JP2016538700A - Thermal transfer film and organic electroluminescence device manufactured using the same - Google Patents

Abstract

The present invention includes a base material layer and a photothermal conversion layer formed on the base material layer and containing carbon black and tungsten oxide, and the thermal transfer in which the deviation of the OD value represented by the following formula 1 is about 4% or less A thermal transfer film that is a film and an organic electroluminescent device manufactured using the same: [Formula 1] OD value deviation: [(| Measured OD value−Target OD value |) / Target OD value] × 100 The measured OD value is an OD value measured at a wavelength of 850 nm and a wavelength of 1100 nm.

Description

  The present invention relates to a thermal transfer film and an organic electroluminescent device produced using the thermal transfer film.

  The thermal transfer film includes a base material layer and a photothermal conversion layer formed on the base material layer. A transfer layer containing a transfer material such as a light emitting material, an electron transport compound or a hole transport compound may be formed on the photothermal conversion layer. When the photothermal conversion layer is irradiated with a laser having an absorption wavelength, the transfer layer can be transferred to the receptor by the heat converted by the photothermal conversion layer.

  A light-to-heat conversion (LTHC) layer includes a light-to-heat conversion material that absorbs light of a desired wavelength and converts at least part of incident light into heat.

  The conventional thermal transfer film has a difference in absorptivity at a wavelength in the near infrared, and an OD value (optical density) varies depending on the laser wavelength to be irradiated. There is a problem that irradiation power and process speed must be changed. In this connection, Korean Published Patent Application No. 2010-0028652 discloses a thermal transfer film including a photothermal conversion layer including carbon black.

  An object of the present invention is to provide a thermal transfer film having a uniform OD value (optical density) irrespective of the laser wavelength.

  Another object of the present invention is to provide a thermal transfer film having high heat conversion efficiency in the same process without adding a process even when the irradiation wavelength of laser is changed.

  The thermal transfer film of the present invention includes a base material layer and a photothermal conversion layer formed on the base material layer and containing carbon black and tungsten oxide, and the deviation of the OD value represented by the following formula 1 (deviation) ) Is about 4% or less.

[Formula 1]
OD value deviation: [(| measured OD value−target OD value |) / target OD value] × 100

  In the above formula, the measured OD value is an OD value measured at a wavelength of 850 nm and a wavelength of 1100 nm.

  The thermal transfer film of the present invention comprises a substrate layer and a photothermal conversion layer formed on the substrate layer and containing carbon black and tungsten oxide, and the OD measured at a wavelength of 850 nm represented by the following formula 2. The difference (ΔOD) between the value and the OD value measured at a wavelength of 1100 nm is about 0.05 or less.

[Formula 2]
ΔOD: | OD value measured at a wavelength of 850 nm−OD value measured at a wavelength of 1100 nm |

  The organic electroluminescent element of the present invention may be manufactured using the thermal transfer film as a donor film for laser transfer.

  The present invention provides a thermal transfer film having a uniform OD value regardless of the laser wavelength. In addition, the thermal transfer film of the present invention enables thermal transfer with the same transfer efficiency and improved processability without changing the laser power and process speed even when the irradiation wavelength of the laser is changed.

It is sectional drawing of the thermal transfer film of one Embodiment of this invention. It is sectional drawing of the thermal transfer film of other embodiment of this invention. 6 is a graph of OD values according to wavelengths of Example 2, Comparative Example 1 and Comparative Example 5.

  The embodiments will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the embodiments. The invention may be implemented in a variety of different forms and is not limited to the embodiments described herein. In the drawings, parts not related to the description are omitted to clearly describe the present invention, and the same or similar components are denoted by the same reference numerals throughout the specification.

  Hereinafter, with reference to FIG. 1, the thermal transfer film which concerns on one Embodiment of this invention is demonstrated. FIG. 1 is a cross-sectional view of a thermal transfer film according to an embodiment of the present invention.

  Referring to FIG. 1, a thermal transfer film 100 according to an embodiment of the present invention includes a base layer 110 and a photothermal conversion layer 115 formed on the base layer 110. The thermal transfer film 100 has an OD value deviation of about 4% or less expressed by the following formula 1.

[Formula 1]
OD value deviation: [(| measured OD value−target OD value |) / target OD value] × 100

  In the above formula, the measured OD value is an OD value measured at a wavelength of 850 nm and a wavelength of 1100 nm.

  In the range of the deviation, the thermal transfer film can achieve a uniform transfer result even if the laser wavelength changes in the transfer process. At this time, the base material layer does not affect the OD value of the thermal transfer film. Further, an intermediate layer shown in FIG. 2 described later does not affect the OD value of the thermal transfer film.

  Specifically, the deviation between the OD value at a wavelength of 850 nm and the OD value at a wavelength of 1100 nm is about 0% to 4%, or about 0.001% to about 4%, and about 0.001% to about 3. It may be 5% or about 0.001% to about 2.5%. When the deviation of the measured OD value with respect to the target OD value exceeds about 4%, defects such as an organic light emitting material not being transferred may occur in the thermal transfer film. Further, a thermal transfer film in which the deviation of the measured OD value with respect to the target OD value exceeds 4%, when the laser irradiation wavelength is changed, the thermal transfer efficiency is lowered and cannot show a uniform OD value. Therefore, high thermal transfer efficiency can be exhibited only when additional steps such as changing the laser irradiation wavelength are performed.

  In this specification, “OD value deviation” means the difference between the OD value measured at the wavelength of 850 nm and the target OD value, or the difference between the OD value measured at the wavelength of 1100 nm and the target OD value as the target OD value. It means the value calculated as a percentage of the absolute value of the divided value.

  In the present specification, the “target OD value” means a numerical OD (optical density) value at which the thermal transfer film to be used can have the necessary optical characteristics at each measurement wavelength. Thus, a person skilled in the art may arbitrarily set depending on the application of the thermal transfer film.

  Further, the target OD values at the wavelengths of 850 nm and 1100 nm are the same. The wavelength of 850 nm and the wavelength of 1100 nm were selected based on the laser wavelength that can be used during the transfer process of the organic light emitting material. Thereby, the thermal transfer film which concerns on one Embodiment of this invention can implement | achieve the same OD value irrespective of the laser wavelength value irradiated at thermal transfer processes, such as an organic luminescent material of OLED using the same. The “same OD value” means not only completely the same OD value but also substantially the same OD value including some errors.

  The target OD value of the thermal transfer film at a wavelength of 850 nm and a wavelength of 1100 nm is, for example, about 0.1 to about 2.9, about 0.5 to about 2.0, or about 1.0 to about 1.5, respectively. May be.

  The OD values at a wavelength of 850 nm and a wavelength of 1100 nm were measured using a UV / VIS spectrophotometer (Lambda 1050, manufactured by PerkinElmer). Specifically, an OD value for a thermal transfer film in which a base layer that is a polyethylene terephthalate film having a thickness of 100 μm and a photothermal conversion layer having a thickness of 3 μm is formed at each wavelength by using the above-described equipment. It was measured.

  In addition, the thermal transfer film 100 may have a difference (ΔOD) between an OD value measured at a wavelength of 850 nm and an OD value measured at a wavelength of 1100 nm shown in the following formula 2 of about 0.3 or less.

[Formula 2]
ΔOD: | OD value measured at a wavelength of 850 nm−OD value measured at a wavelength of 1100 nm |

  In a specific example, the photothermal conversion layer has a difference (ΔOD) between an OD value at a wavelength of 850 nm and an OD value at a wavelength of 1100 nm of about 0.05 or less, for example, about 0.01 to about 0.05. May be. In the said range, it has the further outstanding transfer efficiency and external appearance.

  A thermal transfer film 100 according to another embodiment of the present invention includes a base material layer 110 and a photothermal conversion layer 115 formed on the base material layer 110, and the thermal transfer film 100 has a wavelength of 850 nm expressed by Formula 2 above. The difference (ΔOD) between the measured OD value and the OD value measured at a wavelength of 1100 nm may be about 0.05 or less. In a specific example, the photothermal conversion layer has a difference (ΔOD) between an OD value at a wavelength of 850 nm and an OD value at a wavelength of 1100 nm, for example, from about 0 to about 0.05, from about 0 to about 0.01. There may be. In the said range, it has the further outstanding transfer efficiency and external appearance.

  The photothermal conversion layer may be formed of a composition for photothermal conversion layer. The composition for forming a photothermal conversion layer may include a photothermal conversion substance, a binder, and an initiator.

  The photothermal conversion material includes carbon black and tungsten oxide. The carbon black and tungsten oxide may be about 1 wt% to about 75 wt% in the entire photothermal conversion layer, specifically about 10 wt% to about 60 wt% or about 15 wt% to about 55 wt%, about It may be included at 20% to about 30% by weight. In the said range, the thermal transfer efficiency of a photothermal conversion layer can be improved.

  In one embodiment, the total amount of carbon black and tungsten oxide may include about 25 wt% to about 55 wt% carbon black and about 45 wt% to about 75 wt% tungsten oxide. Good. More specifically, of the total of the carbon black and the tungsten oxide, the carbon black is included at about 30 wt% to about 50 wt%, and the tungsten oxide is included at about 50 wt% to about 70 wt%. Also good. Within the content range, the light-to-heat conversion layer may have a deviation of the OD value measured at a wavelength of 850 nm and the OD value measured at a wavelength of 1100 nm from the target OD value of 4% or less. At this time, carbon black and tungsten oxide in the photothermal conversion layer do not adsorb each other. Further, within the above range, the binder content with respect to the particles is appropriate, the production of the composition for forming the photothermal conversion layer is easy, and the formed photothermal conversion layer has a high curing rate and is not sticky. It can be used for the conversion layer.

  In a specific example, carbon black and tungsten oxide are solid-phase particles each having a specific size, and the absorptance at the time of laser irradiation of a specific wavelength may be different from each other. In one embodiment, the ratio of the average particle size of carbon black to the average particle size of tungsten oxide is about 1: 1 to about 1: 2, such as about 1: 1 to about 1: 1.2 or about 1: It may be 1 to about 1: 1.1. By containing carbon black having a relatively small average particle size between tungsten oxides having a relatively large average particle size within the range of the particle size ratio, a preparation liquid (preparation of a composition for a photothermal conversion layer) The uniformity and stability of the liquid) can be ensured, and the deviation of the measured OD value from the target OD value can be about 4% or less.

  Carbon black has an oil absorption amount (Oil Absorption Number, OAN) according to ASTM D2414 of about 50 cc / 100 gram to about 120 cc / 100 gram, specifically about 65 cc / 100 gram to about 120 cc / 100 gram. Carbon black may have an average particle size of about 40 nm to about 200 nm, specifically about 58 nm to 100 nm, according to ASTM D3849. Within the above range, carbon black can exhibit thermal characteristics effective for thermal transfer. Carbon black is about 1 wt% to about 30 wt%, specifically about 1 wt% to about 20 wt%, about 5 wt% to about 20 wt%, or based on the solid content in the photothermal conversion layer It may be included at about 5% to about 10% by weight. Within the range of the content, it is advantageous to adjust the OD value according to the specific wavelength.

The tungsten oxide may have an average particle size of about 500 nm or less, specifically about 400 nm or less, about 10 nm to about 200 nm, or about 20 nm to about 200 nm. In the above range, the tungsten oxide can exhibit thermal characteristics effective for thermal transfer, and can exhibit a specific OD value at a specific wavelength by adjusting the content of the tungsten oxide. In one embodiment, the tungsten oxide may be represented by the general formula W _y O _z . In the above general formula, W represents a tungsten atom, O represents an oxygen atom, and the ratio of z to y (z / y) may be 2.2 or more and 3.0 or less. For example, the tungsten oxide may be WO ₃ , W ₁₈ O ₄₉ , W ₂₀ O ₅₈ , W ₄ O ₁₁ or the like. If z / y is 2.2 or more, the generation of the WO ₂ crystal phase can be completely prevented, and the chemical stability of the photothermal conversion substance can be obtained. If z / y of the tungsten oxide is 3.0 or less, a sufficient amount of free electrons is generated, which is excellent in efficiency. In one embodiment, when the z / y value is 2.45 or more and 3.0 or less (2.45 ≦ z / y ≦ 3.0), the tungsten oxide has a Magneli phase. And durability can be improved. In another embodiment, the tungsten oxide may be a composite tungsten oxide containing an element other than tungsten. The composite tungsten oxide has the general formula M _x W _y O _z (wherein M is H, He, alkali metal, alkaline earth metal, rare earth element, halogen, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, P, S, Se, Te, 1 or more elements selected from Ti, Nb, V, Mo, Ta, Re, Hf, Os, and Bi, W is tungsten, and O is oxygen). At this time, the ratio of x to y (x / y) may be 0.001 or more and 1.1 or less, and the ratio of z to y (z / y) is 2.2 or more and 3.0 or less. There may be. The alkali metal may be Li, Na, K, Rb, Cs, or Fr. The alkaline earth metal may be Be, Mg, Ca, Sr, Ba or Ra. The rare earth element may be Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu. The halogen may be F, Cl, Br or I. In one embodiment, the composite tungsten oxide fine particles represented by M _x W _y O _z further improve durability by including one or more crystal structures selected from hexagonal, tetragonal and cubic crystals. obtain. For example, in the case of composite tungsten oxide fine particles having a hexagonal crystal structure, as the element M, one or more kinds selected from Cs, Rb, K, Ti, In, Ba, Li, Ca, Sr, Fe, and Sn are used. Fine particles containing an element may be used. At this time, the addition amount x of the element M to be added is about 0.001 or more and about 1.1 or less, for example, about 0.33 ± 0.3 (about 0.03 to about 0.63). ). This is because the value of x / y theoretically calculated from the hexagonal crystal structure is about 0.33. When adjusting the addition amount within the above range, the photothermal conversion layer can obtain excellent optical properties. In the case of oxygen abundance z, z / y may be about 2.2 or more and about 3.0 or less. Specific examples of the composite tungsten oxide fine particles represented by M _x W _y O _z include Cs _0.33 WO ₃ , Rb _0.33 WO ₃ , K _0.33 WO ₃ , Ba _0.33 WO _{3, and the} like. When y and z are within the above ranges, useful near-infrared absorption characteristics can be obtained. The tungsten oxide is about 1 wt% to about 45 wt% based on the solid content in the photothermal conversion layer, specifically, about 1 wt% to about 35 wt%, about 5 wt% to about 25 wt%. % Or from about 5% to about 21% by weight. Within the above range, the photothermal conversion layer can sufficiently fulfill the role of photothermal conversion, so that the thermal transfer rate is high. In addition, since the binder content relative to the particles is appropriate, the production of the composition for forming the light-to-heat conversion layer is easy, and the formed light-to-heat conversion layer has a high curing rate and is not sticky. Can be used.

  The binder embeds carbon black and tungsten oxide to form a photothermal conversion layer structure. The binder may include an ultraviolet curable resin, a polyfunctional monomer, or a mixture thereof. UV curable resins are (meth) acrylate resin, phenol resin, polyvinyl butyl resin, polyvinyl acetate, polyvinyl acetal, polyvinylidene chloride, cellulose ether, cellulose ester, nitrocellulose, polycarbonate, polyalkyl (meth) acrylate, epoxy One or more of (meth) acrylate, epoxy, urethane, alkyd, spiroacetal, and polybutadiene may be included, but are not limited thereto. The UV curable resin is about 10 wt% to about 75 wt%, specifically about 15 wt% to about 75 wt% or about 20 wt% to about 25 wt% in the composition for the photothermal conversion layer based on the solid content. It may be included at about 60% by weight. Within the above range, a stable matrix of the photothermal conversion layer can be formed. The polyfunctional monomer can give a predetermined range of hardness to the photothermal conversion layer. In one embodiment, the polyfunctional monomer may be a monomer having one or more (specifically) 2 to 6 (meth) acrylate groups. Specifically, the polyfunctional monomer may include one or more of a polyfunctional (meth) acrylate monomer and a fluorine-modified polyfunctional (meth) acrylate monomer. Examples of the polyfunctional (meth) acrylate monomer include trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra ( (Meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, di (trimethylolpropane) tetra (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, hexane One or more of diol di (meth) acrylate and cyclodecanedimethanol di (meth) acrylate may be included. The fluorine-modified polyfunctional (meth) acrylate may be, for example, a fluorine-modified polyfunctional (meth) acrylate. The polyfunctional monomer is about 5 wt% to about 70 wt%, specifically about 5 wt% to about 20 wt%, or about 5 wt% to about 5 wt% in the photothermal conversion layer composition based on the solid content. It may be included at 20% by weight. Within the above range, a stable matrix of the photothermal conversion layer can be formed.

  The binder may be contained in the composition for a light-to-heat conversion layer based on the solid content in an amount of about 35 wt% to about 80 wt%, specifically about 35 wt% to about 75 wt%. Within the above range, a stable matrix of the photothermal conversion layer can be formed.

  The initiator serves to cure the binder, and may be, for example, a photopolymerization initiator. A normal initiator may be used as the photopolymerization initiator. Specifically, the photopolymerization initiator may be an α-hydroxyketone type such as 1-hydroxycyclohexyl phenyl ketone, but is not limited thereto. The initiator may be included in the composition for a light-to-heat conversion layer based on solid content in an amount of about 0.1 wt% to about 10 wt%, specifically about 1 wt% to about 4 wt%. . Within the above range, the photothermal conversion layer can be sufficiently formed, and the OD value can be prevented from being lowered due to the unreacted initiator remaining.

  The composition for forming a photothermal conversion layer contains the above-described carbon black, tungsten oxide, binder and initiator, and may further contain a dispersant.

  Examples of the dispersant include a surfactant that disperses and stabilizes carbon black and tungsten oxide, or a polymer dispersant that disperses the photothermal conversion material by steric hindrance of the dispersant adsorbed on the surface of the photothermal conversion material. May be used. As an example, a fluorine-based compound can be used as a dispersant. By using a fluorine-based compound, the effect of dispersion stability of the composition can be further improved. The fluorine-based compound may be represented by the following chemical formula 1.

[Chemical formula 1]
(CH ₂ = CR ¹ -C (= O) -O-) _n R ^f

In Formula 1, n is an integer of 1 or more, R ¹ is hydrogen or a methyl group, R ^f is a C 2-50 fluoroalkyl group, a C 2-50 perfluoroalkyl group, or C 2 It may be a ˜50 fluoroalkylene group or a C 2-50 perfluoroalkylene group. Specifically, n is an integer of 2 to 5, R ^f is a C 2-15 fluoroalkyl group, a C 2-15 perfluoroalkyl group, a C 2-15 fluoroalkylene group, or a carbon number. It may be 2 to 15 perfluoroalkylene groups. For example, 1H, 1H, 10H, 10H-perfluoro-1,10-decanediol diacrylate (Exfluor Research Corporation) may be used as the fluorine-based compound, but is not limited thereto. The fluorine-based compound may be included in an amount of about 1 part by weight to about 5 parts by weight, specifically about 1 part by weight to about 3 parts by weight with respect to 100 parts by weight of the total of carbon black and tungsten oxide. Within this range, the deviation of the OD value at the wavelength of 850 nm and the OD value at the wavelength of 1100 nm from the target OD value is about 4% or less, and the OD value can be uniform regardless of the laser wavelength.

  As the polymer dispersant, for example, an acrylic or acrylate polymer dispersant may be used. The acrylic polymer dispersant has an acrylic acid ester system such as ethyl acrylate and butyl acrylate or a copolymer thereof as a main skeleton, and further has a functional group for adsorbing to tungsten oxide particles or composite tungsten oxide particles. You may have. The acrylic or acrylate polymer dispersant may have an acid value of about 0 mgKOH / g to about 23 mgKOH / g, and an amine value of about 30 mgKOH / g to about 50 mgKOH / g. Within the above range, the polymer dispersant can effectively disperse the photothermal conversion substance. As the dispersant, a commonly known dispersant may be further used. Further, the dispersant used is a conductive polymer selected from the group consisting of polyaniline, polythiophene, polypyrrole and derivatives thereof; polyphenylene, poly (phenylene vinylene), polyfluorene, poly (3,4-disubstituted thiophene), Polybenzothiophene, polyisothianaphthene, polypyrrole, polyfuran, polypyridine, poly-1,3,4-oxadiazole, polyazulene, polyselenophene, polybenzofuran, polyindole, polypyridazine, polypyrene, polyarylamine, and the like One or more semiconductive polymers selected from the group consisting of derivatives; or polyvinyl acetate and copolymers thereof may be used, but are not limited thereto.

  The dispersant is about 0.1 wt% to about 30 wt%, specifically, about 0.1 wt% to about 10 wt% or about 0.1 wt% in the composition for the photothermal conversion layer based on the solid content. 1% to about 5% by weight may be included. Within the above range, the thermal transfer rate can be increased while improving the dispersibility of the photothermal conversion substance.

  The dispersant may be added separately from the light-to-heat conversion substance at the time of producing the composition, but generally it may be added to the composition in the form of a dispersion containing the dispersant and the light-to-heat conversion substance. The dispersion may contain, for example, carbon black, tungsten oxide, a dispersant and a solvent. As the solvent, a solvent that does not inhibit the dispersion of the above-described tungsten oxide or carbon black may be used. For example, the solvent may include one or more of ketones, esters, hydrocarbons, and ethers. Specifically, the solvent includes ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate Hydrocarbons such as toluene and xylene; ethers such as ethyl ether and propyl ether may be used. When such a solvent is used, the dispersibility of the photothermal conversion substance can be further improved.

  In one embodiment, the dispersion comprises about 20% to about 60% carbon black, about 24% to about 72% tungsten oxide, about 0.1% to about 10% dispersant, and the balance. It may consist of an amount of solvent. The “remaining amount” means the remaining amount excluding carbon black, tungsten oxide and dispersant in the dispersion.

  The base material layer may be a transparent resin film that has good adhesion to the light-to-heat conversion layer and can control temperature transfer between the light-to-heat conversion layer and other layers. Specifically, the base material layer may be one or more resin films of polyester, polyacrylic, polyepoxy, polyethylene, polypropylene and other polyolefins, and polystyrene. It is not limited. More specifically, the base material layer is a polyester film, and may be a polyethylene terephthalate film or a polyethylene naphthalate film. The base material layer may have a thickness of about 10 μm to about 500 μm, specifically about 40 μm to about 100 μm. In the said range, a base material layer can support a thermal transfer film and can be used for a thermal transfer film.

  The photothermal conversion layer may have a surface roughness of about 200 nm or less, specifically about 1 nm to about 100 nm. Within the above range, there can be an effect that defects due to pressing of the final product are reduced.

In one embodiment, the light-to-heat conversion layer is coated with a composition comprising carbon black, tungsten oxide, binder, initiator, dispersant, etc. on a substrate film and dried, and then about 100 mJ / cm ² to about It can manufacture by making it harden | cure by irradiation of 500 mJ / cm < ² >. Drying may be performed at about 50 ° C. to about 100 ° C., specifically about 80 ° C.

  The photothermal conversion layer may have a thickness of more than about 0 μm and about 6 μm or less, specifically about 0.5 μm to about 5 μm, more specifically about 0.5 μm to about 3 μm. Within the above range, the photothermal conversion layer can efficiently perform thermal transfer.

  Hereinafter, with reference to FIG. 2, the thermal transfer film which concerns on other embodiment of this invention is demonstrated. FIG. 2 is a cross-sectional view of a thermal transfer film according to another embodiment of the present invention.

  Referring to FIG. 2, a thermal transfer film 200 according to another embodiment of the present invention includes a base layer 110, a photothermal conversion layer 115 formed on the base layer 110, and an intermediate formed on the photothermal conversion layer 115. Layer 120 may be included. The thermal transfer film of FIG. 2 is the same as FIG. 1 except that an intermediate layer is further formed.

  The intermediate layer is used to minimize damage and contamination of the transfer material of the transfer layer, which will be described later, and can also reduce the twist of the transfer material. Further, the intermediate layer can control the adhesion of the transfer layer to the portion where the receptor pattern is formed and the portion where the pattern is not formed.

  In one embodiment, the intermediate layer can be a polymer film, a metal layer, an inorganic layer (eg, a layer on which an inorganic oxide such as silica, titania or other metal oxide is sol-gel deposited or vapor deposited) or organic / Includes an inorganic composite layer. The organic material of the organic composite layer may include all of thermosetting or thermoplastic materials.

  In another embodiment, the intermediate layer may be formed of a composition including an ultraviolet curable resin, a polyfunctional monomer, and an initiator. Specifically, the intermediate layer comprises about 40 wt% to about 95 wt% UV curable resin, about 1 wt% to about 50 wt% polyfunctional monomer, and about 1 wt% to about 10 wt% initiator. A cured product of the product may be included. The intermediate layer may further include one or more of an ultraviolet curable fluorine compound and an ultraviolet curable siloxane compound. The ultraviolet curable fluorine-based compound may be, for example, a fluorine-modified polyfunctional (meth) acrylate including 1H, 1H, 10H, 10H-perfluoro-1,10-decandiol di (meth) acrylate. The ultraviolet curable siloxane compound may be, for example, a polyether-modified dialkylpolysiloxane containing a (meth) acryl group, but is not limited thereto.

  The intermediate layer may have a thickness of about 1 μm to about 10 μm, specifically about 2 μm to about 5 μm. Within the above range, the intermediate layer may have advantageous physical properties for application to a thermal transfer film.

  The thermal transfer film of the present invention may further include a transfer layer. The transfer layer may be formed, for example, on the above-described photothermal conversion layer or on the intermediate layer.

  The transfer layer may include a transfer material, and the transfer material may include, for example, an organic EL. When a laser with a specific wavelength is irradiated while the transfer layer is in contact with the surface of a receptor having a specific pattern, the photothermal conversion layer absorbs light energy and expands by generating heat, so that it corresponds to the pattern. The transfer material of the transfer layer is thermally transferred to the receptor. The transfer layer may include one or more layers for transferring the transfer material to the receptor. These may be formed using organic, inorganic, organometallic materials or other materials including electroluminescent materials or electrically active materials. In one embodiment, the transfer layer may be coated into a uniform layer by evaporation, sputtering or solvent coating. In other embodiments, the transfer layer may be formed by pattern printing using digital printing, lithographic printing, or sputtering through a mask.

  Although the thermal transfer film of this invention may be used as a donor film for OLED and a donor film for laser transfer, it is not limited to this.

  In one embodiment, the organic electroluminescent device (including OLED) of the present invention may be manufactured using the thermal transfer film according to the embodiment of the present invention as a donor film. Specifically, a donor film is disposed on a substrate on which a transparent electrode layer is formed. At this time, the donor film may be, for example, a film in which the above-described base material layer, photothermal conversion layer, and transfer layer are laminated. Thereafter, the donor film is irradiated with an energy source. The energy source passes through the base material layer from the exposure apparatus to activate the photothermal conversion layer, and the activated photothermal conversion layer releases heat by a thermal decomposition reaction. The transfer layer is separated from the donor film while the photothermal conversion layer of the donor film expands due to the released heat, and the transfer material is formed on the pixel region defined by the pixel definition film on the organic electroluminescence device substrate. A light emitting layer is transferred to a desired pattern and thickness.

  Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention in any way.

  Specific specifications of the components used in the following examples and comparative examples are as follows.

(A) Photothermal conversion substance: Tungsten oxide and carbon black * Tungsten oxide fine particle dispersion (T-sol, AMTE) was used as tungsten oxide. The tungsten oxide fine particle dispersion contains 30% by weight of tungsten oxide particles, 12% by weight of acrylic polymer dispersant, and 58% by weight of methyl ethyl ketone. The tungsten oxide particles are WO ₃ and have an average particle size of 70 nm.
* Carbon black is a dispersion of carbon black particles (average particle size 65 nm, oil absorption 65 cc / 100 gram, average particle size measured by ASTM D3849 method, oil absorption measured by ASTM D2414 method) as a dispersion, 30% by weight. A mill base (Columbia, Raven 450) containing 4.5 wt% polyvinyl acetate and 65.5 wt% solvent methyl ethyl ketone was used.
(B) Binder: Polymethyl methacrylate resin and epoxy acrylate resin as UV curable resin, trifunctional acrylate monomer as polyfunctional monomer (Sartomer, SR351)
(C) Initiator: Irgacure 184 (manufactured by CIBA)
(D) Base material layer: polyethylene terephthalate film (PET, manufactured by Toyobo Co., Ltd., A4100, thickness: 75 μm)

[Example 1]
25 parts by weight of polymethyl methacrylate, 30 parts by weight of an epoxy acrylate resin, 8 parts by weight of a trifunctional acrylate monomer, and 2 parts by weight of an initiator were mixed with 100 parts by weight of the solvent methyl ethyl ketone. 60 parts by weight of a mixture of the carbon black dispersion and the tungsten oxide dispersion (the ratio of the carbon black dispersion to the tungsten oxide is 50% by weight: 50% by weight) is added to the resulting mixture, and 30 parts thereof are added. Stir for minutes. Add 0.5 parts by weight of fluorine compound (1H, 1H, 10H, 10H-perfluoro-1,10-decyl diacrylate, manufactured by Exfluor Research Corporation) for dispersion stability of tungsten oxide and carbon black The composition for photothermal conversion layers was manufactured. The obtained composition for a photothermal conversion layer was applied to a PET film with a wired bar No. 8 Bar coating using an applicator, drying at 80 ° C. for 2 minutes using an applicator, curing by UV irradiation at 300 mJ / cm ² , thermal transfer film of substrate layer / photothermal conversion layer (coating thickness: 3 μm) Manufactured.

[Examples 2-3]
Evaluation was made in the same manner as in Example 1 except that the percentage% of tungsten oxide and carbon black in the mixture of the tungsten oxide dispersion and the carbon black dispersion was changed as shown in Table 1 below. .

[Example 4]
25 parts by weight of polymethyl methacrylate, 30 parts by weight of an epoxy acrylate resin, 8 parts by weight of a trifunctional acrylate monomer, and 2 parts by weight of an initiator were mixed with 100 parts by weight of the solvent methyl ethyl ketone. 60 parts by weight of a mixture of the carbon black dispersion and the tungsten oxide dispersion (the ratio of the carbon black dispersion to the tungsten oxide is 50% by weight: 50% by weight) is added to the resulting mixture, and 30 parts thereof are added. Stir for minutes. Add 0.5 parts by weight of fluorine compound (1H, 1H, 10H, 10H-perfluoro-1,10-decyl diacrylate, manufactured by Exfluor Research Corporation) for dispersion stability of tungsten oxide and carbon black The composition for photothermal conversion layers was manufactured. A mixture of 47.15 g of methyl ethyl ketone (MEK) and 26.05 g of propylene glycol monomethyl ether acetate, 17.99 g of a hexafunctional urethane acrylate oligomer (Sartomer, CN9006) as an ultraviolet curable resin, and a trifunctional acrylate monomer as a polyfunctional monomer (Sartomer Co., SR351) 7.44 g, and ultraviolet curable fluorine compound 1H, 1H, 10H, 10H-perfluoro-1,10-decanediol diacrylate (manufactured by Exfulor Research Corporation) 0.62 g, This was stirred for 30 minutes. Subsequently, 0.75 g of Irgacure 184 (manufactured by Basf) was added as an initiator, and the mixture was finally stirred for 30 minutes to produce an intermediate layer composition. The composition for a photothermal conversion layer that has already been prepared is coated with a wire bar no. 8 was bar coated and dried at 80 ° C. for 2 minutes using an applicator. Then, the composition for intermediate | middle layers was wired bar No.2. 8 was bar coated and dried at 80 ° C. for 2 minutes using an applicator. Curing was carried out by irradiation with ultraviolet rays at 300 mJ / cm ² to produce a thermal transfer film of base layer / photothermal conversion layer (coating thickness: 3 μm) / intermediate layer.

[Comparative Examples 1-5]
Evaluation was made in the same manner as in Example 1 except that the percentage% of tungsten oxide and carbon black in 35 parts by weight of the tungsten oxide and carbon black mixture was changed as shown in Table 1 below.

[Evaluation of the physical properties]
The following physical properties were evaluated for the thermal transfer films of Examples and Comparative Examples, and the results are shown in Table 1 below.

  (1) OD value: The optical density value is measured using a Perkin Elmer Lambda 1050 UV / VIS spectrophotometer at a wavelength of 850 nm and a wavelength of 1100 nm for the thermal transfer film.

  (2) OD value deviation: For each of the OD values measured at a wavelength of 850 nm and a wavelength of 1100 nm, the OD value is calculated using the equation [(| Measured OD value−Target OD value |) / Target OD value] × 100. Deviation was calculated. At this time, the target OD values of Examples 1 to 4 and Comparative Examples 5 to 5 were set to 1.20 at the same wavelength at 850 nm and 1100 nm.

  (3) Appearance: The photothermal conversion layer is confirmed with the naked eye using a reflector or a transmission system. The appearance in which the coating is uniformly distributed is indicated as “good”, and when the stain is visible, it is indicated as “bad”.

  (4) Transfer efficiency: A luminescent material is vapor-deposited on the manufactured thermal transfer film, and a test piece having a size of 1 cm × 1 cm (width × length) is exposed to a laser. When the portion exposed to the laser was viewed with a microscope, it was evaluated as “good” when 80% or more of the deposited luminescent material was transferred, and “bad” when less than 80% was transferred.

  As shown in Table 1 and FIG. 3, the thermal transfer film of the present invention has an OD value measured at a wavelength of 850 nm and a deviation of the OD value measured at a wavelength of 1100 nm from a target OD value of 4% or less, and a wavelength of 850 nm. It was confirmed that the OD value measured at a wavelength of 1100 nm was substantially uniform. Moreover, it was confirmed that the thermal transfer film of the present invention has good transfer efficiency and good appearance.

  On the other hand, as shown in Table 1 and FIG. 3, as in Comparative Example 1 and Comparative Example 5, the thermal transfer film containing only carbon black or only tungsten oxide has an OD value deviation exceeding 4%. It was confirmed that the OD value was not uniform over the entire wavelength range. In addition, when the contents of carbon black and tungsten oxide are large, there is a problem that the transfer efficiency and appearance at the time of laser irradiation of 1100 nm and 850 nm are not good. In addition, Comparative Examples 2 to 4 containing carbon black and tungsten oxide whose contents depart from the scope of the present invention have a problem that transfer efficiency and / or appearance are not good.

Claims (16)

A base material layer;
A photothermal conversion layer formed on the base material layer and containing carbon black and tungsten oxide;
Including
Thermal transfer film having an OD value deviation of about 4% or less represented by the following formula 1:
[Formula 1]
OD value deviation: [(| measured OD value−target OD value |) / target OD value] × 100
In the above formula, the measured OD value is an OD value measured at a wavelength of 850 nm and a wavelength of 1100 nm. The carbon black and the tungsten oxide may include about 25 wt% to about 55 wt%, and the tungsten oxide may include about 45 wt% to about 75 wt% of the total of the carbon black and the tungsten oxide. Heat transfer film. The thermal transfer film of claim 1, wherein the carbon black and the tungsten oxide have an average particle size ratio of about 1: 1 to about 1: 2. The thermal transfer film of claim 1, wherein the carbon black has an average particle size of about 40 nm to about 200 nm, and the tungsten oxide has an average particle size of about 20 nm to about 200 nm. The thermal transfer film according to claim 1, wherein the carbon black and the tungsten oxide are included in the light-to-heat conversion layer at about 15 wt% to about 55 wt%. The thermal transfer film according to claim 1, wherein the carbon black has an oil absorption number (Oil Absorption Number, OAN) according to ASTM D2414 of about 50 cc / 100 gram to about 120 cc / 100 gram. The thermal transfer film according to claim 1, wherein an intermediate layer is further formed on the photothermal conversion layer. 2. The thermal transfer film according to claim 1, wherein a difference (ΔOD) between an OD value measured at a wavelength of 850 nm and an OD value measured at a wavelength of 1100 nm represented by the following formula 2 is about 0.3 or less:
[Formula 2]
ΔOD: | OD value measured at a wavelength of 850 nm−OD value measured at a wavelength of 1100 nm | A base material layer;
A photothermal conversion layer formed on the base material layer and containing carbon black and tungsten oxide;
Including
A thermal transfer film in which a difference (ΔOD) between an OD value measured at a wavelength of 850 nm and an OD value measured at a wavelength of 1100 nm represented by the following formula 2 is about 0.05 or less.
[Formula 2]
ΔOD: | OD value measured at a wavelength of 850 nm−OD value measured at a wavelength of 1100 nm | 10. The carbon black and the tungsten oxide, wherein the carbon black is included at about 25 wt% to about 55 wt%, and the tungsten oxide is included at about 45 wt% to about 75 wt%. Heat transfer film. The thermal transfer film of claim 9, wherein the ratio of the average particle size of the carbon black to the tungsten oxide is about 1: 1 to about 1: 2. The thermal transfer film of claim 9, wherein the carbon black has an average particle size of about 40 nm to about 200 nm, and the tungsten oxide has an average particle size of about 20 nm to about 200 nm. The thermal transfer film according to claim 9, wherein the carbon black and the tungsten oxide are included in the light-to-heat conversion layer in an amount of about 15 wt% to about 55 wt%. The thermal transfer film according to claim 9, wherein the carbon black has an oil absorption number (Oil Absorption Number, OAN) according to ASTM D2414 of about 50 cc / 100 gram to about 120 cc / 100 gram. The thermal transfer film according to claim 9, wherein an intermediate layer is further formed on the photothermal conversion layer. The organic electroluminescent element manufactured using the thermal transfer film by any one of Claims 1-15 as a donor film.

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