KR20180001175A - Polyimide Substrate having antistatic property And Display Substrate Module Including The Same - Google Patents

Abstract

The present invention relates to a polyimide substrate which comprises: a polyimide layer; and an optical antistatic layer including a silazane-siloxane compound on at least one surface of the polyimide layer, and a display substrate module having the same. The polyimide substrate has excellent bending properties and impact resistance so as to be beneficial as a cover substrate of an electronic device.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an antistatic polyimide substrate and a display substrate module including the same,

The present invention relates to a polyimide substrate and a display substrate module including the same.

Flexible electronic devices such as flexible OLEDs, lightweight displays, flexible encapsulants, color EPDs, plastic LCDs, TSPs, and OPVs have attracted attention as electronic devices that can bend or bend into one of the next generation displays have. Flexible or foldable foldable or flexible type displays are possible, and a new type of flexible cover substrate is required to replace the existing glass cover substrate in order to protect the lower element. Such a substrate needs to maintain high hardness, low moisture permeability, chemical resistance and light transmittance in order to protect the parts contained in the display device. In addition, in order to minimize defects in the display process, such a substrate is required to prevent a short circuit due to static electricity and to prevent the adsorption of foreign substances, and thus an antistatic function is required.

As such flexible display cover substrate materials, various high-hardness plastic substrates have been studied as candidates, and a transparent polyimide film capable of realizing a thinner thickness and a higher hardness has been considered as a major candidate. Transparent polyimide plastic substrates, however, have a high sheet resistance of more than 10 ¹⁵ ohm / square, which is very high in static electricity. For this purpose, antistatic coating technology for improving the antistatic function of the polymer film is an important issue.

Many researches on carbon nanotubes, graphenes, silver nano wires, metal oxides, etc. have been carried out for the purpose of improving the antistatic function, but satisfactory levels of physical properties have not been secured.

The present invention provides a cover substrate for a flexible electronic device which is excellent in bending properties and impact resistance while minimizing static electricity generated during the process, reducing defects due to shorting, minimizing adsorption to foreign matter in the air, A useful polyimide substrate and a display substrate module including the same.

According to a first aspect of the present invention, there is provided a semiconductor device comprising: a polyimide layer; And an antistatic layer comprising an antistatic resin copolymerized with at least one side of the polyimide layer, the antistatic resin comprising a silazane-siloxane compound represented by the following formula (1) and a compound represented by the following formula (2) Is a polyimide substrate.

≪ Formula 1 >

Wherein R is a urethane group having at least one bonding structure selected from the group consisting of a hydroxyl group, a vinyl group, an acrylic group, an epoxy group and an amine group, R 'is a hydroxyl group, a vinyl group, An epoxy group, and an amine group, and m and n are integers of 1 to 10. The cyanate group may be a cyanate group having at least one bond structure selected from the group consisting of an epoxy group and an amine group.

(2)

(3)

In the general formulas (2) and (3), R _x , R _y and R _z are each independently selected from a hydrogen atom, a hydroxyl group, a hydroxylalkyl group, an alkyl group, an alkoxy group and a carboxyl group. The silazane-siloxane compound has a weight average molecular weight of 500 to 500,000 g / mol.

The antistatic resin has a weight average molecular weight of 3,000 to 20,000 g / mol.

The optical antistatic layer comprises the silazane-siloxane compound represented by Formula 1 and the antistatic resin in a weight ratio of 1: 0.01 to 0.05.

The antistatic resin is obtained by copolymerizing the compound represented by Formula 2 and the compound represented by Formula 3 in a molar ratio of 1: 0.1 to 0.3.

The optical antistatic layer has a thickness of 0.1 to 3 占 퐉.

The polyimide substrate has a yellowness of 2.5 or less and a light transmittance of 85 to 93% at 350 to 700 nm as measured by KONICA MINOLTA CM-3700D measurement standard.

The polyimide substrate further comprises a hard coat layer.

The polyimide substrate has an electrical resistance of 10 ⁵ to 10 ¹⁰ ohm / square.

The polyimide substrate has an electrostatic voltage with a charge peeling pressure of -300 to + 300V.

The hard coating layer comprises a resin for hard coating formed from a siloxane resin containing a chemical reactant or a mixture containing an alkoxysilane represented by the following formula (4) and an alkoxy metal represented by the following formula (5).

≪ Formula 4 >

≪ Formula 5 >

Wherein R ¹ is a linear, branched, alicyclic or aromatic organic compound containing an epoxy, an acryl or an isocyanate, R ² and R ³ are a linear, branched or cyclic organic compound containing a hetero compound such as oxygen or nitrogen, Branched or alicyclic C ₁ to C ₈ alkyl group, and n is an integer of 1 to 3. M is a metal element including a transition metal, and m is an integer of 1 to 10.

The hard coating layer has a thickness of 10 to 50 mu m.

The polyimide substrate has a surface hardness of 5H to 9H measured with the direction in which the hard coating layer is formed as an upper surface in accordance with JIS K56000 measurement standard.

The polyimide substrate has a water permeability of 0.001 to 10 g / m ² * day as measured by ASTM E96BW.

Further, a second preferred embodiment of the present invention is a display substrate module comprising a transparent adhesive layer, a black metal layer, and a polyimide substrate of the first embodiment.

According to the present invention, it is possible to provide a transparent polyimide substrate having excellent solvent resistance, optical characteristics, moisture barrier properties and scratch resistance, while having excellent bending property and impact resistance. The transparent polyimide substrate according to the present invention can be usefully used as a cover substrate of a flexible electronic device, thereby providing a flexible display substrate module having excellent bending properties and impact resistance. In addition, by adding antistatic function, it is possible to minimize the defect and foreign matter adsorption due to the electrostatic short-circuit between the processes, thereby securing a higher process yield than the existing process.

1 is a structural view illustrating an example of a display substrate module including a polyimide substrate according to an embodiment of the present invention.

According to one aspect of the present invention there is provided a polyimide layer; And an antistatic layer comprising an antistatic resin copolymerized with at least one side of the polyimide layer, the antistatic resin comprising a silazane-siloxane compound represented by the following formula (1) and a compound represented by the following formula (2) A polyimide substrate can be provided.

≪ Formula 1 >

Wherein R is a urethane group having at least one bonding structure selected from the group consisting of a hydroxyl group, a vinyl group, an acrylic group, an epoxy group and an amine group, R 'is a hydroxyl group, a vinyl group, An epoxy group, and an amine group, and m and n are integers of 1 to 10. The cyanate group may be a cyanate group having at least one bond structure selected from the group consisting of an epoxy group and an amine group.

(2)

(3)

In the general formulas (2) and (3), R _x , R _y and R _z are each independently selected from a hydrogen atom, a hydroxyl group, a hydroxylalkyl group, an alkyl group, an alkoxy group and a carboxyl group.

In the present invention, the polyimide layer is made of a polyimide film, and may be a conventional polyimide film obtained by polymerizing a diamine and an acid dianhydride followed by imidization. The polyimide layer of the present invention can be applied to any colorless transparent polyimide film which has inherent heat resistance of a polyimide resin and does not appear yellow, and can be applied to a film having a thickness of 10 to 100 μm by a UV spectrophotometer The measured average transmittance at 350 to 700 nm is 85% or more, the yellowness is 5 or less, and the average linear expansion coefficient (CTE) measured at 50 to 250 according to the TMA-Method is 50.0 ppm / can do.

If the average transmittance of the polyimide film is less than 85% based on the thickness of the polyimide film of 10 to 100 占 퐉 or the yellowness exceeds 5, the transparency becomes poor and it can not be applied to displays or optical elements. (CTE) is more than 50.0 ppm /, the thermal expansion coefficient difference with the plastic substrate becomes large, so that the device may be overheated or short-circuited if the temperature is high.

The silazane-siloxane compound according to the present invention can be represented by the following formula (1) and has a weight average molecular weight measured by gel permeation chromatography (GPC) of 500 to 500,000 g / mol, preferably 10,000 to 30,000 g / mol good.

≪ Formula 1 >

Wherein R is a urethane group having at least one bonding structure selected from the group consisting of a hydroxyl group, a vinyl group, an acrylic group, an epoxy group and an amine group, R 'is a hydroxyl group, a vinyl group, An epoxy group, and an amine group, and m and n are integers of 1 to 10. The cyanate group may be a cyanate group having at least one bond structure selected from the group consisting of an epoxy group and an amine group.

When the weight average molecular weight of the silazane-siloxane compound represented by the formula (1) is less than 500 g / mol, the effect of improving the solvent resistance, heat resistance and moisture barrier property is insignificant, and when it exceeds 50,000 g / mol, It may lack adhesion with other compounds. The silazane-siloxane compound has a high-density structure and improves the chemical resistance of the substrate. Since the refractive index of the silazane-siloxane compound is lower than that of the substrate, the optical characteristics of the polyimide film can be improved Can be improved.

In the present invention, the silazane-siloxane compound is dissolved in an organic solvent and applied. In this case, the organic solvent may include isopropyl alcohol (IPA), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (Propylene glycol monomethyl ether acetate (PGMEA)), n-butanol, pentanol, methyl ethyl ketone (MEK), acetone, methyl alchol, ethyl alchol ) May be suitable. At this time, the amount of the organic solvent may be selected according to the thickness to be applied, preferably 0.5 to 90 wt%, more preferably 1 to 50 wt%, and most preferably 1 to 50 wt% 20% by weight. If the amount of the organic solvent is less than 0.5% by weight, the coating may not be uniformly formed at the time of coating, resulting in a thickness variation on the surface of the substrate, and if it exceeds 90% by weight,

The antistatic resin included in the optical antistatic layer according to the present invention is preferably copolymerized with a compound represented by the following formula (2) and (3).

(2)

(3)

In the general formulas (2) and (3), R _x , R _y and R _z are each independently selected from a hydrogen atom, a hydroxyl group, a hydroxylalkyl group, an alkyl group, an alkoxy group and a carboxyl group.

The antistatic resin preferably has a weight average molecular weight of 3,000 to 20,000 g / mol, and preferably 3,000 to 10,000 g / mol.

The optical antistatic layer preferably contains the silazane-siloxane compound represented by Formula 1 and the antistatic resin in a weight ratio of 1: 0.01 to 0.05, preferably 0.01 to 0.04, more preferably 0.01 to 0.03 . When the antistatic resin is contained in an amount less than 0.01 wt%, the electrical resistance is high and the antistatic function is degraded. When the antistatic resin is contained in an amount of more than 0.05 wt%, the electrical resistance is charged to a reverberated charge.

In the antistatic resin according to the present invention, the compound represented by Formula 2 and the compound represented by Formula 3 may be copolymerized in a molar ratio of 1: 0.1 to 1, preferably 1: 0.1 to 0.3. When the ratio of the compound represented by the general formula (3) is less than 0.1 molar ratio in the reaction ratio, adhesion with the black matrix and the PSA layer is weak, resulting in problems such as bubbling and cracking during dynamic bending of 3R, There is a problem that the refractive index increases and the optical transmittance decreases.

At this time, the antistatic resin includes a compound represented by Chemical Formula 2 and Chemical Formula 3 to copolymerize by adding a compound for forming a micelle and an oxidizing agent. The micelle forming compound includes, for example, PVP (polyvinyl pyrrolidone), which can prevent agglomeration. The oxidizing agent includes, for example, APS (Ammonium persulfate), FeCl ₃ and the like, and by adding it, polymerization is initiated.

In the present invention, the antistatic function and optical properties can be improved by including the silazane-siloxane compound represented by the above formula (1) together with the above-mentioned antistatic resin. Specifically, an electron chanel The static electricity is effectively removed and high optical characteristics can be obtained by the optical compensation effect of the siloxane compound and the transparent polyimide

The optical antistatic layer according to the present invention preferably has a thickness of 0.1 탆 or more in order to secure solvent resistance and optical properties and to improve moisture barrier properties, It is preferable that the thickness is 3 mu m or less. The optical antistatic layer may be formed on the lower or upper surface of the polyimide film, but may be formed on both surfaces of the polyimide film. The polyimide substrate including the optical antistatic layer according to the present invention can be used as a measurement standard of CM-3700D of KONICA MINOLTA, which can exhibit excellent optical characteristics having a yellow lightness of 2.5 or less and a light transmittance of 350 to 700 nm of 85 to 93% do.

In the present invention, the optical antistatic layer may be coated by a suitable method selected from a variety of methods such as spray coating, bar coating, spin coating, and dip coating. But is not limited thereto as long as it is usually applicable. The optical antistatic layer is thermally cured by heat treatment at a temperature of 200 to 300 ° C to have an intramolecular network structure. The optical antistatic layer can further improve the chemical resistance and heat resistance by making the film more rigid.

According to a preferred embodiment of the present invention, the polyimide substrate further includes a hard coat layer, thereby ensuring chemical resistance and impact resistance, and exhibiting a surface hardness of 5H to 9H according to JIS K56000 measurement standard. Preferably, the hard coat layer should be formed on the surface of the substrate. By forming both the optical antistatic layer and the hard coat layer on the polyimide layer in this way, the transmittance of the film and the yellow The water permeability can be reduced to 0.001 to 10 g / m ² * day in accordance with the ASTM E96BW measurement standard while maintaining the optical properties such as transparency and the like. In particular, the polyimide substrate of the present invention may be more advantageous in protecting TFTs and OLED devices from external humid environments by exhibiting a low water permeability in the above range

In the present invention, the hard coating layer may include a resin for hard coating formed from a siloxane resin containing a chemical reactant or a mixture comprising an alkoxysilane represented by the following general formula (4) and an alkoxy metal represented by the following general formula .

≪ Formula 4 >

≪ Formula 5 >

Wherein R ¹ is a linear, branched, alicyclic or aromatic organic compound containing an epoxy group, an acrylic group or an isocyanate group, R ² and R ³ are substituted or not substituted with a hetero compound such as oxygen or nitrogen, hwandoen linear, branched or alicyclic alkyl group is C ₁ to C _8, n is an integer from 1 to 3, m is a metal element, including a transition metal, m is an integer from 1 to 10.

In the present invention, the siloxane resin may be prepared from the polymerization reaction of the alkoxysilane of formula (4) alone or may be prepared as a siloxane resin in which the chemical bond of the metal element is present by introducing the alkoxy metal of formula (5) . The siloxane resin may be reacted with an alkoxysilane represented by the general formula (4) and a compound other than an alkoxy metal represented by the following general formula (5), if necessary. The reaction of forming the siloxane resin may proceed at room temperature, but may be stirred at 50 to 120 ° C for 1 to 120 hours to promote the reaction.

As a catalyst for carrying out the hydrolysis and condensation reaction during the reaction, an acid catalyst such as hydrochloric acid, acetic acid, hydrogen fluoride, nitric acid, and sulfuric acid iodic acid, a base such as ammonia, potassium hydroxide, sodium hydroxide, barium hydroxide, imidazole A catalyst, and an amberite. These catalysts may be used alone or in combination. The amount of the catalyst is not particularly limited, but 0.0001 to about 10 parts by weight based on 100 parts by weight of the siloxane resin may be added.

When the hydrolysis and condensation reaction proceeds, alcohol as a by-product is produced. By eliminating it, the reverse reaction can be reduced and the reaction can proceed more quickly, and the reaction rate can be controlled through the reaction. After completion of the reaction, the by-product may be removed by decompression and heating.

The siloxane resin synthesized by the condensation reaction can control the viscosity and the curing rate by the monomers added during the reaction, thereby providing an optimal resin composition suitable for the application. In addition, the siloxane resin obtained through the above reaction can prevent the curling due to curing shrinkage because intermolecular space is secured during crosslinking, and it is possible to realize high surface hardness by crosslinking and metal elements.

The hard coating layer may further include a resin for hard coating formed by further including a compound other than the alkoxysilane represented by Formula 4 and the alkoxysilane represented by Formula 5 below.

According to a preferred embodiment of the present invention, the resin composition for hard coating may further include an initiator for the polymerization of the siloxane resin. For example, a photopolymerization initiator such as an organic metal salt and a thermal polymerization initiator such as an amine or imidazole Can be used. In this case, the amount of the initiator to be added is not particularly limited, but about 0.01 to 10 parts by weight may be added to about 100 parts by weight of the siloxane resin.

In addition, the resin composition for hard coating of the present invention may further include an organic solvent for controlling the viscosity of the siloxane resin to facilitate workability and adjusting the thickness of the coating film. The amount of the organic solvent to be added is not particularly limited and examples of usable organic solvents include ketones such as acetone, methyl ethyl ketone, methyl butyl ketone and cyclohexanone, cellosolves such as methyl cellosolve and butyl cellosolve, Or alcohols such as ethers such as ethyl ether and dioxane, isobutyl alcohol, isopropyl alcohol, butanol and methanol, halogenated hydrocarbons such as dichloromethane, chloroform and trichlorethylene, and halogenated hydrocarbons such as n-hexane, And solvents composed of hydrocarbons and the like.

The siloxane resin of the present invention may further include an antioxidant to inhibit the oxidation reaction resulting from the polymerization reaction, and may further include a leveling agent or a coating aid, but the present invention is not limited thereto.

The resin composition for hard coating of the present invention can be prepared by hardening a hard coat by photopolymerization or thermal polymerization after molding such as coating, casting or molding. For the photopolymerization it is possible to obtain a uniform surface over the light article pre-heat treatment, which can be carried out at a temperature below about 300 ℃ than 40 ℃, if the irradiation light amount performed under the conditions of 50mJ / cm ² or more 20000mJ / cm ² or less But is not limited thereto. Further, in the case of thermal polymerization, it may be carried out at a temperature of from 40 ° C to about 300 ° C, but is not limited thereto.

In the present invention, the hard coat layer formed as described above preferably has a dry thickness of 10 탆 or more in order to obtain excellent surface hardness, impact resistance and chemical resistance, and is preferably formed to be less than 50 탆 in order to prevent warpage and excessive rigidity .

Further, the present invention can provide a display substrate module including a transparent adhesive layer , a black matrix, and a polyimide substrate of the above-described characteristics. Although not limited thereto, the display substrate module of the present invention may include a polyimide structure in which an optical antistatic layer 20, a polyimide layer 10, and a hard coating layer 30 are sequentially stacked, A transparent adhesive layer 40 and a black mattress 50 may be formed on the bottom surface of the optical primer layer.

The polyimide substrate including the above-described structure may have conductivity and may have an electrical resistance of 10 ⁵ to 10 ¹⁰ ohm / square.

In addition, the polyimide substrate may have an electrostatic voltage with a charge peeling pressure of -300 to + 300V.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are for the purpose of illustrating the present invention more specifically, and the present invention is not limited thereto.

≪ Preparation Example 1: Production of polyimide film &

1-1: Preparation of polyimide powder

832 g of N, N-dimethylacetamide (DMAc) was charged into a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser while nitrogen was passed through the reactor. 64.046 g (0.2 mol) of bistrifluoromethylbenzidine (TFDB) was dissolved and the solution was maintained at 25 占 폚. Thereto were added 31.09 g (0.07 mol) of 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanedioanhydride (6FDA) and 8.83 g (0.03 mol) of biphenyltetracarboxylic dianhydride (BPDA) ) Was added and stirred for a certain period of time to dissolve and react. The temperature of the solution was maintained at 25 占 폚. Then, 20.302 g (0.1 mol) of terephthaloyl chloride (TPC) was added to obtain a polyamic acid solution having a solid content of 13 wt%.

25.6 g of pyridine and 33.1 g of acetic anhydride were added to the polyamic acid solution, stirred for 30 minutes, and further stirred at 70 ° C for 1 hour. The mixture was cooled to room temperature and precipitated with 20 L of methanol. The precipitated solid was filtered and pulverized And then dried at 100 DEG C under vacuum for 6 hours to obtain 111 g of a solid powdery polyimide.

1-2: Production of polyimide film

0.03 g (0.03 wt%) of OH group-bonded amorphous silica particles was added to N, N-dimethylacetamide (DMAc) at a dispersion concentration of 0.1% and ultrasonic treatment was performed until the solvent became transparent. 100 g of the obtained polyimide powder as a solid powder was dissolved in 670 g of N, N-dimethylacetamide (DMAc) to obtain a 13 wt% solution. The solution thus obtained was applied to a stainless steel plate, cast to 340 占 퐉 and dried with hot air at 130 占 폚 for 30 minutes, and then the film was peeled off from the stainless plate and fixed to the frame with a pin.

The frame with the film fixed therein was placed in a vacuum oven, slowly heated from 100 ° C to 300 ° C for 2 hours, cooled gradually and separated from the frame to obtain a polyimide film. Thereafter, the substrate was subjected to heat treatment at 300 ° C for 30 minutes as a final heat treatment process. The prepared polyimide film had a thickness of 80 μm, an average light transmittance of 87%, a haze of 4.5, and an average coefficient of linear thermal expansion (CTE) measured at 50 to 250 ° C. according to the TMA-Method was 20 ppm / ° C. .

≪ Preparation Example 2: Preparation of resin for hard coating >

The mixture was mixed with KBM-303 (Shinetsu), Titanium isopropoxide (Sigma-Aldrich) and H ₂ O at a ratio of 227.96 mL: 1.94 mL: 21.61 mL and put into a 500 mL flask. 0.2 g of sodium hydroxide was added as a catalyst to 60 Lt; / RTI > for 24 hours. Thereafter, the number average molecular weight by 0.45um filtration using a Teflon filter 7245, a weight average molecular weight of 20146 and a polydispersity index (PDI, M _w / M _n) is to obtain a 2.78 siloxane resin. 3 parts by weight of IRGACURE 250 (BASF) as a photoinitiator relative to 100 parts by weight of the resin was added to finally obtain a resin for hard coating.

≪ Preparation Example 3: Antistatic resin preparation >

PVP (polyvinyl pyrrolidone) having a weight average molecular weight of 10,000 g / mol by Aldrich Co. was sufficiently stirred in 500 mL containing DI Water at 1 wt% to form Micell. Thereafter, 2.3 M of APS (Ammonium persulfate) was added and sufficiently dissolved. EDOT monomer (R _x and R _y are each a hydrogen atom in formula (2)) and 2-carboxyethyl acrylate (R _z in formula (3) is carboxyethyl). ) Was dropped in a 1: 0.3 molar ratio using a burette dropwise and maintained for 4 hours to obtain a PEDOT-acrylate polymer resin. After that, APS was washed with DI Water and Methanol, and dried at 100 ° C oven to obtain PEDOT-Acrylate. The obtained PEDOT-Acrylate was dispersed in DI Water and Ethanol at 1.5 wt%. The PEDOT-acrylate polymer resin thus prepared had a weight average molecular weight of 8,000 g / mol.

≪ Preparation Example 4: Antistatic resin preparation >

PVP (polyvinyl pyrrolidone) having a weight average molecular weight of 10,000 g / mol by Aldrich Co. was sufficiently stirred in 500 mL containing DI Water at 1 wt% to form Micell. After the addition of 2.3 M of APS (Ammonium persulfate), the EDOT monomer (R _x is a hydrogen atom and R _y is a carboxylic acid) and 2-Carboxyethyl acrylate (in formula (2), R _z is carboxymethyl ) Was dropped in a 1: 0.3 molar ratio using a burette dropwise and maintained for 4 hours to obtain a PEDOT-acrylate polymer resin. After that, APS was washed with DI Water and Methanol, and dried at 100 ° C oven to obtain PEDOT-Acrylate. The obtained PEDOT-Acrylate was dispersed in DI Water and Ethanol at 2.5 wt%. The PEDOT-acrylate polymer resin thus prepared had a weight average molecular weight of 8,500 g / mol.

≪ Preparation Example 5: Antistatic resin preparation >

PVP (polyvinyl pyrrolidone) having a weight average molecular weight of 10,000 g / mol by Aldrich Co. was sufficiently stirred in 500 mL containing DI Water at 1 wt% to form Micell. After the addition of 2.3 M of APS (Ammonium persulfate), the EDOT monomer (R _x and R _y are each methyl carboxyl group) and 2-carboxyethyl acrylate (R _z in formula (3) 1: 0.3 molar ratio, dropwise dropwise using a burette and maintained for 4 hours to obtain a PEDOT-acrylate polymer resin. After that, APS was washed with DI Water and Methanol, and dried at 100 ° C oven to obtain PEDOT-Acrylate. The obtained PEDOT-Acrylate was dispersed in DI water and ethanol at 2.2 wt%. The PEDOT-acrylate polymer resin thus prepared had a weight average molecular weight of 10,000 g / mol.

Example 1

To a solution obtained by dissolving 1.3 wt% of a polysilazane-siloxane compound (DCT) having a weight average molecular weight of 2,000 g / mol in PGME (manufactured by Daehwa Fine Chemical Co., Ltd.), the resin prepared in Preparation Example 3 was added to the polysilazane- 0.02 weight ratio, and coated on one surface of the colorless transparent polyimide film prepared in Preparation Example 1 by wire, followed by drying at 80 ° C. to form a polysilazane siloxane compound film having a thickness of 0.1 μm. Thereafter, the film was allowed to stand at room temperature for about 2 minutes, and then thermally cured at a temperature of about 250 DEG C for 4 minutes to produce a polyimide substrate having an optical antistatic layer having a thickness of 0.1 mu m.

Example 2

To a solution obtained by dissolving 1.3 wt% of a polysilazane siloxane compound (DCT Co.) having a weight average molecular weight of 2,000 g / mol in PGME (manufactured by Daehwa Fine Chemical Co., Ltd.), 0.025 And then dried at a temperature of 80 캜 to form a polysilazane siloxane compound film having a thickness of 0.1 탆. Thereafter, the film was allowed to stand at room temperature for about 2 minutes, and then thermally cured at a temperature of about 250 DEG C for 4 minutes to produce a polyimide substrate having an optical antistatic layer having a thickness of 0.1 mu m.

Example 3

To a solution obtained by dissolving 1.3 wt% of a polysilazane siloxane compound (DCT Co.) having a weight average molecular weight of 2,000 g / mol in PGME (manufactured by Daehwa Fine Chemical Co., Ltd.), 0.03 And then dried at a temperature of 80 캜 to form a polysilazane siloxane compound film having a thickness of 0.1 탆. Thereafter, the film was allowed to stand at room temperature for about 2 minutes, and then thermally cured at a temperature of about 250 DEG C for 4 minutes to produce a polyimide substrate having an optical antistatic layer having a thickness of 0.1 mu m.

Example 4

10% by weight of a polysilazane siloxane compound (DCT Co.) having a weight average molecular weight of 2,000 g / mol was dissolved in PGME (manufactured by Daehwa Fine Chemical Co., Ltd.) in a ratio of 0.02 weight ratio with respect to the polysilazane-siloxane compound 1 , And then coated on one surface of the colorless transparent polyimide film prepared in Production Example 1 by wire and dried at a temperature of 80 캜 to form a polysilazane siloxane compound film having a thickness of 1 탆. Thereafter, the substrate was allowed to stand at room temperature for about 2 minutes, and thermally cured at a temperature of about 250 ° C for 4 minutes to produce a polyimide substrate having an optical antistatic layer having a thickness of 1 μm.

Example 5

The procedure of Example 1 was repeated except that the resin prepared in Production Example 4 was used in place of the resin produced in Production Example 3 in Example 1.

Example 6

The procedure of Example 1 was repeated except that the resin prepared in Production Example 5 was used instead of the resin produced in Production Example 3 in Example 1. [

Comparative Example 1

The polyimide film prepared in Production Example 1 was prepared as it was and was designated as Comparative Example 1. [

Comparative Example 2

A polyimide substrate was prepared by forming only a hard coating layer in the same manner as in Example 8 except for the optical antistatic layer in the polyimide film of Production Example 1.

Comparative Example 3

The hard coating layer was formed in the same manner as in Example 8 except that acrylic resin was used in place of the hard coating resin of Production Example 2, but the shrinkage ratio was not appropriate, and curl was severely generated during curing, and surface cracks were visually confirmed.

Comparative Example 4

The polyimide substrate was prepared in the same manner as in Example 1, except that the optical antistatic layer was formed to have a thickness of 3.5 탆. However, it was confirmed that the polyimide substrate was hardly produced by curing when cured.

<Measurement method>

Subsequently, physical properties were measured by the following methods in the above-mentioned Examples and Comparative Examples, except for Comparative Examples 3 and 4, in which the analysis was impossible due to the occurrence of crake in the naked eyes. The results are shown in Tables 1 and 2 Respectively.

(1) Average light transmittance (%): The optical transmittance at 350 to 700 nm was measured using a spectrophotometer (CM-3700D, KONICA MINOLTA) according to the standard specification ASTM E313.

(2) Yellowness: Yellowness was measured using a spectrophotometer (CM-3700D, KONICA MINOLTA) according to ASTM D1925.

(3) Water Permeability (g / m ² * day): Water permeability (WVTR) was measured using a standard ASTM E69BW using a water-based transient (MOCON / US / Aquatran-model-1).

(4) Pencil hardness: 50 mm at a speed of 180 mm / min under a load of 1 kg (using an electric pencil hardness meter) with a pencil (UNI) for evaluation of Mitsubishi as a standard standard ASTM D3363 After 5 strokes, the pencil hardness at which no scratches were generated on the surface was measured.

(5) Adhesion (detachment after detachment with tape): Measured by tapping after cross cutting according to standard (ASTM D3359).

(6) Flexural characteristics: The substrate was wound around a circular tool having a diameter of 2 mm, and the substrate was wound. The film was repeated 200,000 times to observe the film with a naked eye or a microscope. If there was any cracking, the film was marked as 'Failed' 'OK'.

(7) Chemical resistance measurement: 2.38% of tetramethylammonium hydroxide (TMAH), dimethylacetamide (DMAc), N-methyl-2-pyrrolidone ), Sodium hydroxide (KOH) 1%, acetone, isopropyl alcohol (IPA), methylethylketone (MEK) and MASO ₂ (sodium sulfate) for 1 hour, X 'when white turbidity or anomaly occurs, and''when the weight change rate after drying is within 0.01%.

(8) Measurement of surface resistance: MCP-HT45 4-probe manufactured by Mitsubishi Chemical Co., Ltd. was used to measure the surface resistance at a temperature of 25 ° C and a humidity of 40% and a voltage of 100V.

(9) Static electricity: Using an electrostatic meter at 25 ° C and a humidity of 40% using MODEL KSD-100 of Kasuga Electric Co., Ltd., an MB grade protective film of Yoo Sang Company was laminated and peeled at a rate of 10 cm / Were measured.

(10) Molecular weight measurement: After dissolving about 0.2% of the sample in DMAc, filter it with 0.45um PEFE syringe filter. Instrument is Sykam pump + RI Detector. Styragel HR 4E + 5E for stationary phase, 30mM LiBr for mobile phase, and 30mM H3PO4 in THF: DMF (1: 1) for RI for 30 min at 1.0 mL / in at 50 ℃. The calibration curve is prepared using 0.1% Polystyrene in DMAc standard foam.

(11) Measurement of weight average molecular weight: The molecular weight and the molecular weight distribution (PDI, Mw / Mn) of the present invention were measured by polystyrene conversion weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) And the number average molecular weight (Mn). More specifically, the polymer may be dissolved in tetrahydrofuran to a concentration of 1% and injected into GPC at a flow rate of 1.0 ml / min at a flow rate of 30 ml / min. At this time, the column may be a series of two Styragel HR3 Waters or two Mixed Waters, and an RI detector (Waters, 2414) may be used as the detector.

division Permeability (%) Yellowness Water permeability (g / m ² / day) Surface resistance (ohm / square) Daejeon pressure (V) Pencil hardness Adhesiveness Bending characteristic Example 1 90 0.7 > 50 1.2 * 10 ⁶ +50 2H 5B OK Example 2 90 0.8 > 50 8.6 * 10 ⁹ -2,000 2H 5B OK Example 3 89 0.5 > 50 4.4 * 10 ⁴ +800 2H 5B OK Example 4 88 -1.2 > 50 2.1 * 10 ⁶ +30 2H 5B OK Example 5 89 0.6 > 50 3.1 * 10 ⁷ -160 2H 5B OK Example 6 90 0.7 > 50 2.7 * 10 ⁶ +35 2H 5B OK Example 7 93 0.0 > 50 1.3 * 10 ⁶ +3 2H 5B OK Example 8 91 0.6 3.1 1.1 * 10 ⁶ +55 9H 5B OK Comparative Example 1 88   3.8 > 50 Over -15,000 2H 5B OK Comparative Example 2 88 3.7 17.0 1 * 10 ⁶ -9,500 9H 5B OK Comparative Example 3 Measure
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division TMAH DMAc NMP KOH IPA MASO ₂ Example 1 ○ ○ ○ ○ ○ ○ Example 2 ○ ○ ○ ○ ○ ○ Example 3 ○ ○ ○ ○ ○ ○ Example 4 ○ ○ ○ ○ ○ ○ Example 5 ○ ○ ○ ○ ○ ○ Example 6 ○ ○ ○ ○ ○ ○ Example 7 ○ ○    ○ ○ ○ ○ Example 8 ○ ○ ○ ○ ○ ○ Comparative Example 1 ○ x x x ○ x Comparative Example 2 ○ ○ ○ ○ ○ ○

As can be seen from the results of Tables 1 and 2, in Examples 1 to 8 in which an optical antistatic layer containing silazane-siloxane was formed on the surface of the polyimide film, Comparative Example 1 The optical properties such as light transmittance and yellowness as well as the chemical resistance were improved. In addition, when the surface resistance is maintained at about 10 ⁶ ohm / square, it is confirmed that when the protective film is desorbed from the base film, the electrons are desorbed but the electrons are rich and the electron path is formed. However, it was confirmed that the charge peeling pressure was higher in Example 2 where the antistatic resin content was lower than that of Example 1 and higher than that of Example 3.

 On the other hand, Example 8 in which the optical antistatic layer and the hard coat layer were formed showed little change in physical properties such as chemical resistance and pencil hardness compared to Comparative Example 2 in which the optical antistatic layer was omitted and only the hard coat layer was formed, And it was confirmed that the sheet resistance and the peeling pressure of the electrification can be greatly improved as compared with Comparative Example 2.

These results show that the polyimide substrate according to the present invention is excellent in optical characteristics and antistatic function as well as excellent in surface hardness, chemical resistance, and warpage characteristics, and thus is suitable as a display substrate module for flexible electronic devices. Particularly, It would be advantageous to protect the TFT and the OLED element from the external humid environment.

10: polyimide layer 20: optical antistatic layer
30: hard coating layer 40: transparent adhesive layer
50: Black mattress layer

Claims (15)

A polyimide layer; And
And an antistatic layer comprising an antistatic resin copolymerized with at least one side of the polyimide layer comprising a silazane-siloxane compound represented by the following formula (1) and a compound represented by the following formula (2) Polyimide substrate.
&Lt; Formula 1 >

Wherein R is a urethane group having at least one bonding structure selected from the group consisting of a hydroxyl group, a vinyl group, an acrylic group, an epoxy group and an amine group, R 'is a hydroxyl group, a vinyl group, An epoxy group, and an amine group, and m and n are integers of 1 to 10. The cyanate group may be a cyanate group having at least one bond structure selected from the group consisting of an epoxy group and an amine group.
(2)

(3)

In the general formulas (2) and (3), R _x , R _y and R _z are each independently selected from hydrogen, a hydroxyl group, a hydroxyl alkyl group, an alkyl group, an alkoxy group and a carboxyl group. The polyimide substrate according to claim 1, wherein the silazane-siloxane compound has a weight average molecular weight of 500 to 500,000 g / mol.
The polyimide substrate according to claim 1, wherein the antistatic resin has a weight average molecular weight of 3,000 to 20,000 g / mol.
The polyimide substrate according to claim 1, wherein the optical antistatic layer comprises the silazane-siloxane compound represented by Formula 1 and the antistatic resin at a weight ratio of 1: 0.01 to 0.05.
The polyimide substrate according to claim 1, wherein the antistatic resin is a copolymer of the compound represented by Formula 2 and the compound represented by Formula 3 in a molar ratio of 1: 0.3 to 1.0.
The polyimide substrate according to claim 1, wherein the optical antistatic layer has a thickness of 0.1 to 3 占 퐉.
The polyimide substrate according to claim 1, wherein the polyimide substrate has a yellowness value of 2.5 or less and a light transmittance of 85 to 93% at 350 to 700 nm as measured by KONICA MINOLTA CM-3700D.
2. The polyimide substrate of claim 1, wherein the polyimide substrate further comprises a hard coat layer.
The polyimide substrate according to claim 1, wherein the polyimide substrate has a surface resistance of 10 ⁵ to 10 ¹⁰ ohm / square.
The polyimide substrate according to claim 1, wherein the polyimide substrate has an electrostatic voltage with a charge peeling pressure of -300 to +300 V.
[8] The hard coating layer of claim 8, wherein the hard coating layer comprises a resin for hard coating formed from a siloxane resin containing a chemical reactant or a mixture comprising an alkoxysilane represented by the following formula (4) and an alkoxy metal represented by the following formula To a polyimide substrate.
&Lt; Formula 4 >

&Lt; Formula 5 >

Wherein R ¹ is a linear, branched, alicyclic or aromatic organic compound containing an epoxy group, an acrylic group or an isocyanate group, R ² and R ³ are substituted with a hetero compound such as oxygen or nitrogen, Beach an alkyl group of C ₁ to C ₈ unsubstituted linear, branched, or alicyclic, n is an integer from 1 to 3, M is a metal element, including a transition metal, m is an integer from 1 to 10.
The polyimide substrate according to claim 8, wherein the hard coating layer has a thickness of 10 to 50 占 퐉.
The polyimide substrate according to claim 8, wherein the polyimide substrate has a surface hardness of 5H to 9H measured with an upper surface of the hard coating layer in a direction of measurement according to JIS K56000 measurement standard.
9. The polyimide substrate according to claim 8, wherein the polyimide substrate has a water permeability of 0.001 to 10 g / m ² * day as measured by ASTM E96BW.
A transparent bonding layer, a black matrix layer, and a polyimide substrate according to any one of claims 1 to 14.

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