KR20160000851A - Light to heat conversion layer and donor sheet - Google Patents

Abstract

The present invention is to provide a light-to-heat conversion layer with visible light penetrability. The light-to-heat conversion layer contains tungsten compound particles and binder components. The tungsten compound particles are tungsten oxide particles and/or composite tungsten oxide particles, and a volume average particle size of the tungsten compound particles is 35 nm or greater and 500 nm or less.

Description

[0001] LIGHT TO HEAT CONVERSION LAYER AND DONOR SHEET [0002]

The present invention relates to a photo-thermal conversion layer and a donor sheet.

As a method of forming an organic electroluminescence device on a substrate, a metal mask method, a laser transfer method, an ink jet method, and the like have been studied. Since the metal mask method is difficult to cope with large-sized next-generation large display devices, and the inkjet method has many technical problems to be applied, the laser transfer method is considered to be the mainstream process for large display processes .

There are several methods of laser transfer, but the mainstream is to deposit films using a so-called donor sheet. Examples of the donor sheet include a layer for absorbing light called a light to heat conversion (LTHC) layer and a layer of an organic compound having an electroluminescent property, for example, And the one that has been formed is used. Various proposals have been made for a method of forming an organic electroluminescence device on a substrate by a laser transfer method, but the basic operation principle is common. That is, by irradiating the laser light to a specific point of the photo-thermal conversion layer, light is absorbed into the photo-thermal conversion layer to generate heat, and the organic electroluminescence device formed as the layer to be transferred by the action of heat can be transferred.

As the light absorbing material of the photo-thermal conversion layer of the donor sheet, various materials have been proposed. For example, Patent Document 1 discloses dyes that absorb light in the infrared region, organic and inorganic absorbing materials such as carbon black, metals, metal oxides or metal sulfides, and other pigments and absorbers that are already known. In Patent Document 2, dyes, pigments, metals, metal compounds, metal films and the like are disclosed. Patent Document 3 discloses black aluminum. In Patent Document 4, carbon black, graphite and infrared dyes are disclosed.

Japanese Patent Publication No. 2000-515083 Japanese Published Patent Application No. 2002-534782 Japanese Patent No. 3562830 Japanese Laid-Open Patent Publication No. 2004-200170

In the case of forming the organic electroluminescence element by the laser transfer method as described above, for example, the laser light is irradiated to a desired point in the photo-thermal conversion layer of the donor sheet, and the organic electroluminescent element It can be carried out by transferring the sist element. However, when the donor sheet contains defects such as foreign matter or coating unevenness, for example, the organic electroluminescence element at the laser irradiation point is not normally transferred, causing a dot not to light when turned into a display device do. For this reason, in order to improve the yield, it is necessary to detect the donor sheet including defects before the laser transfer by a naked eye or a visible light sensor or the like.

However, when the materials disclosed in Patent Documents 1 to 4 are used as the light absorbing material to be applied to the photo-thermal conversion layer, the visible light transmittance of the photo-thermal conversion layer is not sufficient. That is, when the light absorbing materials disclosed in Patent Documents 1 to 4 are used, the photo-thermal conversion layer exhibits a very dark black color having substantially no light transmittance. Therefore, when such a photo-thermal conversion layer is applied to a donor sheet, it is impossible to detect defects by a naked eye or a visible light sensor.

In this way, even a defective donor sheet can not be sufficiently detected by inspection in the past, leading to defects of the organic electroluminescence device, which has been a major cause of a reduction in the yield of the display device.

Therefore, in view of the problems of the prior art, one aspect of the present invention is to provide a photo-thermal conversion layer having visible light transmittance.

According to one aspect of the present invention, there is provided a photo-thermal conversion layer containing tungsten compound particles and a binder component,

The tungsten compound particle is a tungsten oxide particle and / or a composite tungsten oxide particle,

Wherein the tungsten compound particles have a volume average particle diameter of 35 nm or more and 500 nm or less.

According to an embodiment of the photo-thermal conversion layer of the present invention, a photo-thermal conversion layer having visible light transmittance can be provided.

1 is a schematic view of a crystal structure of a composite tungsten oxide having a hexagonal crystal structure.
2 is an explanatory diagram of an example of a cross-sectional configuration of a donor sheet;
3 is a transmission curve of the donor sheet measured in Examples 1 to 3 and Comparative Examples 1 and 2;

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and permutations may be added to the following embodiments without departing from the scope of the present invention. can do.

(Photo-thermal conversion layer)

In this embodiment, first, a structural example of the photo-thermal conversion layer will be described.

The photo-thermal conversion layer of the present embodiment may contain a tungsten compound particle and a binder component. The tungsten compound particles are preferably tungsten oxide particles and / or composite tungsten oxide particles, and the volume average particle diameter of the tungsten compound particles is preferably 35 nm or more and 500 nm or less.

The components contained in the photo-thermal conversion layer of the present embodiment will be described below.

First, the tungsten compound particles will be described.

The tungsten compound particles can function as an infrared absorbing particle which absorbs such laser light to generate heat when laser light is irradiated to the photo-thermal conversion layer. Since the photo-thermal conversion layer of the present embodiment preferably has visible light transmittance, it is preferable that the tungsten compound particles also have high transmittance for light in the visible region.

Therefore, in the photo-thermal conversion layer of the present embodiment, tungsten oxide particles and / or composite tungsten oxide particles can be used as the tungsten compound particles. According to a study by the inventors of the present invention, the tungsten oxide particles and / or the composite tungsten oxide particles exhibit transmittance to light in the visible region and can generate heat by absorbing the laser light in the infrared region, particularly near infrared region .

The tungsten compound particles are preferably fine particles. Specifically, for example, the volume average particle diameter of the tungsten compound particles is preferably 35 nm or more and 500 nm or less, more preferably 35 nm or more and 150 nm or less, And more preferably 90 nm or less.

The volume average particle diameter means the particle diameter at an integrated value of 50% in the particle size distribution obtained by the laser diffraction / scattering method, and the volume average particle diameter has the same meaning in other parts in this specification.

For tungsten compound particles, it is considered desirable to suppress the diffusion of light due to Rayleigh scattering and non-scattering in order to increase the transmittance of light in the visible region. For this reason, it has been considered desirable to reduce the particle size sufficiently. For this reason, it has been considered desirable that the volume average particle diameter is, for example, less than 35 nm.

However, the inventors of the present invention have found that the photo-thermal conversion layer has sufficient visible light transmittance even when the volume average particle diameter of the tungsten compound particles is 35 nm or more and 500 nm or less. The photo-thermal conversion layer containing the tungsten compound particles having a volume average particle diameter of 35 nm or more is superior to the photo-thermal conversion layer containing the same weight of the tungsten compound particles having a volume average particle diameter of less than 35 nm, And completed the present invention.

It has been considered that a material having absorption due to the local surface plasmon resonance such as tungsten oxide particles, which are conventional tungsten compound particles or composite tungsten oxide particles, is not strengthened even if absorption of infrared light is weakened by increasing the particle diameter. According to a study by the inventors of the present invention, the photo-thermal conversion layer containing tungsten compound particles having a volume average particle diameter of 35 nm or more has particularly enhanced absorption of light in the near-infrared region. The cause of the above-mentioned phenomenon contrary to the conventional sense is not clear, but the present inventors think that it is caused by deterioration in the vicinity of the surface of the tungsten compound particles. This point will be described below.

The outermost surface of the tungsten compound particles is affected by oxygen defects, desorption of the doping element, and surface relaxation of the crystal structure, and an incomplete crystal structure different from that of the bulk tungsten compound particles is formed in the region from several atom to ten atoms . The larger the particle diameter of the tungsten compound particles, the smaller the ratio of the incomplete area on the outermost surface of the tungsten compound particles that does not substantially contribute to the absorption of light in the near infrared region, and the larger is the absorption per unit weight. Therefore, by setting the volume average particle diameter of the tungsten compound particles to 35 nm or more, it is possible to reduce the ratio of the incomplete area of the outermost surface, thereby enhancing the absorption of light in the near infrared region.

On the other hand, the inventors of the present invention have found that when the volume average particle diameter is larger than 500 nm, the local surface plasmon resonance is weakened, so that the light absorption per unit weight is rather weak and the light scattering becomes large, At the same time. Therefore, in the photo-thermal conversion layer of the present embodiment, it is preferable that the volume average particle diameter of the tungsten compound particles is 500 nm or less as described above.

As described above, the tungsten compound particles having a volume average particle diameter of 35 nm or more and 500 nm or less are excellent in light absorption characteristics in the near infrared region per unit weight. Therefore, even when an amount of tungsten compound particles exhibiting sufficient absorption in the near infrared region is added to the photo-thermal conversion layer, the thickness of the photo-thermal conversion layer can be reduced.

The photo-thermal conversion layer containing such tungsten compound particles has high transmittance in the visible region. For this reason, even when such a photo-thermal conversion layer is applied to a donor sheet or the like, it is very easy to detect defects by the naked eye or a visible light sensor.

As described above, as the tungsten compound particles, tungsten oxide particles and / or composite tungsten oxide particles can be preferably used. The tungsten compound particles are not limited to one kind of material, but may contain a plurality of different materials can do. For this reason, the tungsten compound particles may contain, for example, tungsten oxide particles and composite tungsten oxide particles at the same time. The tungsten compound particles may contain only either one of tungsten oxide particles and composite tungsten oxide particles. However, since the composite tungsten oxide particles are superior in transmittance of visible light and absorption of near-infrared light than tungsten oxide particles, it is preferable that the tungsten compound particles contain the composite tungsten oxide particles.

The specific composition of the tungsten compound particles is not limited. However, the tungsten compound particle is a tungsten oxide particle represented by the formula W _y O _z (2.2? _Z / y < 3.0) and a tungsten oxide particle represented by the formula M _x W _y O _z (wherein M is H, He, A rare earth element, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, , At least one element selected from among Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, x / y? 0.8, and 2.2? z / y? 3.0), more preferably at least one kind selected from the group consisting of composite tungsten oxide particles.

The tungsten oxide particles represented by the formula W _y O _z will be described. In the formula W _y O _z , W represents tungsten and O represents oxygen.

In general, since tungsten trioxide (WO ₃ ) does not have effective free electrons, its absorption and reflection characteristics in the near infrared region are small, and the infrared absorbing particles may not exhibit sufficient functions. However, according to the study by the inventors of the present invention, by reducing the ratio of oxygen to tungsten in tungsten trioxide to less than 3, that is, by setting z / y <3.0 in the above-described formula, free electrons are generated in the tungsten oxide . For this reason, infrared absorbing particles having good efficiency can be obtained.

In addition, the crystal phase of WO ₂ causes absorption or scattering of light in the visible region, and there is a fear that the absorption of light in the near-infrared region is lowered. Therefore, as described above, it is preferable to suppress the generation of a crystalline phase of WO ₂ by making 2.2? Z / y for the tungsten oxide particles. It is preferable to set z / y within the above range because chemical stability as a material can be obtained and applicable as effective infrared absorbing particles.

Therefore, in the tungsten oxide particles W _y O _z , it is preferable that the relationship of 2.2? Z / y &lt; 3.0 is satisfied.

The so-called &quot; Magneley phase &quot; having a composition ratio represented by the general formula W _y O _z of 2.45? Z / y &lt; 3.0 is chemically stable and has good absorption properties of light in the near infrared region, Particle. Therefore, it is more preferable to satisfy the relationship of 2.45? Z / y &lt; 3.0 with respect to the tungsten oxide particles (W _y O _z ).

Next, the composite tungsten oxide particles represented by the formula M _x W _y O _z will be described.

As the tungsten compound particles, a composite tungsten oxide (M _x W _y O _z ) in which an element M is added in addition to the above-described tungsten oxide may also be used. When element M is added to tungsten oxide to form composite tungsten oxide, free electrons are generated in the composite tungsten oxide, and stronger absorption characteristics derived from free electrons are expressed in the near infrared region. For this reason, it is particularly effective as an infrared absorbing material for absorbing near infrared rays having a wavelength of about 1000 nm.

In the formula M _x W _y O _z representing the composite tungsten oxide particles, W represents tungsten and O represents oxygen. The element M in the above formula includes, for example, H, He, an alkali metal, an alkaline earth metal, a rare earth element, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Ti, Nb, V, Mo, Ta, Ta, Ti, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Re, Hf, Os, Bi, and I.

In particular, from the viewpoint of stability in the composite tungsten oxide to which the element M is added, the element M is an alkali metal, an alkaline earth metal, a rare earth element, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ti, Nb, V, Pb, Sb, B, F, P, Sb, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Mo, Ta, Re, Hf, Os, Bi, and I.

(Rare-earth element, Zr, Cr, Mn, or the like) among the more preferable elements as the above-described element M from the viewpoint of improving the optical characteristics and the weather resistance of the composite tungsten oxide particle as the infrared- And more preferably belong to Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Ti, Nb, V, Mo, Ta, Re, Hf and Os.

With respect to the composite tungsten oxide, by using the control of the oxygen amount described in the tungsten oxide and the addition of the element M for generating free electrons, a more excellent infrared absorbing material can be obtained. When the control of the amount of oxygen and the addition of the element M that generates the free electrons are used in combination, it is preferable that 0.001? X / _y? 0.8 and 2.2? Z / _y? 3.0 in the formula M _x W _y O _z representing the complex tungsten oxide It is preferable to satisfy the relationship.

Here, the value of x / y representing the addition amount of the element M in the formula of the above-described composite tungsten oxide will be described. When the value of x / y is 0.001 or more, a sufficient amount of free electrons is generated and the desired infrared absorption effect can be obtained. As the addition amount of the element M increases, the supply amount of the free electrons increases and the infrared absorption efficiency increases. When the value of x / y is about 0.8, the effect is also saturated. When the value of x / y is 0.8 or less, the formation of an impurity phase in the infrared absorbing material can be avoided.

Next, the value of z / y representing the control of the oxygen amount will be described. With regard to the value of z / y, in the infrared absorbing material represented by M _x W _y O _z , the same mechanism as that of the infrared absorbing material represented by W _y O _z described above works, and z / y = 3.0 There is a supply of free electrons by the addition amount of the element M described above. Therefore, 2.2? Z / y? 3.0 is preferable.

The crystal structure of the composite tungsten oxide contained in the composite tungsten oxide particles is not particularly limited and may contain a composite tungsten oxide having an arbitrary crystal structure. However, when the composite tungsten oxide contained in the composite tungsten oxide particle has a hexagonal crystal structure, the transmittance of light in the visible region of the particle and the absorption of light in the near-infrared region are particularly improved.

A schematic plan view of such a hexagonal crystal structure is shown in Fig. In Fig. 1, _six octahedral bodies formed by WO ₆ units denoted by reference numeral 11 are assembled to form hexagonal voids (tunnels). An element M represented by the symbol 12 is arranged in the pores to constitute one unit, and a plurality of such units are assembled to constitute a hexagonal crystal structure.

In this manner, when hexagonal voids are formed by assembling six octahedral bodies in which the composite tungsten oxide particles are formed in WO ₆ units and a composite tungsten oxide containing a unit structure in which the element M is disposed in the voids, And the absorption of light in the near-infrared region can be particularly improved. Further, the composite tungsten oxide particles do not need to be composed of the crystalline composite tungsten oxide particles having the structure shown in Fig. 1. For example, even when the composite tungsten oxide particles have such a structure locally, the transmittance of light in the visible region, It is possible to obtain an effect of improving absorption of light in the region. Therefore, the composite tungsten oxide particle as a whole may be crystalline or amorphous.

When the element M having a large ionic radius is added as the element M of the complex tungsten oxide, the hexagonal crystal described above tends to be formed. Concretely, hexagonal crystal is likely to be formed when at least one of Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe and Sn is added as the element M. Further, in order to form a hexagonal crystal, the element M must be present in hexagonal pores formed by WO ₆ units even if other elements are present, and the present invention is not limited to the case where the element M is added as the element M.

When the crystal structure of the composite tungsten oxide contained in the composite tungsten oxide particle is made uniform hexagonal crystal, the addition amount of the element M is preferably 0.20 or more and 0.50 or less and more preferably 0.25 or more and 0.40 or less in terms of x / y. z / y is preferably 2.2? z / y? 3.0 as described above. Further, when z / y = 3.0, it is considered that the value of x / y is 0.33, whereby the element M is disposed in all hexagonal voids.

The composite tungsten oxide contained in the composite tungsten oxide particles may have a structure of tetragonal or cubic tungsten bronze in addition to the hexagonal crystal described above, and the composite tungsten oxide having such a structure is also effective as an infrared absorbing material. The composite tungsten oxide tends to change its absorption position in the near infrared region depending on its crystal structure. For example, the absorption position of the near infrared region tends to move to the long wavelength side when it is tetragonal rather than cubic, and to the long wavelength side when it is hexagonal. In addition to the fluctuation of the absorption position, the absorption of light in the visible region is the least, and the cubic crystal is the most tetragonal, and the cubic crystal has the largest absorption of light in the visible region among these. Therefore, it is preferable to use hexagonal tungsten bronze for applications in which the transmittance of light in the visible region is high and the light absorption rate in the near infrared region is required to be high. However, the tendency of the optical characteristics described here is a rough tendency, and may vary depending on the kind of the added element M, the addition amount, and the oxygen amount. For this reason, the material of the infrared absorbing particle used in the photo-thermal conversion layer of the present embodiment is not limited thereto.

The crystal structure of the composite tungsten oxide contained in the composite tungsten oxide particle that can be used for the photo-thermal conversion layer of the present embodiment is not limited to the above-described crystal structure and may include, for example, a composite tungsten oxide having a different crystal structure .

However, as described above, the hexagonal-definite complex tungsten oxide particles can be particularly preferably used as the tungsten compound particles used in the photo-thermal conversion layer of the present embodiment, since the transmittance of visible light and the absorption of near-infrared light can be increased. When cesium is used as the element M, hexagonal cesium tungsten oxide particles can be more preferably used as the composite tungsten oxide particles since the crystal structure of the composite tungsten oxide tends to be hexagonal.

It is particularly preferable to use hexagonal cesium oxide tungsten particles as the tungsten compound particles because the composite tungsten oxide particles can more preferably be used as the tungsten compound particles as described above.

According to a study by the inventors of the present invention, hexacystic cesium oxide tungsten particles have a very high molar extinction coefficient with respect to light near a wavelength of 1000 nm. Further, since the transmittance of light in the visible region is high and the transmittance of light in the infrared region, particularly near infrared region, is low, the contrast of the light transmittance in the visible region and the light transmittance in the infrared region is large. Therefore, even when a sufficient amount of hexagonal cesium oxide-tungsten oxide particles for absorbing light in the near infrared region is added to the photo-thermal conversion layer, the transmittance of light in the visible region can be kept high, have.

Next, the binder component will be described.

The binder component is not particularly limited, and any binder component may be used. However, in the present embodiment, from the viewpoint of providing a photo-thermal conversion layer having visible light transmittance, it is preferable to use a binder component having excellent visible light transmittance when it becomes a solid phase. When laser light is irradiated to the photo-thermal conversion layer, the transmittance of light in the infrared region, particularly in the near infrared region, such that the laser light can be irradiated to the tungsten compound particles serving as the infrared absorbing particles contained in the photo- It is preferable to use an excellent binder component.

As the binder component, for example, a UV curable resin (ultraviolet curable resin), a thermosetting resin, an electron beam curing resin, a room temperature curing resin, a thermoplastic resin and the like can be selected depending on the purpose. Specific examples thereof include polyethylene resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyvinyl alcohol resins, polystyrene resins, polypropylene resins, ethylene vinyl acetate copolymers, polyester resins, polyethylene terephthalate resins, fluororesins, polycarbonate resins , Acrylic resin, polyvinyl butyral resin, and the like. These resins may be used alone or in combination. It is also possible to use a metal alkoxide as the binder component. Examples of the metal alkoxide include alkoxides such as Si, Ti, Al and Zr. The binder using these metal alkoxides can be hydrolyzed and condensed by heating to form an oxide film.

The ratio of the tungsten compound particles to the binder component contained in the photo-thermal conversion layer is not particularly limited and may be arbitrarily selected depending on the thickness of the photo-thermal conversion layer, the absorption characteristics of laser light required for the photo-thermal conversion layer, and the like, and is not particularly limited . However, for example, when using a photo-thermal conversion layer in various applications, it is preferable to select the ratio of the tungsten compound particles and the binder component so that the photo-thermal conversion layer can maintain the film shape.

In the photo-thermal conversion layer, in addition to the above-described tungsten compound particles and the binder component, an arbitrary component may be further added. For example, components other than the tungsten compound particles may be added as the infrared absorbing particles. However, it is preferable that the infrared absorbing particles contain only tungsten compound particles in order to enhance the transparency of visible light and sufficiently increase the absorption of light in the near infrared region.

Further, as described later, when forming the photo-thermal conversion layer, for example, a dispersant, a solvent and the like may be added to the ink serving as a raw material of the photo-thermal conversion layer, and these components may remain and be contained in the photo-thermal conversion layer .

The visible light transmittance of the photo-thermal conversion layer of the present embodiment calculated based on JIS R 3106 is preferably 50% or more, more preferably 60% or more, and still more preferably 63% or more.

When the visible light transmittance of the photo-thermal conversion layer is 50% or more, the transparency of the photo-thermal conversion layer can be sufficiently enhanced. Therefore, for example, when a photo-thermal conversion layer and an image receiving layer are formed on a film substrate of a donor sheet, the image receiving layer and the like can be visually recognized via the film base and the photo-thermal conversion layer.

In the photo-thermal conversion layer of the present embodiment, the transmittance of light having a wavelength of 1000 nm is preferably 10% or less, more preferably 9% or less.

This is because, for example, laser light having a wavelength in the near infrared region, especially near the wavelength 1000 nm, is used when transferring the transfer layer in the donor sheet. Therefore, it is preferable that the photo-thermal conversion layer has a high absorption rate of light in this region. That is, it is preferable that the transmittance of light in this region is low. When the transmittance of light having a wavelength of 1000 nm or less is 10% or less, the photo-thermal conversion layer is preferable because it can sufficiently absorb light near a wavelength of 1000 nm to generate heat.

The thickness of the photo-thermal conversion layer is not particularly limited, and the infrared absorption characteristics of the tungsten compound particles added to the photo-thermal conversion layer, the filling density of the tungsten compound particles in the photo-thermal conversion layer, the required visible light transmittance, And the like.

However, the thickness of the photo-thermal conversion layer is preferably 5 占 퐉 or less, for example, and more preferably 3 占 퐉 or less. This is because if the thickness of the photo-thermal conversion layer is increased, the heat generated when the laser light is irradiated to the photo-thermal conversion layer is likely to diffuse. For example, when used as a photo-thermal conversion layer of a donor sheet, if heat is diffused in the in-plane direction from the point of irradiation with laser light, the layer to be transferred may be peeled off and transferred to a portion not irradiated with laser light, It is not.

The lower limit of the thickness of the photo-thermal conversion layer is not particularly limited, and may be arbitrarily selected depending on the infrared absorption characteristics of the tungsten compound particles. For this reason, the thickness of the photo-thermal conversion layer may be larger than 0, but it is preferably 500 nm or more, more preferably 1 占 퐉 or more. If the thickness of the photo-thermal conversion layer is reduced, it is necessary to increase the filling density of the tungsten compound particles to be filled in the photo-thermal conversion layer to make the amount of heat generated when the laser light is irradiated to be not less than a predetermined value, This is because of concerns.

Next, a structural example of a method for manufacturing a photo-thermal conversion layer will be described.

The above-described photothermal conversion layer can be formed, for example, by applying an ink containing tungsten compound particles, a dispersant, a solvent and a binder component on a substrate, drying the applied ink, and then curing the dried ink have.

Further, as the substrate to which the ink containing the tungsten compound particles, the dispersant, the solvent, and the binder component is applied, it is preferable that the substrate is a substrate containing, for example, a film substrate. For this reason, the base material may be composed of only the film base material, but a base material on which an arbitrary layer is formed on the film base material, for example, a substrate having an intermediate layer formed on the side of the film base material side to which the ink is applied may also be used.

Therefore, the application of the ink containing the tungsten compound particles, the dispersant, the solvent, and the binder component onto the substrate is not limited to the case where the ink described above is directly applied onto the film substrate. For example, an intermediate layer or the like to be described later is formed on a film substrate, and the ink is applied on the intermediate layer formed on the film substrate. In the case where an arbitrary layer is disposed on the film substrate as described above, the photo-thermal conversion layer can be formed by applying ink and then drying and curing the ink.

The method of manufacturing the photo-thermal conversion layer may have the following steps, for example.

An ink containing a tungsten compound particle, a dispersant, a solvent, and a binder component is applied onto a substrate.

A drying process for drying ink applied on a substrate.

A curing process in which the ink dried in the drying process is cured.

First, the coating process will be described.

The ink used in the coating step may contain tungsten compound particles, a dispersant, a solvent, and a binder component as described above.

The tungsten compound particles, and the binder component have already been described, so the explanation is omitted.

The dispersing agent is an additive for stably dispersing the tungsten compound particles in a solvent when the ink is used, and various known dispersing agents can be used. For example, a polymer dispersant such as an acrylic polymer dispersant, a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent can be preferably used.

The solvent is a solvent for dispersing the tungsten compound particles when the ink is used, and it is possible to select a variety of solvents such as an alcohol type, a ketone type, a hydrocarbon type, a glycol type, and an aqueous type. Specific examples thereof include alcohol solvents such as methanol, ethanol, 1-propanol, isopropanol, butanol, pentanol, benzyl alcohol and diacetone alcohol; Ketone solvents such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, cyclohexanone and isophorone; Ester solvents such as 3-methyl-methoxy-propionate; Glycol derivatives such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol isopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol methyl ether acetate and propylene glycol ethyl ether acetate; Amides such as formamide, N-methylformamide, dimethylformamide, dimethylacetamide and N-methyl-2-pyrrolidone; Aromatic hydrocarbons such as toluene and xylene; And halogenated hydrocarbons such as ethylene chloride and chlorobenzene. Of these, organic solvents having a low polarity are preferable, and particularly preferred are organic solvents such as isopropyl alcohol, ethanol, 1-methoxy-2-propanol, dimethyl ketone, methyl ethyl ketone, methyl isobutyl ketone, toluene, propylene glycol monomethyl ether acetate, -Butyl and the like are more preferable. These solvents may be used alone or in combination of two or more.

The amount of the dispersing agent and the solvent to be added is not particularly limited, and the amount of the dispersing agent to be added may be arbitrarily selected depending on the addition amount of the tungsten compound particles and the dispersing ability of the dispersing agent. The amount of the solvent to be added can be arbitrarily selected in consideration of the workability at the time of applying the ink on the substrate and the time required for the drying step after coating.

In addition to the tungsten compound particles, the dispersant, the solvent, and the binder component described above, optional additives may be added to the ink, if necessary. For example, in order to enhance the dispersibility of the tungsten compound particles, a coating aid such as a surfactant may be added.

The method of preparing the ink is not particularly limited, and the ink can be prepared by weighing and mixing the materials to be the raw materials of the ink described above to a desired ratio.

For example, it is possible to prepare a dispersion by previously pulverizing and dispersing tungsten compound particles, a dispersant and a solvent, and then adding a binder component to the obtained dispersion to prepare an ink. The method of pulverizing and dispersing the tungsten compound particles, the dispersant, and the solvent is not particularly limited, and can be carried out using, for example, a paint shaker, ultrasonic irradiation, a bead mill, or a sand mill.

The volume average particle diameter of the tungsten compound particles in the dispersion is preferably 35 nm or more and 500 nm or less, more preferably 35 nm or more and 150 nm or less, still more preferably 35 nm or more and 90 nm or less.

When the dispersion liquid and the binder component are mixed to form an ink, they may be mixed sufficiently to each other. This is because it is preferable to set the volume average particle diameter of the tungsten compound particles to the volume average particle diameter desired in the photo-thermal conversion layer in the step of the dispersion.

The method of mixing the dispersion and the binder component is not particularly limited, and the dispersion and the binder component may be mixed by using the same means as the pulverizing and dispersing means used for preparing the dispersion, for example. However, when the ink is prepared as described above, the dispersion liquid and the binder component may be sufficiently mixed so that the mixing time can be shortened compared to when the dispersion liquid is prepared.

The method of applying the ink on the substrate is not particularly limited, and it can be applied by, for example, a bar coating method, a gravure coating method, a spray coating method, a dip coating method, or the like.

The substrate may include a film substrate as described above. The film substrate is not particularly limited, and any film substrate may be used depending on the application. For example, the same film substrate as the donor sheet described later may be used.

The method for drying the ink in the drying step is not particularly limited, and for example, the drying temperature can be selected according to the boiling point of the solvent used to dry the ink.

In the curing step, the method of curing the ink dried in the drying step is not particularly limited, and can be cured by a method such as the resin of the binder component. For example, when the binder component is an ultraviolet curing resin, it can be cured by irradiating ultraviolet rays. When the binder component is a thermosetting resin, it can be cured by raising the temperature to the curing temperature.

According to the light-heat conversion layer of the present embodiment described above, a light-heat conversion layer having excellent visible light transmittance can be obtained. Therefore, when the photo-thermal conversion layer of the present embodiment is applied to a donor sheet or the like, defects can be detected very easily by naked eyes or a visible light sensor.

The photo-thermal conversion layer of the present embodiment contains tungsten compound particles having a volume average particle diameter of 35 nm or more and 500 nm or less, particularly excellent in absorption characteristics of light in the near-infrared region. Therefore, even when an amount of tungsten compound particles exhibiting sufficient absorption in the near infrared region is added to the photo-thermal conversion layer, the thickness of the photo-thermal conversion layer can be reduced.

The photo-thermal conversion layer of the present embodiment can be used for various applications requiring a photo-thermal conversion layer that absorbs laser light to generate heat, and its application is not particularly limited. For example, a photo-thermal conversion layer of a donor sheet Can be preferably used.

(Donor sheet)

Next, a configuration example of the donor sheet of the present embodiment will be described.

The donor sheet of the present embodiment may have the photo-thermal conversion layer, the film base, and the transfer layer described so far.

Fig. 2 shows an example of the sectional configuration of the donor sheet. 2, the donor sheet 20 includes a photo-thermal conversion layer 22 containing tungsten compound particles 221 on the one surface 21A of the film base 21, 23) may be stacked.

Here, a configuration example of each layer of the donor sheet 20 shown in Fig. 2 will be described.

First, the film base 21 will be described.

The film substrate 21 is a layer for supporting the photo-thermal conversion layer 22 and the transfer source layer 23. When laser light is irradiated to the donor sheet 20, for example, laser light having a wavelength of about 1000 nm is irradiated from the other surface 21B side of the film base 21. For this reason, it is preferable that the film base material 21 has excellent transmittance of light in the infrared region, particularly in the near infrared region, so that the laser beam can be transmitted to the photo-thermal conversion layer 22. It is preferable that the film base material 21 is excellent also in the transparency of visible light so that defects such as foreign substances or coating unevenness in the donor sheet 20 can be detected with naked eyes or a visible light sensor.

For this reason, as the film base 21, a material having excellent transparency to visible light and infrared region, particularly near-infrared region, can be preferably used. Concretely, for example, at least one material selected from glass, polyethylene terephthalate (PET), acrylic, urethane, polycarbonate, polyethylene, ethylene vinyl acetate copolymer, vinyl chloride, Can be used.

The thickness of the film substrate 21 is not particularly limited and can be arbitrarily selected depending on the kind of the material used for the film substrate 21 and the transparency of visible light or infrared light required for the donor sheet.

The thickness of the film substrate 21 is preferably 1 m or more and 200 m or less, for example, and more preferably 2 m or more and 50 m or less. This is because the thickness of the film base 21 is preferably 200 占 퐉 or less because the transmittance of visible light or infrared light can be increased. It is also possible to prevent the donor sheet 20 from being damaged by supporting the photo-thermal conversion layer 22 or the like formed on the film base 21 by setting the thickness of the film base 21 to 1 m or more .

Since the light-to-heat conversion layer 22 has already been described, the description is omitted.

The transfer source layer 23 is a layer that is peeled and transferred from the donor sheet 20 by irradiating the donor sheet 20 with a laser beam. The structure is not particularly limited, and may be any layer. 2 shows an example in which the transfer source layer 23 is composed of one layer. However, the present invention is not limited to this. For example, the transfer source layer 23 composed of two or more layers may be formed.

As described above, the donor sheet 20 can be used, for example, in forming an organic electroluminescence element. For this reason, the transfer source layer 23 may include at least one layer selected from a hole injecting layer, a hole transporting layer, an organic light emitting layer, an electron transporting layer, a blocking layer, and an electron transporting layer constituting the organic electroluminescence element Can be configured.

The method of forming the transfer source layer 23 is not particularly limited and may be formed by any method depending on the kind of the material constituting the layer.

The donor sheet 20 can be used not only in the case of forming an organic electroluminescence device but also in various electronic devices such as electronic circuits, resistors, capacitors, diodes, rectifiers, memory devices and transistors, And the like. For this reason, the transfer source layer 23 can have any arbitrary configuration depending on the use.

Although a configuration example of the donor sheet has been described so far, the configuration of the donor sheet is not limited to this embodiment, and an arbitrary layer may be added. An intermediate layer may be formed between the film base material 21 and the photo-thermal conversion layer 22, for example, and / or between the photo-thermal conversion layer 22 and the transfer source layer 23. By forming the intermediate layer, for example, damage and contamination of the transferring portion of the transfer source layer 23 can be suppressed. Or the adhesion between the layer and the layer can be adjusted by the intermediate layer. Alternatively, the intermediate layer may be configured to adjust the wettability and the adhesion so that the transfer source layer 23 is well separated from the substrate and transferred to the substrate side when the transfer source layer is heated by the effect of the photo-thermal conversion layer by laser irradiation .

The constitution of the intermediate layer is not particularly limited and can be constituted by, for example, a polymer film, a metal layer, an inorganic layer (for example, an inorganic oxide layer such as silica, titania or zirconia), an organic /

The sequence of laminating each layer of the donor sheet is not limited to the embodiment shown in Fig. For example, the transfer layer 23 may be disposed on one surface 21A of the film base 21, and the photo-thermal conversion layer 22 may be disposed on the other surface 21B.

As described above, one example of the structure of the donor sheet of the present embodiment has been described. The donor sheet of this embodiment has the above-described photo-thermal conversion layer. Since such a photothermal conversion layer has high transmittance of visible light, defects in the donor sheet can be detected by the naked eye or a visible light sensor through the photothermal conversion layer, and the defective donor sheet can be removed by inspection. For this reason, it is possible to increase the yield when an electronic device such as an organic electroluminescence device or an optical device is manufactured using a donor sheet.

Example

Hereinafter, the present invention will be described by way of specific examples, but the present invention is not limited to these examples.

[Example 1]

(Fabrication of photo-thermal conversion layer)

The photo-thermal conversion layer was produced by the following procedure.

First, tungsten compound particles serving as infrared absorbing particles, a dispersant and a solvent were pulverized and dispersed to prepare a dispersion.

At this time, as the tungsten compound particles, Cs _0.33 WO ₃ (hexagonal cesium tungsten oxide), which is a composite tungsten oxide particle, was used and weighed so that the ratio in the dispersion was 20 wt%.

As the dispersing agent, an acrylic polymer dispersant having an amine group as a functional group (an acrylic polymer dispersant having an amine value of 48 mg KOH / g and a decomposition temperature of 250 캜) (hereinafter, abbreviated as dispersant a) %.

As the solvent, methyl isobutyl ketone was used and weighed so that the ratio in the dispersion was 70% by weight.

The composite tungsten oxide particles, the dispersant and the solvent were charged in a paint shaker with 0.3 mm? ZrO ₂ beads and pulverized and dispersed for 2.3 hours to obtain a composite tungsten oxide particle dispersion (hereinafter referred to as dispersion A).

Here, the volume average particle diameter of the composite tungsten oxide particles in the dispersion A was measured using a laser diffraction / scattering particle distribution measuring device (Nano Truck UPA-UT, manufactured by Nikkiso Co., Ltd.), and it was confirmed that the particle size was 52 nm.

Next, the obtained dispersion and the binder component were mixed to prepare an ink. In this embodiment, an ultraviolet curing resin for hard coating was used as a binder component.

50 parts by weight of Aronix UV-3701 (hereinafter abbreviated as UV-3701) manufactured by Toa Synthetic Manufacturing Co., Ltd., which is an ultraviolet ray hardening resin for hard coat, is mixed with 100 parts by weight of Dispersion Liquid A to obtain a composition containing composite tungsten oxide particles Ink.

The volume average particle diameter of the composite tungsten oxide particles was measured in the same manner as described above even after the ink was formed, and it was confirmed to be 52 nm. In the subsequent operation, it is considered that there is no change in the volume average particle diameter of the composite tungsten oxide particles. Therefore, it can be said that the volume average particle diameter of the composite tungsten oxide particles in the photo-thermal conversion layer described later is also the same.

Next, the obtained ink (coating liquid) was applied onto a PET film (HPE-50 manufactured by Teijin Co., Ltd., the same as in the other examples and comparative examples) having a thickness of 50 탆. Was applied by a bar coater to form a coating film (coating step).

The coating film formed in the coating step was dried at 80 DEG C for 60 seconds to evaporate the solvent (drying step).

After the drying step, a photo-thermal conversion layer containing the composite tungsten oxide particles was formed on the film substrate (curing step) by curing the binder component using a high-pressure mercury lamp.

As a result of TEM observation on the cross section of the film substrate, it was confirmed that the thickness of the photo-thermal conversion layer was about 2.0 탆.

The optical characteristics of the sheet on which the photo-thermal conversion layer was formed on the film substrate were measured using a spectrophotometer (model: U-4100, Hitachi, Ltd.).

Optical characteristics were measured in the same manner for the used film substrate, and the optical characteristics of the thermal conversion layer were calculated from the above-described measured values.

Based on the optical characteristics of the photo-thermal conversion layer thus calculated, the visible light transmittance was calculated based on JIS R 3106: 1998.

Based on the calculated optical characteristics of the photo-thermal conversion layer, the transmittance of light having a wavelength of 1000 nm was calculated.

The visible light transmittance of the photo-thermal conversion layer and the transmittance of light having a wavelength of 1000 nm were calculated in the above procedure, and as a result, it was confirmed that the visible light transmittance was 66%. It was also confirmed that the transmittance of light having a wavelength of 1000 nm was 8%. The results are shown in Table 1.

In Table 1, the volume average particle diameter of the tungsten compound particles in the photo-thermal conversion layer, that is, the composite tungsten oxide particles in this embodiment, is shown together with the column titled "volume average particle diameter of the tungsten compound particles". As described above, the volume average particle diameter of the composite tungsten oxide particles in the ink can be made the volume average particle diameter of the composite tungsten oxide particles (tungsten compound particles) in the photo-thermal conversion layer. The same can be said for the following examples and comparative examples.

The transmission curve of the photo-thermal conversion layer calculated from the measurement results is shown in Fig.

(Production of donor sheet)

Further, a transfer target layer was further formed on the produced photo-thermal conversion layer to form a donor sheet. The donor sheet was formed so as to have the structure shown in Fig.

More specifically, the transfer target layer 23 was formed on the upper surface of the photo-thermal conversion layer 22. As the transfer source layer 23, an electron transporting layer, an organic light emitting layer, a hole transporting layer, and a hole injecting layer were laminated in this order from the light-heat conversion layer 22 side.

Each layer included in the transfer source layer 23 was formed in the following manner.

As the electron transporting layer, Alq3 [tris (8-quinolinolato) aluminum (III)] was deposited by a vapor deposition method to have a thickness of 20 nm.

The organic luminescent layer is formed by mixing 4,4'-bis [2? {4? (N, N? Diphenylamino) phenyl} vinyl] Phenyl (DPAVBi) at 2.5 wt% was formed by a vapor deposition method, and the film thickness was set to about 25 nm.

As the hole transport layer, α-NPD [4,4-bis (N-1-naphthyl-N-phenylamino) biphenyl] was deposited by a vapor deposition method to have a film thickness of 30 nm.

As the hole injection layer, m-MTDATA [4,4,4-tris (3-methylphenylphenylamino) triphenylamine] was deposited by a vapor deposition method and the film thickness was set to 10 nm.

With respect to the obtained donor sheet, the transferred layer 23 was visually observed from the film substrate side, and the state thereof was confirmed.

[Example 2]

A composite tungsten oxide particle dispersion (hereinafter abbreviated as dispersion B) was obtained in the same manner as in Example 1, except that the time for pulverization and dispersion by the paint shaker was 3.4 hours in preparing the composite tungsten oxide particle dispersion.

Here, the volume average particle diameter of the composite tungsten oxide particles in the dispersion B was measured using a laser diffraction / scattering particle size distribution analyzer, and it was confirmed that it was 39 nm.

A photo-thermal conversion layer was formed on a film substrate in the same manner as in Example 1 except that the dispersion B was used as a substitute for the dispersion A, and the evaluation was carried out.

The volume average particle diameter of the composite tungsten oxide particles obtained by mixing the binder component with the dispersion B and preparing the ink was measured in the same manner as in Example 1, and it was confirmed to be 39 nm. In the subsequent operation, it is considered that the volume average particle diameter of the composite tungsten oxide particle is not changed, so that the volume average particle diameter of the composite tungsten oxide particle in the photo-thermal conversion layer can be said to be the same.

As a result of TEM observation on the cross section of the film substrate in the same manner as in Example 1, it was confirmed that the thickness of the photo-thermal conversion layer was about 2.0 탆.

The visible light transmittance of the photo-thermal conversion layer and the transmittance of light having a wavelength of 1000 nm were calculated in the same manner as in Example 1. As a result, it was confirmed that the visible light transmittance was 69%. It was also confirmed that the transmittance of light having a wavelength of 1000 nm was 9%. The results are shown in Table 1.

The transmission curve of the photo-thermal conversion layer calculated from the measurement results is shown in Fig.

Further, on the produced photo-thermal conversion layer, a transfer source layer was further formed in the same manner as in Example 1 to prepare a donor sheet.

[Example 3]

A composite tungsten oxide particle dispersion (hereinafter abbreviated as dispersion C) was obtained in the same manner as in Example 1, except that the time for pulverization and dispersion by the paint shaker was changed to 1.0 hour in preparing the composite tungsten oxide particle dispersion.

Here, the volume average particle diameter of the composite tungsten oxide particle in the dispersion C was measured using a laser diffraction / scattering particle size distribution measurement apparatus, and it was confirmed that it was 98 nm.

A photo-thermal conversion layer was formed on a film substrate in the same manner as in Example 1 except that the dispersion C was used as a substitute for the dispersion A, and the evaluation was carried out.

The volume average particle diameter of the composite tungsten oxide particle after mixing the dispersion component C with the binder component to prepare the ink was measured in the same manner as in Example 1, and it was confirmed to be 98 nm. The volume average particle diameter of the composite tungsten oxide particles in the photothermal conversion layer is considered to be the same as the volume average particle diameter of the composite tungsten oxide particles in the subsequent operation.

As a result of TEM observation on the cross section of the film substrate in the same manner as in Example 1, it was confirmed that the thickness of the photo-thermal conversion layer was about 2.0 탆.

The visible light transmittance of the photo-thermal conversion layer and the transmittance of light having a wavelength of 1000 nm were calculated in the same manner as in Example 1. As a result, it was confirmed that the visible light transmittance was 56%. It was also confirmed that the transmittance of light having a wavelength of 1000 nm was 10%. The results are shown in Table 1. The transmission curve of the photo-thermal conversion layer calculated from the measurement results is shown in Fig.

Further, on the produced photo-thermal conversion layer, a transfer source layer was further formed in the same manner as in Example 1 to prepare a donor sheet.

[Comparative Example 1]

A composite tungsten oxide particle dispersion (hereinafter abbreviated as dispersion?) Was obtained in the same manner as in Example 1, except that the time for pulverization and dispersion by the paint shaker was 10 hours in preparing the composite tungsten oxide particle dispersion.

Here, the volume average particle diameter of the composite tungsten oxide particle in the dispersion liquid? Was measured using a laser diffraction / scattering particle distribution measuring apparatus, and it was confirmed that it was 21 nm.

A photo-thermal conversion layer was formed on a film base material in the same manner as in Example 1 except that the dispersion solution? Was used as a substitute for the dispersion solution A, and the evaluation was carried out.

The volume average particle diameter of the composite tungsten oxide particles after mixing the binder component with the dispersion solution? To prepare an ink was measured in the same manner as in Example 1. As a result, it was confirmed that the composite tungsten oxide particles had a volume average particle diameter of 21 nm. In the subsequent operation, it is considered that the volume average particle diameter of the composite tungsten oxide particle is not changed, so that the volume average particle diameter of the composite tungsten oxide particle in the photo-thermal conversion layer can be said to be the same.

As a result of TEM observation on the cross section of the film substrate in the same manner as in Example 1, it was confirmed that the thickness of the photo-thermal conversion layer was about 2.0 탆.

The visible light transmittance of the photo-thermal conversion layer and the transmittance of light having a wavelength of 1000 nm were calculated in the same manner as in Example 1. As a result, it was confirmed that the visible light transmittance was 75%. It was also confirmed that the transmittance of light having a wavelength of 1000 nm was 15%. The results are shown in Table 1. The transmission curve of the photo-thermal conversion layer calculated from the measurement results is shown in Fig.

Further, on the produced photo-thermal conversion layer, a transfer source layer was further formed in the same manner as in Example 1 to prepare a donor sheet.

[Comparative Example 2]

A composite tungsten oxide particle dispersion (hereinafter abbreviated as dispersion?) Was obtained in the same manner as in Example 1, except that the time for pulverization and dispersion by a paint shaker was 0.2 hour in preparing the composite tungsten oxide particle dispersion.

Here, the volume average particle diameter of the composite tungsten oxide particles in the dispersion β was measured using a laser diffraction / scattering particle distribution measuring apparatus, and it was confirmed that the volume average particle diameter was 537 nm. A photo-thermal conversion layer was formed on a film base material in the same manner as in Example 1 except that the dispersion solution? Was used as a substitute for the dispersion solution A, and the evaluation was carried out.

Further, the volume average particle diameter of the composite tungsten oxide particle after mixing the binder component with the dispersion beta and preparing the ink was measured in the same manner as in Example 1. As a result, it was confirmed that the composite tungsten oxide particle was 537 nm. In the subsequent operation, it is considered that the volume average particle diameter of the composite tungsten oxide particle is not changed, so that the volume average particle diameter of the composite tungsten oxide particle in the photo-thermal conversion layer can be said to be the same.

As a result of TEM observation on the cross section of the film substrate in the same manner as in Example 1, it was confirmed that the thickness of the photo-thermal conversion layer was about 2.0 탆.

The visible light transmittance of the photo-thermal conversion layer and the transmittance of light having a wavelength of 1000 nm were calculated in the same manner as in Example 1, and as a result, it was confirmed that the visible light transmittance was 60%. It was also confirmed that the transmittance of light having a wavelength of 1000 nm was 35%. The results are shown in Table 1. The transmission curve of the photo-thermal conversion layer calculated from the measurement results is shown in Fig.

Further, on the produced photo-thermal conversion layer, a transfer source layer was further formed in the same manner as in Example 1 to prepare a donor sheet.

According to the above results, it was confirmed that the visible light transmittance of Examples 1 to 3 was 50% or more, and the visible light transmittance was sufficient. It was also confirmed that the transmittance of light having a wavelength of 1000 nm was lowered to 10% or less.

In Examples 1 to 3 and Comparative Examples 1 and 2, an ink in which a dispersion liquid in which the same composite tungsten oxide was dispersed at the same ratio was mixed with a binder in the same ratio at the time of forming the photo-thermal conversion layer was used have. In addition, And the film thickness of the obtained photo-thermal conversion layer was almost constant. That is, in all Examples and Comparative Examples, the weight of the composite tungsten oxide particles as the tungsten compound particles contained in the unit area of the photo-thermal conversion layer was the same.

However, in Comparative Example 1 in which the volume average particle diameter of the composite tungsten oxide particles was less than 35 nm, the transmittance of light having a wavelength of 1000 nm was 15%, and the transmittance of light with a wavelength of 1000 nm And it was confirmed that it is very high.

The outermost surface of the tungsten compound particle such as the composite tungsten oxide particle has an incomplete crystal structure different from that of the bulk tungsten compound particle due to the influence of the oxygen deficiency and the desorption of the doping element or the surface relaxation of the crystal structure, And is considered to be an incomplete area which hardly contributes to absorption of light.

When the particle diameter of the composite tungsten oxide particles is less than 35 nm as in Comparative Example 1, the ratio of the incomplete region is increased and the absorption rate of light in the near infrared region is considered to be lowered. Therefore, in Comparative Example 1, although the weight of the composite tungsten oxide particles per unit area was the same as in Examples 1 to 3, it was considered that the transmittance of light with a wavelength of 1000 nm was increased.

Also in Comparative Example 2, it was confirmed that the transmittance of light having a wavelength of 1000 nm was 35%, which was much higher than those of Examples 1 to 3. This is because in Comparative Example 2, since the volume average particle diameter of the tungsten compound particles was made larger than 500 nm at 537 nm, the local surface plasmon resonance, which is a phenomenon accompanied by particle atomization, was not sufficiently manifested, And the transmittance of light having a wavelength of 1000 nm is increased.

With respect to the donor sheet produced in each of the examples and the comparative examples, the state of the transferable layer can be visually confirmed from the film base side with respect to the examples 1 to 3 and the comparative example 1, The transparency of the photo-thermal conversion layer was not sufficient due to strong light scattering caused by the composite tungsten oxide, and the state of the transferred layer could not be visually confirmed.

20 donor sheet
21 film base
22 photo-thermal conversion layer
23 Transferred layer

Claims (6)

As a photo-thermal conversion layer containing tungsten compound particles and a binder component,
Wherein the tungsten compound particles are tungsten oxide particles and / or composite tungsten oxide particles,
Wherein the volume average particle diameter of the tungsten compound particles is 35 nm or more and 500 nm or less. The method according to claim 1,
Wherein the tungsten compound particles have a composition represented by W _y O _z (2.2? _Z / y &lt; 3.0) and a tungsten oxide particle represented by the formula M _x W _y O _z (wherein M is H, He, A rare earth element, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, , At least one element selected from among Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, x / y? 0.8, and 2.2? z / y? 3.0). 3. The method of claim 2,
Wherein the tungsten compound particles are hexagonal cesium tungsten oxide particles. 4. The method according to any one of claims 1 to 3,
And a thickness of 5 탆 or less. 5. The method according to any one of claims 1 to 4,
A photo-thermal conversion layer formed by applying the ink containing the tungsten compound particles, the dispersant, the solvent, and the binder component onto a substrate, drying the applied ink, and then curing the dried ink. A donor sheet comprising the photo-thermal conversion layer according to any one of claims 1 to 5, a film base and an image receiving layer.

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