the monomer represented by the formula (4-2) in a molar ratio of 1: 2 to 6 can do.

As a preferred embodiment of the present invention, when the base material of the flexible OTFT device is a polyamide paper, the planarizing film has a single layer structure of PMF, PVP, PGMEA, PEGDMA, PPGDMA, PPGDA, PDEGDA, POSS Based compound represented by Formula 2, and a polysilazane-based compound.

In a preferred embodiment of the present invention, when the substrate of the flexible OTFT device is a polyamide film, the planarizing film may have a single-layer structure and include a polymer represented by the above-mentioned formula (3).

In a preferred embodiment of the present invention, when the base material of the flexible OTFT device is a polyamide paper or polyamide film, the planarizing film has a multi-layered structure of PMF, PVP, PGMEA, PEGDMA, PPGDMA, PPGDA, PDEGDA, A first planarization layer comprising at least one selected from the group consisting of a POSS compound represented by Formula 2, a silazane compound represented by Formula 2 and a polysilazane compound; And a second planarizing layer comprising a polymer represented by Formula 3, wherein a first planarizing layer and a second planarizing layer are sequentially stacked on the upper surface of the substrate.

Also, as a preferred embodiment of the present invention, the planarizing film may be a dimethacrylate-based compound containing at least one selected from PEGDMA and PPGDMA; And a mixture containing the POSS compound, the silazane and the polysilazane in a weight ratio of 1: 0.1 to 1.5.

Further, as a preferred embodiment of the present invention, the planarizing film may have an average thickness of 0.1 to 10 m.

In a preferred embodiment of the present invention, the first planarizing layer and the second planarizing layer have a thickness ratio of 1: 0.1 to 10.

In one preferred embodiment of the present invention, the planarizing film is formed between a substrate and a gate of the OTFT device to form a planarization layer.

As a preferred embodiment of the present invention, in the substrate flattening film of the flexible OTFT device of the present invention, the substrate of the flexible OTFT device may be a polyamide paper or a polyamide film.

In one preferred embodiment of the present invention, the polyamide paper may include at least one selected from the group consisting of a meta-polyamide paper, a para-polyamide paper, and a meta-para-polyamide paper.

In a preferred embodiment of the present invention, when a meta-polyamide paper is used as the base material of the flexible OTFT device, the meta-polyamide paper has an apparent density of 0.20 g / cm 3 to 0.40 g / cm 3, ASTM D-828 , The tensile strength in the MD direction is not less than 25 N / cm, the elongation in the MD direction is not less than 5.0%, and the tear strength in the MD direction when measured according to TAPPI T414 is 0.95 N Or more. The metapolyamide paper having a basis weight of 0.14 mm may have a tensile strength in the MD direction of 20 to 30 Nm 2 / kg, wherein the metapolyamide paper has a basis weight of 35 To 50 g / m < 2 >.

In one preferred embodiment of the present invention, the meta-polyamide paper comprises a meta-polyamide floc and a meta-amide fibrid, wherein the floc and the fibrid have an intrinsic viscosity (IV) of 1.5 to 2.0 have.

As a preferred embodiment of the present invention, as a base material of the flexible OTFT device, a polyamide film is obtained by curing a polyamide resin containing a polymer of a diamine and a phthaloyl compound, wherein the polyamide resin is a mixture of a diamine and a phthaloyl Compound in an equivalent ratio of 1: 0.9 to 1.1.

As a preferred embodiment of the present invention, the present invention provides a substrate for a flexible OTFT, wherein the diamine of the polyamide resin is at least one selected from the group consisting of phenylenediamine containing at least one selected from the group consisting of metaphenylenediamine and paraphenylenediamine; And at least one selected from 3,3'-oxydianiline and 3,4'-oxydianiline is oxydianiline; And the like. The phthaloyl compound of the polyamide resin is a terephthaloyl compound containing at least one selected from terephthaloyl chloride and terephthaloyl bromide; And an isophthaloyl compound containing at least one selected from isophthaloyl chloride and isophthaloyl bromide; , And the like.

In one preferred embodiment of the present invention, the polyamide resin may include the phenylenediamine and the oxydianiline in a weight ratio of 7: 9: 1 to 3: Phenylenediamine and paraphenylenediamine in a weight ratio of 1: 1 to 3: 1.

In another preferred embodiment of the present invention, the diamine of the polyamide resin is selected from the group consisting of mephenylenediamine, paraphenylenediamine, 3,4'-oxydianiline and 4,4'-oxydianiline in a molar ratio of 3.5 to 4.5: 3.5 to 4.5: 0.5 to 1.5: 0.5 to 1.5 in weight ratio.

In another preferred embodiment of the present invention, the diamine of the polyamide resin comprises the phenylenediamine and the oxydianiline in a weight ratio of 7 to 8: 2 to 3, and the phenylenediamine is paraphenylenediamine And the oxydianiline includes at least one selected from the group consisting of 3,4'-oxydianiline and 4,4'-oxydianiline, and the phthaloyl compound is selected from the group consisting of a terephthaloyl compound and an isophthaloyl compound in an amount of 6 To 8: 2 to 4 weight ratio.

As a preferred embodiment of the present invention, in the present invention, the polyamide resin is a neutralizer containing at least one member selected from calcium hydroxide, calcium oxide and lithium hydroxide, based on 100 parts by weight of the polymer of the diamine and phthaloyl compound And 2 to 8 parts by weight of a pore-forming agent containing at least one selected from the group consisting of polyvinylpyrrolidone and polyethylene glycol, based on 100 parts by weight of the polymer, And the like.

In one preferred embodiment of the present invention, the pore-forming agent may be polyvinylpyrrolidone having a weight average molecular weight of 5,000 to 45,000.

Also, as a preferred embodiment of the present invention, the polymer may be characterized by a para content of 80% to 90%.

In a preferred embodiment of the present invention, the polyamide resin has a solution viscosity of 45,000 to 120,000 cP and a coefficient of thermal expansion (CTE) of 15 ppm / m 2, measured at 25 ° C with a Brookfield viscometer, ° C. to 25 ppm / ° C. and a glass transition temperature (Tg) of 300 ° C. to 340 ° C.

In a preferred embodiment of the present invention, the polyamide resin has a heat shrinkage of 0.01% to 0.4% when measured according to IPC TM6502.2.4A, a young's modulus when measured according to ASTM D882, Is in the range of 5.8 Gpa to 7.0 Gpa.

Another object of the present invention is to provide a flexible OTFT device which includes various types of planarization films as described above, and more specifically, a substrate (or a base layer) including the polyamide paper, a planarizing film (or a planarization layer) (Or substrate layer), the planarization film (or planarization layer), the gate, and the gate, and may comprise a gate, a gate insulator, a source, a drain, Gate electrode insulators may be stacked in order.

In a preferred embodiment of the present invention, in the flexible OTFT device of the present invention, the substrate has an average thickness of 0.1 to 150 μm, and the flattened film has an average thickness of 0.1 to 10 μm.

Further, in a preferred embodiment of the present invention, in the flexible OTFT device of the present invention, the flattening film has a root mean square surface roughness (RMS) of 0.1 nm to 300 nm.

As a preferred embodiment of the present invention, in the flexible OTFT device of the present invention, when the base material is a polyamide film, the ratio of the current values when the device is on and off with a parameter measuring device (Semiconductor Parameter Analyzer, Aigilent 4155C) In the measurement, the transfer curve (I _on / I _off ) ratio may be 1.0 × 10 ^-4 to 1.0 × 10 ^-2 .

As a preferred embodiment of the present invention, in the flexible OTFT device of the present invention, when the base material is a polyamide film, when the electron mobility is measured at 10 V to -30 V by a semiconductor parameter analyzer, ^-4 to 1.0 x 10 ^-2 cm ² / V · s.

As a preferred embodiment of the present invention, in the flexible OTFT device of the present invention, when the base material is a polyamide film, when measuring the gate voltage at the turn-on time of the device with the semiconductor parameter analyzer, Voltage, V _th ) value may be from -12.0V to -6.0V.

As a preferred embodiment of the present invention, in the flexible OTFT device of the present invention, when the substrate is a polyamide paper, when measuring the ratio of the current value when the device is on and off with a semiconductor parameter measurer, the transfer curve , I _on / I _off ) ratio of 1.0 × 10 ² to 1.0 × 10 ⁴ .

In one embodiment of the present invention, in flexible OTFT devices of the present invention, the substrate is polyamide paper one time, when measured by a semiconductor parameter analyzer to -100 V from 10V, also the value of 1.0 × 10 ^-4 electromigration ~ 3.5 × 10 ^-2 cm may be characterized in that the ² / V · s.

As a preferred embodiment of the present invention, in the flexible OTFT device of the present invention, when the base material is a polyamide paper, when measuring the gate voltage at the time when the device is turned on by the semiconductor parameter analyzer, -14.0V.

The planarizing film of the present invention is a substrate of an OTFT for producing a flexible OTFT, and it is an object of the present invention to prevent deterioration of electrical characteristics due to high surface roughness of the substrate itself, which is a problem that occurs when a film or paper substrate is introduced, and / It is possible to obtain an electric characteristic having an excellent electron mobility and a high threshold voltage (V _th ) value while having a high transfer curve (I _on / I _off ) To a planarizing film capable of producing a flexible organic thin film transistor.

FIG. 1 is a schematic view of an organic thin film transistor including a planarizing structure to facilitate understanding of the present invention, which is a preferred embodiment of the present invention.
2 is a schematic view of a process for producing a polyamide paper.
3 is an AFM (atomic force microscope) measurement image obtained by measuring the surface roughness of the planarizing layer of the flexible OTFT device of Comparative Example 2-3 conducted in Experimental Example 4. FIG.
4 is an AFM measurement photograph of the surface roughness of the planarizing layer of the flexible OTFT device of Example 2-1 performed in Experimental Example 4. FIG.
5 is an AFM measurement photograph of the surface roughness of the planarizing layer of the flexible OTFT device of Comparative Example 2-4 conducted in Experimental Example 4. FIG.
Fig. 6 is an AFM measurement photograph of the surface roughness of the planarization layer of the flexible OTFT device of Example 2-2 performed in Experimental Example 4. Fig.
7 is a graph showing the operation and electric characteristic measurement of the OTFT device of Example 2-1, Example 2-3, and Comparative Example 2-1 performed in Experimental Example 5. V _GS (gate voltage) is a gate voltage, and V _DS (I _DS ) denotes the current flowing between the source and the drain, and W / L denotes the gate width / channel length. .
FIG. 8 is a graph illustrating the operation and electrical characteristics of the OTFT device of Examples 2-8 and 2-5 performed in Experimental Example 5. V _GS (gate voltage) is a gate voltage, and I _DS and source) refers to the current flowing between the source and the drain.
FIG. 9 is a graph showing the operation and electrical characteristics of the OTFT device of Examples 1-7 and Comparative Example 2-1 performed in Experimental Example 5. FIG.
10 is an operation and electrical property measurement experiment of the OTFT device of Example 1-1 performed in Experimental Example 5. FIG.

The term " film " used in the present invention has a broad meaning including a sheet form, a thin film form, and a coating form as well as a film form commonly used in the art.

The term [C1], [C2], etc. used in the present invention means the number of carbon atoms. For example, [C1 to C5 alkyl] means an alkyl group having 1 to 5 carbon atoms.

"로 표현된 화학식에서, [R₁은 독립적으로 수소원자, 메틸기 또는 에틸기이며, a는 1 ~ 3이다.]라고 치환기에 대해 표현되어 있을 때, a가 3인 경우, 복수의 R¹, 즉 R¹ 치환기가 3개가 있고, 이들 복수 개의 R¹들 각각은 서로 같거나 다른 것으로서, R¹들 각각은 모두 수소원자, 메틸기 또는 에틸기일 수 있으며, 또는 R¹들 각각은 다른 것으로서, R¹ 중 하나는 수소원자, 다른 하나는 메틸기 및 또 다른 하나는 에틸기일 수 있음을 의미하는 것이다. 그리고, 상기 내용은 본 발명에서 표현된 치환기를 해석하는 일례로서, 다른 형태의 유사 치환기도 동일한 방법으로 해석되어야 할 것이다.In the present invention,

In the formula represented by R ₁ is independently a hydrogen atom, a methyl group or an ethyl group, and a is 1 to 3. When a is 3, a plurality of R ¹ , that is, R ¹ As there are three substituents, each of a plurality of R ¹ which are the same or different, R ¹ in each of both may be a hydrogen atom, methyl or ethyl, or R ¹ as each of the other, R ¹ One of Hydrogen atom, the other is a methyl group, and the other is an ethyl group. The above is an example of interpreting the substituent represented by the present invention, and other similar substituents should also be interpreted in the same way.

As used herein, the term "flock" refers to fibers of shorter length than staple fibers, the flock length is from about 0.5 to about 15 mm, the diameter is from 4 to 50 micrometers, To 12 mm and a diameter of from 8 to 40 [mu] m. The polyamide flock has a short length of polyamide fibers without significant or optional fibrillization as produced by, for example, the methods described in U.S. Patent Nos. 3,063,966, 3,133,138, 3,767,756 and 3,869,430 And can be produced by cutting. In addition, the term "fibrids " as used herein means non-granular pulp or film-like particles, preferably the melting point or decomposition point thereof may exceed 320 ° C. The fibrids have an average length of 0.5 to 2 mm and an aspect ratio of 15: 1 to 50: 1. Including the use of a fibridation apparatus of the type disclosed in U.S. Patent No. 3,018,091, and any method in which the polymer solution is precipitated and sheared in a single step.

Hereinafter, the present invention will be described in more detail.

In order to ensure flexibility in the flexible OTFT device, a polyamide film and / or a polyamide paper can be introduced as a base material into the substrate 10, and at this time, due to the surface roughness of the polyamide film and / or the polyamide paper, The present invention is intended to provide a planarizing film as a means for preventing the electrical properties of the substrate from being degraded due to surface roughness.

The flattening film of the present invention is formed on the upper surface of the substrate (or base layer) of the flexible OTFT device as schematically shown in Fig. 1, and the flattening film 20 may be formed in a single layer structure, 1, the planarization film 20 may be formed in a multi-layered structure of a first planarization layer 21 and a second planarization layer 22. [

The planarizing film of the present invention can be formed by using PMF (poly (4-vinylphenol), PVMEA (propylene glycol monomethyl ether acetate), PEGDMA (poly ethylene glycol dimethacrylate), PPGDMA (polypropylene glycol dimethacrylate ), PPGDA (poly propylene glycol diacrylate), PDEGDA (poly diethylene glycol diacrylate), POSS compound represented by the following formula 1, silazane compound represented by the following formula 2, polysilazane compound, And the like.

[Chemical Formula 1]

,

또는

이고, 바람직하게는

또는

이다. 그리고, 상기 R¹, R³ 및 R⁴ 각각은 독립적인 것으로서, 탄소수 2 ~ 5의 알킬렌기이며, 바람직하게는 탄소수 2 ~ 3의 알킬렌기이다. 또한, 상기 R²는 수소원자 또는 탄소수 1 ~ 5의 알킬기이고, 바람직하게는 탄소수 1 ~ 3의 알킬기, 더욱 바람직하게는 탄소수 1 ~ 2의 알킬기이다. 그리고, 상기 X는 -NHR⁵이고, 상기 R⁵는 수소원자 또는 탄소수 1 ~ 5의 알킬기이며, 바람직하게는 수소원자이다.In Formula 1, E is

,

or

, And preferably

or

to be. The above R ¹ and R ³ And Each R ⁴ is independently an alkylene group having 2 to 5 carbon atoms, preferably an alkylene group having 2 to 3 carbon atoms. R ² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, more preferably an alkyl group having 1 to 2 carbon atoms. X is -NHR ⁵ , and R ⁵ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom.

(2)

In Formula 2, R < ^{1 >} To R ⁹ Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, preferably a hydrogen atom. B is -NHR ¹⁰ , R ¹⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and preferably R ¹⁰ is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms.

(3)

In the general formula (3), R &^lt; ¹ > Each R ⁸ is independently a hydrogen atom, a halogen atom, a carboxyl group, an amide group, -CF ₃ , -Si (OR) _m H _3-m , a formyl group or An acyl group is preferable, and R &^lt; ¹ > to R &^lt; Each R < ⁸ > is independently a fluorine atom, a chlorine atom or a formyl group, more preferably R &^lt; Each R < ⁸ > is a fluorine atom. The polymer represented by the formula (3) is a rational number satisfying a weight average molecular weight of 50,000 to 200,000, preferably a rational number satisfying a weight average molecular weight of 70,000 to 150,000. M is an integer of 0 to 3, preferably an integer of 2 to 3, more preferably 3.

The polysilazane compound may be a polymer of a monomer represented by the following formula (4-1); A copolymer comprising a compound represented by the following formula (4-1) and a compound represented by the following formula (4-2); And a polymer represented by the following formula (4-3), preferably a copolymer comprising a compound represented by the following formula (4-1) and a compound represented by the following formula (4-2) And more preferably a copolymer obtained by copolymerizing the monomer represented by Formula 4-1 and the monomer represented by Formula 4-2 at a molar ratio of 1: 2 to 6.

[Formula 4-1]

In Formula 4-1, R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 carbon atom.

[Formula 4-2]

In the formula (4-2), R ¹ is an alkyl group having 1 to 3 carbon atoms, preferably an alkyl group having 1 carbon atom.

[Formula 4-3]

In Formula 4-3, R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, preferably an alkyl group having 1 carbon atom. R ² is an alkylene group having 2 to 5 carbon atoms, preferably an alkylene group having 2 to 3 carbon atoms. R ³ and R ⁴ are independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, preferably an alkoxy group having 1 to 3 carbon atoms. And R ⁵ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, preferably an alkyl group having 1 carbon atom.

In the present invention, when a polyamide paper is introduced as a base material of a flexible OTFT device, the planarizing film may be formed as a single layer structure. Here, the planarizing film may be PMF, PVP, PGMEA, PEGDMA, PPGDMA, PPGDA, PDEGDA , A POSS compound represented by the formula (1), a silazane compound represented by the formula (2), and a polysilazane compound, and preferably at least one selected from PEGDMA and PPGDMA Dimethacrylate-based compounds; And a mixture containing the POSS compound, the silazane, and the polysilazane in a weight ratio of 1: 0.1 to 1.5.

In addition, when the substrate of the flexible OTFT element introduces the polyamide film as the base material of the flexible OTFT device, the planarizing film may be formed as a single layer structure, wherein the planarizing film includes the polymer represented by the above formula (3) .

1, the planarizing film 20 may be formed of a first planarizing layer 21 and a second planarizing layer 21. In this case, the first planarizing layer 21 may be formed of a polyimide film and / or a polyamide film. And the second planarizing layer 22 are laminated on the upper surface of the substrate. The first planarization layer may include one selected from the group consisting of PMF, PVP, PGMEA, PEGDMA, PPGDMA, PPGDA, PDEGDA, the POSS compound represented by Formula 1, the silazane compound represented by Formula 2 and the polysilazane compound And the second planarization layer may include the polymer represented by Formula 3.

The first planarization layer may include a dimethacrylate-based compound containing at least one selected from PEGDMA and PPGDMA; And a mixture containing the POSS compound, the silazane, and the polysilazane in a weight ratio of 1: 0.1 to 1.5.

The flattening total average thickness of the present invention is 0.1 mu m to 10 mu m, preferably 0.2 mu m to 5 mu m, and more preferably 0.2 mu m to 1 mu m. At this time, if the total thickness of the planarizing film including the first planarizing layer and / or the second planarizing layer is less than 0.1 탆, the surface roughness may increase to affect the electrical characteristics of the OTFT device. If the total thickness of the planarizing layer is 10 It is not necessary to make the thickness larger than 탆.

In the planarizing film of the present invention, the first planarizing layer and the second planarizing layer may be formed to have a thickness ratio of 1: 0.1 to 10, wherein the second planarizing layer has a thickness ratio of 1: 0.1 to the first planarizing layer The effect of reducing the surface roughness may be deteriorated. If the second planarizing layer is formed to be unnecessarily too thick to form the second planarizing layer at a ratio of 1: 10, the thickness of the second planarizing layer is rather disadvantageous. It is advantageous to form the first planarization layer and the second planarization layer.

1, a planarization film (or a planarization layer 20) of the first planarization layer 21 and the second planarization layer 22 is formed on the upper surface of the substrate (or the substrate layer 10) , The surface roughness of the planarizing film may be 0.1 nm to 300 nm, preferably 1 nm to 100 nm, and more preferably 2 nm to 50 nm.

The flexible OTFT device of the present invention is a flexible OTFT device in which a polyamide paper or a polyamide film is introduced into a substrate to enable flexibility of the OTFT device and the surface of the OTFT device is rough The flattening film is used as a flattening layer for a specific material.

The flexible OTFT device of the present invention can introduce the substrate layer and the planarization layer into various types of flexible OTFT devices. For example, in order to facilitate understanding of the present invention, the substrate 10 A planarizing structure 20, a gate 30, a gate electrode insulator 40, a source 50, a drain 60, and an active material 70, The first planarization layer 21 and the second planarization layer 22 may be stacked in order.

As described above, the flexible OTFT of the present invention can use a polyamide film and / or a polyamide paper as the substrate 10, and when a polyamide film is introduced as a substrate, the average thickness of the substrate is 20 μm to 60 μm The average thickness of the substrate is preferably from 20 to 40 탆. If the average thickness of the substrate is less than 20 탆, the film may be torn. If the average thickness exceeds 100 탆, the transparency of the flexible OTFT may be deteriorated It is preferable to have a thickness within the above range.

When a polyamide paper is used as the substrate 10, the average thickness of the substrate is 0.1 to 150 μm, preferably 0.1 to 100 μm, more preferably 0.2 to 80 μm At this time, if the average thickness of the base layer is less than 0.1 탆, there may be a problem that the paper tears. When the average thickness exceeds 150 탆, the flexibility of the OTFT device may deteriorate.

When the metapolyamide paper is used as the base material, the metropolyamide paper has an apparent density of 0.20 to 0.40 g / cm 3 and a thickness of 10 to 150 탆 measured according to ASTM D-828 , A tensile strength in the MD direction of 25 N / cm or more, preferably 25 to 35 N / cm, an elongation in the MD direction of 5.0% or more, preferably 5.0 to 10.0%, and a tensile strength in the MD direction measured in accordance with TAPPI T414 A tear strength of 0.95 N or more, preferably 1.00 to 1.20 N can be used. In addition, the metapolyamide paper may have a tensile strength in the MD direction of 20 to 30 Nm 2 / kg, preferably a non-drawn strength of 22 to 28 Nm 2 / kg when the thickness is 0.14 mm, The polyamide paper may have a basis weight of 35 to 50 g / m 2, preferably 38 to 45 g / m 2. The metapolyamide paper includes metapolyamide flock and meta-amide fibrid, and the floc and fibrid have an intrinsic viscosity (IV) of 1.5 to 2.0.

In the OTFT device of the present invention, the gate (gate) 30 can be made of a material commonly used in the art, and examples thereof include N doped silicone, Au, Ag ) And the like. The average thickness of the gate is about 25 nm to 80 nm, preferably about 40 nm to 70 nm.

In the OTFT device of the present invention, a general material used in the industry per the gate electrode insulator 40 can be used. For example, the gate electrode insulator 40 can be formed of silica (SiO ₂ ) or the like and has an average thickness of 50 nm to 500 The average thickness of the gate electrode insulator is preferably 80 nm to 150 nm, more preferably 80 nm to 400 nm when the substrate is a polyamide film, and more preferably, In the case of a polyamide paper, the average thickness of the gate electrode insulator is preferably 250 nm to 400 nm.

In the OTFT device of the present invention, the source 50 and / or the drain 60 may be made of a material commonly used in the art. For example, gold (Au), silver (Ag) The gate can be made of material. The average thickness of the source and / or drain can be about 40 nm to 90 nm, preferably about 50 nm to 80 nm.

In the OTFT device of the present invention, the active material (or the active layer) 70 may be formed of a material commonly used in the art, for example, a resin using pentacene or the like as an addressing material It is possible. The average thickness of the active material is about 30 nm to 70 nm, preferably about 40 nm to 60 nm.

Hereinafter, a substrate constituting the OTFT device of the present invention will be described in more detail. A polyamide paper or polyamide film is used as the substrate for a flexible OTFT of the present invention.

First, polyamide paper will be described as a substrate for a flexible OTFT of the present invention.

Specifically, FIG. 2 is a process diagram for a method of manufacturing a polyamide paper according to an embodiment of the present invention, and a preferred example of manufacturing the polyamide paper will be described below.

A step of preparing a wet-web by inputting a feedstock containing polyamide floc and amarylated fibrids; A second step of dewatering the wet paper; A third step of drying the dehydrated wet paper by a first hot air blow; A fourth step of secondary drying the dried wet paper; And 5 steps of drying the dried paper at a temperature of 250 to 320 DEG C in a tertiary manner to prepare a polyamide paper.

In the step of producing the wet paper web, the polyamide flock and the polyamide fibrid may be prepared by using meta-aramid floc and meta-polyamide fibrids when preparing the methacrylic polyamide paper. The amount of the metapolyamide fibrids to be used may be 80 to 200 parts by weight of metapolyamide fibrids per 100 parts by weight of the metapolyamide flocs. Metapolyamide polymers suitable for use in metapolyamide fibrids and methacrylamide flocs may be polyamides in which at least 85% of the amide (-CO-NH-) linkages are attached directly to the two aromatic rings, And as many as 10% by weight of many other polymeric materials can be blended with the meta-polyamide. As a specific example, a copolymer having 10% of diacid chloride replacing the diamine of the polyamide may be used. And, the metallopolyamide polymer may be a polymer of poly (metaphenylene isophthalamide), 4,4-diaminodiphenyl sulfone and / or 3,3-diaminodiphenyl sulfone, preferably poly Methaphenylene isophthalamide). ≪ / RTI >

On the other hand, the intrinsic viscosity (IV) of the meta-polyamide polymer contained in the meta-polyamide fibrid and the meta-polyamide floc is 1.5 to 2.0 in relation to the primary hot air drying, the secondary drying and the tertiary drying, Which is very advantageous for improving. If the intrinsic viscosity (I.V) of the metallopolyamide polymer is less than 1.5 or more than 2.0, the degree of improvement of physical properties will be significantly deteriorated.

On the other hand, in step 1, a refiner (refiner: 100) can be used to produce a ground by mixing polyamide floc and polyamide fibrids in water. The polyamide floc and fibrids may be present in an amount of 1 to 10% by weight, based on the total groundbreaking composition, but are not limited thereto. The material passing through the defuzzifier 100 is conveyed to the wire part 210 through the head box 120. The gold net 210 is formed by a fourdrinier machine formed in endless form, a cylinder machine having a large cylindrical shape, an inclinable machine, and a net net formed up and down. And a gap former, which can be used without limitation in the present invention. Specifically, the material discharged from the head box 120 forms a wet web through the forming board 211 of the gold net.

Next, in step 2, the wet paper is dehydrated. The wet paper is fed by a plurality of rollers provided in the gold net 210, and the dehydration process is performed while passing through the dehydrating part 212. The dewatering unit may be achieved through a suction box, and the suction box may include a plurality of suction boxes. The suction box is installed so as to be in contact with the bottom of the net, and the dewatered water is discharged to the outside of the net.

Next, in step 3, the dehydrated wet paper is subjected to a primary hot air drying in a hot air drying unit 220. The above step 3 is performed in order to increase moisture removal of the wet paper web and minimize the thickness reduction of the wet paper web structure The physical properties such as bulk, air permeability and absorbency are improved as compared with the paper which is not subjected to this. The third step is advantageously performed at a temperature of 195 ° C to 250 ° C. If the hot air drying is performed outside the temperature range, the degree of property improvement may become insignificant. In addition, the third step must be accomplished through hot air drying. Examples of the hot air dryer include a through air dryer, a spooner, and the like. If a dryer other than hot air drying is used (for example, Cylinder Dryer, Yankee Dryer, Lab water drier, etc.), the moisture in the paper remains in the form of pockets, And the thickness of the wet paper is reduced as the wet paper is dried by the dry felt, and it may be difficult to achieve the object of the present invention even when the temperature condition is satisfied.

According to another preferred embodiment of the present invention, the method may further include compressing and dewatering the wet paper between the second and third steps or between the third and fourth steps in the compressing / dehydrating unit 230. Even in this case, the compression dehydration can be selectively carried out in the case of satisfying the low density range of the meta-polyamide paper.

Next, as the fourth step, the hot-air dried wet paper is subjected to secondary drying in the secondary drying unit 240 to produce paper. This is to effectively remove moisture from wet paper pellets, and the drying temperature may be from 100 ° C to 150 ° C. If the drying temperature is less than 100 ° C, drying may not be performed as desired, and drying problems may occur. If the drying temperature exceeds 150 ° C, the moisture inside the wet paper filter may remain in the form of a pocket due to rapid drying. The drying time may be from 30 seconds to 600 seconds.

Next, in step 5, the hot air-dried paper is thirdly dried in a tertiary drying part 250 at 250 ° C to 320 ° C. Conventional polyamide paper did not go through steps 3 and 5 but merely obtained four steps of drying at 100 ° C to 150 ° C through an amarylized paper. As a result, it was confirmed that extensibility, tear strength and the like were remarkably improved compared with conventional polyamide paper while maintaining low density because no calendering was performed. Specifically, the tertiary drying is carried out at 250 ° C to 320 ° C, which is very advantageous in improving the physical properties. If the tertiary drying temperature is lower than 250 ° C or exceeds 320 ° C, it is difficult to satisfy desired properties. Meanwhile, the tertiary drying may be performed for 10 to 80 seconds. If it is less than 10 seconds, it is difficult to achieve the desired purpose, and if it exceeds 80 seconds, the flexibility of the paper is decreased, which may cause problems in workability of the product.

Next, the polyamide film will be described as a substrate for a flexible OTFT of the present invention.

The polyamide resin used for forming the polyamide film comprises a polymer of a diamine and a phthaloyl compound, wherein the polyamide resin is prepared by reacting a diamine and a phthaloyl compound in an equivalent ratio of 1: 0.9 to 1.1, preferably 1: 1 , And preferably the polymer may comprise a meta-polyamide polymer and / or a meta-para-polyamide polymer. If the ratio of the diamine to the phthaloyl compound is less than 1: 0.9, the degree of polymerization may be lowered. If the diamine and the phthaloyl compound are used in excess of 1: 1.1, the remaining amount of the unreacted phthaloyl compound is uneconomical. That is, the base component formed by curing the polyamide resin may form a meta-polyamide film or a meta-para-polyamide film depending on the type of the polymer constituting the polyamide resin.

As the flexible OTFT substrate of the present invention, the polyamide film may be a meta-polyamide film or a meta-para-polyamide film, preferably a meta-para-polyamide film. Thus, the resin used in the film formation may be a polyamide resin comprising a meta-polyamide polymer and / or a meta-para-polyamide polymer, preferably a polyamide resin comprising a meta-para- Can be used. The meta-para-polyamide polymer preferably has a para content of 80% or more, preferably 80% to 90%, more preferably 80 to 85% in terms of securing heat resistance and securing an appropriate viscosity .

In the polyamide film which is a flexible OTFT substrate, the polyamide polymer can be prepared by polymerizing a diamine and a phthaloyl compound as described above, wherein the diamine used in the production is selected from the group consisting of phenylenediamine and And oxydianiline, preferably two kinds, may be mixed and used.

The oxydianiline may be a mixture of one or two selected from 3,4'-oxydianiline and 4,4'-oxydianiline. When 3,4'-oxydianiline is used, the viscosity And the use of 3,4'-oxydianiline tends to be more advantageous than 3,4'-oxydianiline in terms of heat resistance, so that 3,4'-oxydianiline and 4,4'- It is possible to control physical properties such as viscosity and glass transition temperature through the use of oxydianiline.

 In the polyamide film which is the flexible OTFT substrate of the present invention, when the polyamide polymer is polymerized, the appropriate amount of the phenylenediamine and the oxydianiline is preferably 7 to 9: 1 to 3: 3 by weight in terms of phenylenediamine and oxydianiline , Preferably from 7.5 to 8.5: 1.5 to 2.5, more preferably from 7.2 to 8.2: 1.8 to 2.2. The amount of phenylenediamine and oxydianiline to be used is less than 7: 3 by weight, When the diamine is used in a small amount, the heat resistance and the mechanical properties are increased, but the solution viscosity is increased. If phenylene diamine is used in excess of 9: 1 by weight, the solution viscosity may be lowered but the heat resistance may be lowered.

In this case, when two kinds of meta-phenylenediamine and paraphenylenediamine are used as the phenylenediamine, the meta- phenylenediamine and the paraphenylenediamine are used at a weight ratio of 1: 1 to 3, preferably 1: 1.4 to 1.8, If para-phenylenediamine is used in an amount of less than 1: 1 by weight of the metaphenylenediamine and para-phenylenediamine, the para-content of the polymer or polyamide resin as the final reactant is too low, And if paraphenylenediamine is used in excess of 1: 3 by weight of metaphenylenediamine and paraphenylenediamine, the para content may be too high, resulting in a problem that the solution viscosity becomes too high.

When four diamines are used in the polymerization of the above polyamide polymer, as one example, there may be mentioned metaphenylenediamine, paraphenylenediamine, 3,4'-oxydianiline and 4,4'-oxydianiline In the case of using a diamine of the following formula (1), the molar ratio of m-phenylenediamine, paraphenylenediamine, 3,4'-oxydianiline and 4,4'-oxydianiline is 3.5 to 4.5: 3.5 to 4.5: 0.5 to 1.5: 0.5 to 1.5 It is advantageous in terms of the appropriate viscosity, thermal expansion, heat resistance and mechanical properties.

In the polyamide film, in the polymerization of the polyamide polymer, only p-phenylenediamine may be used as the phenylenediamine. In this case, as the phthaloyl-based compound, two kinds of terephthaloyl-based compounds and two isophthaloyl- By using this, the para content of the polymer can be controlled by controlling the amount of isophthaloyl compound used. More specifically, when only paraphenylenediamine is used as the diamine, it is preferable to use paraphenylenediamine and oxydianiline in a weight ratio of 7: 3 to 8: 2, wherein the paraphenylenediamine content When the amount is less than 7 parts by weight, the amount of oxydianiline to be used increases relatively, resulting in a problem that the solution viscosity is excessively increased and the thermal expansion property is poor. When the paraphenylenediamine content is more than 8 parts by weight, There may be a problem of lowering.

When only para-phenylenediamine is used as the phenylenediamine, the phthaloyl-based compound is obtained by controlling the para-content of the polymer by using the terephthaloyl-based compound and the isophthaloyl-based compound at a weight ratio of 6-8: 2-4 It is preferable to have a physical property such that

In the polyamide film, the phthaloyl compound used in the polyamide polymer polymerization may be a terephthaloyl compound containing at least one selected from terephthaloyl chloride and terephthaloyl bromide; And an isophthaloyl compound containing at least one selected from isophthaloyl chloride and isophthaloyl bromide; , And it is preferable to use terephthaloyl chloride and / or isophthaloyl chloride.

As the above-mentioned flexible OTFT substrate of the present invention, a polyamide resin for producing a polyamide film is prepared by adding the above diamine, terephthaloyl chloride and isophthaloyl compound to a solvent and then polymerizing to prepare a polymer solution containing the polymer 1 to 5 parts by weight of a neutralizing agent containing at least one selected from calcium oxide (CaO), calcium hydroxide (CaO ₂ ) and basic compounds such as lithium hydroxide (LiOH) is added to 100 parts by weight of the polymer, ≪ / RTI >

At this time, the solvent may be a solvent commonly used in the art, and preferably at least one selected from NMP (n-methyl 2-pyrrolidone) and DMAc (dimethyl acetamide) may be used.

The produced polyamide resin can be used as a film-forming substrate for a flexible OTFT.

The above-described flexible OTFT device of the present invention can be fabricated by using a transfer curve (transfer curve) when a polyamide film is used as a base material, and when a current value ratio is measured on a semiconductor parameter analyzer (AIGilent 4155C) , I _on / I _off ) ratio may be 1.0 × 10 ^-4 to 1.0 × 10 ^-2 , preferably 2.50 × 10 ^-4 to 9.00 × 10 ^-3 .

When the substrate is a polyamide film, the flexible OTFT of the present invention has an electron mobility of 2.0 × 10 ^-4 to 1.0 × 10 ^-2 cm ² when measured at 10 V to -30 V by a semiconductor parameter analyzer / V · s, and preferably 2.10 × 10 ^-4 to 9.50 × 10 ^-3 ㎠ / V · s.

When the substrate is a polyamide film, the flexible OTFT of the present invention has a threshold voltage (V _th ) at the time of measuring the gate voltage at the turn-on of the device by the semiconductor parameter analyzer, May have a value of -12.0 V to -6.0 V, preferably -11.0 to -7.0 V.

In the flexible OTFT device of the present invention, when the substrate is made of polyamide paper and the ratio of the current value when the device is on and off is measured with a semiconductor parameter measuring device, the transfer curve (I _on / I _off ) 10 ² ~ 1.0 × 10 ⁴ may be, and preferably 1.0 × 10 ² ~ may be 7.0 × 10 ^3.

When a polyamide paper is used as the base material, the flexible OTFT of the present invention has an electron mobility of 1.0 × 10 ^-4 to 3.5 × 10 ^-2 cm ² when measured by a semiconductor parameter analyzer at 10 V to -100 V / V · s, and preferably 1.0 × 10 ^-3 to 3.5 × 10 ^-2 cm 2 / V · s.

In the case of the base material using a polyamide paper, flexible OTFT includes a gate voltage (gate voltage), the threshold voltage (Threshold Voltage, V _th) during the measurement of the point element is on a semiconductor parameter analyzer (turn on) of the present invention And a value of -7.0 V to -14.0 V, preferably -7.0 V to -11.0 V.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

[ Example ]

Preparation Example  1-1: Flexible  For substrate OTFT  For substrate Polyamide  Production of film

4 parts by weight of m-phenylene diamine (MPD), 100 parts by weight of p-phenylenediamine (NMP) as n-methyl-2-pyrrolidone 4 parts by weight of 4,4'-oxydianiline, and 10 parts by weight of terephthaloyl chloride (TPC) were mixed and polymerized to carry out a polymerization process. To prepare a polymerization solution containing the polyamide polymer.

Next, after the above-mentioned polymerization step, 3 parts by weight of calcium hydroxide (Ca (OH) ₂ ) was added to 100 parts by weight of the polymerization solution and neutralized to prepare a polyamide resin.

Next, the polyamide resin was cast on one side of a glass substrate, dried at 120 DEG C, and washed to obtain a transparent polyimide film having an average thickness of 20 mu m for an OTFT substrate.

Preparation Example  1-2 to 1-6 and Example of comparison preparation  1-1 to 1-6

A polyamide resin and a polyamide film for an OTFT substrate were prepared in the same manner as in Preparation Example 1-1 except that MPD, PPD, 3,4'-ODA, 4,4'-ODA, TPC And IPC were used to prepare a polyamide resin and a polyamide film for an OTFT substrate.

division Composition ratio
(Weight ratio) Composition ratio
(Equivalent ratio) Polymer
Para content (%) Weight average
Molecular Weight Solubility MPD PPD 3,4 '
-ODA 4,4 '
-ODA Sum TPC IPC Preparation Example 1-1 4 4 - 2 10 10 - 80% 138,000 ○ Preparation Example 1-2 2 6 2 - 10 - 80% 121,000 ○ Preparation Example 1-3 2.5 5 - 2.5 10 - 87.5% 168,000 ○ Preparation Example 1-4 3.5 4.5 0.5 1.5 10 - 80% 110,000 ○ Preparation Example 1-5 - 8 - 2 6 4 80% 142,000 ○ Preparation Example 1-6 - 8 2 - 8 2 80% 115,000 ○ Preparation Example 1-7 4 6 - - 10 - 80% 207,000 ○ Example of comparison preparation
1-1 - 10 - - 10 - 100% × × Example of comparison preparation
1-2 10 - - - - 10 0% 199,000 ○ Example of comparison preparation
1-3 - 6 - 4 10 - 100% 231,000 △ Example of comparison preparation
1-4 - 6 4 - 10 - 80% 220,000 ○ Example of comparison preparation
1-5 2 6 - 2 10 - 90% 218,000 ○ ?: Good solubility,?: Solubility common, X: Solubility poor

In the case of Preparation Examples 1-1 to 1-7, the solubility of the polyamide resin of Comparative Preparation Example 1-1, in which the solubility was excellent but the polymer had a para content of 100%, was not very good, and PPD, 4,4 In the case of the polyamide resin having a para content of 100% of the polymer synthesized by '-ODA and TPC, the other Preparation Examples 1-1 to 1-7 and Comparative Preparation Examples 1-2 and Comparative Preparation Examples 1-4 to 1-5 , The solubility was relatively low.

From the results of the experiment shown in Table 1, it was confirmed that increasing the meta content in the polymer tends to increase the solubility.

Experimental Example  2 : Polyamide  Resin and Polyamide  Measurement of physical properties of film

The solution viscosity of the polyamide resin prepared in Preparation Examples 1-1 to 1-7 and Comparative Preparation Examples 1-1 to 1-5 was measured and the thermal expansion index, the glass transition temperature, the heat shrinkage rate, The results are shown in Table 2 below.

 (1) Method of measuring solution viscosity

The solution viscosity was measured at 25 캜 using a Brookfield viscometer.

(2) Thermal Expansion Index ( CTE ) How to measure

(Mechanical direction) in the range of 50 ° to 200 ° using a thermal mechanical analysis (TMA) apparatus, which is a thermal mechanical analyzer, by tensile method.

(3) Glass transition temperature ( Tg ) How to measure

The direction of the mechanical direction (MD) was determined by a tensile method using a dynamic mechanical analysis (DMA) apparatus as a thermal mechanical analyzer.

(4) Heat shrinkage (%) How to measure

According to IPC TM6502.2.4A, the dimensions (initial dimensions) in the initial state of cutting 10 cm in length and width and the dimensions (after heating) after heat treatment at 150 캜 for 1 hour were measured. From these measurements, The heat shrinkage rate was calculated.

[Equation 1]

Heat shrinkage percentage (%) = {(Initial dimension - Dimension after heating) / Initial dimension} × 100

(5) Young's modulus ( young's modulus ) How to measure

An aestron-type tensile tester is used in accordance with ASTM D882, and the average value of the five measurement results is set to the Young's modulus in the present invention.

division Composition ratio
(Weight ratio) Composition ratio
(Equivalent ratio) solution
Viscosity (cP) CTE
(ppm / DEG C) Tg
(° C) Ten
Shrinkage rate
(%) Young's modulus
(Gpa) MPD PPD 3,4 '
-ODA 4,4 '
-ODA Sum TPC IPC Preparation Example 1-1 4 4 - 2 10 10 - 87,000 16 310 0.20 6.5 Preparation Example 1-2 2 6 2 - 10 - 85,000 18 309 0.21 6.3 Preparation Example 1-3 2.5 5 - 2.5 10 - 102,000 14 311 0.20 6.6 Preparation Example 1-4 3 5 One One 10 - 90,000 18 307 0.24 6.3 Preparation Example 1-5 - 8 - 2 6 4 89,000 17 306 0.27 6.4 Preparation Example 1-6 - 8 2 - 8 2 79,000 19 307 0.22 6.1 Preparation Example 1-7 4 6 - - 10 - 217,000 15 322 0.2 6.5 Example of comparison preparation
1-1 - 10 - - 10 - × 9 350 0.1 7.0 Example of comparison preparation
1-2 10 - - - 10 178,000 40 270 0.5 5.0 Example of comparison preparation
1-3 - 6 - 4 10 - 298,000 11 320 0.2 6.0 Example of comparison preparation
1-4 - 6 4 - 10 - 230,000 15 317 0.2 6.3 Example of comparison preparation
1-5 2 6 - 2 10 - 224,000 12 319 0.2 6.1

As a result of the test results of Table 2, it can be confirmed that Preparation Examples 1-1 to 1-7 have excellent CTE, Tg, heat shrinkage and Young's modulus while having a solution viscosity of 12,000 cP (25 ° C) or less. However, Comparative Preparation Example 1-1, which has almost no meta content, has excellent heat resistance, but the viscosity of the solution can not be measured due to gelation of the polymer, and the thermal expansion index is too low. In Comparative Preparation Example 1-2, in which the para content was almost zero, the CTE was excellent but the heat resistance was extremely poor.

Also, in Comparative Preparation Example 1-3 and Comparative Preparation Examples 1-4, in which phenylene diamine and oxydianiline were used in a weight ratio of 6: 4 out of the 7: 3 weight ratio, the solution viscosity was too high.

Comparative Example 5 using MPD and PPD at a weight ratio of 1: 3 exceeding 1: 3 by weight had excellent overall physical properties such as heat resistance, but also had a too high solution viscosity.

Through the above experimental example, the polyamide resin used for the polyamide film for OTFT substrate of the present invention has a low solution viscosity, that is, an appropriate solution viscosity of about 45,000 to 12,000 cP (25 캜), and thus has excellent processability and solubility . The polyamide film for an OTFT base material of the present invention not only has excellent CTE, heat shrinkage and mechanical properties of Young's modulus, but also has excellent heat resistance at a glass transition temperature of 300 ° C or higher, preferably 300 ° C to 340 ° C I could confirm.

Preparation Example  2-1: Polyamide  Manufacture of paper

(Polyphenylene isophthalamide) dope (mA Dope) having an intrinsic viscosity of 1.8 was prepared, and a fibril production apparatus was used to prepare a metapolyamide fibrid (manufactured by Mitsui Chemicals, Inc.) having a density of 150 ml of Canadian Standard Freeness Fibrid). The prepared fibrids were adjusted to a concentration of 0.8% using a double disk refiner to improve the processability of the wet nonwoven fabric and to improve the physical properties of the final product, thus adjusting the freeness of the fibrids to 80 ml.

On the other hand, after 2.0 denier fibers were produced by using the same polymer, floc was prepared by cutting the fiber length to 7 mm. The strength of the flock was 5.3 g / de and elongation was 35%.

Thereafter, the fibrids and flocs were mixed in water at a weight ratio of 6: 4, and the resultant mixture was added in an amount of 0.5 wt% with respect to water to prepare a ground.

The above-mentioned materials were put into the paper making apparatus of FIG. 2 to prepare wet paper pills. After that, primary hot air drying was performed at 200 ° C for 30 seconds in a hot air drier. Secondary drying at 120 ° C for 60 seconds was followed by tertiary drying at 300 ° C for 20 seconds in a cylinder dryer. Paper (average thickness 60 占 퐉).

Preparation Example  2-2

A metallopolyamide paper was prepared in the same manner as in Preparation Example 2-1, except that the temperature of the hot-air dryer was 235 DEG C and the average thickness of the metallopolyamide paper was 80 mu m.

Preparation Example  2-3

(Average thickness 60 占 퐉) was prepared in the same manner as in Preparation Example 2-1, except that a meta-polyamide having an intrinsic viscosity of 1.5 was used.

Preparation Example  2-4

Metapolyamide paper having an intrinsic viscosity of 2.0 was used and the same procedure as in Preparation Example 2-1 was carried out except that the average thickness of the methacrylamide paper was 80 占 퐉.

Preparation Example  2-5

A metallopolyamide paper was prepared in the same manner as in Preparation Example 2-1 except that the average thickness of the metallopolyamide paper was 130 탆.

Example of comparison preparation  2-1

A metallopolyamide paper was prepared in the same manner as in Preparation Example 2-1 except that the average thickness of the metallopolyamide paper was 170 탆.

Example of comparison preparation  2-2

The average thickness of the methacrylamide paper was 0.07 mu m, but the paper broke and it was difficult to process.

Experimental Example  3: Polyamide  Physical property measurement of paper

The physical properties of the polyamide paper prepared in Preparation Examples 2-1 to 2-5 and Comparative Preparation Example 2-1 were measured as follows. The results are shown in Table 3 below.

(One) The tensile strength (N / cm ) And Elongation rate (%)

The tensile strength and elongation were measured according to ASTM D-828 for 24 hours under constant temperature and humidity conditions, and then the specimens were cut in the machine direction and subjected to MD (machine direction) load in a horizontal tensile strength meter. And elongation was measured by the length ratio of the specimen until the tensile failure.

(2) Phosphorus strength (N)

The tear strength was measured according to TAPPI T414 for 24 hours under constant temperature and humidity conditions. The sample was cut in the width direction and the tear strength in MD (machine direction) was measured in an Elmendorf tear strength tester.

(3) Intangible strength ( Nm ² / kg )

The non-inhaled strength was calculated by the following formula (1) using the measured basis weight and tear strength.

[Equation 1]

Tensile strength (Nm ² / kg) = Tear strength (N) x 1000 / gram (g / m 2)

(4) Absorption amount

The amount of water absorption was measured by a Cobb tester having an area of 100 cm2 according to TAPPI T441. After the thermo-hygroscopic treatment, the weighed sample was loaded, and then 100 ml of water was poured into the tester. After 60 seconds, the unabsorbed water was discarded. After the water was removed, weighing was carried out and the amount of water absorption was calculated by the following equation (2).

&Quot; (2) "

(G / m 2) = (weight of final sample (g) - weight (g) of sample subjected to constant temperature and humidity treatment) × 100

division Basis weight
(g / m 2) thickness
(탆) surface
density
(g / cm2) MD Tensile Strength
(N / cm) MD elongation
(%) MD
Phosphorus strength
(N) MD
Non-invasive strength
(Nm ² / kg) Absorption
(g / m 2) Preparation Example 2-1 41.3 60 0.29 29.45 6.79 1.08 26.2 13.5 Preparation Example 2-2 41.6 80 0.30 29.59 7.26 1.07 25.8 13.5 Preparation Example 2-3 41.4 60 0.28 32.72 7.36 1.15 27.8 13.7 Preparation Example 2-4 42.0 80 0.28 31.03 7.14 1.13 26.9 14.1 Preparation Example 2-5 41.8 130 0.28 30.12 6.92 1.08 25.8 13.0 Comparative Preparation Example 2-1 42.0 170 0.40 36.12 7.62 1.33 28.8 16.0

Preparation Example  3 -1: Preparation of first planarization resin

96% by weight of a mixture of PEGDMA (poly ethylene glycol dimethacrylate) and a POSS compound (hybrid plastics) represented by the following formula 1-1 in a weight ratio of 1: 1 and 4% by weight of Darocur 1173 (Ciba specialty chemicals) % Were mixed, coated and UV-cured to prepare a solventless type first planarizing resin.

[Formula 1-1]

이고, R¹은 -CH₂-CH₂-이고, R²는 메틸기이다.
In Formula 1, E is

, R ¹ is -CH ₂ -CH ₂ -, and R ² is a methyl group.

Preparation Example  3 -2

0.1 weight ratio of PEGDMA (poly ethylene glycol dimethacrylate) and POSS compound represented by the following formula 1-2 was mixed and 98 weight% of the mixture and 2 weight% of Irgacure 250 (Ciba specialty chemicals) as a photoinitiator were mixed, Followed by UV curing to prepare a solventless type first planarizing resin.

 [Formula 1-2]

이고, R³는 -CH₂-CH₂-이고, R⁴는 ?H₂-이다.
In Formula 1, E is

, R ³ is -CH ₂ -CH ₂ -, and R ⁴ is? H ₂ -.

Preparation Example  3-3

(Trade name: KION 1800) containing a compound represented by the following formula (4-1) and a compound represented by the formula (4-2) in a molar ratio of 0.8: 0.2 was prepared.

Then, PEGDMA and the polysilazane were mixed in a weight ratio of 1: 1, and 96% by weight of the mixture and 4% by weight of Darocur 1173 (Ciba specialty chemicals), a photoinitiator, were mixed and UV-cured after coating to form a non- .

[Formula 4-1]

In Formula 4-1, R ¹ is a methyl group, and R ² is a hydrogen atom.

[Formula 4-2]

In Formula 4-2, R ¹ is a methyl group.

Preparation Example  3-4

The mixture of 96% by weight of the mixture and 4% by weight of Darocur 1173 (Ciba Specialty Chemicals) as a photoinitiator was mixed with PPGDA (Polypropylene glycol diacrylate) and the POSS compound of Formula 1-1 at a weight ratio of 1: And cured to prepare a solventless type planarizing resin.

Example of comparison preparation  3-1

96% by weight of a trifunctional acid ester (CD9051 from SARTOMER) and 4% by weight of a photoinitiator Darocur 1173 (Ciba Specialty Chemicals) were mixed, coated and UV-cured to prepare a solventless type of planarizing resin.

Example of comparison preparation  3-2

96% by weight of the POSS compound represented by the formula 1-1 of Preparation Example 3-1 and 4% by weight of Darocur 1173 (Ciba Specialty Chemicals) as a photoinitiator were mixed, coated and UV cured to prepare a first planarization resin .

Example of comparison preparation  3-3

96% by weight of the polysilazane-based compound (trade name: KION 1800) and 4% by weight of Darocur 1173 (Ciba Specialty Chemicals) as a photoinitiator were prepared, coated, and UV cured to prepare a first planarizing resin .

Preparation Example  4: Preparation of second planarization resin

A second planarization resin was prepared by mixing a fluorocarbon solvent (CT-solv. 180, asahi glass) and a polymer represented by the following formula (3-1) in a volume ratio of 1: 0.5.

[Formula 3-1]

In the formula (3-1), R &^lt; ¹ > R ⁸ is a fluorine atom.

Example  1-1: Polyamide  Film-based Flexible OTFT Manufacturing

A polyamide film as a substrate for an OTFT prepared in Preparation Example 1-1 was fixed on the upper surface of the glass, and then, on one side of the polyamide film, using a vacuum evaporator by thermal evaporation, A flexible organic thin film transistor (OTFT) was fabricated by depositing a gate 30, a gate electrode insulator 40, an activator 70, a source 50, a source and a drain 60 in the form shown in FIG. .

At this time, the gate (gate) 30 was formed using Au and deposited at a rate of 1.0 to 1.5 A / sec to have an average thickness of 50 nm.

The gate insulator 40 was deposited with SiO ₂ at a rate of 0.5 ANGSTROM / sec to have an average thickness of 100 nm

The active material 70 was deposited with Pentacene at a rate of 0.2 to 0.3 Å / sec to have an average thickness of 50 nm.

The source 50 and the drain 60 were respectively formed by depositing Au at a rate of 1.0 to 1.5 A / sec to have an average thickness of 70 nm.

Example  1-2 ~ Example  1-6

A flexible organic thin film transistor (OTFT) was produced in the same manner as in Example 1-1 except that the polyamide film prepared in Preparation Example 1-1 was replaced with the polyamide prepared in Preparation Examples 1-2 to 1-6 Each of the films was used as an OTFT substrate to prepare an organic thin film transistor, and Examples 1-2 to 1-6 were respectively performed.

Example  1-7

A flexible organic thin film transistor (OTFT) was produced in the same manner as in Example 1-1, except that the polyamide film was coated on one surface thereof with an average thickness of 100 nm using the second planarizing resin prepared in Preparation Example 1-7 , A flexible OTFT in which a planarization layer 20 was formed between the substrate 10 of the polyamide film and the gate 30 was manufactured.

Comparative Example  1-1

A flexible OTFT device was fabricated in the same manner as in Example 1-1 except that a glass substrate having an average thickness of 20 占 퐉 was used as a base material instead of a base material layer of a meta-polyamide film material and a planarizing layer was not formed. A flexible OTFT device was fabricated.

Example  2-1: Polyamide  Paper-based Flexible OTFT (A planarization layer of a multilayer structure)

The metapolyamide paper (average thickness 60 mu m) prepared in Preparation Example 2-1 was fixed on the upper surface of the glass. Next, the first planarizing resin prepared in Preparative Example 2-1 was spin-coated on the upper surface of the polyamide paper and then UV-cured to form a first planarizing layer 21 having an average thickness of 0.5 탆.

Next, the second planarizing resin prepared in Preparation Example 3 was spin-coated on the upper surface of the first planarization layer 21 under the condition of 2,000 rpm / 60 sec to form a second planarization layer 22 having an average thickness of 360 nm .

Next, a gate 30, a dielectric 40, and an active material (not shown) are formed on one surface of the second planarization layer 22 by thermal evaporation using a vacuum evaporator, 70, a source 50, and a drain 60 were deposited to fabricate a flexible organic thin film transistor (OTFT).

At this time, the gate (gate) 30 was formed using Au and deposited at a rate of 1.0 to 1.5 A / sec to have an average thickness of 50 nm.

Dielectric (40) was deposited with SiO ₂ at a rate of 0.5 A / sec to have an average thickness of 300 nm

The active material 70 was deposited with pentacene at a rate of 0.2 to 0.3 Å / sec to have an average thickness of 50 nm.

The source 50 and the drain 60 were respectively formed by depositing Au at a rate of 1.0 to 1.5 A / sec to have an average thickness of 70 nm.

Example  2-2

A flexible OTFT device was fabricated in the same manner as in Example 2-1 except that, in forming the first planarization layer, the first planarization resin of Preparation Example 3-1 (POSS planarization resin of Formula 1-1) A first flattening layer was formed using the first flattening resin (POSS flattening resin of Higgs type 1-2) prepared in Example 2 to prepare a flexible OTFT device.

Example  2-3

A flexible OTFT device was fabricated in the same manner as in Example 2-1 except that, in forming the first flattening layer, the first flattening resin (POSS-based flattening resin of Formula 1-1) A first planarization layer was formed using the first planarization resin (polysilazane-based planarization resin) prepared in 3-3 to fabricate a flexible OTFT device.

Example  2-4 ~ Example  2-7

A flexible OTFT device was produced in the same manner as in Example 2-1 except that the material of the substrate layer was a mixture of the metapolyamide paper of Preparative Examples 2-2 to 2-5, which is not a metapolyamide paper of Preparation Example 2-1 Were used to fabricate flexible OTFT devices, and Examples 2-4 to 2-7 were performed.

Example  2-8

In the same manner as in Example 2-1, A flexible OTFT device was prepared in the same manner as in Preparation Example 3-1 except that the planarizing resin of Preparative Example 3-4 was coated on the upper surface of the polyamide paper and then UV-cured to form a single-layer flattening layer having an average thickness of 0.54 탆.

A gate 30, a dielectric 40, an active material 70, a source 50, and a drain 60 are deposited on the top surface of the planarization layer in the same manner as in Example 2-1 , And flexible organic thin film transistor (OTFT).

Comparative Example  2-1

A flexible OTFT device was fabricated in the same manner as in Example 2-1 except that a glass substrate was used as a substrate in place of the base layer of the meta-polyamide paper substrate, and a flexible OTFT device was fabricated without forming a planarization layer.

Comparative Example  2-2

A flexible OTFT device was manufactured in the same manner as in Example 2-1 except that the material of the substrate layer was a flexible OTFT using Metapolyamide paper of Comparative Preparation Example 2-1 instead of the metapolyamide paper of Preparation Example 2-1. And Comparative Example 2-2 were carried out.

Comparative Example  2-3

A flexible OTFT device was fabricated in the same manner as in Example 2-1 except that a first planarizing layer was formed using the first planarizing resin prepared in Comparative Preparation Example 3-2 as a first flat layer material, .

Comparative Example  2-4

A flexible OTFT device was fabricated in the same manner as in Example 2-1 except that a first planarizing layer was formed using the first planarizing resin prepared in Comparative Preparation Example 3-3 as a first flat layer material, .

Comparative Example  2-5

A flexible OTFT device was produced in the same manner as in Example 2-8 except that the POSS compound of Formula 1-1 and the trifunctional acid ester material of Comparative Preparation Example 3-1 were mixed at a ratio of 1: A flattening layer having a single-layer structure having an average thickness of 0.55 mu m was formed using a planarizing resin mixed in a weight ratio to prepare a flexible OTFT device.

Comparative Example  2-6

A flexible OTFT device was produced in the same manner as in Example 2-8, except that a base layer having an average thickness of 60 mu m was produced using a polyethylene terephthalate film (manufactured by Toray Chemical Co., Ltd.) as a base layer material, A second planarization layer, a gate, a dielectric, an active material, a source, and a drain were formed on the top surface of the substrate, thereby fabricating a flexible OTFT device.

Comparative Example  2-7

A flexible OTFT device was manufactured in the same manner as in Example 2-8, except that a substrate layer having an average thickness of 60 占 퐉 was produced by using a material in which a polyurethane film and a PET fabric (Toray chemical) were laminated as a base layer material Then, a flexible flattening layer, a second flattening layer, a gate, a dielectric, an activator, a source and a drain were formed on the upper surface of the substrate layer to prepare a flexible OTFT device.

Comparative Example  2-8

A flexible OTFT device was produced in the same manner as in Example 2-8, except that a base layer having an average thickness of 60 μm was produced using polyamide fabric (Toray chemical, ARAWIN) as a base layer material, A second planarization layer, a gate, a dielectric, an active material, a source, and a drain were formed on the top surface of the substrate, thereby fabricating a flexible OTFT device.

Experimental Example  4 : Flexible OTFT of Planarization layer  Surface roughness measurement experiment

Since the surface roughness of the planarization layer affects the electrical characteristics of the OTFT, the lower the surface roughness, the less the electrical and electronic properties of the OTFT are adversely affected.

The results of measurement of surface roughness of Examples 1-1 to 1-7 in which the substrate is a polyamide film are shown in Table 4, Examples 2-1 to 2-8 in which the substrate is a polyamide paper, The results of the surface roughness measurement of Examples 2-1 to 2-8 are shown in Table 5 below.

AFM (Atomic Force Microscope) measurement results of the surface roughness of the planarizing structure of the flexible OTFT device manufactured in Examples 2-1 to 2-2 and Comparative Examples 2-3 to 2-4 are shown in Fig. 3 2-3) and Fig. 4 (Example 2-1). 5 (Comparative Example 2-4) and Fig. 6 (Example 2-2).

The RMS surface roughness was measured using an AFM (Park Systems, XE-100) instrument. The tip was 320 kHz and 42 N / m, and the measured images were imaged using the Gwyddion program.

In the case of the planarization layer of Comparative Example 2-3 (Fig. 3) and the planarization layer of Comparative Example 2-4 (Fig. 5), surface roughnesses of 94 nm and 102 nm were respectively shown.

On the other hand, unlike Comparative Example 2-3 in which only the POSS-based first planarization resin layer was formed and Comparative Example 2-4 in which only the polysilazane-based first planarization resin layer was formed, Example 2-1 (FIG. 4) and Example 2-2 (FIG. 6), the surface roughness was 7.2 nm and 4.3 nm, respectively, and the surface roughness was remarkably improved by forming the second planarization resin layer And it was confirmed that by forming the second planarization resin layer with a specific material, it is possible to minimize the electric influence that may be caused by introducing the base material of the paper material.

division Rq,
RMS surface roughness
(nm) Base thickness
(탆) division Rq,
RMS surface roughness
(nm) Base thickness
(탆) Example 1-1 6.21 20 Examples 1-5 5.12 20 Examples 1-2 4.32 20 Examples 1-6 4.87 20 Example 1-3 5.77 20 Examples 1-7 3.51 0.1 Examples 1-4 5.13 20 Comparative Example 1-1 15.3 20

As a result of the measurement of the results shown in Table 4, the results of Examples 1-1 to 1-6 showed excellent overall surface roughness of 4.0 to 7.0 nm, which is lower than Comparative Example 2-1 using a glass substrate Roughness. In the case of Examples 1-7 in which a planarization layer was further formed with the compound represented by Formula 3, the surface roughness was relatively lower as compared with Examples 1-1 to 1-6.

division Rq,
RMS surface roughness
(nm) Base thickness
(탆) division Rq,
RMS surface roughness
(nm) Base thickness
(탆) Example 2-1 0.64 60 Comparative Example 2-1 0.50 60 Example 2-2 0.73 60 Comparative Example 2-2 3.24 170 Example 2-3 0.58 60 Comparative Example 2-3 8.3 60 Examples 2-4 0.82 80 Comparative Example 2-4 6.29 60 Example 2-5 0.76 60 Comparative Example 2-5 11.4 60 Examples 2-6 0.94 80 Comparative Example 2-6 0.72 60 Examples 2-7 1.05 130 Comparative Example 2-7 97 60 Examples 2-8 1.57 60 Comparative Example 2-8 152 60

As shown in Table 5, in Examples 2-1 to 2-8, it was confirmed that the RMS surface roughness was very small, ranging from 0.58 nm to 1.57 nm. On the other hand, It was confirmed that Comparative Example 2-5 and Comparative Examples 2-7 to 2-8 had very high surface roughness values.

Particularly, in Examples 2-1 to 2-3, the surface roughnesses were 0.64 nm, 0.73 nm, and 0.58 nm, respectively, which were similar to those of Comparative Example 2-1 (0.50) And the surface roughness was similar or lower than that of Comparative Example 2-6 of the PET film material of the film material.

Through this, it was confirmed that the surface roughness can be greatly improved by forming a planarization layer with a specific material, even though a base material having a high surface roughness is used. In addition, It is possible to minimize the electrical influence that may be caused by the base layer and the planarization layer of the OTFT device.

Experimental Example  5: Flexible OTFT Electrical Characteristic Evaluation Experiment

The transfer curves (Transfer curve, I _on / I) of the OTFT devices manufactured in Examples 1-1 to 1-7, Examples 2-1 to 2-8, and Comparative Examples 1-1 to 1-7, _off) ratio, electron mobility (mobility, ㎠ / (V · s)) and was measured threshold voltage (threshold voltage, V _th) of the gate voltage (gate voltage), and the results in Table 6 and shown in Table 7 .

The measurement results of Example 2-1, Example 2-3, and Comparative Example 2-1 are shown in Fig. 7, and measurement graphs of Example 2-8 and Comparative Example 2-5 are shown in Fig.

The measurement results of Example 1-7 and Comparative Example 2-1 are shown in Fig.

7 to 9, I _DS is measured based on the following equation (1).

[Equation 1]

In the above Equation 1, W is the gate width, L is the channel length, C _I is the gate capacitance, μ is the electron mobility, and V _T (V _th ) is the threshold voltage.

Electrical characteristics of the OTFT device is holding the V _DS (voltage of drain and source), V _GS to a transfer characteristic (Transfer Characteristics, the form of the effect of the gate voltage of the electric field channel that represents a variation of I _DS for the (gate voltage) (Referred to as the output characteristic), and the output characteristics (referred to as output characteristics in general, where the source and the drain are used as the output stages), which represent the change in I _DS for the output voltage V _DS with respect to each V _GS .

FIG. 10 shows the result of measuring the degree of saturation of the current according to the voltage of Example 1-1.

division Electron mobility
[Cm 2 / ( V · s )] Threshold voltage
( V _{th )} Transfer curve
( I _on / I _{off )} Example  1-1 2.16 x 10 ^-4 -9.0 7.50 x 10 ^-3 Example  1-2 2.54 x 10 ^-4 -10.0 5.51 × 10 ^-3 Example  1-3 7.54 × 10 ^-4 -11.0 7.24 x 10 ^-4 Example  1-4 3.99 × 10 ^-4 -10.0 5.07 x 10 ^-4 Example  1-5 8.54 × 10 ^-3 -8.0 6.83 × 10 ^-4 Example  1-6 2.58 x 10 ^-4 -9.0 2.52 x 10 ^-4 Example  1-7 7.71 × 10 ^-3 -7.67 2.54 x 10 ^-3 Comparative Example  1-1 8.67 × 10 ^-3 -6.02 8.02 x 10 ^-2

In Examples 1-1 to 1-7, excellent electron mobility of 2 × 10 ^-4 or more, preferably 2.16 × 10 ^-4 to 8.54 × 10 ^-3 cm 2 / (V · s) was exhibited, A threshold voltage of -12 V or higher, preferably a high threshold voltage of -11 V to -7.67 V, which was almost similar to that of Comparative Example 1-1 using an organic substrate as a substrate. In addition, the transfer curve value was 2.50 x 10 < ^-4 > or more, preferably 2.52 x 10 < ^-4 > to 7.50 x 10 < ^-3 >

The graph of the saturation degree of the current according to the voltage of the OTFT device of Example 1-1 shown in FIG. 10 shows that the graph curve is very smooth. This shows that the output characteristic of the OTFT device is uniform and excellent there was.

division Electron mobility
[Cm 2 / (V · s)] Threshold voltage
( V _{th )} Transfer curve
( I _on / I _{off )} Example  2-1 2.18 x 10 ^-2 -7.01 1.38 x 10 ³ Example  2-2 2.07 x 10 ^-4 -8.02 1.12 x 10 ³ Example  2-3 2.65 x 10 ^-3 -10.83 5.81 × 10 ³ Example  2-4 2.52 x 10 ^-4 -12.47 1.30 x 10 ³ Example  2-5 2.48 × 10 ^-4 -12.88 1.43 x 10 ³ Example  2-6 2.18 x 10 ^-4 -12.49 1.38 x 10 ³ Example  2-7 2.54 x 10 ^-4 -11.02 1.45 x 10 ³ Example  2-8 1.46 x 10 ^-4 -12.14 1.38 x 10 ³ Comparative Example  2-1 8.41 x 10 ^-4 -22.08 6.08 × 10 ³ Comparative Example  2-2 2.05 × 10 ^-4 -12.36 1.10 x 10 ³ Comparative Example  2-3 - - - Comparative Example  2-4 - - - Comparative Example  2-5 1.94 × 10 ^-3 -14.35 5.81 × 10 ³ Comparative Example  2-6 2.16 x 10 ^-4 -12.12 1.18 x 10 ³ Comparative Example  2-7 2.01 × 10 ^-4 -10.78 1.18 x 10 ³

In the case of Examples 2-1 to 2-8, when the electron mobility is 2.0 × 10 ^-4 cm 2 / (V · s) or more, preferably, It was confirmed that the electron mobility of 2.18 × 10 ^-4 to 2.18 × 10 ^-2 cm 2 / (V · s) was high and that the threshold voltage was -13 V or more, preferably -7.01 V to -12.88 V And the I _on / I _off ratio was 1.0 × 10 ³ or more, preferably 1.12 × 10 ³ to 5.81 × 10 ³ .

In Comparative Example 2-3 in which the first flattening layer was formed only from the POSS compound represented by Formula 1-1 and Comparative Example 2-4 in which the first flattening layer was formed only from the polysilazane based compound, It was impossible.

In addition, in Comparative Example 2-1 and Comparative Example 2-5, the threshold voltage was relatively low as compared with the implementation.

In addition, Comparative Example 2-2, Comparative Examples 2-6 to 2-7, and Comparative Examples 2-1 to 2-2 exhibited relatively low electrical characteristics.

Through the above-described examples and experimental examples, the flexible OTFT device of the present invention uses the substrate of the polyamide paper material to secure the flexibility, and can be used as a flexible OTFT-based wearable and / or rollable display Electronic equipment and wearable lighting equipment can be provided and a specific material can be introduced into the planarizing layer to prevent deterioration of electrical and optical characteristics due to the introduction of the base material of the polyamide paper material, It is confirmed that this excellent flexible OTFT device and a device using the same can be provided.

10: substrate 20: planarization structure 21: first planarization layer
22: second planarization layer 30: gate 40: gate electrode insulator
50: source 60: drain 70: active material (or active layer)
100: demolisher 120: head box 210: gold net
211: Grubboard 212: Dewatering unit 220: Hot air dryer
230 compression dehydration part 240 secondary drying part 250 tertiary drying part

Claims (21)

Polypropylene glycol dimethacrylate (PPGDMA), polypropylene glycol dimethacrylate (PPGDA), polypropylene glycol dimethacrylate (PEGDMA), polypropylene glycol dimethacrylate (PVP) glycol diacrylate, PDEGDA (poly diethylene glycol diacrylate), a POSS compound represented by the following formula (1), a silazane compound represented by the following formula (2), a polysilazane compound, and a polymer represented by the following formula A flattening film for a substrate of a flexible OTFT (organic thin-film transistor) device;
[Chemical Formula 1]

In Formula 1, E is

,

 or

, R^One, R³ And R⁴Each independently represents an alkylene group having 2 to 5 carbon atoms, and R²Is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and X is -NHR⁵, And R⁵Is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms,
(2)

In Formula 2, R^One To R⁹ Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, B represents -NHR¹⁰, And R¹⁰Is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms,
(3)

In Formula 3, R^One To R⁸ Each independently represents a hydrogen atom, a halogen atom, a carboxyl group, an amide group, -CF₃, -Si (OR)_mH_3-mA formyl group or an acyl group, n is a rational number satisfying a weight average molecular weight of 50,000 to 200,000, and m is an integer of 0 to 3. The method according to claim 1, wherein the polysilazane compound
A polymer of a monomer represented by the following formula 4-1;
A copolymer comprising a compound represented by the following formula (4-1) and a compound represented by the following formula (4-2); And
A flattening film for substrate of a flexible OTFT device, comprising: a polymer represented by the following formula (4-3);
[Formula 4-1]

In Formula 4-1, R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms,
[Formula 4-2]

In Formula 4-2, R ¹ is an alkyl group having 1 to 3 carbon atoms,
[Formula 4-3]

In Formula 4-3, R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ² is an alkylene group having 2 to 5 carbon atoms, R ³ and R ⁴ are independently a hydrogen atom, An alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, and R ⁵ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
[3] The flattening film for substrate of claim 2, wherein the copolymer is a copolymer of the monomer represented by Formula 4-1 and the monomer represented by Formula 4-2 at a molar ratio of 1: 2 to 6:
The flattening film according to claim 1, wherein when the substrate of the flexible OTFT element is a polyamide paper, the flattening film has a single-
And at least one selected from the group consisting of PMF, PVP, PGMEA, PEGDMA, PPGDMA, PPGDA, PDEGDA, the POSS compound represented by the formula 1, the silazane compound represented by the formula 2 and the polysilazane compound. Planarizing film for substrate of flexible OTFT device.
The flattening film according to claim 1, wherein when the substrate of the flexible OTFT device is a polyamide film, the flattening film has a single-
A flattening film for substrate of a flexible OTFT device, which comprises a polymer represented by the above formula (3).
The method of claim 1, wherein the planarizing film has a multi-layer structure,
Wherein the first planarization layer comprises at least one selected from the group consisting of PMF, PVP, PGMEA, PEGDMA, PPGDMA, PPGDA, PDEGDA, POSS compounds represented by Formula 1, silazane compounds represented by Formula 2, ; And
And a second planarization layer comprising a polymer represented by Formula 3,
Wherein the first flattening layer and the second flattening layer are sequentially stacked on the upper surface of the substrate.
The method of claim 1, wherein the planarizing film
A dimethacrylate-based compound containing at least one selected from PEGDMA and PPGDMA; And
A mixture containing the POSS compound, the silazane, and the polysilazane in a weight ratio of 1: 0.1 to 1.5.
The flattening film for a base of a flexible OTFT device according to claim 1, wherein the flattening film has an average thickness of 0.1 탆 to 10 탆.
The flattening film of claim 6, wherein the first planarizing layer and the second planarizing layer have a thickness ratio of 1: 0.1 to 10.
The flattening film as claimed in claim 1, wherein the flattening film is formed between the substrate and the gate of the OTFT.
The flattening film of claim 4, wherein the polyamide paper comprises at least one selected from the group consisting of a polyamide paper, a para-polyamide paper, and a meta-para-polyamide paper.
12. The sheet according to claim 11, wherein the polyamide paper is a polyamide paper, wherein the polyamide paper has an apparent density of 0.20 g / cm3 to 0.40 g / cm3, a thickness of 10 占 퐉 according to ASTM D- And a tensile strength in the MD direction of not less than 0.95 N when measured according to TAPPI T414, wherein the tensile strength in the MD direction is not less than 25 N / cm, the elongation in the MD direction is not less than 5.0% Of the substrate.
13. The flattening film for substrate of claim 12, wherein the metapolyamide paper has a tear strength in the MD direction of 20 Nm 2 / kg to 30 Nm 2 / kg when the thickness is 0.14 mm.
The polyamide film according to claim 5, wherein the polyamide film is a film obtained by curing a polyamide resin containing a polymer of a diamine and a phthaloyl compound,
The polymer comprises diamine and phthaloyl compound in an equivalent ratio of 1: 0.9 to 1.1,
The diamine is phenylenediamine containing at least one selected from the group consisting of metaphenylenediamine and paraphenylenediamine; And at least one selected from 3,3'-oxydianiline and 3,4'-oxydianiline is oxydianiline; , ≪ / RTI >
The phthaloyl compound is a terephthaloyl compound containing at least one selected from terephthaloyl chloride and terephthaloyl bromide; And an isophthaloyl compound containing at least one selected from isophthaloyl chloride and isophthaloyl bromide; Wherein the at least one of the planarization film and the planarization film is formed on the substrate.
15. The flattening film for substrate of claim 14, wherein the phenylenediamine and the oxydianiline are present in a weight ratio of 7: 9: 1 to 3: 1.
15. The flattening film for substrate of claim 14, wherein the phenylenediamine comprises metaphenylenediamine and paraphenylenediamine in a weight ratio of 1: 1 to 3: 1.
15. The method of claim 14, wherein the diamine is selected from the group consisting of
And a ratio by weight of 3.5 to 4.5: 3.5 to 4.5: 0.5 to 1.5: 0.5 to 1.5, based on the total weight of the composition, of at least one selected from the group consisting of metaphenylenediamine, paraphenylenediamine, 3,4'- oxydianiline and 4,4'- Wherein the flattening film is a substrate for a flexible OTFT device.
15. The method of claim 14, wherein the diamine comprises the phenylenediamine and the oxydianiline in a weight ratio of 7 to 8: 2 to 3, the phenylenediamine is paraphenylenediamine, and the oxydianiline is 3,4 '- oxydianiline, and 4,4'-oxydianiline,
Wherein the phthaloyl compound comprises a terephthaloyl compound and an isophthaloyl compound at a weight ratio of 6-8: 2 to 4: 1.
A planarization film, a gate, a gate insulator, a source, a drain, and an active material according to any one of claims 1 to 18,
Wherein the planarizing film, the gate and the gate electrode insulator are stacked in this order.
20. The method of claim 19, wherein when the substrate is a polyamide film,
The transfer curve (I _on / I _off ) ratio is 1.0 × 10 ^-4 to 1.0 × 10 ^-2 when the ratio of the current value at the on and off states of the device is measured with a semiconductor parameter analyzer,
The threshold voltage (V _th ) is -12.0 V to -6.0 V when the gate voltage of the turn-on device is turned on by the semiconductor parameter analyzer,
Wherein a value of an electron mobility is 2.0 x 10 < ^-4 > to 1.0 x 10 < ^-2 > / Vs when the semiconductor parameter analyzer measures 10 V to -30 V.
20. The method of claim 19, wherein when the substrate is a polyamide paper,
The transfer curve (I _on / I _off ) ratio is 1.0 × 10 ² to 1.0 × 10 ⁴ when the current value ratio is measured at on and off of the device with a semiconductor parameter analyzer,
When measuring the gate voltage at the time when the device is turned on with the semiconductor parameter analyzer, the threshold voltage value is -7.0 V to -14.0 V,
Wherein the electron mobility value is 1.0 x 10 < ^-4 > to 3.5 x 10 < ^-2 > cm < ² > / V s when the semiconductor parameter analyzer measures 10 V to -100 V.

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