KR101381266B1 - Donor film having antistatic property - Google Patents

Abstract

The present invention relates to a donor film having antistatic properties.
According to the present invention, a base film; A photothermal conversion layer laminated on the base film to convert light into thermal energy; A protective layer laminated on the photothermal conversion layer; And a donor film including a transfer layer laminated on the protective layer, wherein the coating layer comprises a mixed resin of an organic binder and a conductive polymer in a lower portion of the base film. Accordingly, the donor film of the present invention protects the phosphor layer from the static electricity generated when handling the donor film on which the phosphor is deposited, and at the same time, thermally transfers the donor film after laminating it onto an acceptor substrate to transfer the phosphor of the donor film. By the static electricity generated during removal, damage of the transferred phosphor can be reduced.

Description

Donor film with antistatic property {DONOR FILM HAVING ANTISTATIC PROPERTY}

The present invention relates to a donor film having an antistatic property, and more particularly to a donor film having an antistatic property introduced with a coating layer for imparting antistatic properties as a thermal transfer.

A donor film typically forms an optical element, particularly an organic EL device, and is used in a thermal imaging process using laser light, including a light to heat conversion (LTHC), and a donor substrate or Also called donor sheet. The thermal imaging process using laser light is generally referred to as laser induced thermal imaging (LITI).

The most common pixel formation method of an organic EL device among conventional flat panel displays is a method of forming a light emitting layer in a desired area by arranging a fine metal mask (FMM) in a vacuum chamber with respect to a substrate. In the case of the FMM method, due to the characteristics of the technology, there are many problems in applying a large area due to the weight of the mask frame, difficulty in stretching the mask, sagging of the mask itself, and expansion due to temperature. In order to form area pixels, a new concept of process technology is required.

In order to meet this need, a typical method that has been studied to replace the method of forming the R, G, and B light emitting layers individually using a conventional fine metal mask is the above-mentioned laser light thermal transfer method (LITI). In addition, the ink jet method, the white OLED & color filter method, etc. of a solution process can be mentioned. Among them, laser technology represented by LITI and laser induced pattern-wise sublimation (LIPS) or radiation induced sublimation transfer (RIS) is applied to a donor film (also referred to as a donor sheet or donor substrate) on which a light emitting layer is formed. It is a technique of forming a pixel by separating from a donor film and transferring to an acceptor substrate side. In the case of the LITI process used to form the pixel of the organic electroluminescent device using the donor film including the above-described photothermal conversion layer, some methods of more efficiently manufacturing the donor film and the thermal transfer method using the donor film Methods are proposed.

For example, there is a method of closely attaching an acceptor substrate and a donor film by a conventional vacuum pump in a thermal transfer method using a donor film, which is different from the process of manufacturing an organic EL device by maintaining a vacuum state. Otherwise, the problem of not having a vacuum inside the chamber has a problem that adversely affects the reliability and life of the product. In order to solve this problem, Korean Patent Application No. 2005-0080349 discloses "a step of placing an acceptor substrate on which a magnetic material is formed on one surface of a substrate chamber inner substrate stage; and placing a donor film including a permanent magnet layer on the acceptor substrate. Laminating the donor film and the acceptor substrate by a magnetic force acting between a permanent magnet included in the donor film and a magnetic material formed on the acceptor substrate, and irradiating a laser onto the donor film to transfer a layer. Laser thermal transfer method comprising transferring at least one region of the substrate onto an acceptor substrate. In addition, in order to manufacture the donor film more efficiently, Korean Patent Application No. 2007-0016489 ("donor substrate, its manufacturing method and organic electroluminescent device manufacturing method using the same") to prepare a base layer; Forming a photothermal conversion layer on the substrate layer; Disclosing a method of manufacturing a donor substrate to form a transfer layer including a quantum dot on the light-to-heat conversion layer, applying a laser induced thermal imaging to the donor substrate prepared from the method to form a light emitting layer comprising a quantum dot It also discloses a method for producing an organic electroluminescent device excellent in patterning and excellent in luminous efficiency by forming.

On the other hand, the donor film is manufactured in the form of a roll, the static electricity is generated by the friction during the unwinding process, which may contaminate the surface of the charged donor film, and also to transfer the donor film on which the phosphor is deposited After laminating onto the acceptor substrate, the laser is irradiated to transfer the organic phosphor to a desired position and pattern, and then the donor film is removed. This may cause damage to the electrophosphorescent pattern transferred by the static electricity generated from the donor film. have.

Therefore, there is a need for a donor film having antistatic properties to protect the organic phosphor layer from static electricity generated during handling and removal of the donor film and to minimize damage thereof. There is no mention of anti-static measures that occur during operation.

In general, in order to impart an antistatic function to the film, a conductive polymer is used, and a representative example thereof is PEDOT (poly 3,4-ethylenedioxythiophene): PSS (polystyrene sulfonate). PEDOT: PSS, recently developed by Bayer, has a low bandgap (1.6-1.7 eV), resulting in high transparency. Specifically, Bayer's PEDOT: PSS is a PEDOT prepared in the form of an aqueous solution by using PSS as a dopant, polymerizing EDOT (3,4-ethylenedioxythiophene) in an aqueous solution, transparency, electrical conductivity, thermal stability , And exhibited the ability to improve processability and dispersibility and are dispersed in a solvent such as water, are supplied under the name "Bayton (P, PH, PAG)".

Accordingly, the present inventors have found that by forming a coating layer containing a conductive polymer such as PEDOT: PSS under the base layer of the donor film, it is possible to efficiently impart antistatic properties to the donor film, thereby completing the present invention.

It is an object of the present invention to provide a donor film imparted with antistatic properties.

Another object of the present invention is to provide a donor film to which antistatic properties are imparted, which can reduce the damage of the transferred phosphor by static electricity generated when removing the donor film.

The present invention relates to a base film; A photothermal conversion layer laminated on the base film to convert light into thermal energy; A protective layer laminated on the photothermal conversion layer; And a donor film including a transfer layer laminated on the protective layer, wherein a coating layer comprising a mixed resin of an organic binder and a conductive polymer is formed under the base film. It provides a donor film having.

The organic binder is characterized in that the polymer backbone is any one selected from the group consisting of acrylic resins, urethane resins and polyester resins, or a mixture between the copolymers, the conductive polymer is polythiophene, polyaniline, polypyrrole, PEDOT (poly 3 , 4-ethylenedioxythiophene) and PEDOT / PSS (polystyrene sulfonic acid), characterized in that at least one mixture selected from the group consisting of. In addition, the conductive polymer may be used in an amount of 1 to 30 parts by weight based on 100 parts by weight of the organic binder.

More specifically, the coating layer of the present invention is formed by a coating liquid containing 10 to 20 parts by weight of an organic binder, 1 to 6 parts by weight of a conductive polymer, and 0.2 to 1.0 parts by weight of a curing agent, based on 100 parts by weight of a solvent. The conductive polymer will be contained within a range that satisfies the mutual mixing ratio.

In the present invention, a polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) film may be used as the base film.

In the present invention, the light-to-heat conversion layer includes a light absorber selected from carbon black, metal oxides, metal sulfides, infrared pigments and pigments that can absorb infrared rays to generate thermal energy, and an organic binder curable by ultraviolet rays or heat. .

The donor film according to the present invention may further include an interlayer including an organic binder of acrylic and urethane in order to protect the light-to-heat conversion layer.

The heat transfer donor film according to the present invention has an antistatic property, thereby protecting the phosphor layer from static electricity generated during handling of the donor film, and laminating the phosphor of the donor film on a substrate to be transferred, followed by thermal transfer. Damage to the phosphor transferred by static electricity generated when removing the donor film can be reduced.

1 is a schematic cross sectional view of a structure of a donor film in accordance with one embodiment of the invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

As illustrated in FIG. 1, the donor film according to the present invention includes a polyester base film 4, a photothermal conversion layer 3 laminated on the base film, and a protective layer laminated on the photothermal conversion layer. (2), a transfer layer (1) laminated on the protective layer and including a light emitting layer, and a coating layer (5) having an antistatic property laminated on a lower portion of the base film.

The coating layer 5 having the antistatic property is coated with a conductive liquid, an organic binder resin, and an optional curing agent in an organic solvent in a lower portion of the base film 4, then dried, and then dried in a thermal or UV manner. It forms by hardening. At this time, the stacking order of the coating layer 5 can be both before or after the formation of the other functional layers. That is, after forming the light-to-heat conversion layer 3, the protective layer (2), etc. on the base film 4 first, the coating layer 5 may be laminated, or the coating layer 5 is first placed below the base film 4. After forming, the other functional layers may be sequentially formed on the opposite side.

Since the coating layer 5 having the antistatic property is placed under the base film 4, the adhesion to the base film 4 should be excellent, and the lower part of the base film 4 is a portion directly irradiated with a laser. Transparency must be maintained so as not to interfere with laser irradiation, and physical and chemical reactions by laser irradiation should not occur.

Referring to the coating liquid constituting the coating layer 5 having the antistatic property of the present invention in detail, 10 to 20 parts by weight of the organic binder, 1 to 6 parts by weight of the conductive polymer, and 0.2 to 1.0 weight of the curing agent, based on 100 parts by weight of the solvent. It is an addition.

In particular, the coating solution of the present invention is to be provided with antistatic properties by the mixed resin between the organic binder and the conductive polymer, it is contained in the mixing ratio range consisting of 1 to 30 parts by weight of the conductive polymer with respect to 100 parts by weight of the organic binder.

The organic binder may be any one selected from the group consisting of an acrylic resin, a urethane resin, and a polyester resin, or a mixture between copolymers thereof. In the embodiment of the present invention, but described using a urethane resin having a fluorinated hydrocarbon group side chain having a solid content of 15% by weight, but is not limited thereto.

In addition, the conductive polymer contained in the coating solution of the present invention is any one or more selected from the group consisting of polythiophene, polyaniline, polypyrrole, PEDOT (poly 3,4-ethylenedioxythiophene) and PEDOT / PSS (polystyrene sulfonic acid) Mixtures can be used.

At this time, the conductive polymer is preferably contained in a ratio of 1 to 30 parts by weight with respect to 100 parts by weight of the organic binder, when the content of the conductive polymer is less than 1 part by weight, the antistatic property is weak, 30 weight If it is contained in excess of part, the effect of imparting antistatic property is improved, but it is not economical due to the use of expensive conductive polymer, so it is preferable to be controlled according to the surface resistance of the desired level range.

The curing agent used in the coating liquid of the present invention is an additive for forming a coating layer, and can be suitably used among the curing agents applicable to acrylic resins, urethane resins, and polyester resins. At this time, the preferable content of the curing agent is to use 0.2 to 1.0 parts by weight. If the content is less than 0.2 part by weight, the adhesion between the base film and the coating layer is lowered, and if it exceeds 1.0 part by weight, there is a problem in compatibility between compositions.

The solvent used in the coating liquid of the present invention can be used as long as it can uniformly dissolve or disperse the mixed resin of the organic binder and the conductive polymer, and preferably a plurality of mixed solvents are used. Thus, as a most preferred example, in the embodiment of the present invention, a mixed solvent consisting of water, ethanol, isopropyl alcohol and butyl alcohol is used.

Among the components of the donor film according to the present invention, the polyester base film 4 serving as a mechanical support should have not only mechanical / thermal properties but also a wide range of transmittance, and an organic binder used in the photothermal conversion layer 3. Depending on the resin, it should be possible to have a primer layer that can control the adhesion at the interface between the base film 4 and the photothermal conversion layer (3).

In general, the material forming the base film 4 of the donor film improves the adhesion between the base film and the adjacent layer, controls the temperature transfer between the base film and the adjacent layer, and the image forming radiation to the photothermal conversion layer. It may be chosen to be advantageous to control delivery.

Therefore, in this invention, it is preferable to use the general-purpose polymer film with high transmittance | permeability as a base film 4, for example, a polyethylene terephthalate (PET) or a polyethylene naphthalate (PEN) film.

As an example of the base film 4 which satisfies the above basic physical properties and has excellent adhesion with the photothermal conversion layer 3, the product number XU series / XG series (Toray Advanced Materials Co., Ltd., Gumi, Gyeongsangbuk-do, Korea) Optical / graphic films, such as Toray Advanced Materials Inc.).

In the present invention, the light-to-heat conversion layer (3) is a light absorber selected from carbon black, metal oxides, metal sulfides, infrared pigments and pigments that can absorb infrared radiation on the base film (4) to generate thermal energy, and ultraviolet light Or by applying a coating liquid comprising a thermally curable organic binder. Of these light absorbers, carbon black is preferred because it is inexpensive, stable, easily processed and absorbs infrared radiation at near infrared (NIR) imaging laser wavelengths of 808 nm and 1064 nm.

According to a preferred embodiment of the present invention, the light absorbing agent of the photothermal conversion layer 3 has a uniform concentration distribution and nanoparticles of different particle size sizes are blended and stably nanodispersed.

In the present invention, the transfer layer 1 including the green / red / blue light emitting layer may be formed to a certain thickness on the protective layer 2 using thermal deposition, sputtering, solvent coating, spin coating, or the like .

The donor film according to the present invention may further include an interlayer including an organic binder of acrylic and urethane in order to protect the light-to-heat conversion layer.

Hereinafter, the present invention will be described in more detail with reference to Examples.

This is for further illustrating the present invention, and the scope of the present invention is not limited to these examples.

≪ Example 1 >

1 g of PEDOT / PSS (Baytron PH, manufactured by Bayer), 20 g of a urethane resin (manufactured by Daiichi Seika, Japan) having a fluorinated hydrocarbon group side chain having a solid content of 15 wt%, and 0.4 g of aziridine curing agent A coating solution was prepared by dispersing in 100 g of a mixed solvent containing propyl alcohol and butyl alcohol. The prepared coating solution was applied to a polyester film having a thickness of 100 μm and then dried to form a coating layer. Thereafter, a photothermal conversion layer and a protective layer were laminated on opposite surfaces to obtain a heat transfer donor film having antistatic properties.

<Example 2>

A thermal transfer donor film was obtained in the same manner as in Example 1 except that the amount of PEDOT / PSS added was 2 g.

&Lt; Example 3 >

A thermal transfer donor film was obtained in the same manner as in Example 1 except that the amount of PEDOT / PSS added was 4 g.

<Example 4>

A thermal transfer donor film was obtained in the same manner as in Example 1 except that the amount of PEDOT / PSS added was 6 g.

&Lt; Example 5 >

A heat transfer donor film was obtained in the same manner as in Example 1, except that the amount of the urethane resin having a fluorinated hydrocarbon group side chain having a solid content of 15% by weight was 10 g.

&Lt; Example 6 >

A thermal transfer donor film was obtained in the same manner as in Example 1 except that the amount of the aziridine curing agent added in 0.2 g was used.

&Lt; Comparative Example 1 &

A thermal transfer donor film was obtained in the same manner as in Example 1 except that the coating layer was formed using a coating solution containing no PEDOT / PSS.

&Lt; Comparative Example 2 &

A thermal transfer donor film was obtained without forming a coating layer having antistatic properties.

After performing the performance evaluation for the donor film prepared according to Examples 1 to 6 and Comparative Examples 1 to 2 as follows, the results are shown in Table 1.

Experimental Example 1 Surface Resistance Measurement

After mounting the sample in the environment of the temperature of 23 degreeC, and 50% of a relative humidity using the antistatic measuring device (Mitsubishi Corporation: model name MCP-T600), surface resistance was measured based on JISK7194.

Experimental Example 2 Transparency (Haze) Measurement

A sample 10 cm x 10 cm in size was placed vertically on a haze meter (AUTOMATIC DIGITAL HAZEMETER, manufactured by Nippon Denshoku Co., Ltd.) and transmitted through a light having a wavelength of 400 to 700 nm in a direction perpendicular to the sample placed vertically Respectively. At this time, the haze value was calculated by the following equation (1).

Equation 1

Haze (%) = (1-amount of scattered light / total transmission of light) × 100

As confirmed in Table 1, in the case of the donor film formed with a coating layer having an antistatic property prepared according to Examples 1 to 6, the higher the content of PEDOT / PSS, the lower the surface resistance, from this PEDOT / PSS It can be seen indirectly that the higher the content, the greater the antistatic function.

On the other hand, the donor film of Comparative Example 1 in which the coating layer was formed using the coating liquid containing no PEDOT / PSS, and Comparative Example 2, which is a conventional donor film not coated, had a low haze value and a high surface resistance value. Confirmed.

Thus, when using a donor film having a coating layer having an antistatic property according to the present invention to protect the phosphor layer from the static electricity generated when handling the donor film on which the phosphor is deposited, and to transfer the phosphor of the donor film The damage of the phosphor transferred by the static electricity generated when laminating on the substrate and thermally transferring and then removing the donor film can be reduced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

1: transfer layer 2: protective layer
3: photothermal conversion layer 4: base film
5: coating layer having antistatic properties

Claims (8)

A base film; A photothermal conversion layer laminated on the base film to convert light into thermal energy; A protective layer laminated on the photothermal conversion layer; And a transfer layer stacked on the protective layer.
On the lower front surface of the base film, a coating layer having antistatic properties satisfying the following physical properties 1) and physical properties 2) is formed at the same time,
A donor film having an antistatic property, wherein the coating layer is formed by a coating liquid containing 10 to 20 parts by weight of an organic binder, 1 to 6 parts by weight of a conductive polymer, and 0.2 to 1.0 parts by weight of a curing agent, based on 100 parts by weight of a solvent:
1) The surface resistance is 10 ¹⁰ Ω / □ or less,
2) The haze is 1.2 to 3.3%. The donor film of claim 1, wherein the organic binder is any one selected from the group consisting of an acrylic resin, a urethane resin, and a polyester resin, or a mixture between copolymers thereof. The method of claim 1, wherein the conductive polymer is one or more mixtures selected from the group consisting of polythiophene, polyaniline, polypyrrole, PEDOT (poly 3,4-ethylenedioxythiophene) and PEDOT / PSS (polystyrene sulfonic acid) A donor film having the above antistatic property. The donor film having the antistatic property according to claim 1, wherein the conductive polymer is included in an amount of 1 to 30 parts by weight based on 100 parts by weight of the organic binder. delete delete According to claim 1, wherein the light-to-heat conversion layer includes a light absorbing agent selected from carbon black, metal oxides, metal sulfides, infrared pigments and pigments that can absorb infrared radiation to generate thermal energy, and an organic binder curable by ultraviolet or heat The donor film which has the said antistatic property characterized by the above-mentioned. The donor film having the antistatic property according to claim 1, wherein the interlayer comprises an acrylic binder or an organic binder of urethane.

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