JP7549822B2 - Projectile transfer method, image forming method, and method for manufacturing three-dimensional object - Google Patents

Description

The present invention relates to a flying object transfer method , an image forming method, and a method for manufacturing a three-dimensional object.

The Laser-Induced Forward Transfer (LIFT) method is a method in which a donor substrate on which a material to be transferred containing a light absorbing material is placed is irradiated with a laser beam from the substrate side of the donor substrate, causing the material to fly and transfer the material to the desired position on a recipient (acceptor substrate) placed opposite the material to be transferred.

As an example of such a LIFT method, an image formation method has been proposed that uses an optical vortex laser beam as the laser beam, enabling precise transfer without scattering a highly viscous liquid containing a light absorbing material (see, for example, Patent Document 1).

The present invention aims to provide a projectile transfer method that can transfer a material to be transferred, including a light absorbing material, without scattering it, while suppressing the aggregation of the light absorbing material.

The flying object transfer method of the present invention as a means for solving the above problem includes a flying step in which a donor substrate having a substrate and a transfer target material containing a light absorbing material and a dispersion medium arranged on the substrate is irradiated with an optical vortex laser beam from the substrate side of the donor substrate to cause the transfer target material to fly, and an application step in which the flown transfer target material is applied to an object to be applied, and the complex viscosity of the transfer target material at a shear stress of 200 Pa at 25°C is 88 mPa·s or more and 4,300 mPa·s or less.

The present invention provides a projectile transfer method that can transfer a material to be transferred, including a light absorbing material, without scattering it, while suppressing the aggregation of the light absorbing material.

FIG. 1A is a schematic diagram showing an example of a wavefront (equal phase surface) in a typical laser beam. FIG. 1B is a diagram showing an example of a light intensity distribution in a typical laser beam. FIG. 1C is a diagram showing an example of a phase distribution in a typical laser beam. FIG. 2A is a schematic diagram showing an example of a wavefront (equal phase surface) in an optical vortex laser beam. FIG. 2B is a diagram showing an example of the light intensity distribution of an optical vortex laser beam. FIG. 2C is a diagram showing an example of a phase distribution in an optical vortex laser beam. FIG. 3A is a photograph showing an example of a light absorbing material being irradiated with a general laser beam. FIG. 3B is a photograph showing an example of an optical vortex laser beam being irradiated onto a light absorbing material. FIG. 4A is an explanatory diagram showing an example of the results of interference measurement of an optical vortex laser beam. FIG. 4B is an explanatory diagram showing an example of the result of interference measurement of a laser beam having a point of zero light intensity at its center. FIG. 5A is an explanatory diagram showing an example of the projectile transfer device of the present invention. FIG. 5B is an explanatory diagram showing another example of the projectile transfer device of the present invention. FIG. 5C is an explanatory diagram showing another example of the projectile transfer device of the present invention. FIG. 6A is a schematic cross-sectional view showing an example of the image forming apparatus of the present invention. FIG. 6B is a schematic cross-sectional view showing another example of the image forming apparatus of the present invention. FIG. 7A is a schematic cross-sectional view showing another example of the image forming apparatus of the present invention. FIG. 7B is a schematic cross-sectional view showing another example of the image forming apparatus of the present invention. FIG. 7C is a schematic cross-sectional view showing another example of the image forming apparatus of the present invention. FIG. 8A is a schematic cross-sectional view showing another example of the image forming apparatus of the present invention. FIG. 8B is a schematic cross-sectional view showing another example of the image forming apparatus of the present invention. FIG. 9 is a schematic cross-sectional view showing an example of a manufacturing apparatus for a three-dimensional object. FIG. 10 is a graph showing the relationship between the glycerol concentration and the complex viscosity in the transfer target material used in the examples. FIG. 11 is a schematic diagram showing an example of a projectile transfer device used in the examples. FIG. 12 is a diagram showing the behavior of a material to be transferred when irradiated with an optical vortex laser beam. 13A is an image of a droplet of the transfer target material No. 9 (glycerol concentration: 44% by mass) transferred to a recipient. 13B is a histogram showing the distribution of inorganic particles in the droplets of the transfer target material No. 9 (glycerol concentration: 44% by mass) transferred to the application target object. 14A is an image of a droplet of the transfer target material No. 3 (glycerol concentration 87% by mass) transferred to a recipient. 14B is a histogram showing the distribution of inorganic particles in the droplets of the transfer target material No. 3 (glycerol concentration 87% by mass) transferred to the application target object. 15A is an image of a droplet of the transfer target material No. 1 (glycerol concentration: 98% by mass) transferred to a recipient. 15B is a histogram showing the distribution of inorganic particles in the droplet of the transfer target material No. 1 (glycerol concentration: 98% by mass) transferred to the object to be transferred. 16A is a diagram for explaining a method for analyzing the spatial distribution of inorganic particles in a droplet of a transfer target material, and is an image of a droplet of the transfer target material No. 3 (glycerol concentration 87% by mass) transferred to a substrate. 16B is a diagram for explaining a method for analyzing the spatial distribution of inorganic particles in a droplet of a transfer target material, and is an image of a droplet of the transfer target material No. 3 (glycerol concentration 87% by mass) transferred to a substrate. 16C is a diagram for explaining a method for analyzing the spatial distribution of inorganic particles in a droplet of a transfer target material, and is an image of a droplet of the transfer target material No. 3 (glycerol concentration 87% by mass) transferred to a substrate. FIG. 17 is a graph showing the relationship between (R _G /R _drop *100) at which the area ratio of inorganic particles in a droplet of the material to be transferred becomes 90% and the complex viscosity of the material to be transferred.

(Projectile transfer method and projectile transfer device)
The flying object transfer method of the present invention includes a flying step in which a donor substrate having a substrate and a transfer target material containing a light absorber and a dispersion medium arranged on the substrate is irradiated with an optical vortex laser beam from the substrate side of the donor substrate to cause the transfer target material to fly, and an application step in which the flown transfer target material is applied to an object to be applied, wherein the complex viscosity of the transfer target material at a shear stress of 200 Pa at 25°C is 88 mPa·s or more and 4,300 mPa·s or less, and the method further includes other steps as necessary.

The projectile transfer device of the present invention has a donor substrate having a substrate and a transfer target material containing a light absorbing material and a dispersion medium arranged on the substrate, a flying means for irradiating the transfer target material from the substrate side of the donor substrate with an optical vortex laser beam to cause the transfer target material to fly, and an application means for applying the transferred target material to an object to be applied, and the complex viscosity of the transfer target material at 25°C and a shear stress of 200 Pa is 88 mPa·s or more and 4,300 mPa·s or less, and further has other means as necessary.

The projectile transfer method of the present invention can be suitably carried out by the projectile transfer device of the present invention, and the projectile step can be carried out by a projectile means, the application step can be carried out by an application means, and the other steps can be carried out by other means.

In conventional technology, there is no mention of the spatial distribution of the light absorbing material inside the transfer target material transferred onto the substrate, making it difficult to control the spatial distribution of the light absorbing material.

Therefore, the present invention includes a flying step of irradiating a light vortex laser beam from the substrate side of the donor substrate to the transfer target material, which includes a substrate and a transfer target material containing a light absorbing material and a dispersion medium on the substrate, to cause the transfer target material to fly, and an application step of applying the flown transfer target material to an object to be applied, and the complex viscosity of the transfer target material at 25°C and a shear stress of 200 Pa is 88 mPa·s or more and 4,300 mPa·s or less, so that the light absorbing material that absorbs the light vortex laser beam of a predetermined wavelength can be transferred without agglomeration in a projectile transfer method using an optical vortex laser beam. The spatial distribution of the light absorbing material dispersed in the transfer target material is maintained on the object to be applied. Therefore, the thickness of the transfer target material becomes constant, and the uneven thickness of the transfer target material, which is a problem in printing technology in general, is suppressed, and uneven brightness and color on the image are improved. Furthermore, by using a dispersion medium with low ignition residue when heated as the dispersion medium contained in the material to be transferred, it becomes possible to transfer a high-purity light absorbing material.

<Flying process and flying means>
The flying process is a process in which a donor substrate having a substrate and a transfer target material containing a light absorbing material and a dispersion medium arranged on the substrate is irradiated with an optical vortex laser beam from the substrate side of the donor substrate to cause the transfer target material to fly, and can be performed by a flying means.

<<Donor Substrate>>
The donor substrate has a substrate and a transfer target material, which contains a light absorbing material and a dispersion medium, disposed on the substrate.
In the present invention, "flying" means moving through the air or traveling through the air.
In the present invention, "scattering" means scattering by flying away.

-substrate-
The substrate is not particularly limited in shape, structure, size, material, etc., and may be appropriately selected depending on the purpose.

The shape of the substrate is not particularly limited and can be appropriately selected according to the purpose, and examples thereof include a flat plate, a cylindrical shape such as a perfect circle or ellipse, a surface cut out from a cylindrical shape, and an endless belt shape. Among these, it is preferable that the substrate is cylindrical and has a supplying means for supplying the transfer target material to the surface of the substrate rotating in the circumferential direction. When the transfer target material is supported on the surface of the cylindrical substrate, it can be supplied regardless of the size of the object in the circumferential direction. In this case, the flying means is arranged inside the cylinder, and the optical vortex laser beam can be irradiated from the inside toward the periphery, and continuous irradiation can be performed by rotating the substrate in the circumferential direction.
The flat substrate may be, for example, a glass slide.

There are no particular limitations on the structure of the substrate, and it can be selected appropriately depending on the purpose.

The size of the substrate is not particularly limited and can be selected appropriately depending on the purpose, but it is preferable for the dimensions to match the width of the object to which the transfer material is to be applied.

The material of the substrate is not particularly limited as long as it transmits light, and can be appropriately selected depending on the purpose, but inorganic materials such as various glasses containing silicon oxide as the main component, transparent heat-resistant plastics, and organic materials such as elastomers are preferred in terms of transmittance and heat resistance.

The transmittance of the optical vortex laser beam in the substrate is not particularly limited and can be appropriately selected according to the purpose, but is preferably 75% or more, more preferably 85% or more. If the transmittance is within the preferred range, the energy of the optical vortex laser beam absorbed in the substrate is not easily converted into heat, so that the transfer target material is less likely to be changed, such as dried or melted, and the energy given to the transfer target material is less likely to decrease, which is advantageous in that the position where the transferred material is applied is less likely to vary.
The transmittance can be measured, for example, by using a spectrophotometer (V-660DS, manufactured by JASCO Corporation).

The surface roughness Ra of the substrate is not particularly limited and can be appropriately selected according to the purpose, but it is preferable that both the front and back surfaces are 1 μm or less in order to suppress refraction and scattering of the optical vortex laser beam and not to reduce the energy applied to the transfer target material. In addition, if the surface roughness Ra is within a preferred range, it is advantageous in that it is possible to suppress the variation in the average thickness of the transfer target material applied to the object to which the transfer target material is applied, and it is possible to apply the desired amount of the transfer target material.
The surface roughness Ra can be measured in accordance with JIS B0601, for example, using a stylus-type surface profiler (Dektak150, manufactured by Bruker AXS K.K.).

-Transfer target material-
The material to be transferred contains a light absorbing material and a dispersion medium, and further contains other components as required.
The transfer target material has a complex viscosity of 88 mPa·s or more and 4,300 mPa·s or less at 25°C and a shear stress of 200 Pa. When the transfer target material has a complex viscosity of 88 mPa·s or more and 4,300 mPa·s or less, the light absorbing material can be transferred without agglomeration, and the spatial distribution of the light absorbing material uniformly dispersed in the transfer target material is maintained on the object to which the material is applied. Therefore, the thickness of the transfer target material becomes constant, thickness unevenness of the transfer target material is suppressed, and brightness unevenness and color unevenness on the image are improved.
The complex viscosity can be measured under the following conditions by a dynamic viscoelasticity measuring device using a stress control method in which the applied stress is changed and the amount of strain generated at that time is measured.
- Measurement conditions -
Device name: Rheometer, HAAKE RheoStress 600, manufactured by Thermo Fisher Scientific Temperature: 25°C
Shear stress: 200 Pa

--Light absorbing material--
The light absorbing material preferably has an absorbance for a wavelength of light greater than 1, and more preferably greater than 2. When the light absorbing material has an absorbance for a wavelength of light greater than 2, it is advantageous in that energy efficiency can be improved.

There are no particular limitations on the light absorbing material as long as it absorbs light of a specific wavelength, and it can be selected appropriately depending on the purpose, and examples include inorganic materials.

The inorganic material is not particularly limited with respect to its shape, size, material, etc., and can be appropriately selected depending on the purpose.
The form of the inorganic material may be, for example, a solid, a powder, etc. The term "solid" refers to a material that retains its shape at 25° C. regardless of the shape of the container.

Examples of the inorganic material include manganese ferrite, iron ferrite, magnesium ferrite, strontium ferrite, triiron tetroxide, titanium oxide, zinc sulfide, black iron oxide, black copper oxide, black chromium oxide, yellow iron oxide, yellow nickel titanium, cadmium sulfide, selenium, cadmium selenide, lead chromate, lead molybdate, red iron oxide, cobalt oxide, hydrous chromium oxide, chromium oxide, gold, lead antimony, nickel oxide, manganese oxide, neodymium oxide, erbium oxide, cerium oxide, aluminum oxide, aluminum, bronze, mica, carbon black, carbon, zeolite, calcium carbonate, barium sulfate, zinc oxide, antimony trioxide, mercury cadmium sulfide, iron blue, ultramarine, etc. These may be used alone or in combination of two or more.
The median diameter (D ₅₀ ) of the inorganic material is preferably 50 nm or more and 500 nm or less, and more preferably 50 nm or more and 240 nm or less.
The median diameter (D ₅₀ ) is measured, for example, using a scanning electron microscope (SU8200 series, manufactured by Hitachi High-Technologies Corporation). The obtained image is binarized using image processing software A-zo-kun (manufactured by Asahi Kasei Engineering Co., Ltd.), and the median diameter (D ₅₀ ) can be calculated. Alternatively, the measurement is performed, for example, using a transmission electron microscope (JEM-2100, manufactured by JEOL Ltd.). As an observation sample, an ethanol dispersion containing 0.4% by mass of inorganic material is prepared, and the inorganic material is dispersed in an ultrasonic cleaner for about 1 hour, and then a collodion film-attached mesh (manufactured by Nissin EM Co., Ltd.) is used for measurement. The obtained image is binarized using image processing software A-zo-kun (manufactured by Asahi Kasei Engineering Co., Ltd.), and the median diameter (D ₅₀ ) can be calculated.

--Dispersion medium--
The dispersion medium is not particularly limited as long as it can disperse the light absorbing material, and can be appropriately selected according to the purpose, and examples thereof include water, organic solvents, wax, and resin varnish. These may be used alone or in combination of two or more. Among these, a carboxymethylcellulose aqueous solution and a glycerol aqueous solution are preferred, and a glycerol aqueous solution is more preferred because a dispersion medium with an ignition residue of 0.1% or less or an evaporation residue of 1.0 or less allows the transfer of a transfer target material with high purity.
The glycerol concentration in the aqueous glycerol solution is preferably 87% by mass or more, and more preferably 90% by mass or more.

Examples of the water include pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, and distilled water, and ultrapure water.
The organic solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the organic solvent include glycerol, ethanol, and acetone.

The wax is not particularly limited and can be appropriately selected depending on the purpose. Examples of the wax include hydrocarbon wax, ester wax, and ketone wax.

The resin varnish is not particularly limited and can be appropriately selected depending on the purpose. Examples include acrylic, polyester, styrene, polyurethane, alkyd, epoxy, amber, and rosin-based varnishes.

The dispersion medium may contain a surfactant from the viewpoint of dispersibility of the light absorbing material.
The surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples of the surfactant include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants.

Examples of the anionic surfactant include fatty acid soap, alkyl succinate, sodium alkylbenzene sulfonate, sodium alkylnaphthalene sulfonate, sodium alkyl sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium dialkyl sulfosuccinate, sodium alkyl phosphate, polycarboxylic acid type polymer surfactant, etc. In addition to the above-mentioned sodium salts, any metal salt, ammonium salt, etc. may also be used.
Examples of the cationic surfactant include alkyltrimethylammonium chloride and alkyldimethylbenzylammonium chloride.
Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, and sorbitan fatty acid ester.
Examples of the amphoteric surfactant include alkyl betaines and amido betaines.

-Other ingredients-
Examples of other components include colorants, dispersants, heat stabilizers, antioxidants, anti-reducing agents, preservatives, pH adjusters, antifoaming agents, wetting agents, and penetrating agents.

The transfer target material is liquid, and the viscosity of the liquid transfer target material is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 Pa·s or more, and more preferably 1 Pa·s or more and 20 Pa·s or less.
The viscosity can be measured, for example, using a rotational viscometer (VISCOMATE VM-150III, manufactured by Toki Sangyo Co., Ltd.) in an environment of 25°C.

The material to be transferred in the donor substrate disposed on the substrate may be in the form of a layer or a film, and can be appropriately selected depending on the purpose.
The material to be transferred may form an integral (continuous) layer (film) on the substrate, or may form an intermittent layer (film).

The average thickness of the transfer target material (transfer target layer) is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 μm or more, more preferably 10 μm to 50 μm, and even more preferably 20 μm to 50 μm, when the transfer target layer is a liquid at 25° C. When the transfer target layer is a liquid at 25° C., if the average thickness of the transfer target layer is 10 μm or more, scattering of the transfer target material when irradiated with light can be suppressed.
Furthermore, when the layer to be transferred is a liquid at 25°C, if the average thickness of the layer to be transferred is 10 μm or more, when the continuous material is supplied in a layered form, the strength of the layer on the substrate can be ensured even when the material is continuously flown, which is preferable in that the material to be transferred can be continuously flown.
Furthermore, when the layer to be transferred is liquid at 25°C, if the average thickness of the layer to be transferred is 50 μm or less, the light energy required to make the material to be transferred fly does not become too large, which is advantageous in that deterioration and decomposition are less likely to occur, particularly when the light absorbing material is organic.
Depending on the application method, it may be possible to supply the material as a layer that maintains a certain pattern.
The average thickness of the transfer target layer is not particularly limited and can be appropriately selected depending on the purpose, but when the transfer target layer is a solid at 25° C., it is preferably 40 μm or less, more preferably 0.2 μm or more and 20 μm or less, and even more preferably 5 μm or more and 18 μm or less. When the transfer target layer is a solid at 25° C., if the average thickness of the transfer target layer is 40 μm or less, transfer is possible with relatively weak light energy, and damage to the light absorbing material can be suppressed.

The method for measuring the average thickness of the transfer target layer is not particularly limited and can be appropriately selected according to the purpose, and can be, for example, a method of selecting multiple arbitrary points on the transfer target layer and calculating the average thickness of the multiple points. The average is preferably the average thickness of 5 points, more preferably the average thickness of 10 points, and particularly preferably the average thickness of 20 points.
The measuring device for the average thickness is not particularly limited and can be appropriately selected depending on the purpose. For example, a laser displacement meter, a micrometer, or the like can be used for a non-contact or contact method.

In the present invention, the donor substrate is used, and an optical vortex laser beam is irradiated onto a material to be transferred from the substrate side of the donor substrate, causing the material to be transferred to fly.
In the present invention, the term "flying" means that at least a part of the material to be transferred is detached from the donor substrate.
By using an optical vortex laser beam, it is possible to prevent the flying transfer target material from scattering.

The optical vortex laser beam is described in detail below.
A typical laser beam has a planar equiphase surface (wavefront) as shown in FIG. 1A because the phase is uniform. Since the direction of the Poynting vector of the laser beam is perpendicular to the planar equiphase surface, it is the same direction as the irradiation direction of the laser beam. Therefore, when the laser beam is irradiated to the light absorbing material in the transfer target material, a force acts on the light absorbing material in the irradiation direction. However, since the light intensity distribution in the cross section of the laser beam is a normal distribution (Gaussian distribution) in which the center of the beam is the strongest as shown in FIG. 1B, the transfer target material is likely to scatter. In addition, when the phase distribution is observed, it is confirmed that there is no phase difference as shown in FIG. 1C.
In contrast, the optical vortex laser beam has a helical equiphase surface as shown in FIG. 2A. Since the direction of the Poynting vector of the optical vortex laser beam is perpendicular to the helical equiphase surface, when the optical vortex laser beam is irradiated to the light absorbing material in the transfer target material, a force acts in the perpendicular direction. Therefore, as shown in FIG. 2B, the light intensity distribution becomes a concave donut-shaped distribution with the center of the beam being zero, and the donut-shaped energy is applied as radiation pressure to the light absorbing material irradiated with the optical vortex laser beam. Then, the light absorbing material irradiated with the optical vortex laser beam flies along the irradiation direction of the optical vortex laser beam and is applied to the object in a state where it is difficult to scatter. In addition, when the phase distribution is observed, it is confirmed that a phase difference occurs as shown in FIG. 2C.

3A is a photograph showing an example of a typical laser beam irradiated onto a light absorbing material in a transfer target material, and FIG. 3B is a photograph showing an example of a light vortex laser beam irradiated onto a light absorbing material in a transfer target material.
3A and 3B, it can be seen that the transfer target material is scattered more in Fig. 3A than in Fig. 3B. This shows that the light absorbing material in the transfer target material irradiated with the optical vortex laser beam is applied with doughnut-shaped energy as radiation pressure, so that it flies along the irradiation direction of the optical vortex laser beam and is applied to the object in a state that is less likely to scatter.

There are no particular limitations on the method for determining whether or not an optical vortex laser beam is present, and it can be selected appropriately depending on the purpose. For example, the method can include the aforementioned observation of the phase distribution and interferometry, with interferometry being the most common.
The interference measurement can be performed using a laser beam profiler (such as a laser beam profiler manufactured by Spiricon or a laser beam profiler manufactured by Hamamatsu Photonics KK), and examples of the results of the interference measurement are shown in FIGS. 4A and 4B.
FIG. 4A is an explanatory diagram showing an example of the results of interferometry of an optical vortex laser beam, and FIG. 4B is an explanatory diagram showing an example of the results of interferometry of a laser beam having a point of zero light intensity at its center.
When an optical vortex laser beam is subjected to interference measurement, it can be confirmed that the energy distribution is donut-shaped, as shown in Figure 4A, and that the laser beam has a point of zero light intensity in the center, as in Figure 1C.
On the other hand, when an ordinary laser beam having a point of zero light intensity at its center is subjected to interferometric measurement, as shown in FIG. 4B, it is similar to the interferometric measurement of the optical vortex laser beam shown in FIG. 4A. However, the energy distribution in the donut-shaped portion is not uniform, which confirms the difference from the optical vortex laser beam.

-Means of flight-
The flying means irradiates light onto the material to be transferred from the substrate side of the donor substrate, in other words, irradiates light onto the surface of the substrate opposite the side on which the material to be transferred is arranged, thereby causing the material to be transferred to fly in the direction of light irradiation.

The flying means also has a laser light source, an optical vortex conversion unit, and a wavelength conversion unit, and may further have other components as necessary.

--Laser light source--
The laser light source is not particularly limited and can be appropriately selected depending on the purpose. Examples of the laser light source include solid-state lasers, gas lasers, and semiconductor lasers that generate laser beams, and those capable of pulse oscillation are preferable.
Examples of the solid-state laser include a YAG laser and a titanium sapphire laser.
Examples of the gas laser include an argon laser, a helium-neon laser, and a carbon dioxide laser.
Among these, a semiconductor laser with an output of about 30 mW is preferable from the viewpoint of miniaturization and cost reduction of the device, however, in this embodiment, a titanium sapphire laser is used.
The wavelength of the laser beam is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 300 nm to 11 μm, and more preferably from 350 nm to 1100 nm.
The beam diameter of the laser beam is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 10 μm to 10 mm, and more preferably from 10 μm to 1 mm.
The pulse width of the laser beam is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 2 nanoseconds to 100 nanoseconds, and more preferably from 2 nanoseconds to 10 nanoseconds.
The pulse frequency of the laser beam is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 10 Hz to 200 Hz, and more preferably from 20 Hz to 100 Hz.
The laser light source may be a laser light source capable of outputting an optical vortex laser beam.

--Optical vortex converter--
The optical vortex converter is not particularly limited as long as it can convert a laser beam into an optical vortex laser beam, and can be appropriately selected depending on the purpose. Examples of the optical vortex converter include a diffractive optical element, a multimode fiber, and a liquid crystal phase modulator.
Examples of the diffractive optical element include a spiral phase plate, a hologram element, etc. Among these, a spiral phase plate is preferable.
The method of generating the optical vortex laser beam is not limited to the method using the optical vortex converter, but may include, for example, a method of oscillating an optical vortex as an eigenmode from a laser resonator, a method of inserting a hologram element into a resonator, etc. Other methods of generating the optical vortex laser beam include, for example, a method of using excitation light converted into a doughnut beam, a method of using a resonator mirror with a dark spot, and a method of oscillating in an optical vortex mode using the thermal lens effect generated by a side-excited solid-state laser as a spatial filter.

--Wavelength conversion section--
There are no particular limitations on the wavelength conversion unit, and it can be appropriately selected depending on the purpose as long as it can provide circular polarization to the optical vortex laser beam so that the total rotational moment JL _,S , expressed by the following mathematical formula (1), satisfies | _JL,S |≧0.
Examples of the wavelength conversion unit include a quarter-wave plate. In the case of a quarter-wave plate, the optical axis may be set at an angle other than +45° or -45° to impart elliptical circular polarization (elliptical polarization) to the optical vortex laser beam, but it is preferable to set the optical axis at +45° or -45° to impart true circular circular polarization to the optical vortex laser beam and satisfy the above conditions. This allows the projectile transfer device to stably fly the light absorbing material and increase the effect of imparting it to the object in a shape that suppresses scattering.

In the above formula (1), ε ₀ is the dielectric constant in a vacuum, ω is the angular frequency of light, L is the topological charge, I is the orbital angular momentum corresponding to the vortex order of the optical vortex laser beam expressed by the following formula (2), S is the spin angular momentum for circularly polarized light, and r is the radius of the cylindrical coordinate system.
In the above formula (2), ω ₀ is the beam waist size of the light.
The topological charge refers to the quantum number that appears from the periodic boundary condition in the azimuth direction of the cylindrical coordinate system of the optical vortex laser beam, and the beam waist size refers to the minimum value of the beam diameter of the optical vortex laser beam.

L is a parameter determined by the number of turns of the helical wavefront in the wave plate. S is a parameter determined by the direction of the circularly polarized light in the wave plate. Both L and S are integers. The signs of L and S indicate the direction of the helix (clockwise, counterclockwise), respectively.
If the total rotational moment in the optical vortex laser beam is J, it can be expressed as J = L + S.

The flying object transfer device of the present invention includes, for example, an optical vortex conversion unit that converts a laser beam into an optical vortex laser beam, and a wavelength conversion unit that imparts circular polarization to the optical vortex laser beam. By setting | _JL,S |≧0, it is possible to express linear directivity of flying objects of a highly viscous material to be transferred, and to improve the effect of suppressing scattering of the material to be transferred.

--Other parts--
The other members are not particularly limited and can be appropriately selected depending on the purpose. Examples of the other members include a beam diameter changing member, a beam wavelength changing element, and an output adjustment unit.

---Beam diameter changing parts---
There are no particular limitations on the beam diameter changing member as long as it can change the beam diameter of the optical vortex laser beam, and it can be selected appropriately depending on the purpose, such as a focusing lens.
The beam diameter (irradiation diameter) of the optical vortex laser beam is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 100 μm or less. If the irradiation diameter of the optical vortex laser beam is 100 μm or less, it is preferable in that it is easy to form a high-resolution image.
The beam diameter can be changed by, for example, the laser spot diameter and the condenser lens.
In addition, when the material to be transferred is a dispersion, the beam diameter is preferably equal to or larger than the maximum volume average particle diameter of the material to be transferred, and more preferably three times the maximum volume average particle diameter of the dispersion. If the beam diameter is within the more preferred range, it is advantageous in that the material to be transferred can be stably ejected.

---Beam wavelength changing element---
The beam wavelength changing element is not particularly limited as long as it can change the wavelength of the optical vortex laser beam to a wavelength that can be absorbed by the light absorbing material in the transfer target material and can be transmitted through the substrate described below, and can be appropriately selected according to the purpose. Examples of the beam wavelength changing element include KTP crystal, BBO crystal, LBO crystal, and CLBO crystal.

---Output adjustment section---
The output adjustment unit is not particularly limited as long as it can adjust the laser beam or optical vortex laser beam to an appropriate output value, and can be appropriately selected depending on the purpose. For example, glass can be used.

The output value of the optical vortex laser beam irradiated onto the transfer target material is not particularly limited, and can be appropriately selected according to the purpose, as long as it can produce a state in which a liquid column that converges to a diameter smaller than the irradiation diameter while rotating around the central axis of the irradiation diameter with the irradiation direction as the axis, or a state in which a part of the liquid column is detached and a droplet is produced. Note that, hereinafter, "output value" may also be referred to as "irradiation energy".
The irradiation energy of the optical vortex laser beam is preferably adjusted appropriately since the appropriate value changes depending on the viscosity and film thickness of the material to be transferred, but specifically, 100 μJ/dot or less is more preferable, and 60 μJ/dot or less is even more preferable. If the irradiation energy of the optical vortex laser beam is 60 μJ/dot or less, it is advantageous in that it is easy to realize a state in which a liquid column that converges to a diameter smaller than the irradiation diameter while rotating around the central axis of the irradiation diameter with the irradiation direction as the axis can be generated, or a state in which a part can be detached and a droplet can be generated.

<Application step and application means>
The applying step is a step of applying the flying transfer target material to an object to be transferred.
The application means is a means for applying the flying transfer target material to an object to be transferred.
The applying step is suitably carried out by the applying means.
In the present invention, the term "imparting" is almost synonymous with the term "attaching."
The application means is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a means having a mechanism for contacting a liquid column or droplet of the transfer target material with an object to be applied, etc. Specifically, examples of the application means include a mechanism for adjusting the gap between the object to be applied and the transfer target material, and a mechanism for transporting the object to be applied, etc.

-Item to be granted-
The object to be applied is not particularly limited as long as it can be contacted by the liquid column or droplets generated from the transfer target material, and can be appropriately selected depending on the purpose, and examples thereof include recording media and intermediate transfer belts conventionally used in image forming apparatuses, object support substrates for forming three-dimensional objects, etc. In this specification, the object to be applied is sometimes referred to as a transfer medium.
The recording medium is not particularly limited and can be appropriately selected depending on the purpose. Examples of the recording medium include coated paper, wood-free paper, film, cloth, and fiber.

The gap (gap, distance) between the object to be applied and the transfer target material is not particularly limited as long as the object to be applied and the transfer target material are not in contact with each other, and can be appropriately selected according to the purpose, but is preferably 0.05 mm or more and 5 mm or less, more preferably 0.10 mm or more and 1 mm or less, and particularly preferably 0.10 mm or more and 0.50 mm or less. If the gap between the object to be applied and the transfer target material is within a preferred range, it is advantageous in that the accuracy of the application position of the transfer target material to the object to be applied is unlikely to decrease. In addition, by not contacting the object to be applied and the transfer target material, it is possible to apply the transfer target material to the object to be applied regardless of the composition of the light absorbing material and the object to be applied.
Further, it is preferable that the gap is kept constant by, for example, a position control means for maintaining the position of the object to be applied constant. In this case, it is important to arrange each part in consideration of the positional fluctuation of the transfer target material and the object to be applied and the variation in the average thickness.

In addition, the average diameter (average dot diameter) of the transfer target material applied to the substrate is not particularly limited and may be appropriately selected depending on the purpose. For example, it is preferable to set the average diameter to 100 μm or less, since this can further improve the resolution of the image or three-dimensional object to be formed.
In addition, the average dot diameter can be obtained, for example, by obtaining a dot image of the material to be transferred using a microscope or the like, detecting a dot area from image brightness information, calculating the area of each dot from the number of pixels in the detected dot area, and taking the diameter when converted into a circle as the dot diameter, and averaging these.

Furthermore, the variation value of the average diameter (dot diameter) of the transfer target material applied to the object is preferably 10% or less, and more preferably 6% or less. By setting the variation value of the average diameter of the transfer target material applied to the object to the preferred range described above, it is possible to further improve the accuracy in forming an image or a three-dimensional object.
In addition, the value of the variation in the average diameter of the material to be transferred applied to the object to be transferred can be obtained, for example, by acquiring a dot image of the material to be transferred using a microscope or the like, detecting a dot area from image brightness information, calculating the area of each dot from the number of pixels in the detected dot area, defining the diameter when converted into a circle as the dot diameter, and calculating it from the average particle size and standard deviation of the particle size distribution of each dot.

In addition, the value of the variation in the position (dot position) of the transfer target material applied to the object to be applied is preferably 10 μm or less, more preferably 5 μm or less. By setting the value of the variation in the position of the transfer target material applied to the object to be applied within the above-mentioned preferred range, the accuracy of forming an image or a three-dimensional object can be further improved. Note that, for example, when dots of the transfer target material are applied in a row, the value of the variation in the position of each of the transfer target materials in the direction perpendicular to the row of dots can be used as the value of the variation in the position of each of the transfer target materials applied to the object to be applied.
For example, the dot image of the material to be transferred is obtained using a microscope or the like, and dot areas are detected from image brightness information. The coordinates of the center of gravity of each detected dot area are then calculated, and the deviation of each center of gravity from an approximate straight line using the least squares method is calculated to obtain the desired value.

The average thickness of the material to be transferred applied to the object to be applied is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 100 μm or less. If the average thickness of the material to be transferred applied to the object to be applied is 100 μm or less, the energy required to fly the material to be transferred can be reduced, which is advantageous in terms of the durability of the material to be transferred and the fact that decomposition of the composition is less likely to occur when the light absorbing material is an organic material. The average thickness of the material to be transferred applied to the object to be applied can be appropriately selected depending on the recording medium, purpose, etc.

<Other processes>
Examples of the other steps include a supplying step, a light scanning step, and a control step.

<<Supplying step and supplying means>>
The supply step is not particularly limited as long as it is a step of supplying the transfer target material to the optical path between the flying means and the object to be transferred, and can be appropriately selected depending on the purpose. For example, it can be suitably performed using the supply means.
The supplying means is not particularly limited as long as it is a means for supplying the transfer target material to the optical path between the flying means and the object to be transferred, and can be appropriately selected depending on the purpose.

The supplying means may be, for example, a cylindrical substrate, etc. In the case where the cylindrical substrate is used, the cylindrical substrate may be disposed on an optical path, and the transfer target material may be supplied to the donor substrate via the cylindrical substrate.
More specifically, when the material to be transferred is liquid and is supplied to the donor substrate, it is preferable to provide a supply roller and a regulating blade as the supply means, since this is a very simple configuration that allows the material to be supplied to the surface of the substrate at a constant average thickness.
In this case, the supply roller is partially immersed in a storage tank that stores the transfer target material, rotates while carrying the transfer target material on its surface, and abuts against the donor substrate to supply the transfer target material. The regulating blade is disposed downstream of the storage tank in the rotation direction of the supply roller, and regulates the transfer target material carried by the supply roller to make the average thickness uniform and stabilize the amount of the transfer target material to be flown. By making the average thickness of the transfer target material to be supplied very thin, the amount of the transfer target material to be flown can be reduced, so that the transfer target material can be applied to the object as minute dots with reduced scattering, and dot gain, which causes the halftone dots to thicken, can be suppressed. The regulating blade may be disposed downstream of the supply roller in the rotation direction of the supply roller.

In addition, when the material to be transferred is highly viscous, it is preferable that the material of the supply roller has at least an elastic surface so as to ensure contact with the donor substrate. When the material to be transferred is relatively low viscous, examples of the supply roller include gravure rolls, microgravure rolls, and forward rolls used in precision wet coating.

Furthermore, as a supply means that does not include a supply roller, the donor substrate may be directly contacted with the material to be transferred in the storage tank, and then excess material to be transferred is scraped off with a wire bar or the like to form a layer of the material to be transferred on the surface of the donor substrate.
The storage tank may be provided separately from the supply means, and the transfer target material may be supplied to the supply means by a hose or the like.

<<Optical Scanning Process and Optical Scanning Means>>
The optical scanning process is not particularly limited as long as it is a process of scanning the optical vortex laser beam onto the transfer target material, and can be appropriately selected depending on the purpose. For example, it can be suitably performed using the optical scanning means.
The optical scanning means is not particularly limited as long as it can scan the optical vortex laser beam on the transfer target material, and can be appropriately selected according to the purpose. For example, the optical scanning means may have a reflector that reflects the light irradiated from the flying means toward the transfer target material, and a reflector driving unit that changes the angle and position of the reflector to scan the optical vortex laser beam on the transfer target material.

<<Control process>>
The control step is a step of controlling each step and can be suitably performed by a control means. The control means is not particularly limited as long as it can control the movement of each means and can be appropriately selected depending on the purpose. Examples of the control means include devices such as a sequencer and a computer.

Next, an example of a projectile transfer device according to the present invention will be described with reference to the drawings.
The number, positions, shapes, etc. of the members of the projectile transfer device of the present invention are not limited to those in this embodiment, and the number, positions, shapes, etc. may be any number, positions, shapes, etc. that are preferable for implementing the present invention.

FIG. 5A is an explanatory diagram showing an example of the projectile transfer device of the present invention.
5A, the flying object transfer device 300 has a flying means 1, a transfer target material (transfer target layer) 20, an object to be applied 30, and a donor substrate 40. The donor substrate 40 is provided on the upper surface of the transfer target layer 20 on the opposite side to the donor substrate 40.
The flying object transfer device 300 irradiates the transfer target layer 20 carried on the donor substrate 40 with a laser beam 112 by the flying means 1, and causes the transfer target layer 20 to fly in the irradiation direction by the energy of the optical vortex laser beam 12. In Fig. 5A, an object to be applied 30 is an object to which the flown transfer target layer 20 is applied. By arranging the object to be applied 30 opposite the transfer target layer 20, the transfer target layer 20 can be applied to the object to be applied 30.

The flying means 1 has a laser light source 2, beam diameter changing members 3 and 7, a beam wavelength changing member 4, an optical vortex conversion unit 5, and a wavelength conversion unit 6.

The laser light source 2 is, for example, a titanium sapphire laser, which generates a pulsed laser beam 11 and irradiates the beam diameter changing member 3 with the laser beam 11 .
The beam diameter changing member 3 is, for example, a condenser lens, and is disposed downstream of the laser light source 2 in the optical path of the laser beam 11 generated by the laser light source 2 , and changes the diameter of the laser beam 11 .
The beam wavelength changing member 4 is, for example, a KTP crystal, and is disposed downstream of the beam diameter changing member 3 in the optical path of the laser beam 11 to change the wavelength of the laser beam 11 to a wavelength that can be absorbed by the transfer target layer 20 .
The optical vortex converter 5 is, for example, a spiral phase plate, and is arranged downstream of the beam wavelength changing member 4 in the optical path of the laser beam 11 , and converts the laser beam 11 into an optical vortex laser beam 12 .
The wavelength conversion unit 6 is, for example, a quarter-wave plate, and provides the optical vortex laser beam 12 with circular polarization.

The transfer target layer 20 is irradiated with the optical vortex laser beam 12 from the flying means 1, and flies by receiving energy within the range of the diameter of the optical vortex laser beam 12. By placing an object 30 opposite the transfer target layer 20, the transfer target layer 20 can be applied to the object 30.
In addition, the flying transfer target layer 20 is twisted while converging near the central axis of the beam diameter due to the forward propulsion and gyro effect caused by the moderate energy imparted by the optical vortex laser beam 12, thereby being applied to the object 30 while preventing it from scattering to the surrounding area.
At this time, the flying amount of the transfer target layer 20 is a portion of the area of the transfer target layer 20 irradiated with the optical vortex laser beam 12, and can be adjusted by the wavelength conversion unit 6, etc.

FIG. 5B is an explanatory diagram showing another example of the projectile transfer device of the present invention.
In FIG. 5B, the flying object transfer device 301 has an optical scanning means 60 in addition to each means of the flying object transfer device 300 shown in FIG. 5A. In FIG. 5B, the donor substrate 40 is arranged such that the long axis direction of the donor substrate 40 is perpendicular to the irradiation direction of the optical vortex laser beam 12. In this flying object transfer device 301, the optical scanning means 60 scans the optical vortex laser beam 12 generated by the flying means 1 onto the donor substrate 40. As a result, the flying object transfer device 301 can irradiate any position on the donor substrate 40 and fly the transfer target material (transfer target layer) 20. As a result, when the object to be applied 30 is placed opposite the transfer target layer 20, the transfer target layer 20 can be applied to any position on the object to be applied 30.

The optical scanning means 60 is disposed downstream of the flying means 1 in the optical path of the optical vortex laser beam 12 , and has a reflecting mirror 61 .
The reflecting mirror 61 is movable in the scanning direction indicated by the arrow S in FIG. 5B by a reflecting mirror driving means, and reflects the optical vortex laser beam 12 to an arbitrary position on the transfer target layer 20 .
In addition, the optical scanning means 60 may change the irradiation direction of the optical vortex laser beam 12 by, for example, moving the flying means 1 itself or rotating the flying means 1. Alternatively, the optical scanning means 60 may use the polygon mirror as the reflecting mirror 61 to scan the optical vortex laser beam 12 at any position.

The donor substrate 40 is disposed downstream of the optical scanning means 60 in the optical path of the optical vortex laser beam 12, and is used for the purpose of applying and fixing the transfer target layer 20 when the transfer target layer 20 is a high-viscosity liquid, for example. The donor substrate 40 is transmissive to the light, and supports the transfer target layer 20 on the surface opposite to the surface irradiated with the optical vortex laser beam 12.
In addition, by controlling the average thickness of the layer to be transferred 20 formed into a layer to be constant at the stage where the layer to be transferred 20 is supported on the donor substrate 40, the flying amount of the layer to be transferred 20 can be stabilized.
The combination of the flying means 1 and the optical scanning means 60 is referred to as a laser beam irradiation unit 100.

FIG. 5C is an explanatory diagram showing another example of the projectile transfer device of the present invention.
5C, the flying object transfer device 301a has galvanometer scanners (galvanometer mirrors) 62a and 62b as the optical scanning means 60 in the flying object transfer device 301 shown in FIG. 5B. The galvanometer scanners 62a and 62b are movable in independent scanning directions (two-dimensionally) and can reflect the optical vortex laser beam 12 to any position on the transfer target layer 20. By using the galvanometer scanners 62a and 62b as the optical scanning means 60, the scanning speed and scanning accuracy of the optical vortex laser beam 12 can be further improved.
In the projectile transfer device 301 a, it is also preferable to dispose an fθ lens between the galvano scanner 62 b and the substrate 40, for example.

The applications of the projectile transfer method and projectile transfer device of the present invention are not particularly limited and can be appropriately selected according to the purpose, and examples include image formation, manufacturing of three-dimensional objects, and printable circuit formation.

(Image forming method)
The image forming method of the present invention includes a step of the projectile transfer method of the present invention, and further includes other steps as necessary. Specifically, the image forming method of the present invention includes a projectile step and an application step, and further includes other steps as necessary.
The flying step is the same as the flying step in the flying object transfer method of the present invention.
The application step is the same as the application step in the flying object transfer method of the present invention.

When forming an image, a colorant is used as the material to be transferred.
The colorant is not particularly limited with respect to its shape, material, etc., and may be appropriately selected depending on the purpose.

There are no particular limitations on the liquid colorant, and it can be selected appropriately depending on the purpose. For example, water-based inks can be used, in which coloring materials such as dyes, pigments, colored particles, and colored oil droplets are dispersed in water as a solvent. In addition to water-based inks, colorants containing relatively low-boiling liquids as solvents, such as hydrocarbon organic solvents and various alcohols, can also be used. Among these, water-based inks are preferred from the standpoint of safety of volatile components and risk of explosion.

In addition, the image forming apparatus can also form images using process inks for offset printing that uses plates, JAPAN COLOR compatible inks, special color inks, and the like, so digital images that match the colors used in offset printing can be easily reproduced without plates.
Furthermore, since image formation is also possible with UV-curable ink, by curing the ink by irradiating it with ultraviolet light in the fixing process, blocking, in which overlapping recording media stick to each other, can be prevented, and the drying process can be simplified.

Examples of the coloring material include organic pigments, inorganic pigments, dyes, etc. These may be used alone or in combination of two or more.

Examples of the organic pigments include dioxazine violet, quinacridone violet, copper phthalocyanine blue, phthalocyanine green, sap green, monoazo yellow, disazo yellow, polyazo yellow, benzimidazolone yellow, isoindolinone yellow, fast yellow, chromophthalic yellow, nickel azo yellow, azomethine yellow, benzimidazolone orange, alizarin red, quinacridone red, naphthol red, monoazo red, polyazo red, perylene red, anthraquinonyl red, diketopyrrolopyrrole red, diketopyrrolopyrrole orange, benzimidazolone brown, sepia, and aniline black. Examples of metal lake pigments among the organic pigments include rhodamine lake, quinoline yellow lake, and brilliant blue lake.

Examples of the inorganic pigments include cobalt blue, cerulean blue, cobalt violet, cobalt green, zinc white, titanium white, titanium yellow, chrome titanium yellow, light red, chrome oxide green, mars black, viridian, yellow ocher, alumina white, cadmium yellow, cadmium red, vermilion, lithopone, ultramarine, talc, white carbon, clay, mineral violet, rose cobalt violet, silver white, calcium carbonate, magnesium carbonate, , zinc oxide, zinc sulfide, strontium sulfide, strontium aluminate, brass, gold powder, bronze powder, aluminum powder, brass pigment, ivory black, peach black, lamp black, carbon black, Prussian blue, aureolin, titanium mica, yellow ochre, terre belt, raw sienna, raw umber, Cassel earth, chalk, gypsum, burnt sienna, burnt umber, lapis lazuli, azurite, malachite, orpiment, cinnabar, coral powder, chalk powder, red ochre, ultramarine, Prussian blue, fish phosphorus foil, and iron oxide-treated pearls.

Among these, carbon black is preferred as the black pigment from the viewpoints of hue and image storage stability.
As the cyan pigment, C.I. Pigment Blue 15:3, which is copper phthalocyanine blue, is preferred from the viewpoints of hue and image storage stability.

As magenta pigments, C.I. Pigment Red 122, which is quinacridone red, C.I. Pigment Red 269, which is naphthol red, and C.I. Pigment Red 81:4, which is rhodamine lake, are preferred, and these may be used alone or in combination of two or more. Among these, from the viewpoint of hue and image storage stability, a mixture of C.I. Pigment Red 122 and C.I. Pigment Red 269 is more preferred, and as a mixture of C.I. Pigment Red 122 (P.R.122) and C.I. Pigment Red 269 (P.R.269), a mixture of P.R.122:P.R.269 of 5:95 or more and 80:20 or less is particularly preferred. P.R.122:P.R. If 269 is within the particularly preferred range, the hue will not deviate from the magenta color.

As yellow pigments, C.I. Pigment Yellow 74, which is a monoazo yellow, C.I. Pigment Yellow 155, which is a disazo yellow, C.I. Pigment Yellow 180, which is a benzimidazolone yellow, and C.I. Pigment Yellow 185, which is an isoindoline yellow, are preferred. Among these, C.I. Pigment Yellow 185 is more preferred in terms of hue and image storage stability. These may be used alone or in combination of two or more.

When the transfer target material is used as a process color ink as a colorant, it is preferable to use it in a four-color ink set.

The inorganic pigments are often composed of particles having a volume average particle size of more than 10 μm. When an inorganic pigment having a volume average particle size of 10 μm or more is used as a colorant, it is preferable that the colorant is a liquid. If the colorant is a liquid, it is advantageous in that the colorant can be maintained in a stable state without using forces other than non-electrostatic adhesion forces such as electrostatic forces. In addition, in this case, the image forming method of the present invention is very effective compared to the inkjet recording method, in which nozzle clogging and ink settling are likely to become significant and a stable continuous printing process is difficult to achieve. Furthermore, the image forming method of the present invention is very effective compared to the electrophotographic method, in which a sufficient amount of charge cannot be obtained when the surface area of the colorant particles becomes small and a stable continuous printing process cannot be achieved.

Examples of the dyes include monoazo dyes, polyazo dyes, metal complex azo dyes, pyrazolone azo dyes, stilbene azo dyes, thiazole azo dyes, anthraquinone derivatives, anthrone derivatives, indigo derivatives, thioindigo derivatives, phthalocyanine dyes, diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, acridine dyes, azine dyes, oxazine dyes, thiazine dyes, polymethine dyes, azomethine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes, naphthalimide dyes, and perinone dyes.

The viscosity of the colorant is not particularly limited and can be appropriately selected depending on the purpose.
When a liquid colorant that permeates into the recording medium is used, the colorant applied to the recording medium may cause feathering or bleeding, but when a high-viscosity colorant that can be handled by the projectile transfer method of the present invention is used, the colorant dries faster than it permeates into the recording medium, and thus the reduction in bleeding in particular leads to improved color development and sharper edges, making it possible to form high-quality images. Also, when performing gradation expression by applying colorant in layers, bleeding due to an increase in the amount of colorant can be reduced.
Furthermore, since this projectile transfer method involves applying a liquid colorant by projecting it, it is possible to perform recording well even if the recording medium has minute irregularities, as compared with, for example, a so-called thermal transfer method in which a colorant is melt-transferred from a film-like donor substrate by heat.

<Other manual processes and other means>
Examples of the other steps include a step of transporting an object to be treated and a fixing step.

The object transport step is not particularly limited as long as it is a step of transporting the object, and can be appropriately selected depending on the purpose. For example, it can be suitably performed using an object transport means.
The object transport means is not particularly limited as long as it can transport the object, and can be appropriately selected depending on the purpose. For example, a pair of transport rollers can be used.

The fixing means is not particularly limited as long as it can fix the light absorbing material contained in the transfer target material applied to the object, and can be appropriately selected depending on the purpose. For example, a thermocompression method using a heating and pressurizing member can be used.
The heating and pressing member is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a heating roller, a pressure roller, a combination of a heating roller and a pressure roller, etc. Other heating and pressing members include, for example, a combination of these with a fixing belt, and a heating block in place of the heating roller.

The pressure roller is preferably one whose pressure surface moves at the same speed as the object to be applied, which is transported by the object transport means, in order to suppress image deterioration due to friction. Among these, one having an elastic layer formed near the surface is more preferable in order to easily apply pressure to the object to be applied. Furthermore, the pressure roller having a water-repellent surface layer formed on the outermost surface using a low surface energy material such as a silicone-based water-repellent material or a fluorine compound is particularly preferable in order to suppress image distortion caused by the application of the transfer target material to the surface.
Examples of the water-repellent surface layer made of the silicone-based water-repellent material include a film of a silicone-based release agent, a baked film of silicone oil or various modified silicone oils, a film of silicone varnish, a film of silicone rubber, and a film made of a composite of silicone rubber and various metals, rubber, plastic, ceramic, or the like.
Examples of the water-repellent surface layer made of a fluorine compound include a fluororesin film, an organic fluorine compound film, a baked film or adsorption film of fluorine oil, a fluororubber film, and a film made of a composite of fluororubber and various metals, rubber, plastic, ceramic, etc.

The heating temperature of the heating roller is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 80°C or higher and 200°C or lower.

The fixing belt is not particularly limited as long as it is heat-resistant and has high mechanical strength, and can be appropriately selected according to the purpose. For example, films of polyimide, PET, PEN, etc. can be used. In addition, it is preferable to use the same material as that forming the outermost surface of the pressure roller as the fixing belt, in order to suppress image distortion caused by the transfer target material being applied to the surface. The fixing belt can be used immediately after turning on the power because the thickness can be made thin, which reduces the energy required to heat the belt itself. The temperature and pressure at this time vary depending on the composition of the light absorbing material to be fixed, but a temperature of 200°C or less is preferable from the perspective of energy saving, and a pressure of 1 kg/cm or less is preferable from the perspective of the rigidity of the device.

In the image forming method and image forming apparatus of the present invention, the flying means, the supplying means, and the optical scanning means may be integrally treated as a flying unit.
For example, an example will be described in which a colorant containing a coloring material is used as the transfer target material. Four of the flying units may be provided in the image forming apparatus, and the colorants of yellow, magenta, cyan, and black, which are process colors, may be flown. The number of colors of the colorants is not particularly limited and can be appropriately selected according to the purpose, and the number of flying units (hereinafter, colorant flying units) may be increased or decreased as necessary. In addition, by disposing the flying unit having a white colorant upstream of the flying unit having the colorant of the process color in the conveying direction of the recording medium, it is possible to provide a white concealing layer, so that an image with excellent color reproducibility can be formed on a transparent recording medium. However, in particular with yellow, white, and transparent colorants, there are cases in which the laser light source must be appropriately selected, for example, a blue laser beam, an ultraviolet laser beam, or the like, so that the light transmittance (absorbance) of the wavelength of the laser beam is appropriate.

Furthermore, in the image forming apparatus relating to the image forming method of the present invention, a highly viscous colorant can be used. Therefore, even if an image is formed by sequentially overlapping colorants of different colors on a recording medium, the occurrence of bleeding, in which the colorants seep out and mix, can be suppressed, and a high-quality color image can be obtained.
For the purpose of miniaturizing the image forming apparatus relating to the image forming method of the present invention, only one flying unit may be provided, and a multi-color image may be formed by switching the colorant itself supplied to the supply roller and the donor substrate.

Next, an example of an image forming apparatus according to the image forming method of the present invention will be described with reference to the drawings.
The number, position, shape, etc. of the members of the image forming apparatus relating to the image forming method of the present invention are not limited to those in this embodiment, and may be any number, position, shape, etc. that is preferable for implementing the present invention.

FIG. 6A is an explanatory diagram showing an example of an image forming apparatus in which a supplying unit and a target transporting unit are added to the flying object transfer device shown in FIG. 5B.
6A, the image forming apparatus 302 has a supplying means 50 and a target material transporting means 70 in addition to the various means of the projectile transfer apparatus 301 shown in FIG. 5B, and the flat substrate 40 is replaced with a cylindrical carrying roller 41. A laser beam irradiation unit 100 is disposed inside the carrying roller 41, and irradiates an optical vortex laser beam 12 onto the target material (target layer) 20 carried on the outer periphery of the carrying roller 41.

The supplying means 50 includes a storage tank 51 , a supplying roller 52 , and a regulating blade 53 .
The storage tank 51 is disposed below and in the vicinity of the supply roller 52 and stores the transfer target material 20 .
The supply roller 52 is disposed so as to abut against the carrier roller 41, and is partially immersed in the transfer target material 20 in the storage tank 51. The supply roller 52 applies the transfer target material 20 to its surface while rotating in the rotation direction indicated by the arrow R2 in FIG. 6A by a rotation drive means or following the rotation of the carrier roller 41. The applied transfer target material 20 is made uniform in average thickness by a regulating blade 53, and is transferred to the carrier roller 41 and supplied as a layer. The transfer target material 20 supplied to the surface of the carrier roller 41 is continuously supplied to the position irradiated with the optical vortex laser beam 12 as the carrier roller 41 rotates.
The regulating blade 53 is positioned upstream of the carrier roller 41 in the rotation direction indicated by the arrow R2 in Figure 6A, and regulates the transfer target material 20 applied to its surface by the supply roller 52, thereby making the average thickness of the transfer target material 20 supplied to the carrier roller 41 uniform.

The object transport means 70 is disposed near the carrying roller 41 so that the object 30 being transported does not come into contact with the carrying roller 41, and has an object transport roller 71 and an object transport belt 72 stretched around the object transport roller 71. The object transport means 70 rotates the object transport roller 71 by a rotary drive means, and transports the object 30 by the object transport belt 72 in the transport direction shown by the arrow C in Fig. 6A.
At this time, the laser beam irradiation unit 100 irradiates the optical vortex laser beam 12 from the inside of the carrier roller 41 in accordance with the image information, and causes the transfer target material 20 to be applied to the object 30. By performing an application operation in which the transfer target material 20 is applied to the object 30 while the object 30 is moved by the object conveying belt 72, a two-dimensional image can be formed on the object 30.

The transfer target material (transfer target layer) 20 that is supported on the surface of the support roller 41 but not caused to fly accumulates as the support roller 41 rotates and comes into contact with the supply roller 52, and eventually falls into the storage tank 51 for recovery. The method of recovering the transfer target material 20 is not limited to this, and a scraper that scrapes off the transfer target layer 20 from the surface of the support roller 41 may be provided.

FIG. 6B is an explanatory diagram showing another example of an image forming apparatus in which a supplying unit and a target transporting unit are added to the flying object transfer device shown in FIG. 5B.
In FIG. 6B, an image forming apparatus 303 is an image forming apparatus in which the cylindrical support roller 41 in the image forming apparatus 302 shown in FIG. 6A is divided into two support sections 42 along the axial direction, and the arrangement of the image forming apparatus 302 is changed.

The support portion 42 is a surface of a cylinder, and has a shape with no surface on the opposite side of the center line of the cylinder. By making the support body without an opposing surface in this way, it is easier to ensure the optical path of the optical vortex laser beam 12 without providing the laser beam irradiation unit 100 on the cylindrical support roller 41, and therefore the device can be simplified.

FIG. 7A is an explanatory diagram showing an example of the image forming apparatus shown in FIG. 6A to which a fixing unit is added.
In Fig. 7A, the image forming apparatus 305 has a fixing means 80 in addition to the various means of the image forming apparatus 302 shown in Fig. 6A, so as to fix and smooth the transfer target layer 20 applied to the object 30. Note that the object transport means 70 is located on the side of the carrier roller 41 in Fig. 6A, but is located above the carrier roller 41 in Fig. 7A for the sake of convenience of explanation.

The fixing means 80 is a pressure-type fixing means, and is disposed downstream of the carrier roller 41 in the transport direction of the object 30 indicated by the arrow C in FIG. 7A, and has a pressure roller 83 and an opposing roller 84. The fixing means 80 fixes the object 30 to which the transfer target layer 20 has been applied by applying pressure to the object 30 by conveying the object 30 while clamping it.

The pressure roller 83 is biased toward the opposing roller 84, and its surface comes into contact with the object 30 to which the pressure is to be applied, and the object 30 is pressed while being sandwiched between the opposing roller 84 and the pressure roller 83.
The counter roller 84 is disposed at a position where it comes into contact with the pressure roller 83 , and the object 30 is sandwiched between the pressure roller 83 and the object conveying belt 72 .

For example, if the image forming device 305 uses a transfer target material 20 with a very high viscosity of 1,000 mPa·s or more, the transfer target material 20 will tend to penetrate or wet the object 30 slowly. If the transfer target material 20 dries in its original state, the surface roughness of the image may become rough and the gloss of the image may decrease. In such a case, the fixing means 80 presses the object 30 to which the transfer target material 20 has been applied with the pressure roller 83, and can push the transfer target material 20 into the object 30 or crush the transfer target material 20, thereby reducing the surface roughness of the object 30 to which the transfer target material 20 has been applied.

FIG. 7B is an explanatory diagram showing another example of the image forming apparatus shown in FIG. 6A to which a fixing unit is added.
In FIG. 7B, an image forming apparatus 306 is obtained by changing the pressure fixing unit 80 in the image forming apparatus 305 shown in FIG. 7A to a heat and pressure fixing unit 81 .
Fixing means 81 is disposed downstream of carrying roller 41 in the transport direction of object 30 indicated by arrow C in Fig. 7B, and includes heat and pressure roller 85, fixing belt 86, driven roller 87, halogen lamp 88, and opposing roller 84. This fixing means 81 is used when a target image cannot be obtained by applying pressure alone in the case where a dispersion liquid in which a material that needs to be melted is used as transfer target material 20.

The heating and pressing roller 85 is biased toward the opposing roller 84 , and applies heat and pressure to the object 30 while sandwiching it between the opposing roller 84 and the fixing belt 86 .
The fixing belt 86 is an endless belt that is stretched around a heating and pressure roller 85 and a driven roller 87 and has a surface that comes into contact with the object 30 .
The driven roller 87 is disposed below the heating and pressure roller 85 and rotates in accordance with the rotation of the heating and pressure roller 85 .
The halogen lamp 88 is disposed inside the heating and pressure roller 85 and generates heat for fixing the transfer target layer 20 onto the object 30 .
The opposing roller 84 is disposed at a position where it contacts the fixing belt 86 , and the object 30 is sandwiched between the opposing roller 84 and the pressure roller 83 via the object-transport belt 72 .

FIG. 7C is an explanatory diagram showing another example of the image forming apparatus shown in FIG. 6A to which a fixing unit is added.
In FIG. 7C, an image forming apparatus 307 is obtained by changing the pressure fixing unit 80 in the image forming apparatus 305 shown in FIG. 7A to a UV irradiation fixing unit 82 .
The fixing means 82 is disposed downstream of the carrier roller 41 in the transport direction of the object 30 indicated by the arrow C in Fig. 7C, and has a UV lamp 89. This fixing means 81 is used when an ultraviolet-curable material is used as the transfer target layer 20, and fixes the material 30 to the object 30 by irradiating UV light from the UV lamp 89.

FIG. 8A is an explanatory diagram showing an example of an image forming apparatus of the present invention.
In Figure 8A, image forming apparatus 400 has four flying units 120 in addition to the various means of image forming apparatus 306 shown in Figure 7B, and is modified when colorant 21 containing color material is used as the transfer target material 20.
The flying unit 120 is composed of a supplying means 50, a flying means 100, a beam scanning means 60 (not shown), a carrying roller 41, and a transfer target material 20 (colorant 21).

The flying units 120Y, 120M, 120C, and 120K store, as colorants 21, toners of four process colors, yellow (Y), magenta (M), cyan (C), and black (K), respectively.
This makes it possible to apply the toner to a color process in which images of each color are formed in sequence on a recording medium 31 as an object 30 to which toner is to be applied, thereby obtaining a color image.

FIG. 8B is an explanatory diagram showing another example of the image forming apparatus of the present invention.
In FIG. 8B, an image forming apparatus 401 has an intermediate transfer unit 90 as an object to which a toner is applied, in addition to the units of the image forming apparatus 400 shown in FIG. 8A.

The intermediate transfer unit 90 includes an intermediate transfer body 91 , an intermediate transfer body drive roller 92 , and an intermediate transfer body driven roller 93 .
The intermediate transfer body 91 is, for example, an endless belt, and is disposed above the four flying units 120 and suspended between an intermediate transfer body drive roller 92 and an intermediate transfer body driven roller 93 .
The intermediate transfer body drive roller 92 is rotated by a rotation drive means in the direction indicated by the arrow R2 in FIG.
The intermediate transfer member driven roller 93 rotates in accordance with the rotation of the intermediate transfer member drive roller 92 .
In this way, an image may first be formed on the intermediate transfer body 91, and then transferred to a desired recording medium 31. This image forming apparatus 201 can also obtain a high-quality color image, similar to the image forming apparatus 400. Furthermore, when the image formed on the intermediate transfer body 91 is transferred to the recording medium 31, it is pressed by the intermediate transfer body drive roller 92, so that, similar to the image forming apparatus 200, the surface roughness of the recording medium 31 to which the colorant 21 has been applied can be reduced.

In addition, in Figure 5B, the direction in which the laser beam is irradiated is the direction of gravity, but in Figures 5A and 6A to 8B, it is shown that the direction in which the laser beam is irradiated is the opposite direction to the direction of gravity or is horizontal.
In this manner, in the image forming method of the present invention, the direction of irradiation of the laser beam onto the surface of the substrate may be the non-gravity direction, and the liquid column or droplets may be generated in the non-gravity direction, which increases the degree of freedom in the design of the apparatus.

The image forming method and image forming apparatus of the present invention can also be applied to a method and apparatus for manufacturing a three-dimensional object as follows.

(Method of manufacturing a three-dimensional object)
The method for producing a three-dimensional object of the present invention includes a step of the flying object transfer method of the present invention, and further includes other steps as necessary. Specifically, the method includes a flying step and an applying step, and further includes other steps as necessary.
The flying step is the same as the flying step in the flying object transfer method of the present invention.
In the flying step in the method for producing a three-dimensional object, the material to be transferred as a three-dimensional modeling agent is piled up as layers on the object to be modeled, and is modeled three-dimensionally.

- 3D modeling agent -
The three-dimensional modeling agent is not particularly limited in shape, material, etc., as with the transfer target material, and can be appropriately selected depending on the purpose. Hereinafter, differences when using a three-dimensional modeling agent as the transfer target material in the manufacturing method of the three-dimensional object will be described.

The average thickness of each layer of the three-dimensional modeling agent applied to the object to be coated is not particularly limited and can be appropriately selected depending on the purpose. It varies depending on the required precision, but is preferably 5 μm or more and 500 μm or less. If the average thickness of each layer of the three-dimensional modeling agent applied to the object to be coated is 5 μm or more and 500 μm or less, it is advantageous in terms of the precision, texture, smoothness, and manufacturing time of the three-dimensional object. Furthermore, it is more preferable that the average thickness of each layer of the three-dimensional modeling agent applied to the object to be coated is 5 μm or more and 100 μm or less. If the average thickness of each layer of the three-dimensional modeling agent applied to the object to be coated is within the more preferable range, it is advantageous in terms of keeping the energy of the laser beam low and suppressing deterioration of the three-dimensional modeling agent.

The three-dimensional modeling agent contains at least a curable material, and may further contain other components as necessary.

--Hardening materials--
The curable material is not particularly limited as long as it is a compound that undergoes a polymerization reaction and is cured by irradiation with active energy rays (ultraviolet rays, electron beams, etc.), heating, etc., and can be appropriately selected depending on the purpose, and examples thereof include active energy ray curable compounds, thermosetting compounds, etc. Among these, materials that are liquid at room temperature are preferred.
The active energy ray-curable compound is a monomer having a relatively low viscosity and a radically polymerizable unsaturated double bond in the molecular structure, and examples of the monomer include a monofunctional monomer and a polyfunctional monomer.

--Other ingredients--
The other components are not particularly limited and can be appropriately selected depending on the purpose. Examples of the other components include water, organic solvents, photopolymerization initiators, surfactants, colorants, stabilizers, water-soluble resins, low-boiling alcohols, surface treatment agents, viscosity modifiers, adhesion promoters, antioxidants, age resistors, crosslinking accelerators, ultraviolet absorbers, plasticizers, preservatives, and dispersants.

<Other steps and other means>
The other steps are not particularly limited and may be appropriately selected depending on the purpose. Examples of the other steps include a supplying step, a three-dimensional modeling head unit scanning step, a step of adjusting the position of the object to be coated, and a control step.

<<Curing process and curing means>>
The hardening step is a step of hardening a three-dimensional modeling agent serving as the transfer target material.
The hardening means is a means for hardening a three-dimensional modeling agent serving as the transfer target material.
The curing means is not particularly limited and can be appropriately selected depending on the purpose. For example, when the three-dimensional modeling agent is an ultraviolet curable material, an ultraviolet irradiator can be used.
The curing step is not particularly limited and can be appropriately selected depending on the purpose. For example, if the three-dimensional modeling agent is an ultraviolet curable material, an ultraviolet ray irradiation step can be mentioned, and can be suitably carried out using an ultraviolet ray irradiation means.

<<3D modeling agent supplying step and 3D modeling agent supplying means>>
The three-dimensional modeling agent supplying step is the same as the supplying step in the image forming method of the present invention, except that the transfer target material is a three-dimensional modeling agent, and therefore a description thereof will be omitted.
The supplying means is the same as the supplying means in the image forming apparatus of the present invention, except that the transfer target material is a three-dimensional modeling agent, and therefore a description thereof will be omitted.

<<3D Modeling Head Unit Scanning Process and 3D Modeling Head Unit Scanning Means>>
The three-dimensional modeling head unit scanning step is a step of scanning a three-dimensional modeling head unit, which is an integral unit of a flying unit and the curing means, in the width direction (X-axis) of the device above an object to be coated.
The three-dimensional modeling head unit scanning means is a means for scanning a three-dimensional modeling head unit, which is an integral combination of a flying unit and the curing means, in the width direction (X-axis) of the device above an object to be coated.
Further, a plurality of the three-dimensional modeling head units may be provided.

<<Object position adjustment step and object position adjustment means>>
The object position adjusting step is a step of adjusting the position of the object in the depth direction (Y axis) and height direction (Z axis) of the apparatus.
The object position adjusting means is a means for adjusting the position of the object in the depth direction (Y axis) and height direction (Z axis) of the device.
The object position adjusting means may be, for example, a base (stage) capable of adjusting the position of the object in the depth direction (Y axis) and height direction (Z axis) of the device.

<<Control process and control means>>
The control process is the same as that of the image forming apparatus described above.
The control means is the same as the control means of the image forming apparatus described above.

Next, an example of the apparatus for manufacturing a three-dimensional object will be described with reference to the drawings.
The number, positions, shapes, etc. of the members of the apparatus for manufacturing a three-dimensional object are not limited to those in this embodiment, and may be any number, position, shape, etc. that is preferable for implementing the present invention.

FIG. 9 is an explanatory diagram showing an example of a manufacturing apparatus for a three-dimensional object.
9, the apparatus 500 for manufacturing a three-dimensional object includes a support substrate 122 for a model as an object to be treated, a stage 123, and a three-dimensional modeling head unit 130. The apparatus 500 for manufacturing a three-dimensional object manufactures a three-dimensional object 124 by laminating the applied three-dimensional modeling agent 22 while curing it.
The three-dimensional modeling head unit 130 is disposed on the upper part of the three-dimensional object manufacturing apparatus 500, and can be scanned by a driving means in the direction indicated by the arrow L in Fig. 9. The three-dimensional modeling head unit 130 has a flying unit 120 and an ultraviolet irradiator 121 as a curing means.

The flying unit 120 is disposed at the center of the three-dimensional modeling head unit 130, and causes the transfer target material 20 to fly downward and be applied to the object support substrate 122 or the transfer target layer 20 that has already been hardened.
The ultraviolet irradiators 121 are disposed on both sides of the flying unit 120 and irradiate the transfer target material 20 that has been flown by the flying unit 120 with ultraviolet light, thereby hardening the transfer target layer 20 .
The object support substrate 122 is disposed at the bottom of the device 500 for manufacturing a three-dimensional object, and serves as a substrate when the three-dimensional object forming head unit 130 forms a layer of the three-dimensional object forming agent 22 .
The stage 123 is disposed below the object support substrate 122, and can move the object support substrate 122 in the vertical direction in Fig. 9 by a driving means. In addition, the stage 123 can be moved in the direction indicated by the arrow H in Fig. 9, and the gap between the 3D object modeling head unit 130 and the 3D object 124 can be adjusted.

In the image forming apparatus and the three-dimensional object manufacturing apparatus, an example in which the object to be treated (recording medium) is transported or moved has been shown, but the present invention is not limited to this. The object to be treated, etc. may be kept stationary and the flying unit, etc. may be moved. Alternatively, both the object to be treated and the flying unit, etc. may be moved.
In addition, when an image is simultaneously formed over the entire surface of the object, both may be stationary at least during recording, with only the laser operating.

The following describes examples of the present invention, but the present invention is not limited to these examples.

(Transfer target material production example 1)
A transfer target material No. 1 (glycerol concentration 98% by mass) was prepared by adding 1 part by mass of spherical nano ferrite powder_M001 (manufactured by Powder Tech Co., Ltd.) as inorganic particles to a dispersion medium having the following composition with respect to a total of 100 parts by mass of the dispersion medium and the inorganic particles, and stirring the mixture.
[Composition of Dispersion Medium]
Vegetable glycerin 98% or more (manufactured by Natural Cosmetics Laboratory Co., Ltd.): 98 parts by weight Pure water: 2 parts by weight

(Transfer target material production example 2)
Transfer target material No. 2 (glycerol concentration 98% by mass) was prepared in the same manner as in Production Example 1 of the transfer target material, except that 1 part by mass of spherical nano ferrite powder_E001 (manufactured by Powder Tech Co., Ltd.) was added as inorganic particles to a total of 100 parts by mass of the dispersion medium and inorganic particles.

(Transfer Target Material Production Example 3)
A transfer target material No. 3 (glycerol concentration 87% by mass) was prepared by adding 1 part by mass of spherical nano ferrite powder_M001 (manufactured by Powder Tech Co., Ltd.) as inorganic particles to a dispersion medium having the following composition with respect to a total of 100 parts by mass of the dispersion medium and the inorganic particles, and stirring the mixture.
[Composition of Dispersion Medium]
Vegetable glycerin 98% or more (manufactured by Natural Cosmetics Laboratory Co., Ltd.): 87 parts by weight Pure water: 13 parts by weight

(Transfer Target Material Production Example 4)
A transfer target material No. 4 (glycerol concentration 94% by mass) was prepared by adding 1 part by mass of spherical nano ferrite powder_M001 (manufactured by Powder Tech Co., Ltd.) as inorganic particles to a dispersion medium having the following composition with respect to a total of 100 parts by mass of the dispersion medium and the inorganic particles, and stirring the mixture.
[Composition of Dispersion Medium]
Vegetable glycerin 98% or more (manufactured by Natural Cosmetics Laboratory Co., Ltd.): 94 parts by weight Pure water: 6 parts by weight

(Transfer Target Material Production Example 5)
A transfer target material No. 5 (CMC concentration 2% by mass) was prepared by adding 1 part by mass of spherical nano ferrite powder_M001 (manufactured by Powder Tech Co., Ltd.) as inorganic particles to a dispersion medium having the following composition with respect to a total of 100 parts by mass of the dispersion medium and the inorganic particles, and stirring the mixture.
[Composition of Dispersion Medium]
Carboxymethyl cellulose (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 2 parts by weight Pure water: 98 parts by weight

(Transfer Target Material Production Example 6)
A transfer target material No. 6 (CMC concentration 3% by mass) was prepared by adding 1 part by mass of spherical nano ferrite powder_M001 (manufactured by Powder Tech Co., Ltd.) as inorganic particles to a dispersion medium having the following composition with respect to a total of 100 parts by mass of the dispersion medium and the inorganic particles, and stirring the mixture.
[Composition of Dispersion Medium]
Carboxymethyl cellulose (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 3 parts by weight Pure water: 97 parts by weight

(Transfer Target Material Production Example 7)
Transfer target material No. 7 (glycerol concentration 87% by mass) was prepared in the same manner as in Production Example 3 of the transfer target material, except that 1 part by mass of MATB-SA4 (manufactured by Toda Kogyo Co., Ltd.) was added as inorganic particles.

(Transfer Target Material Production Example 8)
Transfer target material No. 8 (glycerol concentration 98% by mass) was prepared in the same manner as in Production Example 1 of the transfer target material, except that 0.8 parts by mass of Zeomic Type AJ (manufactured by Sinanen Zeomic Co., Ltd.) and 0.2 parts by mass of Mitsubishi Carbon Black #44 (manufactured by Mitsubishi Chemical Co., Ltd.) were added as inorganic particles in Production Example 1 of the transfer target material.

(Transfer Target Material Production Example 9)
A transfer target material No. 9 (glycerol concentration 44% by mass) was prepared by adding 1 part by mass of spherical nano ferrite powder_M001 (manufactured by Powder Tech Co., Ltd.) as inorganic particles to a dispersion medium having the following composition with respect to a total of 100 parts by mass of the dispersion medium and inorganic particles, and stirring the mixture.
[Composition of Dispersion Medium]
Vegetable glycerin 98% or more (manufactured by Natural Cosmetics Laboratory Co., Ltd.): 44 parts by weight Pure water: 56 parts by weight

Next, for each of the prepared transfer target materials, the ignition residue or evaporation residue, median diameter (D ₅₀ ), and complex viscosity at 25° C. and a shear stress of 200 Pa were measured as follows. The results are shown in Table 1.

<Measurement of ignition residue or evaporation residue>
Based on JIS K0067, the ignition residue or evaporation residue was measured as follows.
-Ignition residue-
After heating the crucible at 500°C, the mass was measured until it cooled down. The target reagent was weighed and poured into the crucible, and then heated to evaporate the liquid. A small amount of sulfuric acid was then added and gradually heated until no more white smoke was produced. After that, the crucible was heated at 500°C, after which the mass of the residue was measured and the percentage of the residue was confirmed. If the ignition residue was 0.1% or less, it was evaluated as "Good", and if the ignition residue exceeded 0.1%, it was evaluated as "Poor".
- Evaporation residue -
10 mg of the sample was weighed and evaporated by heating on a hot plate at 300° C. Thereafter, the mass of the residue was measured, and the percentage of the remaining glycerol was confirmed. If the evaporation residue was 1.0% or less, it was evaluated as “Good”, and if the evaporation residue exceeded 1.0%, it was evaluated as “Poor”.

<Measurement of Median Diameter ( _D50 )>
The median diameter (D ₅₀ ) was measured using a scanning electron microscope (SU8200 series, manufactured by Hitachi High-Technologies Corporation). The obtained image was binarized using image processing software A-zo-kun (manufactured by Asahi Kasei Engineering Co., Ltd.) to calculate the median diameter (D ₅₀ ).

<Measurement of complex viscosity at 25°C and shear stress of 200 Pa>
The complex viscosity was measured under the following conditions using a dynamic viscoelasticity measuring device by a stress control method in which the applied stress was changed and the amount of strain generated was measured. Figure 10 shows the relationship between the glycerol concentration (mass%) and the complex viscosity (mPa s) in transfer target materials Nos. 1, 3, and 9.
- Measurement conditions -
Device name: Rheometer, HAAKE RheoStress 600, manufactured by Thermo Fisher Scientific Temperature: 25°C
Shear stress: 200 Pa

Details of each component in Table 1 are as follows.
*M001: Spherical nano ferrite powder_M001, iron ferrite, manganese ferrite, manufactured by Powder Tech Co., Ltd. *E001: Spherical nano ferrite powder_E001, iron ferrite, manganese ferrite, magnesium ferrite, strontium ferrite, manufactured by Powder Tech Co., Ltd. *MATB-SA4: Iron tetraoxide, carbon, manufactured by Toda Kogyo Co., Ltd. *Zeomic Type AJ, zeolite, manufactured by Sinanen Zeomic Co., Ltd. *Mitsubishi carbon black #44, manufactured by Mitsubishi Chemical Co., Ltd. *Glycerol: Vegetable glycerin 98% or more, manufactured by Natural Cosmetics Research Institute Co., Ltd. *CMC: Carboxymethylcellulose, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

The results in Table 1 and Figure 10 show that as the glycerol concentration increases, the complex viscosity of the material to be transferred increases, and that the complex viscosity of the material to be transferred at 25°C and a shear stress of 200 Pa varies in the range of 1 mPa·s to 1,336 mPa·s.

(Donor Substrate Manufacturing Examples 1 to 9)
Next, each of the obtained transfer target materials was applied to one side of a slide glass (microslide glass S7213, manufactured by Matsunami Glass Industrial Co., Ltd.; transmittance of 532 nm wavelength light is 99%) using a bar coater to prepare donor substrates 1 to 9 having a transfer target layer with an average thickness of 125 μm.

(Examples 1 to 8 and Comparative Examples 1 to 3)
Next, a transfer method was carried out using the combination of the transfer target material and laser irradiation shown in Table 2.
FIG. 11 shows a schematic diagram of a laser irradiation device having an optical vortex laser beam used in the examples and comparative examples.
A pulsed laser with a wavelength of 532 nm and a nanosecond pulse (about 10 ns) was used as the laser light source, and an optical vortex laser beam was generated by controlling the orbital angular momentum and spin angular momentum with a spatial light modulator (SLM) and a λ/4 plate (QWP). The optical vortex laser beam was focused with a focusing lens (Lens) and irradiated onto the transfer target layer from the substrate side of the donor substrate.
In Comparative Examples 2 and 3, the Gaussian beam was used as it was without modulating the phase with a spatial light modulator (SLM).

12 shows the behavior of the transfer target material No. 9 (glycerol concentration 44% by mass, complex viscosity 6 mPa·s) when irradiated with an optical vortex laser beam.
The optical vortex laser beam is irradiated upward from the bottom surface in FIG. 12, and the line A in FIG. 12 indicates the surface of the layer to be transferred.
From the results in Figure 12, after 6.0 μsec from the laser irradiation, the inorganic particles in the transfer target material gather in the center and a liquid column grows with high directionality while rotating, a phenomenon called "spin jet" can be observed. This "spin jet" is thought to be generated by the circular intensity profile of the optical vortex laser beam and the transfer of orbital angular momentum.

13A to 15B show images of droplets of the target material transferred to an object (S1214, water-polished, thickness 1.3, manufactured by Matsunami Glass Industry Co., Ltd.), and the spatial distribution of inorganic particles in the droplets of the target material.
Fig. 13A is a droplet image of the transfer target material No. 9 (glycerol concentration 44% by mass), Fig. 14A is a droplet image of the transfer target material No. 3 (glycerol concentration 87% by mass), and Fig. 15A is a droplet image of the transfer target material No. 1 (glycerol concentration 98% by mass).
The X-axis of the histograms in Figures 13B to 15B represents the distance in percentage from the center of gravity of the droplet of the material to be transferred to the center of gravity of each inorganic particle when the circle-equivalent radius of the droplet of the material to be transferred is taken as 100% (R _G /R _drop *100).
The first Y axis of the histograms in Figures 13B to 15B represents the area ratio obtained by adding up the areas of inorganic particles whose center of gravity is located in annular regions 5 μm apart from the center of gravity of the droplet of the material to be transferred, and dividing the total area by the area of the corresponding annular regions.
The second Y axis of the histograms in Figures 13B to 15B shows the cumulative value (area proportion of inorganic particles in a droplet of the material to be transferred) when the sum of the first Y axis values at all center of gravity distances is set to 100%.
13B to 15B, as the glycerol concentration increases, the distribution of the inorganic particles spreads to all regions of the X-axis, and the area ratio represented by the first Y-axis also approaches a similar value, so it can be seen that the inorganic particles are uniformly distributed in the space of the droplet of the material to be transferred. This is thought to be because a spiral central force acts on the inorganic particles due to the in-plane radiation force caused by the forward scattering force of the optical vortex laser beam and the radial radiation force caused by the total angular momentum, which promotes the movement of the inorganic particles, but the movement of the inorganic particles is hindered by the increase in the complex viscosity of the material to be transferred.

16A to 16C are diagrams for explaining a method for analyzing the spatial distribution of inorganic particles in a droplet of a transfer target material.
Fig. 16A is an image of a droplet on a substrate obtained by transferring transfer target material No. 3 (glycerol concentration 87% by mass) by a dark field microscope observation method. Fig. 16B is a diagram showing the area S _All [μm ² ] of the entire droplet in Fig. 16A and the center of gravity position [X _LG , Y _LG ] of S _All . Fig. 16C shows the area S (Area) [μm ² ] and center of gravity position [X _G , Y _G ] of each inorganic particle dispersed in the droplet in Fig. 16A.

The spatial distribution of inorganic particles in a droplet of the material to be transferred can be analyzed as follows.
The area S _All [μm ² ] of the entire droplet in FIG. 16A was determined by selecting the edge of the droplet using a polygon selection tool in the image analysis software ImageJ, and the area S _All [μm ² ] and the position of the center of gravity [X _LG , Y _LG ] of S _All were determined.
The area of each inorganic particle in Fig. 16C was determined using the binary image creation function of ImageJ or the binary processing function of the image analysis software "Azokun" manufactured by Asahi Kasei Engineering Co., Ltd. In addition, since the droplets have a dome-like shape, it may be difficult to set a threshold value. In such cases, the range designation function of "Azokun" was used to set a binary threshold value for each area where concentration can be identified, and the area was determined.
The area of each of the obtained inorganic particles was designated as S (Area) [μm ² ], and the position of the center of gravity was designated as [X _G , Y _G ].
The image analysis software used was the free image analysis software ImageJ and the image analysis software "Azo-kun" manufactured by Asahi Kasei Engineering Corporation.

R _G is the distance between the center of gravity of the entire droplet [X _LG , Y _LG ] and the center of gravity of each inorganic particle [X _G , Y _G ], calculated using Pythagoras' theorem, and is represented by the following formula (A).

R _drop indicates a circle-equivalent diameter (radius) relative to the area S _All [μm ² ] of the entire droplet, and is expressed by the following mathematical formula (B).

In the case where 5×r≦R _G <5×(r+1),
S _(r+1) −S _(r) = (5×(r+1)) ² π−(5×r) ² π
Here, r = 0, 1, 2, 3, ... and indicates the area of a circular region divided every 5 μm from the center of gravity position [XLG, YLG] of the entire droplet.
The above formulas are used to create the histograms in Figures 13B to 15B. Below, a method for calculating the accumulation and a method for calculating the histograms will be described.

- Calculation of cumulative amount -
The length from the droplet center of gravity [X _LG , Y _LG ] to the circle equivalent diameter R _drop is set to 100%, and R _G /R _drop *100(%) is defined to express the position of the inorganic particle as a percentage.
The sum of the area S (Area) [μm ² ] of the inorganic particles was set to 100%, and the R _G /R _drop *100(%) values were added in ascending order, and the R _G /R _drop *100(%) value corresponding to the particle with a cumulative value of 90% was evaluated.

--Histogram calculation--
In order to normalize each region area [μm ² ] in the range of 5×r≦R _G <5×(r+1), the area S(Area) [μm ² ] of each inorganic particle is divided by the corresponding region area S(r+1)−S(r) to obtain a value S′(Area).
Here, the length from the droplet center of gravity [X _LG , Y _LG ] to the circle equivalent diameter R _drop is set to 100%, and R _G /R _drop *100(%) is defined to express the position of the inorganic particle as a percentage.
When the sum is taken in the newly defined area S' (Area): 5xn≦R _G /R _drop *100(%)<5x(n+1) (n=0, 1, 2, 3 . . . ) and expressed as a histogram, the histograms in Figs. 13B to 15B are obtained.

Therefore, it can be seen that the LIFT method using an optical vortex laser (OV-LIFT) makes it possible to control the spatial distribution of inorganic particles in droplets of the material to be transferred by controlling the complex viscosity of the material to be transferred.

Next, FIG. 17 is a graph showing the relationship between R _G /R _drop *100(%) at which the accumulation (area ratio of inorganic particles in a droplet of the material to be transferred) shown in FIG. 13B becomes 90% and the complex viscosity (mPa·s) of the material to be transferred.
From the results in FIG. 17, under the condition of a complex viscosity of 88 mPa·s (glycerol concentration of 87% by mass), the distribution of inorganic particles in the droplets of the material to be transferred is such that 90% of the inorganic particles are present in the range of R _G /R _drop *100 = 70%.
17, it can be seen that the change in spatial distribution of inorganic particles with respect to the change in complex viscosity (mPa·s) is significant in the region where the complex viscosity of the transfer target material is less than 88 mPa·s, compared to the region where the complex viscosity of the transfer target material is 88 mPa·s or more. From this, it was found that in order to transfer the inorganic particles dispersed in the transfer target material uniformly without agglomeration, it is necessary to use a transfer target material with a complex viscosity of 88 mPa·s or more and 4,300 mPa·s or less.
In addition, the dispersion medium for the material to be transferred used in the above experiments was selected to have an ignition residue of 0.1% or less or an evaporation residue of 1.0% or less, and since it does not contain impurities, it is possible to transfer the material to be transferred with extremely high purity.

<Evaluation of spatial distribution of inorganic particles>
The droplets on the object were observed using a microscope, and the value of R _G /R _drop *100(%) corresponding to the inorganic particles with a cumulative value of 90% was calculated and evaluated according to the following criteria. The results are shown in Table 2.
[Evaluation Criteria]
◎: 80% or more 〇: 70% or more but less than 80% ×: Less than 70%

From the above results, it is possible to transfer light absorbing materials that absorb a light vortex laser beam of a specified wavelength without agglomeration in a projectile transfer method using an optical vortex laser beam. The spatial distribution of the light absorbing materials dispersed in the transfer target material is maintained on the object to which the material is applied. Therefore, the thickness of the transfer target material becomes constant, and uneven thickness of the transfer target material, which is a problem in printing technology in general, is suppressed, and uneven brightness and color on the image are improved. Furthermore, the inventors' studies have confirmed that even when a transfer target material with a viscosity of 100 Pa·s or more is used, there is no aggregation of the light absorbing material and good transfer is possible. Furthermore, by using a dispersion medium with an ignition residue of 0.1% or less or an evaporation residue of 1.0% or less, it is possible to transfer a high-purity light absorbing material.

For example, aspects of the present invention are as follows.
<1> A step of flying the transfer target material by irradiating an optical vortex laser beam from the substrate side of the donor substrate to a donor substrate having a substrate and a transfer target material including a light absorbing material and a dispersion medium arranged on the substrate, and flying the transfer target material;
and an application step of applying the transferred material to an object to be transferred,
The method for transferring projectiles is characterized in that the complex viscosity of the material to be transferred at 25° C. and a shear stress of 200 Pa is 88 mPa·s or more and 4,300 mPa·s or less.
<2> The method for transferring a flying object according to <1>, wherein the light absorbing material is an inorganic material.
<3> The flying object transferring method according to <2>, wherein the inorganic material has a median diameter (D ₅₀ ) of 50 nm or more and 500 nm or less.
<4> The method for transferring a flying object according to any one of <1> to <3>, wherein the ignition residue in the dispersion medium is 0.1% or less, or the evaporation residue is 1.0% or less.
<5> The method for transferring a flying object according to any one of <1> to <4>, wherein the dispersion medium is an aqueous glycerol solution.
<6> A donor substrate having a substrate and a transfer target material including a light absorbing material and a dispersion medium arranged on the substrate, the donor substrate is irradiated with an optical vortex laser beam from the substrate side of the donor substrate to the transfer target material, and a flying means for flying the transfer target material;
and an application means for applying the flying transfer target material to an object to be transferred,
The projectile transfer device is characterized in that the complex viscosity of the material to be transferred at 25° C. and a shear stress of 200 Pa is 88 mPa·s or more and 4,300 mPa·s or less.
<7> An image forming method, comprising the flying object transfer method according to any one of <1> to <5> above.
<8> A method for producing a three-dimensional object, comprising the method for transferring a flying object according to any one of <1> to <5>.

The flying object transfer method described in any one of <1> to <5>, the flying object transfer device described in <6>, the image forming method described in <7>, and the three-dimensional object manufacturing method described in <8> can solve the various problems in the past and achieve the object of the present invention.

1 Flying means 11 Laser beam 12 Optical vortex laser beam 20 Transfer target material (transfer target layer)
30: object to be applied 31: recording medium 32: substrate 40: donor substrate 300, 301, 301a: projectile transfer device 302-307: image forming device 400, 401: image forming device 500: device for manufacturing a three-dimensional object

Patent No. 6455588

Claims (7)

A flying process in which a donor substrate is provided with a substrate and a transfer target material including a light absorbing material and a dispersion medium on the substrate, and the transfer target material is irradiated with an optical vortex laser beam from the substrate side of the donor substrate to fly the transfer target material;
and an application step of applying the transferred material to an object to be transferred,
A method for transferring projectiles, characterized in that the complex viscosity of the material to be transferred at 25° C. and a shear stress of 200 Pa is 88 mPa·s or more and 1,000 mPa·s or less. The flying object transfer method according to claim 1, wherein the light absorbing material is an inorganic material. The flying object transfer method according to claim 2 , wherein the inorganic material has a median diameter (D ₅₀ ) of 50 nm or more and 500 nm or less. The method for transferring a flying object according to any one of claims 1 to 3, wherein the ignition residue in the dispersion medium is 0.1% or less, or the evaporation residue is 1.0% or less. The method for transferring a projectile according to any one of claims 1 to 4, wherein the dispersion medium is an aqueous glycerol solution. 6. An image forming method comprising a step of the flying object transfer method according to claim 1. A method for producing a three-dimensional object, comprising the steps of the flying object transfer method according to any one of claims 1 to 5.