KR20150037039A - Donor film for liti process - Google Patents

Abstract

The present invention relates to a donor film for a thermal transfer method. The donor film comprises: a base film; a primer layer; a light-heat conversion layer; an intermediate layer; and a thermal transfer layer. The donor film has an excellent transfer performance and produces an aesthetic transferred surface.

Description

[0001] DONOR FILM FOR LITI PROCESS FOR LASER TRANSFER METHOD [0002]

The present invention relates to a donor film for a thermal transfer method comprising a base film, a primer layer, a light-to-heat conversion layer, an intermediate layer and a transfer layer, and more particularly to a donor film for a thermal transfer method will be.

Recently, development trend of display device technology is development of a technology which uses less energy but has excellent visibility at the same time. Accordingly, the development of a display device using an organic light emitting diode (OLED), which is known to have a lower energy consumption compared to the conventional light emitting mode, has been competitive.

In order to realize a full color display device using such an OLED, it is very important to pattern the color of the light emitting device. As a result, the organic film layer of the OLED display, which determines the color of the light emitting device, There is a difference in implementation effect depending on the method of forming the second layer. Methods for forming an organic film layer on an OLED include a deposition method, an inkjet method, and a laser thermal transfer method (LITI). The laser thermal transfer method, commonly referred to as LITI, is a method of converting light from a laser into heat energy and transferring the transfer layer to the substrate of the OLED by the converted heat energy to form an organic film layer in the OLED. The LITI method has advantages such as high resolution pattern formation, film thickness uniformity, multilayer implementation capability, and scalability to a large mother glass.

In this LITI method, the critical medium for converting light into thermal energy and forming a pattern on the substrate of the light emitting device includes a transfer layer having a red pixel region R, a green pixel region G, and a blue pixel region B Is a LITI donor film. The LITI donor film has a structure in which a base film, a light-to-heat conversion layer, and a pattern-directing layer are stacked in this order. Such a LITI donor film selectively includes an interlayer between the light-to-heat conversion layer and the transfer layer to prevent the substance contained in the light-to-heat conversion layer from being transferred to the transfer layer.

In the LITI process, when the laser is irradiated onto the LITI donor film, the light energy of the laser in the light-to-heat conversion layer is converted into heat energy, and the volume expansion of the light-heat conversion layer and the intermediate layer occurs due to heat energy, Is transferred to the OLED substrate.

At this time, if the intermediate layer contains unreacted monomers and oligomers, unreacted carbide is generated on the surface of the transfer layer after the transfer to cause defects.

Therefore, it is necessary to control the unreacted materials in the intermediate layer.

Korean Patent Publication No. 2011-0132021 (December 24, 2011) Korean Patent Publication No. 2012-0138691 (December 26, 2012) Korean Patent Publication No. 2013-0072573 (2013.07.02) Korean Patent Laid-Open Publication No. 2013-0078025 (Jul. Korean Patent Laid-Open Publication No. 2013-0079263 (July 31, 2013)

The inventors of the present invention have conducted studies to solve the problem of transferability and transfer surface defects due to the migration of unreacted monomers and oligomers in the intermediate layer of the donor film. As a result, they have found that the intermediate layer contains thermosetting modified thermoplastic resin, Can be improved and the generation of the carbide layer after the LITI process can be remarkably reduced, thereby completing the present invention.

That is, it is an object of the present invention to provide a donor film for a thermal transfer method having an intermediate layer which improves migration phenomena of unreacted monomers and oligomers. That is, it is an object of the present invention to provide a donor film for a thermal transfer method that does not contain organic substances other than the transfer layer on the surface of the transfer layer in the evaluation of lighting of the organic thin film layer after laser thermal transfer.

It is another object of the present invention to provide a donor film for a thermal transfer method comprising a light-to-heat conversion layer excellent in adhesion to an intermediate layer and excellent in transferability.

Another object of the present invention is to provide a smooth and uniform surface to be transferred from the transfer layer.

In order to achieve the above object, the present invention relates to a donor film for a laser thermal transfer method comprising a base film, a primer layer, a photo-thermal conversion layer, an intermediate layer and a transfer layer, .

The inventors of the present invention have found that the use of a thermosetting resin in the light-to-heat conversion layer and the intermediate layer can eliminate the defects of the transferability and the surface of the transfer layer after transfer.

In particular, the inventors of the present invention confirmed that carbonized carbide blackened on the surface of the transfer layer is recognized as the unreacted monomers and oligomers present in the intermediate layer are transferred together by the laser thermal transfer process, and this carbide causes defects. Therefore, As a result, it has been found that the use of a resin having a low content of unreacted monomers and oligomers as a thermosetting resin in the light-to-heat conversion layer and the intermediate layer can prevent the generation of carbide, thereby completing the present invention.

In order to accomplish the above object, the present invention provides a donor film for a thermal transfer method comprising a base film, a primer layer, a photo-thermal conversion layer, an intermediate layer and a transfer layer,

Wherein the intermediate layer is formed by coating and thermosetting a thermosetting intermediate layer composition comprising a thermosetting modified thermoplastic resin.

The donor film for a thermal transfer method of the present invention is excellent in transferability and can form a beautiful surface without forming a carbonized film on the surface of the transfer layer after transfer.

Further, the donor film for a thermal transfer method of the present invention is excellent in transferability by optimizing the composition and thickness of the light-to-heat conversion layer and the intermediate layer, has no blocking, has excellent transfer width, and obtains a uniform transfer surface And can ultimately optimize the resolution of the display.

In addition, it is possible to transfer the organic material precisely to a desired transfer site, and to prevent edge open or non-transfer.

1 is a cross-sectional view showing a laminated structure of a donor film of the present invention.

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

1, the present invention comprises a base film 10, a primer layer 20, a light-to-heat conversion layer 30, an intermediate layer 40, Layer 50 are sequentially stacked. The transfer layer may be formed in a two-layer structure including an aluminum deposition layer for improving the releasability.

The donor film for a thermal transfer method of the present invention is characterized in that, after laser thermal transfer, there is no transferred material from the intermediate layer on the transfer layer in the lighting evaluation of the organic thin film layer.

Hereinafter, the structure of each layer will be described.

A base film

In the present invention, the base film may be a glass, a transparent film or a polymer film. Examples of the polymer film include, but are not limited to, polyester, polycarbonate, polyolefin, polyvinyl resin, and the like. More specifically, it is preferable to use polyethylene terephthalate or polyethylene naphthalate because of excellent processability, thermal stability and transparency. More preferably, it is preferable to use a light transmittance of 90% or more in order to increase the transmittance of light to be examined during the execution of the LITI method.

The surface of the base film may be modified by surface treatment such as corona or plasma known to those skilled in the art to control adhesion, surface tension and the like in the subsequent process.

The thickness of the base film is preferably 0.025 to 0.15 mm, more preferably 0.05 to 0.1 mm, but is not limited thereto.

The primer layer

In the present invention, the primer layer is for controlling the temperature transfer between the base film and the adjacent layer, improving adhesion between the base film and the adjacent layer, and controlling the image forming radiation transmission to the light- If the layer is not formed, the substrate and the light-to-heat conversion layer may be separated from each other in a transfer process using a laser. As a material suitable for such a primer layer, any one selected from an acrylic resin, a polyurethane resin, and a polyester resin or a mixed resin thereof may be used. If the heat resistant adhesion between the primer layer and the base film or between the primer layer and the light-to-heat conversion layer is poor, the base film and the light-to-heat conversion layer can be separated in a transfer process using a laser.

The thickness of the primer layer is not limited, but may be 0.1 to 1 탆, more preferably 0.1 to 0.5 탆.

The light-to-heat conversion layer (LTHC layer)

The light-to-heat conversion layer of the present invention is a layer that absorbs light in the infrared-visible light region and converts a part of the light into heat. The light-to-heat conversion layer includes a thermosetting modified thermoplastic resin, a thermosetting resin, And may be formed by coating and thermosetting the thermal conversion layer composition.

In the present invention, the above-mentioned " thermosetting modified thermoplastic resin " means a resin containing a thermoplastic resin or a functional group capable of thermosetting by a crosslinking agent.

The thermosetting modified thermoplastic resin is used for improving the adhesiveness with the intermediate layer and improving the solvent resistance and may be one having a weight average molecular weight of 10,000 to 30,000 and a glass transition temperature of 65 to 75 ° C have. In addition, by using a low molecular weight content of 1% or less having a molecular weight of 10,000 or less, it is possible to prevent the formation of a carbonized layer on the surface of the transfer layer after laser thermal transfer. When the weight average molecular weight is less than 10,000, the content of unreacted monomers and oligomers is high and there is a high possibility that unreacted materials transferred onto the surface of the transfer layer after laser thermal transfer are present. When the weight average molecular weight is more than 30,000, The edge open or non-transfer may occur. If the glass transition temperature is lower than 65 ° C, blocking may occur during winding. If the glass transition temperature is higher than 75 ° C, the modulus of the intermediate layer may increase to cause edge open or untransfer.

More specifically, the thermosetting modified thermoplastic resin may be an amine-modified vinyl chloride-vinyl acetate-vinyl alcohol copolymer. Commercial examples include, but are not limited to, Silbin TAO from ShinEtsu.

Since the light-to-heat conversion layer must be expanded due to the heat generation of the photo-thermal conversion material in the laser thermal transfer process, in order to exhibit smooth transfer property, the thermosetting modified thermoplastic resin is required to contain the thermosetting resin and the cross- It is preferable to use an amount smaller than the sum of Specifically, it is preferable that the content of the light-to-heat conversion layer resin composition is less than 50% by weight. Specifically, 1 to 50% by weight can be used, and more preferably 5 to 30% by weight is used.

In the light-to-heat conversion layer composition, the thermosetting resin preferably includes a polyurethane-based thermosetting resin. Specifically, for example, the thermosetting polyurethane includes polycarbonate polyurethane, polyester polyurethane, polyurethane and the like. The polyurethane resin preferably has a glass transition temperature (T _g ) of 10 ° C or higher, more specifically, a glass transition temperature of 10 to 50 ° C. When the glass transition temperature is lower than the above range The coating layer may be partially transferred to the opposite surface in the aging step after the coating of the light-to-heat conversion layer. If the coating layer is excessively transferred, the volume expansion may be reduced during laser irradiation, so that the desired shape transfer may be difficult. The thermosetting resin may be used in an amount of 30 to 70% by weight.

In the light-to-heat conversion layer composition, a thermosetting modified thermoplastic resin and a curing agent may be used to cure the thermosetting water. As the curing agent, an isocyanate curing agent, a peroxide, or the like may be used. The curing agent is preferably used in an amount of 1 to 10 wt%, and the function of the photo-thermal conversion layer can be performed in this range.

In addition, if necessary, it may contain a metal chelating crosslinking agent, a melamine crosslinking agent, an aziridine crosslinking agent, a metal salt, etc. These crosslinking agents may be used alone or in combination of two or more.

When the content of the photo-thermal conversion material is less than 25% by weight, the transfer process using the laser is limited to the swelling of the photo-thermal conversion layer. The desired pattern is not uniformly transferred. If it exceeds 40% by weight, excessive heat may be generated in the laser transfer process, so that the light-to-heat conversion layer may burn and the transfer may not be performed.

The light-to-heat conversion layer is prepared by applying and drying on a substrate containing a primer layer. Since this layer is of the thermosetting type, crosslinking treatment is necessary by appropriate heat treatment. The crosslinking treatment may be carried out at the temperature of the drying step or may be carried out after the drying step by forming a separate crosslinking step.

The light-to-heat conversion material refers to a material that absorbs incident laser light and converts the light into heat. The light-to-heat conversion material includes a dye (for example, a visible light dye, an ultraviolet dye, an infrared dye, a fluorescent dye and a polarizing dye) , A metal compound, a metal film, carbon black, a metal oxide, a metal sulfide, and the like, more preferably carbon black.

It is preferable that the carbon black has an average particle diameter of 10 to 30 nm because it can obtain a flat surface. If necessary, the carbon black may be firstly dispersed with one or two or more resins selected from polyvinyl chloride, polyvinyl chloride-polyvinyl acetate copolymer and thermosetting polyurethane, and subjected to a surface treatment, Can be further improved. As the primary dispersion method, carbon black may be added to a resin such as polyvinyl chloride, and primary dispersion may be performed by a method such as kneading or mixing. The kneading may include a solvent, and the kneading may be carried out using a kneader after preparing the preparation liquid having a solid content of 30 to 70% by weight. When the solid content is less than 30% by weight, the viscosity of the kneading may be low, If the solid content is more than 70% by weight, too much torque is applied and dispersion becomes difficult. The kneaded liquor may add additional milling and filtering processes to optimize dispersion. As the solvent used for kneading, it is preferable to selectively use a solvent capable of dissolving the resin depending on the type of resin used. More specifically, for example, toluene: methyl ethyl ketone: cyclohexanone is used in an amount of 1 to 5 : 1 to 5: 1 to 5 weight ratio can be used.

The photothermal conversion layer may be produced by kneading, milling, filtering and coating processes and may also be manufactured by milling, filtering and coating processes. Knitting and milling are performed to optimize the dispersion of the particles, and various methods such as ring milling and send milling can be used for the milling method.

Milling can be carried out by various methods. For example, in the case of using a ring mill, the first kneading tank liquid may be prepared by adding the residual resin and solvent so that the solid content of the whole liquid is 10 wt% to 20 wt% Carbon black / solvent mixture solution (solid content 10% by weight to 20% by weight) is poured into a main machine of a milling machine, and 0.5 to 2.0 mm zirconium particles are filled in the ring part by 50 to 80% by volume. Stirring is carried out in duplicate. One is for the purpose of injecting the liquid inside the main milling vessel while circulating the inside of the main milling vessel, and the other is for the purpose of dispersing the particles inside the ring part. Milling particles other than zirconium can be used as the particles to be filled in the ring part. Milling can be carried out in several stages as required. Firstly, 2.0mm zirconium particles are first filled and subjected to a first milling, then secondly 1.5mm particles are milled, and then third milling is carried out by filling 0.5mm particles and milling is carried out to achieve more uniform dispersion of carbon black particles have.

Alternatively, the milling may be sequentially performed using a milling machine in which particles of respective sizes are sequentially filled.

The solid content at the time of milling is preferably in the range of 10 wt% to 20 wt%. If the amount is less than 10% by weight, the particle dispersion efficiency is lowered. If the amount is more than 20% by weight, the liquid stability of the milled liquid may be lowered.

The filtering process aims to remove large particles having a particle size of 2.5 μm or more. The coating process may be a bar coating process, a die coating process, or a roll coating process, and various coating processes may be applied if necessary. If additional crosslinking is required after the coating process, the degree of crosslinking can be controlled by separate aging.

In addition to the carbon black, pigments, organic pigments, inorganic pigments, metals, metal compounds, metallic films, iron cyanide pigments, and the like can be used in addition to the carbon black, if necessary, in addition to dyes such as visible light dyes, ultraviolet dyes, infrared dyes, fluorescent dyes, , Phthalocyanine pigments, phthalocyanine dyes, cyanine dyes, cyanine dyes, metal dithiolene pigments, metal dithiolene dyes and other absorbing materials.

The photothermal conversion layer preferably has a dry coating amount of 1 to 3.0 g / m 2. When the coating amount after drying of the light-to-heat conversion layer is less than 1 g / m 2, the light-to-heat conversion layer is burned in the transferring step. When the coating amount is more than 3.0 g / m 2, The problem does not occur.

Interlayer

In the present invention, in order to prevent the photo-thermal conversion material present in the photo-thermal conversion layer from being transferred together when the transfer layer is transferred by the heat generated in the photo-thermal conversion layer, Layer is formed to prevent heat generated in the layer from being transferred to the transfer layer and burned by heat.

In the present invention, the intermediate layer may be formed by applying and thermally curing a thermosetting intermediate layer composition comprising a thermosetting modified thermoplastic resin.

In the present invention, the above-mentioned " thermosetting modified thermoplastic resin " means a resin containing a thermoplastic resin or a functional group capable of thermosetting by a crosslinking agent.

The thermosetting modified thermoplastic resin is used for improving the adhesiveness with the intermediate layer and improving the solvent resistance and may be one having a weight average molecular weight of 10,000 to 30,000 and a glass transition temperature of 65 to 75 ° C have. In addition, by using a low molecular weight content of 1% or less having a molecular weight of 10,000 or less, it is possible to prevent the formation of a carbonized layer on the surface of the transfer layer after laser thermal transfer. When the weight average molecular weight is less than 10,000, the content of unreacted monomers and oligomers is high and there is a high possibility that unreacted materials transferred onto the surface of the transfer layer after laser thermal transfer are present. When the weight average molecular weight is more than 30,000, The edge open or non-transfer may occur. If the glass transition temperature is lower than 65 ° C, blocking may occur during winding. If the glass transition temperature is higher than 75 ° C, the modulus of the intermediate layer may increase to cause edge open or untransfer.

More specifically, the thermosetting modified thermoplastic resin may be an amine-modified vinyl chloride-vinyl acetate-vinyl alcohol copolymer. Commercial examples include, but are not limited to, Silbin TAO from ShinEtsu.

In the intermediate layer, the thermosetting modified thermoplastic resin may be 60 to 80% by weight, more specifically 70 to 76% by weight, of the solid content.

In the present invention, the thermosetting type intermediate layer composition may be a curing agent for curing a thermosetting modified thermoplastic resin. As the curing agent, an isocyanate curing agent, peroxide, or the like may be used. It is preferable that the content of the curing agent is adjusted so that the degree of curing is 95% or more. Such an amount is not limited, but it is preferable to use 1 to 10% by weight, more specifically 2 to 8% by weight, and in this range, physical properties having a degree of curing of 95% or more can be achieved. When the degree of curing is less than 95%, unreacted materials may be transferred during the laser thermal transfer process, or the transfer may not be performed properly, resulting in failure.

In addition, if necessary, it may contain a metal chelating crosslinking agent, a melamine crosslinking agent, an aziridine crosslinking agent, a metal salt, etc. These crosslinking agents may be used alone or in combination of two or more.

In the present invention, since the intermediate layer must simultaneously perform a releasing function to separate the transfer layer, it is preferable to add a fluorine-based or silicone-based resin having a low surface energy to adjust the surface energy to be 35 mN / m or less. When the surface energy exceeds 35 mN / m, the transfer layer may not be separated due to failure of the intermediate layer to perform the releasing function in the transferring process, so that the transferring may not occur. Therefore, the lower the surface energy of the intermediate layer, the lower the adhesive force to the transfer layer, and the more smooth the transfer process can be achieved in the transfer process, and the higher the surface energy of the intermediate layer, the higher the adhesion with the transfer layer.

Specific examples of the fluorine-based additive include a fluorine-based compound having a vinyl group and a non-reactive fluorine-based additive. Examples of the silicone additive include polyether-modified polydimethylsiloxane, polyether-modified dimethylpolysiloxane copolymer, dimethylpolysiloxane-based and modified dimethylpolysiloxane-based, methylalkylsiloxane-based, and reactive silicone acrylate additives. Commercial examples include, but are not limited to, BYK-300, BYK-301, BYK-302, and USO-100 from Amt Company. Specifically, the content of the fluorine-based or silicone-based resin may be 5 to 15% by weight.

If the thickness of the intermediate layer is less than 1.0 탆, the transfer layer may be damaged due to a thermal barrier effect, and a uniform surface shape may not be obtained. Thus, The transferred surface becomes uneven and the resolution of the display is lowered. If the thickness is more than 3 mu m, too much heat may be blocked and the transfer layer may not be transferred.

More specifically, the thickness of the intermediate layer must be increased to secure a flat surface shape when the surface roughness of the photo-thermal conversion layer increases. When the surface roughness (Ra) value of the light-to-heat conversion layer is in the range of 2.5 to 3 占 퐉 in the range of 10 nm to 20 nm and the surface roughness value of the light-to-heat conversion layer is in the range of 5 to 10 nm, the thickness of the intermediate layer is 2 to 3 占 퐉, When the surface roughness value of the thermal conversion layer is 5 nm or less, it is preferable to have a range of 1 to 3 mu m. More preferably, the surface roughness of the light-to-heat conversion layer is 20 nm or less.

The intermediate layer may be formed by a method such as bar coating, roll coating or die coating.

The intermediate layer may be formed as a two-layer structure if necessary, and an aluminum deposition layer may be further formed on the intermediate layer.

The intermediate layer may be cured by drying at 100 to 130 ° C after coating.

The transfer layer

The transfer layer is formed on the intermediate layer by coating with a uniform layer by evaporation, sputtering, solution coating or the like. The transfer layer typically comprises one or more layers for transfer to the receptor. For example, organic, inorganic, organometallic and other materials including electroluminescent materials or electrically active materials.

More specifically, for example, there can be mentioned poly (phenylene vinylene), poly-para-phenylene, polyfluorene, polydialkyl fluorene, polythiophene, poly (9- vinylcarbazole) Carbazole-vinyl alcohol) copolymer, triarylamine, polynorbornene, polyaniline, polyarylpolyamine, triphenylamine-polyetherketone, and the like, but are not limited thereto.

The transfer layer may further include at least one material selected from a known light emitting material, a hole transporting organic material, and an electron transferring organic material so as to be compatible with the characteristics of the organic light emitting device to be manufactured, A non-luminescent charge transporting polymeric material and a curable organic semi-insulating material.

The constitution of such a transfer layer is not specifically limited in the present invention and can be used without limitation as long as it is usually used in the field.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, it should be understood that the present invention is not limited to the following examples, but can be modified within the same or equivalent ranges.

The following properties were measured by the following measurement methods.

1) Surface roughness

Using a two-dimensional surface roughness tester (Kousaka Lab. Surfcorder SE-3300), the measurement was carried out under the conditions of a probe radius of 1 μm, a load of 0.7 mN and a cutoff value of 80 μm. And the average value was calculated. The y = f (x), where the center line is the x-axis and the vertical direction is the y-axis, is calculated by the following equation.

Surface roughness (Ra) = (1 / L)? F (x) dx

2) Surface energy

The surface energy measurement liquid is put on a swab and rubbed on the coating surface. After 10 seconds, the value of the surface energy measurement liquid which does not change the surface area of the measurement liquid and does not cause the liquid aggregation is taken. The value is measured 10 times and then the average value is taken.

KRUSS DSA-100 equipment was used.

Surface energy was calculated using the Owens-Wendt-Rabel-Kaeble equation.

3) Transcriptionality

After transferring Tris (8-hydroxyquinolinato) aluminum (Alq3) as a transfer layer onto the intermediate layer, the transfer was carried out using an Nd YAG laser with a wavelength of 1064 nm at an energy range of 100 to 130W.

If the transferred image after transfer is consistent with the irradiated portion of the laser; O

If there is a part that does not coincide with each other in part,

If the laser is not transferred at the irradiated part; X

4) Hardening degree (%)

The degree of hardening was measured by IR analysis. IR analysis samples were prepared and evaluated before and after curing of the intermediate layer. The intensity of the peak of the double bonds formed after curing was converted into%. As a sample before curing, an intermediate layer was coated on a glass plate and dried to prepare a sample, which was subjected to IR analysis. The intermediate layer was coated on a glass plate, dried, and UV-cured. The area of the peak where the double bonds are formed was calculated and converted.

Hardening degree (%) = area of sample peak / area of double bond peak × 100

The measurement device was AVATAR 360 ESP of Thermo Nisolet and SMART MIRACLE ZnSe ATR crystal acc.

5) Transcription width

After transferring Tris (8-hydroxyquinolinato) aluminum (Alq3) as a transfer layer onto the intermediate layer, the transfer was carried out using an Nd YAG laser with a wavelength of 1064 nm at an energy range of 100 to 130W. After the transcription, it was confirmed through a microscope.

If the transferred width after transfer is wider than the portion irradiated with laser; O

If the transferred width after transfer is consistent with the irradiated portion of the laser; △

The laser beam is narrower than the irradiated portion; X

6) Lighting evaluation

After the laser thermal transfer process, the presence of carbide on the transfer layer was confirmed.

Good: no carbide, no smearing and no warping in the image

Bad: Carbide is present, image is stained or untransferred

[Example 1]

1) Preparation of composition for photothermal conversion layer preparation (A-1)

Vinyl acetate-vinyl alcohol copolymer (ShinEtsu, Solbin TAO grade, weight average molecular weight 15,000, glass transition temperature 77 占 폚) 18 wt%, polyurethane resin (Lubrizol, ESTANE 5715 grade) 43 wt% A mixed solvent of 9 wt% of polyisocyanate (Aekyung Chemical, AK75 grade) and 30 wt% of carbon black (Degussa, PRINTEX L6 grade) in a weight ratio of toluene: methyl ethyl ketone: cyclohexanone = 1: 1: By weight based on the total weight of the composition.

At this time, preparation of the liquid preparation was performed through kneading and milling filtering process as follows.

First, polyvinyl chloride vinyl acetate copolymer was dissolved by heating at 50 DEG C in a mixed solvent of toluene: methyl ethyl ketone: cyclohexanone = 1: 1: 1 by weight, and 13 wt% polyvinyl chloride vinyl acetate solution . After a certain amount of carbon black was put into the kneading machine, a polyvinyl chloride vinyl acetate solution was added in small quantities while the kneading machine was operated, and the kneading was performed for one hour.

After finishing the kneading, the kneaded solution was put into a main milling vessel of a ring mill filled with 80% of 1.2 mm zirconium particles, and mixed in a mixed solvent of toluene: methyl ethyl ketone: cyclohexanone = 1: 1: 1 (Toluene: methyl ethyl ketone: cyclohexanone = 1: 1: 1 by weight) was added to prepare a solution having a solid content ratio of 15% by weight.

After the prepared solution was added, milling was carried out by operating two agitators in a milling machine. The stirrer used for mixing the coating liquid into the milling machine was adjusted to 1000 rpm, and the stirrer provided in the ring portion for stirring the particles was stirred at 2000 rpm for 6 hours.

The milled solution was filtered using a filter capable of filtering particles of 2.5 μm or more. The filtered solution was coated using Meyer Bar # 8 and dried at 120 ° C for 30 seconds. After confirming the surface state with a microscope, the filtration was completed when it was confirmed that there was no particle larger than 2.5 μm. After filtering, polyisocyanate as a curing agent was added and stirred for 1 hour to prepare a photothermal conversion layer composition.

2) Preparation of composition for intermediate layer preparation (B-1)

75 wt% of amine modified vinyl chloride-vinyl acetate-vinyl alcohol copolymer (ShinEtsu, Solbin TAO grade, weight average molecular weight 15,000, glass transition temperature 77 캜), 15 wt% of polyisocyanate (Aekyou Chemical Co., AK75 grade) 10% by weight of an additive (BYK-BYK-302) was added to a mixed solvent of toluene: methyl ethyl ketone: cyclohexanone = 1: 1: 1 by weight so as to have a solid content of 20% by weight, .

3) Manufacture of LITI donor film

A double-sided acrylic primer-treated PET film (H11F, manufactured by Kolon Industries, Ltd.) was prepared as a base film.

The photothermal conversion layer-forming composition (A-1) was coated on the acrylic primer layer of the prepared substrate film by a micro gravure coating method and dried to form a photo-thermal conversion layer. At this time, the coating amount after drying was 1.5 g / m 2. Followed by aging at 50 DEG C for 3 days.

The intermediate layer preparation composition (B-1) prepared above the light-heat conversion layer was coated using a micro gravure coater and dried at 120 ° C to form an intermediate layer. At this time, the coating thickness was adjusted to be 1.5 탆.

The physical properties of the prepared film were measured and are shown in Table 1 below.

[Example 2]

The procedure of Example 1 was repeated except that the thickness of the intermediate layer was adjusted to 2.0 탆.

The physical properties of the prepared film were measured and are shown in Table 1 below.

[Comparative Example 1]

Except that the thickness of the intermediate layer was adjusted to 2.0 탆 and the content of polyisocyanate (Aekyung Chemical, AK75 grade) was adjusted to 10% by weight as a curing agent.

The physical properties of the prepared film were measured and are shown in Table 1 below.

[Comparative Example 2]

Except that the thickness of the intermediate layer was adjusted to 2.0 탆 and the content of polyisocyanate (Aekyung Chemical, AK75 grade) was adjusted to 7 wt% as a curing agent.

The physical properties of the prepared film were measured and are shown in Table 1 below.

[Comparative Example 3]

The procedure of Example 1 was repeated except that the composition of the intermediate layer was changed.

Preparation of Composition (A-2) for Preparing Intermediate Layer

10 parts by weight of a photoinitiator (Irgacure 184, manufactured by Shiba) was added to 100 parts by weight of a solid content of a UV curable urethane acrylate resin (Negami KY11M-45C), and 3 parts by weight of a silicone additive (Amt, USO-100) To prepare a composition for preparing an intermediate layer.

The UV-curable intermediate layer was dried at 80 ° C for 30 seconds and then cured by passing through an electrodeless UV lamp at 500 mJ / sec.

The physical properties of the prepared film were measured and are shown in Table 1 below.

[Comparative Example 4]

The procedure of Comparative Example 1 was repeated except that the content of the photoinitiator was adjusted to 3 parts by weight.

The physical properties of the prepared film were measured and are shown in Table 1 below.

[Table 1]

As shown in the table, the film according to the present invention had a degree of curing of 95% or more, excellent coating appearance, and superior transferability and transfer width. In addition, it was found that a carbonized film due to unreacted material was not formed at the time of lighting evaluation, and no untransferred and image unevenness occurred.

However, in Comparative Example 1 in which the degree of curing of the intermediate layer was 95% or less, the transfer width was good, but the transferability was poor.

In Comparative Example 3, Comparative Example 2 having a degree of curing of 85% or less had poor transferability and transfer width.

In Comparative Example 2, the hardness of the intermediate layer was 85% or more, but the hardness was increased in the UV-curable intermediate layer and the transferability was poor.

DESCRIPTION OF THE DRAWINGS -
10: substrate film
20: Primer layer
30: photo-thermal conversion layer
40: middle layer
50: transfer layer

Claims (15)

A donor film for a thermal transfer method comprising a base film, a primer layer, a photo-thermal conversion layer, an intermediate layer and a transfer layer,
Wherein the intermediate layer is formed by coating and thermosetting a thermosetting intermediate layer composition comprising a thermosetting modified thermoplastic resin. The method according to claim 1,
Wherein the intermediate layer has a curing degree of 95% or more and a surface energy of 35 mN / m or less. The method according to claim 1,
Wherein the intermediate layer has a thickness of 1.0 to 3.0 占 퐉. The method according to claim 1,
Wherein the thermosetting type intermediate layer composition comprises a thermosetting modified thermoplastic resin and a curing agent. The method according to claim 1 or 4,
Wherein the thermosetting modified thermoplastic resin has a weight average molecular weight of 10,000 to 30,000 and a glass transition temperature of 65 to 75 占 폚. 6. The method of claim 5,
Wherein the thermosetting modified thermoplastic resin has a low molecular weight content of 1% or less and a molecular weight of 10,000 or less. The method according to claim 6,
Wherein the thermosetting modified thermoplastic resin is an amine modified vinyl chloride-vinyl acetate-vinyl alcohol copolymer. 5. The method of claim 4,
Wherein the curing agent is selected from an isocyanate-based curing agent and a peroxide. 5. The method of claim 4,
Wherein the thermosetting intermediate layer composition further comprises one or more additives selected from a fluorine-based additive, a silicone-based additive, an epoxy-based cross-linker, a metal chelate-based cross-linker, a melamine-based cross-linker, an aziridine- film. The method according to claim 1,
Wherein the light-to-heat conversion layer is formed by applying and thermally curing a light-to-heat conversion layer composition comprising a thermosetting modified thermoplastic resin, a thermosetting resin and a photo-thermal conversion material. 11. The method of claim 10,
Wherein the thermosetting modified thermoplastic resin is an amine-modified vinyl chloride-vinyl acetate-vinyl alcohol copolymer having a weight average molecular weight of 10,000 to 30,000 and a glass transition temperature of 65 to 75 ° C, wherein the thermosetting resin is a polyurethane resin, Wherein the photo-thermal conversion material is carbon black. 12. The method of claim 11,
Wherein the carbon black is dispersed in one or two or more resins and solvents selected from polyvinyl chloride, polyvinyl chloride polyvinyl acetate copolymer, and thermosetting polyurethane. The method according to claim 1,
Wherein the light-to-heat conversion layer has a surface roughness (Ra) of 20 nm or less. 11. The method of claim 10,
Wherein the thermosetting modified thermoplastic resin comprises less than 50% by weight of the total content of the light-to-heat conversion layer resin composition. 11. The method of claim 10,
Wherein the light-to-heat conversion layer has a coating amount of 1 to 3.0 g / m 2 after drying.

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