JP6287627B2 - Photothermal conversion layer, donor sheet - Google Patents

Description

  The present invention relates to a photothermal conversion layer and a donor sheet.

  As a method for forming an organic electroluminescence element on a substrate, a metal mask method, a laser transfer method, an ink jet method and the like have been studied. The metal mask method is difficult to cope with the large area of next-generation large display devices, etc., and the inkjet method has many technical problems to be applied, so the laser transfer method is a process for large displays. Is expected to become mainstream.

  There are several laser transfer methods, but the main method is to form a film using a film called a donor sheet. As a donor sheet, for example, a layer that absorbs light called a light-to-heat conversion (LTHC) layer and a layer of an organic compound having, for example, electroluminescence characteristics as a transfer layer are formed on a film substrate. Is used. Various proposals have been made for a method of forming an organic electroluminescence element on a substrate by a laser transfer method, but the basic operating principle is common. That is, by irradiating a specific portion of the photothermal conversion layer with laser light, the photothermal conversion layer absorbs light and generates heat, and the organic electroluminescence element formed as the transferred layer is transferred by the action of the heat. Can do.

  Various materials have been proposed as light absorbing materials for the light-to-heat conversion layer of the donor sheet. 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 known pigments and absorbers. . Patent Document 2 discloses dyes, pigments, metals, metal compounds, metal films, and the like. Patent Document 3 discloses black aluminum. Patent Document 4 discloses carbon black, graphite, and infrared dyes.

Special Table 2000-515083 Special Table 2002-53482 Japanese Patent No. 3562830 JP 2004-200170 A

  As described above, for example, when forming an organic electroluminescence element by a laser transfer method, a desired portion of the photothermal conversion layer of the donor sheet is irradiated with laser light to transfer the organic electroluminescence element contained in the donor sheet. Can be done. However, if the donor sheet contains defects such as foreign matter or coating unevenness, the organic electroluminescence element at the laser irradiation site is not transferred normally, causing a dot that does not light up when it becomes a display device. . For this reason, in order to improve the yield, it is necessary to detect a donor sheet containing defects visually or with a visible light sensor before laser transfer.

  However, when the materials disclosed in Patent Documents 1 to 4 are used as the light-absorbing material applied to the light-to-heat conversion layer, the light-to-heat conversion layer has insufficient transparency to visible light. That is, when the light absorbing material disclosed in Patent Documents 1 to 4 is used, the photothermal conversion layer exhibits a very dark black color that does not substantially have light transmittance. For this reason, when such a photothermal conversion layer is applied to a donor sheet, it was impossible to detect defects by visual observation or a visible light sensor.

  Thus, conventionally, even a defective donor sheet could not be sufficiently detected by inspection, leading to a defect of the organic electroluminescence element, which was a major cause of a decrease in the yield of display devices.

  Therefore, in view of the problems of the above-described conventional technology, an object of one aspect of the present invention is to provide a photothermal conversion layer having visible light permeability.

In order to solve the above problems, according to one aspect of the present invention, a photothermal conversion layer containing tungsten compound particles and a binder component,
The tungsten compound particles are tungsten oxide particles and / or composite tungsten oxide particles,
Ri volume average particle diameter of Der than 500nm or less 35nm of the tungsten compound particles,
The transmittance of the light having the wavelength 1000nm is to provide a light-heat conversion layer Ru der 10% or less.

  According to one aspect of the photothermal conversion layer of the present invention, a photothermal conversion layer having visible light transparency can be provided.

The schematic diagram of the crystal structure of the composite tungsten oxide which has a hexagonal crystal. Explanatory drawing of the example of a cross-sectional structure of a donor sheet. The transmission curve of the donor sheet measured in Examples 1-3 and Comparative Examples 1 and 2. FIG.

DESCRIPTION OF EMBODIMENTS 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 the following embodiments are not departed from the scope of the present invention. Various modifications and substitutions can be made.
(Photothermal conversion layer)
In the present embodiment, first, a configuration example of the photothermal conversion layer will be described.

  The photothermal conversion layer of this embodiment can contain tungsten compound particles and a binder component. The tungsten compound particles are tungsten oxide particles and / or composite tungsten oxide particles, and the tungsten compound particles preferably have a volume average particle diameter of 35 nm to 500 nm.

  The components contained in the photothermal conversion layer of this embodiment will be described below.

  First, the tungsten compound particles will be described.

  When the photothermal conversion layer is irradiated with laser light, the tungsten compound particles can function as infrared absorbing particles that absorb the laser light and generate heat. Moreover, since it is preferable that the photothermal conversion layer of this embodiment is provided with visible-light transmittance, it is preferable that a tungsten compound particle is also a material with high transparency about the light of a visible region.

  Therefore, in the photothermal conversion layer of this embodiment, tungsten oxide particles and / or composite tungsten oxide particles can be used as the tungsten compound particles. According to the study of the inventors of the present invention, the tungsten oxide particles and / or the composite tungsten oxide particles exhibit transparency for light in the visible region and absorb laser light in the infrared region, particularly the near infrared region. Heat can be generated.

  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 35 nm or more. More preferably, it is 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 portions in this specification. doing.

  For tungsten compound particles, it is considered preferable to suppress the diffusion of light due to Rayleigh scattering and Mie scattering in order to increase the light transmittance in the visible region. For this purpose, the particle diameter should be sufficiently reduced. It was considered preferable. For this reason, for example, it was thought that the thing whose volume average particle diameter is less than 35 nm is preferable.

  However, as a result of investigations by the inventors of the present invention, it has been found that even when the volume average particle diameter of the tungsten compound particles is 35 nm or more and 500 nm or less, the photothermal conversion layer has sufficient visible light transmittance. Furthermore, the photothermal conversion layer containing tungsten compound particles having a volume average particle diameter of 35 nm or more absorbs light in the near-infrared region as compared with the photothermal conversion layer containing tungsten compound particles having a volume average particle diameter of less than 35 nm in the same weight. Has been found to be particularly strengthened, and the present invention has been completed.

  In addition, the absorption of infrared light is weakened by increasing the particle size of substances having absorption caused by localized surface plasmon resonance, such as tungsten oxide particles, which are conventional tungsten compound particles, and composite tungsten oxide particles. However, it was thought not to be strengthened. However, according to the study by the inventors of the present invention, the absorption of light in the near-infrared region is particularly enhanced in the photothermal conversion layer containing tungsten compound particles having a volume average particle diameter of 35 nm or more. Although the cause of the above phenomenon contrary to the conventional common sense is not clear, the present inventors believe that it is caused by deterioration near the surface of the tungsten compound particles. This will be described below.

  The outermost surface of the tungsten compound particles is affected by oxygen defects, desorption of doping elements, and surface relaxation of the crystal structure, resulting in an incomplete crystal structure different from the bulk tungsten compound particles from the top surface to several atoms inward. It is considered to have a region of more than a dozen atoms. And as the particle size of the tungsten compound particles increases, the proportion of the incomplete region on the outermost surface that hardly contributes to the absorption of light in the near infrared region in the tungsten compound particles decreases, and the absorption per unit weight increases. Conceivable. For this reason, when the volume average particle diameter of the tungsten compound particles is set to 35 nm or more, the proportion of the incomplete region on the outermost surface can be reduced, and the absorption of light in the near infrared region can be enhanced. Conceivable.

  On the other hand, when the volume average particle diameter is larger than 500 nm, the inventors of the present invention may weaken the localized surface plasmon resonance and may weaken the light absorption per unit weight. At the same time, it was found that there is a risk of impairing light transmission. For this reason, in the photothermal conversion layer of this embodiment, it is preferable that the volume average particle diameter of a tungsten compound particle is 500 nm or less as mentioned above.

  As described above, 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. For this reason, the thickness of the light-to-heat conversion layer can be reduced even when tungsten compound particles in an amount that exhibits sufficient absorption for light in the near-infrared region are added to the light-to-heat conversion layer.

  Moreover, the photothermal conversion layer containing such tungsten compound particles has a large transparency in the visible region. For this reason, for example, even when such a photothermal conversion layer is applied to a donor sheet or the like, it becomes very easy to detect defects by visual observation or a visible light sensor.

  As described above, tungsten oxide particles and / or composite tungsten oxide particles can be preferably used as the tungsten compound particles, and the tungsten compound particles are not limited to one kind of material, but are different from each other. Material can be included. Therefore, the tungsten compound particles may contain, for example, tungsten oxide particles and composite tungsten oxide particles at the same time. Further, the tungsten compound particles may contain only one of tungsten oxide particles and composite tungsten oxide particles. However, since the composite tungsten oxide particles are more excellent in visible light transmittance and near-infrared light absorption than tungsten oxide particles, the tungsten compound particles include composite tungsten oxide particles. It is preferable that

The specific composition of the tungsten compound particles is not limited. However, the tungsten compound particles are tungsten oxide particles having a chemical formula of W _y O _z (2.2 ≦ z / y <3.0) and a chemical formula of M _x W _y O _z (where M is H, He, alkali metal, alkaline earth metal, rare earth element, 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, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I One or more elements selected from the group consisting of composite tungsten oxide particles represented by 0.001 ≦ x / y ≦ 0.8 and 2.2 ≦ z / y ≦ 3.0) More preferably.

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

Generally, effective free electrons do not exist in tungsten trioxide (WO ₃ ), so there are few absorption and reflection characteristics in the near-infrared region, and the infrared absorbing particles may not function sufficiently. However, according to the study of the inventors of the present invention, by reducing the ratio of oxygen of tungsten trioxide to tungsten from 3, that is, by setting z / y <3.0 in the above formula, the tungsten Free electrons can be generated in the oxide. For this reason, it can be set as an efficient infrared absorptive particle.

Further, the crystal phase of WO ₂ may cause absorption and scattering of light in the visible region, and may reduce absorption of light in the near infrared region. Therefore, it is preferable to suppress the generation of the WO ₂ crystal phase by setting 2.2 ≦ z / y for the tungsten oxide particles as described above. Further, it is preferable to set z / y in the above range since chemical stability as a material can be obtained and it can be applied as effective infrared absorbing particles.

For this reason, the tungsten oxide particles W _y O _z preferably satisfy the relationship of 2.2 ≦ z / y <3.0.

Furthermore, a so-called “Magneli phase” having a composition ratio represented by 2.45 ≦ z / y <3.0 when represented by the general formula W _y O _z is chemically stable, and has a light in the near infrared region. Are also preferred as infrared absorbing particles. For this reason, it is more preferable that the tungsten oxide particles (W _y O _z ) satisfy the relationship of 2.45 ≦ z / y <3.0.

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

As the tungsten compound particles, composite tungsten oxide (M _x W _y O _z ) in which the element M is further added to the above-described tungsten oxide can also be used. When element M is added to tungsten oxide to form a 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. Therefore, it is particularly effective and preferable as an infrared absorbing material that absorbs near infrared rays having a wavelength of around 1000 nm.

In the chemical formula M _x W _y O _z representing the composite tungsten oxide particles, W represents tungsten and O represents oxygen. Examples of the element M in the above formula include H, He, alkali metal, alkaline earth metal, rare earth element, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, and Cu. , Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta , Re, Hf, Os, Bi, I are preferably one or more elements selected from the group consisting of

  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, Ir Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti Nb, V, Mo, Ta, Re, Hf, Os, Bi, and I are more preferably one or more elements selected from the group consisting of

  From the viewpoint of improving the optical properties and weather resistance of the composite tungsten oxide particles as infrared absorbing particles, among the elements more preferable as the element M described above, alkali metals, alkaline earth metal elements, transition metal elements (rare earth elements) , Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Ti, Nb, V, Mo, Ta, Re, Hf, Os) More preferably, it belongs.

As for the composite tungsten oxide, a more efficient infrared absorbing material can be obtained by combining the control of the oxygen amount described in the tungsten oxide and the addition of the element M that generates free electrons. When the control of the amount of oxygen and the addition of the element M that generates free electrons are used in combination, 0.001 ≦ x / y ≦ 0.8 in the chemical formula M _x W _y O _z indicating the composite tungsten oxide. It is preferable to satisfy the relationship of 2 ≦ z / y ≦ 3.0.

  Here, the value of x / y indicating the addition amount of the element M in the chemical formula of the composite tungsten oxide will be described. A value of x / y of 0.001 or more is preferable because a sufficient amount of free electrons is generated and the intended infrared absorption effect can be obtained. As the amount of element M added increases, the supply amount of free electrons increases and the infrared absorption efficiency also increases, but the effect is saturated when the value of x / y is about 0.8. Moreover, if the value of x / y is 0.8 or less, it is preferable because an impurity phase can be prevented from being generated in the infrared absorbing material.

Next, the value of z / y indicating the control of the oxygen amount will be described. Regarding 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 due to the amount of addition of the element M described above. For this reason, 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 can include a composite tungsten oxide having an arbitrary crystal structure. However, when the composite tungsten oxide contained in the composite tungsten oxide particles has a hexagonal crystal structure, the visible light transmittance of the particles and the absorption of light in the near infrared region are particularly improved, which is preferable. .

A schematic plan view of the hexagonal crystal structure is shown in FIG. In FIG. 1, six octahedrons formed by WO ₆ units indicated by reference numeral 11 are assembled to form a hexagonal void. An element M indicated by reference numeral 12 is arranged in the void to constitute one unit, and a large number of these one units are assembled to constitute a hexagonal crystal structure.

Thus, a composite tungsten oxide including a unit structure in which hexagonal voids are formed by assembling six octahedrons in which complex tungsten oxide particles are formed of WO ₆ units, and a hexagonal void is formed in the voids. In particular, the transmittance of light in the visible region and the absorption of light in the near infrared region can be improved. Note that it is not necessary that the entire composite tungsten oxide particles are 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, transmission of light in the visible region is possible. The effect of improving the absorption of light in the rate and near infrared region can be obtained. For this reason, the composite tungsten oxide particles 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 composite tungsten oxide, the above hexagonal crystal is easily formed. Specifically, for example, when one or more of Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn are added as the element M, hexagonal crystals are easily formed. In order to form a hexagonal crystal, elements other than these may be present in the hexagonal void formed by the WO ₆ unit, and are limited to the case where the element M is added as the element M. Not a translation.

  When the crystal structure of the composite tungsten oxide contained in the composite tungsten oxide particles is a uniform hexagonal crystal, the addition amount of the element M is preferably 0.20 or more and 0.50 or less in terms of x / y. More preferably, it is from 25 to 0.40. As described above, z / y is preferably 2.2 ≦ z / y ≦ 3.0. In addition, when z / y = 3.0, it is considered that the element M is arranged in all the hexagonal voids because the value of x / y becomes 0.33.

  Further, the composite tungsten oxide contained in the composite tungsten oxide particles can have a tetragonal or cubic tungsten bronze structure in addition to the above hexagonal crystal, and the composite tungsten oxide having such a structure is also an infrared absorbing material. It is effective as The composite tungsten oxide tends to change the absorption position in the near infrared region depending on its crystal structure. For example, the absorption position in the near-infrared region tends to move to the longer wavelength side when it is tetragonal than to the cubic crystal, and further to move to the longer wavelength side when it is hexagonal than when it is tetragonal. . Further, accompanying the change in the absorption position, the absorption of light in the visible region is the least in the hexagonal crystal, followed by the tetragonal crystal, and the cubic crystal has the largest absorption in the visible region. Therefore, hexagonal tungsten bronze is preferably used for applications that require high visible light transmittance and high near-infrared light absorption. However, the tendency of the optical characteristics described here is a rough tendency to the last, and changes depending on the kind of added element M, the added amount, and the oxygen amount. For this reason, the material of the infrared absorptive particle used for the photothermal conversion layer of this embodiment is not necessarily limited to this.

  The crystal structure of the composite tungsten oxide included in the composite tungsten oxide particles that can be used in the photothermal conversion layer of the present embodiment is not limited as described above. For example, the composite tungsten oxide includes different composite tungsten oxides at the same time. May be.

  However, as described above, since the hexagonal composite tungsten oxide particles can increase the transmittance of visible light and the absorption of near-infrared light, the tungsten compound particles used in the photothermal conversion layer of the present embodiment are particularly preferable. It can be preferably used. For example, when cesium is used as the element M, the crystal structure of the composite tungsten oxide is likely to be hexagonal, and therefore hexagonal cesium tungsten oxide particles can be more preferably used as the composite tungsten oxide particles.

  Moreover, since composite tungsten oxide particles can be more preferably used as tungsten compound particles as described above, it is particularly preferable to use hexagonal cesium tungsten oxide particles as tungsten compound particles.

  According to the study by the inventors of the present invention, hexagonal cesium tungsten oxide particles have a very high molar extinction coefficient for light in the vicinity of a wavelength of 1000 nm. Furthermore, since the light transmittance in the visible region is high and the light transmittance in the infrared region, particularly the near infrared region, is low, the contrast between the light transmittance in the visible region and the light transmittance in the infrared region. Is big. Therefore, even when a sufficient amount of hexagonal cesium tungsten oxide particles is added to the photothermal conversion layer to absorb light in the near-infrared region, the transmittance of light in the visible region can be maintained high. It can be particularly suitably used as compound particles.

  Next, the binder component will be described.

  The binder component is not particularly limited, and any binder component can be used. However, in this embodiment, since it aims at providing the photothermal conversion layer provided with visible-light transmittance, it is preferable to use the binder component excellent in visible-light transmittance when it becomes solid. . In addition, when the laser beam is irradiated to the photothermal conversion layer, the infrared region, particularly the near infrared region, can be irradiated so that the tungsten compound particles functioning as infrared absorbing particles contained in the photothermal conversion layer can be irradiated. It is preferable to use a binder component having excellent light transmittance.

  Specifically, for example, a UV curable resin (ultraviolet curable resin), a thermosetting resin, an electron beam curable resin, a room temperature curable resin, a thermoplastic resin, or the like can be selected as the binder component. Specifically, polyethylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, polystyrene resin, polypropylene resin, ethylene vinyl acetate copolymer, polyester resin, polyethylene terephthalate resin, fluorine resin, polycarbonate resin, acrylic resin And polyvinyl butyral resin. These resins may be used alone or in combination. Also, a metal alkoxide can be used as a binder component. Examples of the metal alkoxide include alkoxides such as Si, Ti, Al, and Zr. Binders using these metal alkoxides can form oxide films by hydrolysis and condensation polymerization by heating or the like.

  The ratio between the tungsten compound particles contained in the light-to-heat conversion layer and the binder component is not particularly limited, and can be arbitrarily determined according to the thickness of the light-to-heat conversion layer, the absorption characteristics of the laser light required for the light-to-heat conversion layer, and the like. It can be selected and is not particularly limited. However, for example, when the photothermal conversion layer is used in various applications, it is preferable to select the ratio between the tungsten compound particles and the binder component so that the photothermal conversion layer can maintain the film form.

  In addition to the above-described tungsten compound particles and the binder component, the light-to-heat conversion layer can further contain optional components. For example, components other than tungsten compound particles can be added as infrared absorbing particles. However, in order to enhance visible light transmittance and sufficiently enhance absorption of light in the near infrared region, it is preferable that the infrared absorbing particles include only tungsten compound particles.

  Further, as will be described later, when forming the light-to-heat conversion layer, for example, a dispersant, a solvent, or the like can be added to the ink that is the raw material of the light-to-heat conversion layer, and these components remain, and thus the light-to-heat conversion layer It may be included.

  The photothermal conversion layer of the present embodiment preferably has a visible light transmittance calculated based on JIS R 3106 of 50% or more, more preferably 60% or more, and 63% or more. Is more preferable.

  When the visible light transmittance of the photothermal conversion layer is 50% or more, the transparency of the photothermal conversion layer can be sufficiently enhanced. For this reason, when a photothermal conversion layer and a to-be-transferred layer are formed on the film base material of a donor sheet, for example, it becomes possible to visually recognize a to-be-transferred layer etc. via a film base material and a photothermal conversion layer.

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

  For example, laser light having a wavelength in the near-infrared region, particularly in the vicinity of a wavelength of 1000 nm is mainly used when transferring a transfer layer on a donor sheet. For this reason, it is preferable that the photothermal conversion layer has a high light absorptance in the region. That is, it is preferable that the light transmittance of the region is low. And when the transmittance | permeability of the light of wavelength 1000nm or less is 10% or less, since a photothermal conversion layer can fully absorb the light of wavelength 1000nm vicinity and can generate | occur | produce a heat | fever, it is preferable.

  The thickness of the photothermal conversion layer is not particularly limited, and the infrared absorption characteristics of the tungsten compound particles added to the photothermal conversion layer, the packing density of the tungsten compound particles in the photothermal conversion layer, the required visible light transmittance, It can be arbitrarily selected according to the degree of transmittance of light having a wavelength of 1000 nm or less.

  However, the thickness of the photothermal conversion layer is, for example, preferably 5 μm or less, and more preferably 3 μm or less. This is because when the thickness of the photothermal conversion layer is increased, the heat generated when the photothermal conversion layer is irradiated with laser light is likely to diffuse. For example, when used as a photothermal conversion layer of a donor sheet, if the heat diffuses in the in-plane direction from the point irradiated with the laser beam, the transferred layer may be peeled off and transferred even in the portion not irradiated with the laser beam. This is because it is not preferable.

  The lower limit of the thickness of the photothermal conversion layer is not particularly limited, and can be arbitrarily selected according to the infrared absorption characteristics of the tungsten compound particles. For this reason, the thickness of the photothermal conversion layer may be larger than 0, but is preferably 500 nm or more, and more preferably 1 μm or more. This is because when the thickness of the light-to-heat conversion layer is reduced, it is necessary to increase the packing density of the tungsten compound particles filled in the light-to-heat conversion layer in order to increase the amount of heat generated when the laser beam is irradiated to a predetermined value or more. This is because it may be difficult to maintain the shape of the film.

  Next, one structural example of the manufacturing method of a photothermal conversion layer is demonstrated.

  The above-described photothermal conversion layer is formed by, for example, 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. Can be formed.

  In addition, as a base material which apply | coats the ink containing a tungsten compound particle | grain, a dispersing agent, a solvent, and a binder component, it is preferable that it is a base material containing a film base material, for example. For this reason, the substrate can be composed only of the film substrate, but an intermediate layer is formed on the surface of the film substrate on which the ink is applied, for example, a substrate formed with an arbitrary layer on the film substrate. The base material made can also be used.

  Accordingly, the application of the ink containing the tungsten compound particles, the dispersant, the solvent, and the binder component on the substrate is not limited to the case where the above-described ink is directly applied on the film substrate. For example, the case where an intermediate layer or the like to be described later is formed on a film base material and the ink related to the intermediate layer formed on the film base material is applied is also included. Thus, also when arbitrary layers are arrange | positioned on a film base material, a photothermal conversion layer can be formed by drying and hardening an ink after apply | coating an ink.

  The manufacturing method of a photothermal conversion layer can have the following processes, for example.

  A coating process in which an ink containing tungsten compound particles, a dispersant, a solvent, and a binder component is coated on a substrate.

  A drying step of drying the ink applied on the substrate.

  A curing process for curing the ink dried in the drying process.

  First, the coating process will be described.

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

  Since the tungsten compound particles and the binder component have already been described, description thereof will be omitted.

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

  The solvent is a solvent for dispersing the tungsten compound particles in the case of ink, and various solvents such as alcohol, ketone, hydrocarbon, glycol, and water can be selected. Specifically, for example, alcohol solvents such as methanol, ethanol, 1-propanol, isopropanol, butanol, pentanol, benzyl alcohol, diacetone alcohol; acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone, etc. Ketone solvents; ester solvents such as 3-methyl-methoxy-propionate; 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, Glycol derivatives such as propylene glycol ethyl ether acetate; Amides such as amide, N-methylformamide, dimethylformamide, dimethylacetamide and N-methyl-2-pyrrolidone; Aromatic hydrocarbons such as toluene and xylene; Halogenated hydrocarbons such as ethylene chloride and chlorobenzene Can be mentioned. Among these, organic solvents having low polarity are preferable, and isopropyl alcohol, ethanol, 1-methoxy-2-propanol, dimethyl ketone, methyl ethyl ketone, methyl isobutyl ketone, toluene, propylene glycol monomethyl ether acetate, n-butyl acetate and the like are more preferable. preferable. These solvents can be used alone or in combination of two or more.

  The addition amount of the dispersant and the solvent is not particularly limited, and the addition amount of the dispersant can be arbitrarily selected according to the addition amount of the tungsten compound particles, the dispersion performance of the dispersant, and the like. Further, the addition amount of the solvent can be arbitrarily selected in consideration of the workability at the time of applying the ink on the substrate, the time required for the drying process after the application, and the like.

  In addition to the above-described tungsten compound particles, dispersant, solvent, and binder component, optional additive components can be added to the ink as 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 for preparing the ink is not particularly limited, and the ink can be prepared by weighing and mixing the materials used as the raw material of the ink so as to have a desired ratio.

  For example, after preparing a dispersion by previously pulverizing and dispersing tungsten compound particles, a dispersant, and a solvent, a binder component can be added to the obtained dispersion to obtain 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, bead mill, sand mill, or the like.

  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, and further 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 to such an extent that they are sufficiently mixed. For this reason, it is because it is preferable to make the volume average particle diameter of a tungsten compound particle into a suitable volume average particle diameter in a photothermal conversion layer in the stage of a dispersion liquid.

  The method for mixing the dispersion and the binder component is not particularly limited. For example, the dispersion and the binder component are mixed using the same means as the pulverizing / dispersing means used for preparing the dispersion. You can also However, when preparing the ink as described above, it is only necessary to mix the dispersion and the binder component so that they are sufficiently mixed, and the mixing time can be made shorter than when the dispersion is prepared.

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

  In addition, about a base material, a film base material can be included as stated above. It does not specifically limit as a film base material, According to a use, arbitrary film base materials can be used. For example, the same film substrate as that of a donor sheet described later can be used.

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

  In the curing step, the method for curing the ink dried in the drying step is not particularly limited, and the ink can be cured by a method according to the resin or the like of the binder component. For example, when the binder component is an ultraviolet curable resin, it can be cured by irradiating with 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 photothermal conversion layer of the present embodiment described above, a photothermal conversion layer excellent in visible light transmittance can be obtained. For this reason, when the photothermal conversion layer of this embodiment is applied to a donor sheet or the like, defects can be detected very easily by visual observation or a visible light sensor.

  In addition, the photothermal 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 light absorption characteristics in the near infrared region. For this reason, the thickness of the light-to-heat conversion layer can be reduced even when tungsten compound particles in an amount that exhibits sufficient absorption for light in the near-infrared region are added to the light-to-heat conversion layer.

The photothermal conversion layer of the present embodiment can be used in various applications where a photothermal conversion layer that absorbs laser light and generates heat is required, and the use is not particularly limited. It can be suitably used as a photothermal conversion layer.
(Donor sheet)
Next, a configuration example of the donor sheet of this embodiment will be described.

  The donor sheet of this embodiment can have the photothermal conversion layer, the film base material, and the layer to be transferred as described above.

  FIG. 2 shows a cross-sectional configuration example of the donor sheet. As shown in FIG. 2, the donor sheet 20 has a structure in which, for example, a photothermal conversion layer 22 including tungsten compound particles 221 and a transfer target layer 23 are laminated on one surface 21 </ b> A of a film substrate 21. Can do.

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

  First, the film substrate 21 will be described.

  The film substrate 21 is a layer that supports the photothermal conversion layer 22 and the transferred layer 23. And when irradiating a donor sheet 20 with a laser beam, for example, a laser beam having a wavelength of around 1000 nm is irradiated from the other surface 21B side of the film substrate 21. For this reason, it is preferable that the film base material 21 is excellent in the light transmittance of an infrared region, especially a near-infrared region, so that the laser beam concerned can permeate | transmit to the photothermal conversion layer 22. FIG. Moreover, it is preferable that the film base material 21 is excellent also in the transmittance | permeability of visible light so that defects, such as a foreign material and a coating nonuniformity in the donor sheet 20, can be detected with visual observation or a visible light sensor.

  For this reason, as the film base material 21, a material having excellent light transmittance in visible light and infrared region, particularly near infrared region can be preferably used. Specifically, for example, one or more materials selected from glass, polyethylene, terephthalate (PET), acrylic, urethane, polycarbonate, polyethylene, ethylene vinyl acetate copolymer, vinyl chloride, fluorine resin, and the like are used as the film base 21. Can be used as

  The thickness of the film substrate 21 is not particularly limited, and is arbitrarily selected according to the type of material used for the film substrate 21 and the visible light and infrared light transmittance required for the donor sheet. be able to.

  For example, the thickness of the film substrate 21 is preferably 1 μm to 200 μm, and more preferably 2 μm to 50 μm. This is because it is preferable that the thickness of the film substrate 21 be 200 μm or less, whereby the transmittance of visible light and infrared light can be improved. Moreover, it is because the photothermal conversion layer 22 etc. which were formed on the film base material 21 are supported by making the thickness of the film base material 21 1 micrometer or more, and it can prevent especially that the donor sheet 20 is damaged.

  Description of the photothermal conversion layer 22 is omitted because it is already described.

  The transferred layer 23 is a layer that is peeled off and transferred from the donor sheet 20 by irradiating the donor sheet 20 with laser light, and the configuration thereof is not particularly limited, and can be an arbitrary layer. Further, FIG. 2 shows an example in which the transfer layer 23 is composed of a single layer. However, the present invention is not limited to such an embodiment, and for example, the transfer layer 23 composed of two or more layers can be configured.

  As described above, the donor sheet 20 can be used, for example, when forming an organic electroluminescence element. Therefore, the transferred layer 23 includes, for example, one or more layers selected from a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, a blocking layer, an electron transport layer, and the like constituting the organic electroluminescence element. It can be constituted as follows.

  In addition, the formation method of the to-be-transferred layer 23 is not specifically limited, It can form with arbitrary methods according to the kind of material which comprises a layer.

  The donor sheet 20 is not only used for forming organic electroluminescence elements, but also for various electronic devices such as electronic circuits, resistors, capacitors, diodes, rectifiers, memory elements, transistors, and various optical devices such as optical waveguides. It can also be used when forming. For this reason, the transferred layer 23 can have an arbitrary configuration depending on the application.

  Although the example of 1 structure of the donor sheet was demonstrated so far, the structure of a donor sheet is not limited to the form which concerns, Furthermore, arbitrary layers can also be added. For example, an intermediate layer can be provided between the film substrate 21 and the photothermal conversion layer 22 and / or between the photothermal conversion layer 22 and the transferred layer 23. By providing the intermediate layer, for example, damage and contamination of the transfer portion of the transferred layer 23 can be suppressed. Alternatively, the adhesion between the layers can be adjusted by the intermediate layer. Alternatively, when the layer to be transferred is heated by the effect of the light-to-heat conversion layer by laser irradiation, the wettability and the adhesion force are adjusted so that the layer to be transferred 23 is well peeled off from the base material and transferred to the substrate side. An intermediate layer can also be configured.

  The configuration of the intermediate layer is not particularly limited, and may be composed of, for example, a polymer film, a metal layer, an inorganic layer (for example, an inorganic oxide layer such as silica, titania, zirconia), an organic / inorganic composite layer, or the like. .

  The order of laminating each layer of the donor sheet is not limited to the form shown in FIG. For example, the transfer layer 23 can be disposed on one surface 21A of the film base 21, and the photothermal conversion layer 22 can be disposed on the other surface 21B.

  Although the example of 1 structure of the donor sheet of this embodiment was demonstrated above, the donor sheet of this embodiment has the photothermal conversion layer mentioned above. And since the photothermal conversion layer has a high visible light transmittance, defects in the donor sheet can be detected visually or with a visible light sensor even through the photothermal conversion layer, and defective donor sheets can be removed by inspection. it can. For this reason, it becomes possible to increase the yield when an electronic device such as an organic electroluminescence element, an optical device, or the like is manufactured using the donor sheet.

Specific examples will be described below, but the present invention is not limited to these examples.
[Example 1]
(Production of photothermal conversion layer)
A photothermal conversion layer was prepared by the following procedure.

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

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

  As the dispersant, an acrylic polymer dispersant having an amine-containing group as a functional group (an acrylic polymer dispersant having an amine value of 48 mg KOH / g and a decomposition temperature of 250 ° C.) (hereinafter abbreviated as “dispersant a”). ) Was used so that the ratio in the dispersion was 10% by weight.

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

A composite tungsten oxide particle, a dispersant, and a solvent are loaded into a paint shaker containing 0.3 mmφZrO ₂ beads, and pulverized and dispersed for 2.3 hours to obtain a composite tungsten oxide particle dispersion (hereinafter, dispersion liquid). Abbreviated as A).

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

  Next, an ink was prepared by mixing the obtained dispersion and a binder component. In this example, an ultraviolet curable resin for hard coat was used as a binder component.

  50 parts by weight of Aronix UV-3701 manufactured by Toa Gosei Co., Ltd., which is an acrylic resin, is mixed with 100 parts by weight of dispersion A and mixed tungsten oxide particles. An ink containing was used.

  Even after the ink was made, the volume average particle diameter of the composite tungsten oxide particles was measured in the same manner as described above, and it was confirmed that it was 52 nm. Since it is considered that the volume average particle diameter of the composite tungsten oxide particles does not change in the subsequent operation, the volume average particle diameter of the composite tungsten oxide particles in the photothermal conversion layer described later is also the same. It can be said that.

  Next, the obtained ink (coating solution) was placed on a PET film (Teijin HPE-50, which is the same in other examples and comparative examples) as a film substrate with a thickness of 50 μm. Was applied using a bar coater of No. 3 to form a coating film (coating step).

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

  After the drying step, the binder component was cured using a high-pressure mercury lamp to produce a photothermal conversion layer containing composite tungsten oxide particles on the film substrate (curing step).

  When TEM observation was performed on the cross section of the film substrate, it was confirmed that the thickness of the photothermal conversion layer was about 2.0 μm.

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

  The optical properties of only the film substrate used were measured in the same manner, and the optical properties of the photothermal conversion layer were calculated by subtracting from the above measured values.

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

  Moreover, based on the calculated optical characteristics of the photothermal conversion layer, the transmittance of light having a wavelength of 1000 nm was calculated.

  When the visible light transmittance of the light-to-heat conversion layer and the transmittance of light having a wavelength of 1000 nm were calculated by the above procedure, it was confirmed that the visible light transmittance was 66%. Moreover, it has confirmed that the transmittance | permeability of light with a wavelength of 1000 nm was 8%. The results are shown in Table 1.

  In Table 1, the column of “volume average particle diameter of tungsten compound particles” also shows the volume average particle diameter of tungsten compound particles in the photothermal conversion layer, that is, composite tungsten oxide particles in this embodiment. As described above, the volume average particle diameter of the composite tungsten oxide particles in the ink can be set to the volume average particle diameter of the composite tungsten oxide particles (tungsten compound particles) in the photothermal conversion layer. The same can be said for the following examples and comparative examples.

Moreover, the permeation | transmission curve of the photothermal conversion layer computed from the measurement result is shown in FIG.
(Preparation of donor sheet)
Further, a transferred layer was further formed on the produced photothermal conversion layer to form a donor sheet. The donor sheet was formed to have the structure shown in FIG.

  Specifically, the transferred layer 23 was formed on the upper surface of the photothermal conversion layer 22. As the transfer layer 23, an electron transport layer, an organic light emitting layer, a hole transport layer, and a hole injection layer were laminated in this order from the photothermal conversion layer 22 side.

  Each layer included in the transferred layer 23 was formed as follows.

  The electron transport layer was formed by depositing Alq3 [tris (8-quinolinolato) aluminum (III)] by a vapor deposition method, and the film thickness was 20 nm.

  In addition, the organic light emitting layer is composed of an electron transporting host material, ADN (anthracene dinaphthyl), and a blue light emitting guest material, 4,4′≡bis [2≡ {4≡ (N, N≡diphenylamino). [Phenyl} vinyl] biphenyl (DPAVBi) mixed at 2.5% by weight was formed into a film by an evaporation method, and the film thickness was about 25 nm.

  As the hole transport layer, α-NPD [4,4-bis (N-1-naphthyl-N-phenylamino) biphenyl] was formed by an evaporation method, and the film thickness was set to 30 nm.

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

About the obtained donor sheet, the to-be-transferred layer 23 was visually observed from the film base material side, and the state was confirmed.
[Example 2]
A composite tungsten oxide particle dispersion (hereinafter referred to as dispersion B) was prepared in the same manner as in Example 1 except that the pulverization / dispersion time was 3.4 hours using a paint shaker when preparing the composite tungsten oxide particle dispersion. Abbreviated).

Here, when the volume average particle diameter of the composite tungsten oxide particles in the dispersion B was measured using a laser diffraction / scattering particle distribution measuring device, it was confirmed to be 39 nm.
A photothermal conversion layer was produced on a film substrate and evaluated in the same manner as in Example 1 except that the dispersion B was used as an alternative to the dispersion A.

  In addition, when the volume average particle diameter of the composite tungsten oxide particles after preparing the ink by mixing the binder component with the dispersion B was measured in the same manner as in Example 1, it was confirmed to be 39 nm. Since it is considered that the volume average particle diameter of the composite tungsten oxide particles does not change in the subsequent operation, the volume average particle diameter of the composite tungsten oxide particles in the photothermal conversion layer is the same. It can be said.

  When TEM observation was performed on the cross section of the film substrate in the same manner as in Example 1, it was confirmed that the thickness of the photothermal conversion layer was about 2.0 μm.

  When the visible light transmittance of the photothermal conversion layer and the transmittance of light having a wavelength of 1000 nm were calculated in the same manner as in Example 1, it was confirmed that the visible light transmittance was 69%. Moreover, it has confirmed that the transmittance | permeability of light with a wavelength of 1000 nm is 9%. The results are shown in Table 1.

  Moreover, the permeation | transmission curve of the photothermal conversion layer computed from the measurement result is shown in FIG.

Further, a transferred layer was further formed on the produced photothermal conversion layer in the same manner as in Example 1 to produce a donor sheet.
[Example 3]
A composite tungsten oxide particle dispersion (hereinafter referred to as dispersion C) was prepared in the same manner as in Example 1 except that the pulverization / dispersion time was 1.0 hour from the paint shaker when preparing the composite tungsten oxide particle dispersion. Abbreviated).

Here, when the volume average particle diameter of the composite tungsten oxide particles in the dispersion C was measured using a laser diffraction / scattering particle distribution measuring device, it was confirmed to be 98 nm.
A photothermal conversion layer was produced on a film substrate and evaluated in the same manner as in Example 1 except that the dispersion C was used as an alternative to the dispersion A.

  In addition, when the volume average particle diameter of the composite tungsten oxide particles after preparing the ink by mixing the binder component with the dispersion C was measured in the same manner as in Example 1, it was confirmed that it was 98 nm. Since it is considered that the volume average particle diameter of the composite tungsten oxide particles does not change in the subsequent operation, the volume average particle diameter of the composite tungsten oxide particles in the photothermal conversion layer is the same. It can be said.

  When TEM observation was performed on the cross section of the film substrate in the same manner as in Example 1, it was confirmed that the thickness of the photothermal conversion layer was about 2.0 μm.

  When the visible light transmittance of the photothermal conversion layer and the transmittance of light having a wavelength of 1000 nm were calculated in the same manner as in Example 1, it was confirmed that the visible light transmittance was 56%. Moreover, it has confirmed that the transmittance | permeability of the light of wavelength 1000nm was 10%. The results are shown in Table 1. Moreover, the permeation | transmission curve of the photothermal conversion layer computed from the measurement result is shown in FIG.

Further, a transferred layer was further formed on the produced photothermal conversion layer in the same manner as in Example 1 to produce a donor sheet.
[Comparative Example 1]
A composite tungsten oxide particle dispersion (hereinafter abbreviated as dispersion α) was prepared in the same manner as in Example 1 except that the pulverization / dispersion time was 10 hours from the paint shaker when preparing the composite tungsten oxide particle dispersion. Obtained).

Here, when the volume average particle diameter of the composite tungsten oxide particles in the dispersion α was measured using a laser diffraction / scattering particle distribution measuring apparatus, it was confirmed to be 21 nm.
A photothermal conversion layer was produced on a film substrate and evaluated in the same manner as in Example 1 except that the dispersion α was used as an alternative to the dispersion A.

  When the volume average particle diameter of the composite tungsten oxide particles after preparing the ink by mixing the binder component with the dispersion α was measured in the same manner as in Example 1, it was confirmed to be 21 nm. Since it is considered that the volume average particle diameter of the composite tungsten oxide particles does not change in the subsequent operation, the volume average particle diameter of the composite tungsten oxide particles in the photothermal conversion layer is the same. It can be said.

  When TEM observation was performed on the cross section of the film substrate in the same manner as in Example 1, it was confirmed that the thickness of the photothermal conversion layer was about 2.0 μm.

  When the visible light transmittance of the photothermal conversion layer and the transmittance of light having a wavelength of 1000 nm were calculated in the same manner as in Example 1, it was confirmed that the visible light transmittance was 75%. Moreover, it has confirmed that the transmittance | permeability of the light of wavelength 1000nm was 15%. The results are shown in Table 1. Moreover, the permeation | transmission curve of the photothermal conversion layer computed from the measurement result is shown in FIG.

Further, a transferred layer was further formed on the produced photothermal conversion layer in the same manner as in Example 1 to produce a donor sheet.
[Comparative Example 2]
A composite tungsten oxide particle dispersion (hereinafter referred to as dispersion β) was prepared in the same manner as in Example 1 except that the pulverization / dispersion time was 0.2 hours from the paint shaker when preparing the composite tungsten oxide particle dispersion. Abbreviated).

Here, when 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 device, it was confirmed to be 537 nm.
A photothermal conversion layer was produced on a film substrate and evaluated in the same manner as in Example 1 except that the dispersion β was used as an alternative to the dispersion A.

  When the volume average particle diameter of the composite tungsten oxide particles after preparing the ink by mixing the binder component with the dispersion β was measured in the same manner as in Example 1, it was confirmed that it was 537 nm. Since it is considered that the volume average particle diameter of the composite tungsten oxide particles does not change in the subsequent operation, the volume average particle diameter of the composite tungsten oxide particles in the photothermal conversion layer is the same. It can be said.

  When TEM observation was performed on the cross section of the film substrate in the same manner as in Example 1, it was confirmed that the thickness of the photothermal conversion layer was about 2.0 μm.

  When the visible light transmittance of the photothermal conversion layer and the transmittance of light having a wavelength of 1000 nm were calculated in the same manner as in Example 1, it was confirmed that the visible light transmittance was 60%. Moreover, it has confirmed that the transmittance | permeability of light with a wavelength of 1000 nm was 35%. The results are shown in Table 1. Moreover, the permeation | transmission curve of the photothermal conversion layer computed from the measurement result is shown in FIG.

  Further, a transferred layer was further formed on the produced photothermal conversion layer in the same manner as in Example 1 to produce a donor sheet.

以上の結果によると、実施例１〜実施例３については、可視光透過率は５０％以上であり、十分な可視光透過率を有していることも確認できた。また、波長１０００ｎｍの光の透過率が１０％以下と低くなっていることが確認できた。

According to the above result, about Example 1-Example 3, the visible light transmittance | permeability is 50% or more, It has also confirmed that it had sufficient visible light transmittance | permeability. Moreover, it has confirmed that the transmittance | permeability of the light of wavelength 1000nm was as low as 10% or less.

  Here, in Examples 1 to 3 and Comparative Examples 1 and 2, when forming the photothermal conversion layer, a dispersion in which the same composite tungsten oxide was dispersed at the same concentration was mixed with a binder at the same ratio. Used ink. And the same bar No. Ink was applied using a bar coater, and the film thickness of the obtained photothermal conversion layer was almost constant. That is, in all Examples and Comparative Examples, the weight of the composite tungsten oxide particles, which are tungsten compound particles included per unit area of the photothermal conversion layer, was the same.

  However, in Comparative Example 1 in which the volume average particle diameter of the composite tungsten oxide particles is less than 35 nm, the transmittance of light having a wavelength of 1000 nm is 15%, compared with the case of Example 1 to Example 3. It was confirmed that the transmittance of light having a wavelength of 1000 nm was very high.

  The outermost surface of tungsten compound particles such as composite tungsten oxide particles has an incomplete crystal structure that is different from bulk tungsten compound particles due to the influence of oxygen defects, desorption of doping elements, and surface relaxation of the crystal structure. However, it is considered to be an incomplete region that hardly contributes to light absorption in the near infrared region.

  And when the particle diameter of composite tungsten oxide particle is less than 35 nm like the comparative example 1, the ratio which the incomplete area | region occupies becomes high, and it is thought that the light absorption rate of a near-infrared area | region falls. For this reason, in Comparative Example 1, although the weight of the composite tungsten oxide particles per unit area is the same as in Examples 1 to 3, the light transmittance at a wavelength of 1000 nm is considered to be high. .

  Moreover, also in Comparative Example 2, it was confirmed that the transmittance of light having a wavelength of 1000 nm was 35%, which was very high as compared with Examples 1 to 3. In Comparative Example 2, since the volume average particle diameter of the tungsten compound particles was increased to 537 nm, exceeding 500 nm, the localized surface plasmon resonance, which is a phenomenon associated with the atomization of the particles, was not sufficiently exhibited. It is considered that the light absorptance in the infrared region was lowered and the light transmittance at a wavelength of 1000 nm was increased.

  Moreover, although the donor sheet produced by each Example and the comparative example was able to confirm the state of the to-be-transferred layer visually from the film base material side about Examples 1-3 and the comparative example 1, it is coarse about the comparative example 2 Due to strong light scattering caused by complex tungsten oxide, the transparency of the photothermal conversion layer was not sufficient, and the state of the transferred layer could not be confirmed visually.

20 Donor sheet 21 Film substrate 22 Photothermal conversion layer 23 Transfer target layer

Claims (6)

A photothermal conversion layer containing tungsten compound particles and a binder component,
The tungsten compound particles are tungsten oxide particles and / or composite tungsten oxide particles,
Ri volume average particle diameter of Der than 500nm or less 35nm of the tungsten compound particles,
Light-to-heat conversion layer light transmittance Ru der 10% or less of the wavelength of 1000 nm. The tungsten compound particles include tungsten oxide particles having a chemical formula of W _y O _z (2.2 ≦ z / y <3.0), and a chemical formula of M _x W _y O _z (where M is H, He, alkali metal, alkaline earth metal, rare earth element, 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, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I One or more elements selected from the group consisting of composite tungsten oxide particles represented by 0.001 ≦ x / y ≦ 0.8 and 2.2 ≦ z / y ≦ 3.0) The photothermal conversion layer according to claim 1.   The photothermal conversion layer according to claim 2, wherein the tungsten compound particles are hexagonal cesium tungsten oxide particles.   The photothermal conversion layer according to any one of claims 1 to 3, wherein the thickness is 5 µm or less. Heat conversion layer according to any one of claims 1 to 4 further comprising a distributed agent.   The donor sheet which has the photothermal conversion layer as described in any one of Claims 1 thru | or 5, a film base material, and a to-be-transferred layer.

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