JP6763413B2 - Ink, printing equipment, printing method and manufacturing method of modeled object - Google Patents

Description

The present invention manufactures inks, printing devices, printing methods, and shaped objects for forming a photothermal conversion layer for partially or wholly expanding a heat-expandable sheet that foams and expands according to the amount of heat absorbed. Regarding the method.

Conventionally, a heat-expandable sheet in which a heat-expandable layer containing a heat-expandable material that foams and expands according to the amount of heat absorbed is formed on one surface of the base material sheet is known. By forming a photothermal conversion layer that converts light into heat on this heat-expandable sheet and irradiating the photo-heat conversion layer with light, the heat-expandable layer can be partially or wholly expanded. Further, a method of forming a three-dimensional model (three-dimensional image) on a heat-expandable sheet by changing the shape of the photothermal conversion layer is also known (see, for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 64-28660 Japanese Unexamined Patent Publication No. 2001-150812

Conventionally, the photothermal conversion layer has been formed by using black ink containing carbon. However, the black ink used for printing the photothermal conversion layer may affect the color tone of the formed stereoscopic image. For example, when a photothermal conversion layer is formed on the surface of a heat-expandable sheet and a color image is printed on the photothermal conversion layer using color ink, the color image may be dull due to the black ink contained in the photothermal conversion layer. Further, in a region where a photothermal conversion layer is formed on the surface of the heat-expandable sheet and is desired to be expanded without performing color printing, the color of the photothermal conversion layer appears as it is.

Therefore, in order to reduce the influence on the color tone of the stereoscopic image (modeled object), an ink, a printing device, a printing method, and a manufacturing method of the modeled object capable of forming a photothermal conversion layer with suppressed color tint are required. Was being printed.

The present invention has been made in view of the above circumstances, and provides an ink for forming a photothermal conversion layer in which color is suppressed, and a printing apparatus, a printing method, and a method for manufacturing a modeled object using the ink. The purpose is to do.

In order to achieve the above object, the ink according to the present invention is an ink for forming a pattern of a photothermal conversion layer applied to the heating so as to overlap the thermal expansion layer that expands by a predetermined heating, and is infrared. A predetermined region containing a tungsten oxide or a hexaborometal compound as an inorganic infrared absorber having a higher coefficient of linearity than the visible light region in at least one of the regions, and formed so as to overlap the thermal expansion layer. by the fact that tungsten-based oxide or the hexaboride metal compound is acceptance in the ink-receiving layer of the coating by the ink-receiving layer with respect to the surface irregularities of the thermal expansion layer which is formed with the heating while to maintain the sex, the ink-receiving layer of the tungsten-based oxide or the hexaboride metal compound is accepting moiety, Ru denatured in the photothermal conversion layer, it is characterized.

In order to achieve the above object, the printing apparatus according to the present invention has a tungsten oxide or hexabolic as an inorganic infrared absorber having a higher absorbance in at least one of the infrared regions than in the visible light region. Printing an ink containing a metal compound on an ink receiving layer formed so as to overlap the heat expansion layer by a predetermined coating means to allow the ink receiving layer to receive the tungsten oxide or the hexaborometal compound. in, while to maintain the coverage by the ink-receiving layer with respect to the surface irregularities of the thermal expansion layer formed with the heat, the ink-receiving layer of the ink is printed area, the light-to-heat conversion layer Ru denatured, characterized in that.

In order to achieve the above object, the printing method according to the present invention comprises a tungsten oxide or hexabolic as an inorganic infrared absorber having a higher absorbance in at least one of the infrared regions than in the visible light region. By printing an ink containing a metal compound on an ink receiving layer formed so as to overlap the heat expansion layer and allowing the tungsten oxide or the hexaborometal compound to be received by the ink receiving layer, the ink is accompanied by heating. while to maintain the coverage by the ink-receiving layer with respect to the surface irregularities of the thermal expansion layer formed Te, an ink-receiving layer of the ink is printed area, Ru denatured in the light-to-heat conversion layer, it It is characterized by.

In order to achieve the above object, the method for producing a modeled product according to the present invention is a method for producing a modeled product by expanding at least a part of a thermal expansion layer using a photothermal conversion layer, and at least in the infrared region. On an ink receiving layer formed so as to overlap an ink containing a tungsten oxide or a hexaborometal compound as an inorganic infrared absorber having a higher coefficient of linearity than that in the visible light region in any region. By printing on the surface of the tungsten oxide or the hexaborometal compound to allow the ink receiving layer to receive the surface irregularities of the thermal expansion layer formed by heating, the ink receiving layer is used. while to maintain the coverage, the ink-receiving layer of the ink is printed area comprises the photothermal conversion layer photothermal conversion layer forming step of Ru denatured in, characterized in that.

According to the present invention, it is possible to provide an ink for forming a photothermal conversion layer in which color is suppressed, and a printing apparatus, a printing method, and a method for manufacturing a modeled object using the ink.

It is a figure which shows the distribution of the absorbance of each material, the sunlight intensity spectrum, and the sunlight specific strength of a halogen lamp. The radiant energy (%) from the halogen lamp in each wavelength, a graph combined multiplying the extinction coefficient of cesium tungsten oxide or LaB _6. It is sectional drawing which shows the outline of the thermal expansion sheet which concerns on embodiment. It is a figure which shows the outline of the stereoscopic image formation unit which concerns on embodiment. It is a figure which shows the outline of the printing unit which comprises the ink which concerns on embodiment. It is a flowchart which shows the stereoscopic image formation process which concerns on embodiment. It is a figure which shows the stereoscopic image formation process which concerns on embodiment. It is a flowchart which shows the stereoscopic image formation process which concerns on a modification. It is a figure which shows the stereoscopic image formation process which concerns on a modification. (A) is a figure which shows the black density and foaming height after printing of the conventional black ink. (B) is a figure which shows the black density of the ink of Example 1 before printing, the black density after printing, and the foaming height. It is an image of a photothermal conversion layer formed by using the ink according to Example 2.

Hereinafter, the ink, the printing apparatus, the printing method, and the manufacturing method of the modeled object according to the embodiment of the present invention will be described with reference to the drawings. In the present embodiment, as will be described in detail later, as an example of the printing apparatus, the stereoscopic image forming system 50 whose outline is shown in FIGS. 4 (a) to 4 (c) will be described as an example. Further, as an example of the printing method, a configuration for forming a modeled object (three-dimensional image) having unevenness by using the stereoscopic image forming system 50 will be described as an example. Further, the ink 10 of the present embodiment is installed in the printing unit shown in FIG. 5 provided in the stereoscopic image forming system 50, and is used for forming a photothermal conversion layer on the heat-expandable sheet 20.

In the present embodiment, the modeled object is expressed by the ridge of the thermal expansion layer 22 on the surface of the thermal expansion sheet 20. Further, in the present specification, the "modeled object" broadly includes shapes such as simple shapes, geometric shapes, characters, and decorations. Here, the decoration evokes a sense of beauty through the sense of sight and / or the sense of touch. In addition, "modeling (or modeling)" is not limited to simply forming a modeled object, but also includes concepts such as decoration to add decoration and decoration to form decoration. Further, the decorative model refers to a model formed as a result of decoration or decoration.

The ink 10 according to the present embodiment contains an inorganic infrared absorber, and further contains a solvent (water or organic solvent), a colorant (dye or pigment), a dispersant, a penetrant, an antidrying agent, a pH adjuster, a preservative, and the like. It may contain any or all selected from surfactants and the like. These are contained in the ink 10 at an arbitrary concentration.

When the ink 10 is a water-based ink, it contains an inorganic infrared absorber, water, and an aqueous organic solvent. The aqueous organic solvent is not limited to this, but polyalkylene glycols such as polyethylene glycol and polypropylene glycol, alkylene glycols such as ethylene glycol and triethylene glycol, glycerin, glycerols, triethylene glycol monobutyl ether and ethylene. Examples thereof include lower alkyl ethers of polyhydric alcohols such as glycol methyl (ethyl) ether and diethylene glycol methyl (ethyl) ether, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ethanol or isopropanol. .. These aqueous organic solvents are contained in the ink 10 as the above-mentioned moisturizing agent, surfactant and the like. Further, the ink 10 may contain triethanolamine as a pH adjuster, or may contain other additives.

Further, the ink 10 of the present embodiment is used, for example, in the inkjet printing unit 52 shown in FIG. Specifically, the ink 10 is filled in the cartridge and installed in the printing unit 52 as shown in FIG.

The ink 10 may or may not contain a colorant. When the ink 10 is used to form a photothermal conversion layer for heating a specific region of the heat-expandable sheet 20 as in the present embodiment, the photothermal conversion layer does not affect the color tint of the color ink. Is preferable. Therefore, in applications such as this embodiment, it is preferable that the ink 10 does not contain a colorant. When a colorant is contained, the color of the colorant is preferably a color that is difficult to see, such as white or yellow. The color of the colorant is not particularly limited. For example, when the color of the ink 10 does not particularly affect the appearance of the heat-expandable sheet 20, such as when the ink 10 is formed in a place where it is difficult to see, or when the heat-expandable sheet 20 itself is colored. Alternatively, depending on the case where it is preferable to color the printed area so that the printed area can be seen, the colorant may be appropriately selected from cyan, magenta, black, etc. in addition to white and yellow, and may be any color other than these. You may. Further, the concentration of the colorant in the ink 10 is also arbitrary.

Further, as the inorganic infrared absorber contained in the ink 10, an inorganic material having a higher light absorption rate (absorbency) than that in the visible light region is used in at least one of the infrared regions. The inorganic infrared absorber preferably has a higher light absorption rate than the visible light region, particularly in the near infrared region. By selecting a material having a high light transmittance (low absorption rate) in the visible light region, the visible light transmittance of the ink 10 can be improved and the tint of the ink 10 can be suppressed. In particular, as compared with the conventionally used ink using carbon, it is possible to prevent the color tint of the color ink layer from becoming dull due to the photothermal conversion layer printed using the ink 10.

In this embodiment, as the inorganic infrared absorber, for example, a metal oxide, a metal boride, a metal nitride or the like is used.

Specifically, examples of the metal oxide include tungsten oxide compounds, indium oxide, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), titanium oxide, zirconium oxide, tantalum oxide, cesium oxide, and zinc oxide. Etc. can be used.

Further, as the metal boride, a polyboride metal compound is preferable, and a hexaboride metal compound is particularly preferable, and lanthanum hexaboride (LaB ₆ ), cerium hexaboride (CeB ₆ ), and placeodium hexaboride (PrB ₆ ) are preferable. ), hexaboride neodymium _(NdB 6), hexaboride gadolinium _(GdB 6), hexaboride terbium _(TbB 6), hexaboride dysprosium _(DYB 6), hexaboride holmium _(HoB 6), six Yttrium borides (YB ₆ ), cerium hexaboride (SmB ₆ ), europium hexaboride (EuB ₆ ), erbium hexaboride (ErB ₆ ), turium hexaboride (TmB ₆ ), itterbium hexaboride (YbB) ₆ ), lutetium hexaboride (LuB ₆ ), lanthanum hexaboride ((La, Ce) B ₆ ), strontium hexaboride (SrB ₆ ), calcium hexaboride (CaB ₆ ), etc. Use one or more materials to be used.

Examples of the metal nitride include titanium nitride, niobium nitride, tantalum nitride, zirconium nitride, hafnium nitride, and vanadium nitride.

Tungsten oxide compounds are represented by the following general formula.
MxWyOz ... (I)
Here, the element M is at least one element selected from the group consisting of Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe and Sn, W is tungsten and O is oxygen. is there.
Further, the value of x / y preferably satisfies the relationship of 0.001 ≦ x / y ≦ 1.1, and in particular, x / y is preferably around 0.33. In addition, the value of z / y preferably satisfies the relationship of 2.2 ≦ z / y ≦ 3.0. Specifically, Cs _0.33 WO ₃ , Rb _0.33 WO ₃ , K _0.33 WO ₃ , Tl _0.33 WO ₃ , and the like.

Among the above, lanthanum hexaboride compounds or tungsten oxide compounds are preferable, and lanthanum hexaboride is particularly high in the near infrared region (low transmittance) and high in the visible light region. (LaB ₆ ) or cesium tungsten oxide is preferable. Any one of the above-mentioned inorganic infrared absorbers may be used alone, or two or more different materials may be used in combination.

The ink 10 of the present embodiment contains, but is not limited to, an inorganic infrared absorber in a proportion of 20% by weight to 0.10% by weight.

Next, FIG. 1 shows the transmittance distributions of carbon, ITO, ATO, cesium tungsten oxide and LaB ₆ , the spectrum of sunlight, and the spectral distribution of a halogen lamp. In FIG. 1, the spectrum of sunlight and the spectral distribution of the halogen lamp are both intensities with a peak of 100. As shown in FIG. 1, carbon conventionally used for forming a photothermal conversion layer exhibits a substantially constant low transmittance in each wavelength range. In addition, carbon has a low transmittance (high absorptivity) even in the visible light region and exhibits a black color. On the other hand, ITO and ATO, which are examples of metal oxides, have a particularly high transmittance in the visible light region. Further, ITO and ATO have lower transmittance in the near infrared region than in the visible light region, and further exhibit low transmittance (high absorbance) in the mid-infrared region. Further, as an example of the tungsten oxide, cesium tungsten oxide has a lower transmittance in the near infrared region than in the visible light region. In addition, lanthanum hexaboride, which is an example of a metal hexaboride compound, exhibits lower transmittance in the near infrared region within the infrared region than in the visible light region.

Further, FIG. 1 shows the spectral distribution of the halogen lamp used in the irradiation unit. The light emitted from the halogen lamp exhibits high intensity especially in the near infrared region. The tungsten cesium oxide and the lanthanum hexaboride shown in FIG. 1 have low transmittance and high absorbance in the near infrared region where the light emitted from the halogen lamp shows strong intensity. Therefore, when a halogen lamp is used as an irradiation unit, tungsten cesium oxide or LaB ₆ is preferable because it can absorb light particularly efficiently in the near infrared region where the light emitted from the halogen lamp shows strong intensity. In addition, materials other than tungsten cesium oxide and lanthanum hexaboride can be used as long as they are materials that exhibit high absorption in the near infrared region.

Further, FIG. 2 is a graph obtained by multiplying the radiant energy (%) from the halogen lamp at each wavelength by the absorbance of tungsten cesium oxide or LaB ₆ . As the radiant energy (%), the ratio (%) of the radiant energy at the temperature (2900K) to the blackbody radiation energy (the peak is 100%) at the reference temperature (2000K) is used. It can be seen that tungsten cesium oxide can absorb energy well, especially in the near-infrared region and the mid-infrared region.

Further, the value obtained by integrating this graph with wavelength corresponds to the amount of energy that can be absorbed by tungsten cesium oxide or LaB ₆ . Therefore, the ratio of this integral value is proportional to the foam height unless the foam height of the heat-expandable material is saturated.
Specifically, the integrated value is
Tungsten cesium oxide: LaB ₆ = 1: 0.58
Is. Therefore, the photothermal conversion layer using LaB ₆ has a height of about 0.58 times that of the photothermal conversion layer using tungsten cesium oxide.

Next, the heat-expandable sheet 20 forming the photothermal conversion layer with the ink 10 of the present embodiment will be described with reference to the drawings. As shown in FIG. 3, the heat-expandable sheet 20 includes a base material 21, a heat-expandable layer 22, and an ink receiving layer 23. Further, as will be described in detail later, the heat-expandable sheet 20 is a three-dimensional image forming system 50 whose outline is shown in FIGS. 4 (a) to 4 (c), and is printed and has irregularities (three-dimensional shape). Image) is formed.

The base material 21 is a sheet-like member (including a film) that supports the thermal expansion layer 22 and the like. As the base material 21, paper such as wood-free paper or a commonly used plastic film such as polypropylene, polyethylene terephthalate (PET), or polybutylene terephthalate (PBT) can be used. Further, it is also possible to use a cloth or the like as the base material 21. The base material 21 does not rise on the opposite side (lower side shown in FIG. 3) of the base material 21 when the thermal expansion layer 22 expands by foaming entirely or partially, and also causes wrinkles or large waves. It is strong enough not to hit. In addition, it has heat resistance sufficient to withstand the heating when the thermal expansion layer 22 is foamed.

The thermal expansion layer 22 is formed on one surface (upper surface shown in FIG. 3) of the base material 21. The thermal expansion layer 22 is a layer that expands to a size corresponding to the heating temperature and heating time, and a plurality of thermal expansion materials (thermally expandable microcapsules, microcapsules) are dispersedly arranged in the binder. Further, as will be described in detail later, in the present embodiment, a photothermal conversion layer is formed on the ink receiving layer 23 provided on the upper surface (front surface) of the base material 21 and / or on the lower surface (back surface) of the base material 21. By irradiating with light, the region provided with the photothermal conversion layer is heated. Since the thermal expansion layer 22 absorbs heat generated in the photothermal conversion layer on the front surface and / or the back surface of the thermal expansion sheet 20, foams and expands, only a specific region of the thermal expansion sheet 20 is selectively selected. Can be inflated.

As the binder, a thermoplastic resin selected from vinyl acetate-based polymers, acrylic-based polymers and the like is used. Further, the heat-expandable microcapsules are obtained by encapsulating propane, butane, and other low-boiling vaporizable substances in a shell of a thermoplastic resin. The shell is formed from, for example, a thermoplastic resin selected from polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic acid ester, polyacrylonitrile, polybutadiene, and copolymers thereof. The average particle size of the heat-expandable microcapsules is about 5 to 50 μm. When the microcapsules are heated above the thermal expansion start temperature, the polymer shell made of resin softens, the low boiling point vaporizable substance contained therein evaporates, and the capsule expands due to the pressure. Although it depends on the characteristics of the microcapsules used, the microcapsules expand to about 5 times the particle size before expansion.

The ink receiving layer 23 is formed on the thermal expansion layer 22. The ink receiving layer 23 is a layer that receives and fixes ink used in the printing process, for example, ink of an inkjet printer. The ink receiving layer 23 is formed by using a material that is widely used depending on the ink used in the printing process. For example, when water-based ink is used, the ink receiving layer 23 is formed by using a material selected from porous silica, polyvinyl alcohol (PVA), and the like. When the photothermal conversion layer is also formed on the back surface of the base material 21, an ink receiving layer may be formed on the back surface of the base material 21 as well.

(3D image formation system)
Next, a stereoscopic image forming system 50 for forming a stereoscopic image by printing on the heat-expandable sheet 20 of the present embodiment will be described. As shown in FIGS. 4A to 4C, the stereoscopic image forming system 50 includes a control unit 51, a printing unit 52, an expansion unit 53, a display unit 54, a top plate 55, and a frame 60. And. FIG. 4A is a front view of the stereoscopic image forming system 50, FIG. 4B is a plan view of the stereoscopic image forming system 50 with the top plate 55 closed, and FIG. 4C is a plan view of the stereoscopic image forming system 50. , Is a plan view of the stereoscopic image forming system 50 in a state where the top plate 55 is opened. In FIGS. 4 (a) to 4 (c), the X direction is the same as the horizontal direction, the Y direction is the same as the transport direction D in which the sheet is transported, and the Z direction is the same as the vertical direction. is there. The X, Y and Z directions are orthogonal to each other.

The control unit 51, the printing unit 52, and the expansion unit 53 are respectively placed in the frame 60 as shown in FIG. 4A. Specifically, the frame 60 includes a pair of substantially rectangular side plates 61 and a connecting beam 62 provided between the side plates 61, and a top plate 55 is passed above the side plates 61. Further, the printing unit 52 and the expansion unit 53 are installed side by side in the X direction on the connecting beam 62 passed between the side plates 61, and the control unit 51 is fixed under the connecting beam 62. The display unit 54 is embedded in the top plate 55 so that the height coincides with the upper surface of the top plate 55.

The control unit 51 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and controls the printing unit 52, the expansion unit 53, and the display unit 54.

The printing unit 52 is an inkjet printing device. As shown in FIG. 4C, the printing unit 52 includes a carry-in unit 52a for carrying in the heat-expandable sheet 20 and a carry-out part 52b for carrying out the heat-expandable sheet 20. The printing unit 52 prints the designated image on the front surface or the back surface of the heat-expandable sheet 20 sucked from the carry-in unit 52a, and discharges the heat-expandable sheet 20 on which the image is printed from the carry-out unit 52b. Further, the printing unit 52 includes color inks (cyan (C), magenta (M), yellow (Y)) for forming the color ink layer 42, which will be described later, and a front side photothermal conversion layer 41 and a back side photothermal conversion layer. An ink 10 for forming the 43 and the ink 10 is provided. In addition, in order to form a black or gray color in the color ink layer 42, a black color ink that does not contain carbon black may be further provided as the color ink.

The printing unit 52 acquires color image data indicating a color image (color ink layer 42) to be printed on the surface of the heat-expandable sheet 20 from the control unit 51, and based on the color image data, color ink (cyan, magenta, A color image (color ink layer 42) is printed using (yellow). The black or gray color of the color ink layer is formed by mixing the three colors of CMY or by further using a black color ink that does not contain carbon black.

Further, the printing unit 52 prints the front side photothermal conversion layer 41 using the ink 10 based on the surface expansion data which is the data indicating the portion to be expanded and expanded on the surface of the heat-expandable sheet 20. Similarly, the back side photothermal conversion layer 43 is printed using the ink 10 based on the back surface foaming data which is the data indicating the portion to be expanded and expanded on the back surface of the heat expandable sheet 20. The higher the density of the ink 10, the higher the expansion height of the thermal expansion layer 22. Therefore, the density of the ink 10 is determined by the area gradation method or the like so as to correspond to the target height.

FIG. 5 shows a detailed configuration of the printing unit 52. As shown in FIG. 5, the printing unit 52 can reciprocate in the main scanning direction D2 (X direction) orthogonal to the sub-scanning direction D1 (Y direction), which is the direction in which the thermally expandable sheet 20 is conveyed. To be equipped.

A print head 72 for executing printing and an ink cartridge 73 (73e, 73c, 73m, 73y) containing ink are attached to the carriage 71. The ink cartridges 73e, 73c, 73m, and 73y contain the ink 10, cyan C, magenta M, and yellow Y color inks of the present embodiment, respectively. Each ink is ejected from a corresponding nozzle of the print head 72.

The carriage 71 is slidably supported by the guide rail 74 and is narrowly held by the drive belt 75. The carriage 71 moves in the main scanning direction D2 together with the print head 72 and the ink cartridge 73 by driving the drive belt 75 by the rotation of the motor 75 m.

A platen 78 is provided at a position facing the print head 72 at the lower portion of the frame 77. The platen 78 extends in the main scanning direction D2 and forms a part of the transport path of the heat-expandable sheet 20. The transport path of the heat-expandable sheet 20 is provided with a paper feed roller pair 79a (lower roller is not shown) and a paper discharge roller pair 79b (lower roller is not shown). The paper feed roller pair 79a and the paper discharge roller pair 79b convey the heat-expandable sheet 20 supported by the platen 78 in the sub-scanning direction D1.

The printing unit 52 is connected to the control unit 51 via a flexible communication cable 76. The control unit 51 controls the print head 72, the motor 75 m, the paper feed roller pair 79a, and the paper output roller pair 79b via the flexible communication cable 76. Specifically, the control unit 51 controls the paper feed roller pair 79a and the paper discharge roller pair 79b to convey the heat-expandable sheet 20. Further, the control unit 51 rotates the motor 75 m to move the carriage 71, and conveys the print head 72 to an appropriate position in the main scanning direction D2.

The expansion unit 53 is an expansion device that expands the heat-expandable sheet 20 by applying heat. As shown in FIG. 4C, the expansion unit 53 includes a carry-in portion 53a for carrying in the heat-expandable sheet 20 and a carry-out part 53b for carrying out the heat-expandable sheet 20. The expansion unit 53 expands by applying heat while conveying the heat-expandable sheet 20 carried in from the carry-in portion 53a, and carries out the expanded heat-expandable sheet 20 from the carry-out part 53b. The expansion unit 53 includes an irradiation unit (not shown) inside. The irradiation unit is fixed in the expansion unit 53, and the entire thermal expansion sheet 20 is heated by moving the thermal expansion sheet 20 at a constant speed in the vicinity of the irradiation unit. When printing at a low density of ink 10 so that the photothermal conversion layer is difficult to see, the target expansion height can be obtained by slowing down the transport speed and lengthening the time of irradiating light. It is possible.

The irradiation unit is, for example, a halogen lamp, and the heat-expandable sheet 20 has a near-infrared region (wavelength 750 to 1400 nm), a visible light region (wavelength 380 to 750 nm), or a mid-infrared region (wavelength 140 to 4000 nm). ) Is irradiated. The wavelength of the light emitted from the halogen lamp has the characteristics shown in FIG. 1, and particularly strongly irradiates the light in the near infrared region. When a material having a high absorption rate in the near-infrared region as compared with the visible light region is used as the inorganic infrared absorber contained in the ink 10 of the present embodiment, the halogen lamp has a wavelength region having a strong intensity. , It is preferable because the wavelength range that the inorganic infrared absorber efficiently absorbs is the same. In addition to the halogen lamp, a xenon lamp or the like can also be used as the irradiation unit. In this case, it is preferable to select a material having a high absorption rate in the wavelength range where the irradiation intensity of the lamp is high, as the inorganic infrared absorber, according to the lamp to be used. Further, in the region where the photothermal conversion layer is printed, light is converted into heat more efficiently than in the region where the photothermal conversion layer is not printed. Therefore, in the thermal expansion layer 22, the region on which the photothermal conversion layer is printed is mainly heated, and as a result, the region on which the photothermal conversion layer is printed expands in the thermal expansion layer 22.

The display unit 54 is composed of a touch panel or the like. The display unit 54 displays an image (star shown in FIG. 4B) printed on the heat-expandable sheet 20 by the printing unit 52, for example, as shown in FIG. 4B. Further, the display unit 54 displays an operation guide or the like, and the user can operate the stereoscopic image forming system 50 by touching the display unit 54.

(Three-dimensional image formation processing)
Next, referring to the flowchart shown in FIG. 6 and the cross-sectional view of the heat-expandable sheet 20 shown in FIGS. 7 (a) to 7 (e), the stereoscopic image forming system 50 creates a stereoscopic image on the heat-expandable sheet 20. The flow of the processing to be formed will be described. Since the modeled object is manufactured by the stereoscopic image forming process, the stereoscopic image forming process is also a method for manufacturing the modeled object.

First, the user prepares the heat-expandable sheet 20 before the stereoscopic image is formed, and designates the color image data, the front surface foaming data, and the back surface foaming data via the display unit 54. Then, the heat-expandable sheet 20 is inserted into the printing unit 52 with its surface facing upward. The printing unit 52 prints a photothermal conversion layer (front side photothermal conversion layer 41) on the surface of the inserted heat-expandable sheet 20 (step S1). The front side photothermal conversion layer 41 is a layer formed by the ink 10 described above. The printing unit 52 ejects the ink 10 of the present embodiment onto the surface of the heat-expandable sheet 20 according to the designated surface foaming data. As a result, as shown in FIG. 7A, the front photothermal conversion layer 41 is formed on the ink receiving layer 23. For ease of understanding, the front photothermal conversion layer 41 is shown to be formed on the ink receiving layer 23, but more accurately, the ink 10 is received in the ink receiving layer 23. Therefore, the front side photothermal conversion layer 41 is formed in the ink receiving layer 23.

Second, the user inserts the heat-expandable sheet 20 on which the front-side photothermal conversion layer 41 is printed into the expansion unit 53 with its surface facing upward. The expansion unit 53 heats the inserted heat-expandable sheet 20 from the surface (step S2). Specifically, the expansion unit 53 irradiates the surface of the heat-expandable sheet 20 with light by the irradiation unit. The front side photothermal conversion layer 41 printed on the surface of the heat-expandable sheet 20 generates heat by absorbing the irradiated light. As a result, as shown in FIG. 7B, the area of the heat-expandable sheet 20 on which the front side photothermal conversion layer 41 is printed rises and expands. Further, in FIG. 7B, when the density of the ink 10 of the front side photothermal conversion layer 41 shown on the right is darker than that of the front side photothermal conversion layer 41 shown on the left, as shown in the figure, a darkly printed area is displayed. It is possible to inflate higher.

Third, the user inserts the heat-expandable sheet 20 whose surface is heated and expanded into the printing unit 52 with its surface facing upward. The printing unit 52 prints a color image (color ink layer 42) on the surface of the inserted heat-expandable sheet 20 (step S3). Specifically, the printing unit 52 ejects cyan C, magenta M, and yellow Y inks onto the surface of the heat-expandable sheet 20 according to the designated color image data. As a result, as shown in FIG. 7C, a color ink layer 42 is formed on the ink receiving layer 23 and the front side photothermal conversion layer 41.

Fourth, the user inserts the heat-expandable sheet 20 on which the color ink layer 42 is printed into the expansion unit 53 with its back surface facing upward. The expansion unit 53 heats the inserted heat-expandable sheet 20 from the back surface to dry the color ink layer 42 formed on the front surface of the heat-expandable sheet 20 (step S4). Specifically, the expansion unit 53 irradiates the back surface of the heat-expandable sheet 20 with light by the irradiation unit to heat the color ink layer 42 and volatilize the solvent contained in the color ink layer 42.

Fifth, the user inserts the heat-expandable sheet 20 on which the color ink layer 42 is printed into the printing unit 52 with its back surface facing upward. The printing unit 52 prints a photothermal conversion layer (back side photothermal conversion layer 43) on the back surface of the inserted heat-expandable sheet 20 (step S5). The photothermal conversion layer 43 on the back side is a layer formed by the ink 10 of the present embodiment, similarly to the front side photothermal conversion layer 41 printed on the surface of the heat-expandable sheet 20. The printing unit 52 ejects the ink 10 to the back surface of the heat-expandable sheet 20 according to the designated back surface foaming data. As a result, as shown in FIG. 7D, the back side photothermal conversion layer 43 is formed on the back surface of the base material 21. As for the back side photothermal conversion layer 43, when the density of the ink 10 of the back side photothermal conversion layer 43 shown on the left is darker than that of the back side photothermal conversion layer 43 shown on the right, the darkly printed area is higher as shown in the figure. It can be inflated.

Sixth, the user inserts the heat-expandable sheet 20 on which the back side photothermal conversion layer 43 is printed into the expansion unit 53 with the back side facing upward. The expansion unit 53 heats the inserted heat-expandable sheet 20 from the back surface (step S6). Specifically, the expansion unit 53 irradiates the back surface of the heat-expandable sheet 20 with light by an irradiation unit (not shown). The back side photothermal conversion layer 43 printed on the back surface of the heat-expandable sheet 20 generates heat by absorbing the irradiated light. As a result, as shown in FIG. 7 (e), the area of the heat-expandable sheet 20 on which the back side photothermal conversion layer 43 is printed rises and expands.

A stereoscopic image is formed on the heat-expandable sheet 20 by the above procedure.

The ink 10 of the present embodiment has an effect on the tint of a stereoscopic image by containing an inorganic infrared absorber that exhibits a stronger absorbance in at least one wavelength region in the infrared region than in the visible light region. It is possible to print a photothermal conversion layer in which the amount of ink is suppressed. Further, by using the ink 10 of the present embodiment, it is possible to provide an ink, a printing apparatus and a printing method capable of printing a photothermal conversion layer in which the influence on the color of a stereoscopic image is suppressed.

Further, according to the ink 10 of the present embodiment, a photothermal conversion layer having a reduced black density is formed as compared with the case where an ink containing carbon black, which has been conventionally used for forming a photothermal conversion layer, is used. You can also. Further, the ink 10 of the present embodiment can expand the thermal expansion layer even at a concentration at which it is difficult to foam the thermal expansion layer in the conventional example, for example, a black concentration of 0.1 or less. The black density of the photothermal conversion layer is measured using a reflection spectrophotometer after the expansion of the thermal expansion layer.

(Modified example of stereoscopic image formation processing)
The stereoscopic image forming process is not limited to the order of the processes shown in FIG. 6, and the order of each step can be changed as described in detail below.

For convenience of explanation, each step shown in FIG. 6 is referred to as shown below. The step of forming the front side photothermal conversion layer 41 (hereinafter referred to as the front side conversion layer) on the front side (upper surface shown in FIG. 3) of the heat-expandable sheet (step S1 in FIG. 6) is referred to as a front side conversion layer forming step. The step of irradiating electromagnetic waves (light) from the front side of the heat-expandable sheet 20 to expand the heat-expandable layer 22 (step S2 in FIG. 6) is called a front-side expansion step. The step of printing a color image on the front side of the heat-expandable sheet 20 (step S3 in FIG. 6) is called a color printing step. The step of forming the back side photothermal conversion layer 43 (hereinafter, back side conversion layer) on the back side (lower surface shown in FIG. 3) of the heat-expandable sheet (step S5 in FIG. 6) is referred to as a back side conversion layer forming step. The step of irradiating electromagnetic waves from the back side of the heat-expandable sheet 20 to expand the heat-expanding layer 22 (step S6 in FIG. 6) is called a back-side expansion step.

In the step of drying the color ink (step S4) in FIG. 6, it is said that the back side of the sheet is facing up, but the process is not limited to this. In any of the following examples, the drying step may be performed with the surface of the sheet facing up. In the drying step, which surface is the front surface or the back surface is determined in consideration of which surface the conversion layer is formed on, whether the thermal expansion layer 22 is further deformed in the drying step, and the like. In addition, in any of the examples shown below, the drying step (step S4) can be omitted depending on the order in which each step is executed.

For example, the stereoscopic image forming process is not limited to the order of the processes shown in FIG. 6, and the backside conversion layer 43 can be formed first. Specifically, the back side conversion layer forming step is performed first, then the back side expansion step is performed, and then the front side conversion layer forming step and the like are performed. In this case, to explain using the flowchart shown in FIG. 6, steps S5 and S6 are performed, and then steps S1 to S4 are performed in this order. In this case, since the back side conversion layer is formed at the stage of performing step S4, it is preferable to perform the drying step with the surface of the sheet facing upward in step S4. It is also possible to print a color image after completing all the steps of expanding the thermal expansion layer 22. In this case, the front side conversion layer forming step, the front side expansion step, the back side conversion layer forming step, and the back side expansion step are performed in this order, and then the color printing step is performed. After performing steps S1 and S2 shown in FIG. 6, steps S5 and S6 are executed, and then steps S3 and S4 are executed. Note that step S4 may be omitted. It is also possible to perform the back side conversion layer forming step and the back side foaming step first. In this case, steps S5 and S6 are executed first, and then steps S1 to S4 are performed in this order. Note that step S4 may be omitted.

In addition, the color printing step can be performed prior to the front side conversion layer forming step and the like. In particular, in the ink of the present embodiment, since the tint is suppressed, it is possible to suppress the influence on the tint of the color image even when the photothermal conversion layer is formed on the color image. Because. In this case, the color printing step, the drying step, the front side conversion layer forming step, and the front side expansion step can be performed in this order, and the back side conversion layer forming step and the back side expansion step can be performed. Explaining with reference to the flowchart shown in FIG. 6, steps S3 and S4 are executed, and then steps S1 and S2, steps S5 and step S6 are executed in this order. In step S4, the drying step may be performed with the surface of the sheet facing upward. Further, the back side heat conversion layer forming step may be performed first. In this case, steps S3 to S6 are performed in this order, and then steps S1 and S2 are performed. In step S4, the drying step may be performed with the surface of the sheet facing upward.

It is also possible to combine the color printing step and the front side conversion layer forming step to print the color ink layer and the front side conversion layer in one step. In this example, the color ink layer and the front conversion layer are printed at the same time.

Hereinafter, a stereoscopic image is formed on the thermally expandable sheet 20 by the stereoscopic image forming system 50 with reference to the flowchart shown in FIG. 8 and the cross-sectional view of the thermally expandable sheet 20 shown in FIGS. 9 (a) to 9 (d). The flow of processing to be performed will be described. Also in this modification, as shown in FIG. 4C, the color ink for printing a color image and the ink 10 for forming the photothermal conversion layer are set in the printing unit 52. The printing unit 52 prints the front conversion layer 41 using the ink 10 based on the surface expansion data which is the data indicating the portion to be expanded and expanded on the surface of the heat-expandable sheet 20. Similarly, the back side conversion layer 43 is printed using the ink 10 based on the back surface foaming data which is the data indicating the portion to be expanded and expanded on the back surface of the heat expandable sheet 20.

First, the user prepares the heat-expandable sheet 20 before the stereoscopic image is formed, and designates the color image data, the front surface foaming data, and the back surface foaming data via the display unit 54. Then, the heat-expandable sheet 20 is inserted into the printing unit 52 with its surface facing upward. Next, the printing unit 52 prints the front side conversion layer (front side photothermal conversion layer) 41 and the color image (color ink layer 42) on the surface of the inserted heat-expandable sheet 20 (step S21). Specifically, the printing unit 52 ejects the ink 10 of the present embodiment onto the surface of the heat-expandable sheet 20 according to the designated surface foaming data, and cyan C, magenta M, and yellow Y according to the designated color image data. Discharge each ink of. As a result, as shown in FIG. 9A, the front conversion layer 41 and the color ink layer 42 are formed on the ink receiving layer 23. For ease of understanding, the front conversion layer 41 and the color ink layer 42 are shown to be formed on the ink receiving layer 23, but more accurately, the ink 10 and the color ink receive ink. Since it is received in the layer 24, the front conversion layer 41 and the color ink layer 42 are formed in the ink receiving layer 23. Further, since the front conversion layer 41 and the color ink layer 42 are formed at the same time, the front conversion layer 41 is shown by using a broken line in FIG. 9A and the like. After forming the color ink layer 42 (after step S21), a drying step as in step S4 shown in FIG. 6 may be performed.

Second, the user inserts the heat-expandable sheet 20 on which the front-side conversion layer 41 and the color ink layer 42 are printed into the expansion unit 53 with its surface facing upward. The expansion unit 53 heats the inserted heat-expandable sheet 20 from the surface (step S22). Specifically, the expansion unit 53 irradiates the surface of the heat-expandable sheet 20 with light by the irradiation unit. The front conversion layer 41 printed on the surface of the heat-expandable sheet 20 generates heat by absorbing the irradiated light. As a result, as shown in FIG. 9B, the area of the heat-expandable sheet 20 on which the front conversion layer 41 is printed rises and expands.

Third, the user inserts the heat-expandable sheet 20 into the printing unit 52 with its back side facing upward. The printing unit 52 prints the back side conversion layer (back side photothermal conversion layer) 43 on the back surface of the inserted heat-expandable sheet 20 (step S23). The printing unit 52 ejects the ink 10 to the back surface of the heat-expandable sheet 20 according to the designated back surface foaming data. As a result, as shown in FIG. 9C, the back side photothermal conversion layer 43 is formed on the back surface of the base material 21.

Fourth, the user inserts the heat-expandable sheet 20 on which the back-side conversion layer 43 is printed into the expansion unit 53 with its back surface facing upward. The expansion unit 53 heats the inserted heat-expandable sheet 20 from the back surface (step S24). Specifically, the expansion unit 53 irradiates the back surface of the heat-expandable sheet 20 with light by an irradiation unit (not shown). As a result, as shown in FIG. 9D, the area on which the backside conversion layer 43 of the heat-expandable sheet 20 is printed rises and expands.

A stereoscopic image is formed on the heat-expandable sheet 20 by the above procedure.
In particular, since the color of the ink 10 of the present embodiment is suppressed, it is possible to prevent the ink 10 constituting the front conversion layer 41 from affecting the color of the color ink layer 42. Therefore, as shown in step S21 of this modification, the front conversion layer 41 and the color ink layer 42 can be formed in one step, and the front conversion layer 41 and the color ink layer 42 can be formed at the same time. ..

Further, the order of the processes shown in FIG. 8 is not limited, and the backside conversion layer 43 can be formed first. Specifically, to explain using the flowchart shown in FIG. 8, steps S23 and S24 are performed, and then steps S21 and S22 are performed.

Further, it is also possible to provide another step, for example, a color printing step, between the front side conversion layer forming step and the front side expansion step without performing the front side expansion step immediately after forming the front side conversion layer. In this case, it is also possible to perform the front side expansion step after performing steps S1, S3, and S4 shown in FIG. 6 to complete all the printing steps on the front side of the heat-expandable sheet. In this case, step S1 of the flowchart shown in FIG. 6 is executed to form the front conversion layer, and then steps S3 and S4 are executed to print a color image. After that, step S2 is executed to expand the thermal expansion layer. Subsequently, steps S5 and S6 shown in FIG. 6 are executed to form the backside conversion layer and expand the thermal expansion layer. In this example, the backside conversion layer forming step can also be performed first. In this case, after executing steps S5 and S6, each step is executed in the order of steps S1, S3, S4, and S2. In this case, in step S4, the drying step may be performed with the surface of the sheet facing upward. Further, the color printing step can be performed between the back side conversion layer forming step and the back side expansion step. In this case, steps S5, S3, S4 and S6 are executed in this order and then steps S1 and S2 are executed, or steps S1 and S2 are executed and then steps S5, S3, S4 and S6 are executed in this order. In this case, in step S4, the drying step may be performed with the surface of the sheet facing upward.

It is also possible to perform the front side expansion step and the back side expansion step after the front side conversion layer forming step, the color printing step, and the back side conversion layer forming step are performed first. In this case, steps S1, S3, and S5 of the flowchart shown in FIG. 6 are executed first, and then steps S2 and S6 are executed. The order in which steps S1, S3, and S5 are executed is not limited to this order, and can be arbitrarily replaced. For example, the order may be step S5, step S3, and step S1. Further, steps S2 and S6 may be executed in this order or in the reverse order. Further, the drying step (step S4) may be performed as needed or may be omitted.

It is also possible to perform the front side conversion layer forming step and the back side conversion layer forming step first, and then perform the front side expansion step and the back side expansion step, and then perform the color printing step. In this case, for example, the flow chart shown in FIG. 6 is performed in the order of step S1 and step S5, or in the order of step S5 and step S1. Subsequently, step S2 and step S6, or step S6 and step S2 are performed in this order to expand the thermal expansion layer. After that, step S3 and step S4 are executed to print a color image. Note that step S4 may be omitted. It is also possible to execute the color printing step between the front side expansion step and the back side expansion step. In this case, after executing steps S1 and 5, either step S2 or step S6 is executed, and then steps S3 and S4 are executed, and then the other of step S2 or step S6 is executed. Note that step S4 may be omitted.

(Comparison example)
As a comparative example, an example in which a photothermal conversion layer is formed using a black ink (pigment ink) containing carbon, which has been conventionally used for forming a photothermal conversion layer, and a heat-expandable sheet is foamed and expanded is shown in the figure. It is shown in 10 (a). FIG. 10A is a graph showing the relationship between the ink density (black density) of the photothermal conversion layer after printing and the expansion height (foaming height) of the thermal expansion layer after expansion. Specifically, as the black ink, a black pigment ink containing carbon, which is generally commercially available for an inkjet printer, was used. An inkjet printer is used to print the same image with black ink at multiple different densities on the surface of a heat-expandable sheet having the same configuration as the above-described embodiment, thereby forming a plurality of photothermal conversion layers. did. The photothermal conversion layer was formed only on the surface of the heat-expandable sheet. Further, using a halogen lamp, each photothermal conversion layer was irradiated with light under the same conditions, and the expansion height (mm) of the heat-expandable sheet at each concentration was measured. The black density was measured using an Exact reflection spectrophotometer (manufactured by Sakata Inx Engineering Co., Ltd.).

(Example 1)
An example in which a photothermal conversion layer is formed by using the ink corresponding to the ink 10 of the present embodiment and the heat-expandable sheet is foamed and expanded is shown in FIG. 10 (b). FIG. 10B is a graph showing the relationship between the ink density (black density) of the photothermal conversion layer after printing and the expansion height (foaming height) of the thermal expansion layer after expansion. Specifically, the ink corresponding to the ink 10 of the present embodiment contains tungsten cesium oxide as an inorganic infrared absorber in an ink containing the same components as those of a normal ink component and not containing a colorant, 5.3. The one mixed by weight% was used. Using this ink, the same image was printed at different densities as in the comparative example to form a plurality of photothermal conversion layers. The photothermal conversion layer was formed only on the surface of the heat-expandable sheet. Further, as in the comparative example, the photothermal conversion layer was irradiated with light under the same conditions, and the expansion height (mm) of the heat-expandable sheet at each concentration was measured. The black density was measured using a reflection spectrophotometer similar to that of the comparative example.

As shown in FIG. 10 (b), the thermal expansion layer can be expanded even with the ink of the example, and the point that the expansion height increases according to the concentration is that the conventional black ink shown in FIG. 10 (a) is used. It is the same as the comparative example used. Next, in the comparative example shown in FIG. 10A, almost no expansion height was obtained in the photothermal conversion layer having a black density of less than 0.1. On the other hand, in the photothermal conversion layer using the ink of the example, an expansion height of about 1.5 mm was obtained even if the black density was less than 0.1. Further, in the comparative example, the black density at which an expansion height of about 1.5 mm can be obtained is about 0.4. Therefore, by using the ink of the example, it was possible to suppress the tint of the photothermal conversion layer for obtaining the same expansion height.

Further, the color of the photothermal conversion layer can be visually confirmed up to a black density of about 0.02, and if the black density is 0.01, the color of the photothermal conversion layer (ink) cannot be visually confirmed. could not. Therefore, with the ink of the example, it was possible to obtain an expansion height corresponding to the black density of 0.4 to 0.5 of the conventional black ink before and after the visible limit density. Furthermore, the thermal expansion layer could be foamed and expanded even at an invisible black density. At a black concentration of less than 0.01, the expansion height is slightly lower, but by lengthening the time for irradiating the photothermal conversion layer with light, foaming can be performed even higher than the value shown in FIG. 10 (b). Can be done. Further, even in the region where the density exceeds 0.02, it was possible to form the photothermal conversion layer while suppressing the color tint as compared with the conventional black ink.

(Example 2)
Next, in Example 2, lanthanum hexaboride (LaB ₆ ) as an inorganic infrared absorber was mixed in a solvent (Finesolve TH, manufactured by Sankyo Chemical Co., Ltd.) in an amount of 0.18% by weight, and combined with the ink. did. A brush was used to apply this ink onto the heat-expandable sheet. The application was performed 2 to 5 times to form a photothermal conversion layer. When it was applied more than once, it was applied over the place where it was applied immediately before. As the heat-expandable sheet, the same sheet as in Example 1 and Comparative Example was used. The photothermal conversion layer was formed only on the surface of the heat-expandable sheet. Further, as in Example 1 and Comparative Example, the photothermal conversion layer was irradiated with light under the same conditions. The black density was measured using the same reflection spectrophotometer as in the comparative example after the thermal expansion layer was foamed.

Table 1 shows the black density of the photothermal conversion layer after the thermal expansion layer is foamed. Further, FIG. 11 shows an image of the photothermal conversion layer that has been applied twice to five times. As shown in Table 1, the black density of the photothermal conversion layer increased as the number of coatings increased. The black density of the photothermal conversion layer was 0.05 for two coats, 0.07 for three coats, 0.08 for four coats, and 0.09 for five coats.

Further, as shown in FIG. 11, the thermal expansion layer could be expanded by any of the two coatings to the five coatings. Further, the point that the expansion height increases as the concentration increases as the number of coatings increases is the same as in the conventional example. Therefore, in the ink according to Example 2, it was possible to form the photothermal conversion layer while suppressing the color tint as compared with the conventional black ink. Further, in the comparative example shown in FIG. 10A, almost no expansion height was obtained in the photothermal conversion layer having a black density of less than 0.1, but in the photothermal conversion layer using the ink of this example, the expansion height was hardly obtained. As shown in FIG. 11, the thermal expansion layer could be expanded not only with a black density of 0.09 (applied 5 times), which is less than a black density of 0.1, but also with a black density of 0.05 (applied twice). In one application, the black density was 0.02, but almost no foaming was observed.

From the above, according to the ink 10 of the present embodiment, it is possible to form a photothermal conversion layer in which the tint is suppressed.

The present invention is not limited to the above-described embodiment, and various modifications and applications are possible.
In the present embodiment, as the printing device, the stereoscopic image forming system 50 including the control unit 51, the expansion unit 53, and the like is given as an example, but the printing device is not limited to this, and the printing device is an inkjet type as shown in FIG. It may be composed of only the print unit 52.

Further, the ink 10 is not limited to the case where it is a water-based ink used in an inkjet printer, and may be an oil-based ink or an ultraviolet curable ink. When it is an oil-based ink, it contains a solvent, a resin, a dispersant and the like. For example, examples of the solvent include ketones such as acetone and methyl ethyl ketone, alcohols such as methyl alcohol and ethyl alcohol, and esters such as ethyl acetate, and examples of the resin include acrylic resin, rosin resin, epoxy resin and phenol. Examples include system resins. In the case of an ultraviolet curable ink, the ink 10 contains an ultraviolet curable resin such as epoxy acrylate, urethane acrylate, polyester acrylate, a polymerization initiator, and other additives. In either case, a known material can be used. Further, the ink receiving layer 23 can be omitted depending on the material used.

Further, in the above-described embodiment, the case where the cartridge installed in the inkjet printer is filled with ink has been described as an example, but the present invention is not limited to this. The ink 10 of the present embodiment can also be used in other printing methods such as screen printing, gravure printing, offset printing, and flexographic printing. In this case, the ink receiving layer 23 can be omitted.

Further, the ink 10 may be any of a water-based ink, an oil-based ink, and an ultraviolet curable ink. In this case, the ink 10 contains a material corresponding to each printing method, for example, a solvent, a resin for film formation, an auxiliary agent, and the like. As these materials, known ones are used. For example, when the ink 10 is an oil-based ink, it contains a solvent, a resin, and other additives in addition to the inorganic infrared absorber. Further, although not limited to this, examples of the solvent include ketones such as acetone and methyl ethyl ketone, alcohols such as methyl alcohol and ethyl alcohol, and esters such as ethyl acetate, and examples of the resin include acrylic resins. , Rosin-based resin, epoxy resin, phenol-based resin and the like. When the ink 10 is an ultraviolet curable ink, the ink 10 is not limited to this, but the ink 10 is added with an ultraviolet curable resin such as epoxy acrylate, urethane acrylate, polyester acrylate, a polymerization initiator, and other additions in addition to the inorganic infrared absorber. Contains the agent. If the ink 10 is a water-based ink, the ink 10 contains a solvent such as water and alcohol, a resin such as an acrylic resin, and other additives in addition to the inorganic infrared absorber. In either case, a known material can be used.

In addition, for example, when using an offset printing apparatus and combining the color printing process and the front side conversion layer forming step as shown in FIGS. 8 and 9, the color ink layer and the front side conversion layer are printed in one step. The offset printing apparatus includes an ink for printing a color image such as CMYK and the ink 10 of the present embodiment, and prints the color ink layer and the front conversion layer in order using these inks. In this case, the order of printing with the ink 10 can be arbitrarily changed. In other words, the printing using the ink 10 may be before or after printing with the CMYK color ink, or may be between them. The same applies to printing devices other than offset printing devices.

Further, in the above-described embodiment, a configuration in which a photothermal conversion layer for heating a specific region of the heat-expandable sheet 20 is printed has been described as an example, but the ink is used as an ink for heating a specific region. If so, it can be used in addition to the heat-expandable sheet 20.

In the above-described embodiment, the configuration in which the photothermal conversion layer is formed on the front surface and the back surface of the heat-expandable sheet 20 has been described as an example, but the present invention is not limited to this. In any of the embodiments, the photothermal conversion layer can be formed only on the front surface or only on the back surface.

Further, in the figure, each layer of the heat-expandable sheet, the photothermal conversion layer (front side and back side), and the color ink layer are all exaggerated as necessary for explanation. Therefore, it is not intended that these shapes, thicknesses, colors, etc. are limited to those shown in the drawings.

Although some embodiments of the present invention have been described, the present invention is included in the scope of claims and the equivalent scope thereof. Hereinafter, the inventions described in the claims of the original application of the present application will be added.

[Appendix 1]
An ink that forms a photothermal conversion layer used to expand at least a portion of the thermal expansion layer of a thermally expandable sheet.
The ink contains an inorganic infrared absorber having a higher absorbance in at least any region of the infrared region as compared to the visible light region.
Ink characterized by that.
[Appendix 2]
The inorganic infrared absorber is a metal oxide, a metal boride, or a metal nitride.
The ink according to Appendix 1, wherein the ink is characterized by the above.
[Appendix 3]
The inorganic infrared absorber is a tungsten oxide or a hexaborometal compound.
The ink according to Appendix 1 or 2, characterized in that.
[Appendix 4]
The inorganic infrared absorber is tungsten cesium oxide or lanthanum hexaboride.
The ink according to any one of Supplementary note 1 to 3, wherein the ink is characterized by the above.
[Appendix 5]
A printing apparatus for printing a photothermal conversion layer used to expand at least a part of a thermal expansion layer of a thermal expansion sheet.
In at least one region of the infrared region, the ink containing an inorganic infrared absorber having a higher absorbance than the visible light region is used on one and / or the other surface of the heat-expandable sheet. Print the photothermal conversion layer,
A printing device characterized by that.
[Appendix 6]
A printing method for printing a photothermal conversion layer used to expand at least a part of the thermal expansion layer of a heat-expandable sheet.
In at least one region of the infrared region, the ink containing an inorganic infrared absorber having a higher absorbance than the visible light region is used on one and / or the other surface of the heat-expandable sheet. Print the photothermal conversion layer,
A printing method characterized by that.
[Appendix 7]
A method for manufacturing a modeled object by expanding at least a part of the thermal expansion layer of a thermal expansion sheet using a photothermal conversion layer.
In at least one region of the infrared region, the ink containing an inorganic infrared absorber having a higher absorbance than the visible light region is used on one and / or the other surface of the heat-expandable sheet. A step of forming a photothermal conversion layer.
A method for manufacturing a modeled object, which is characterized in that.
[Appendix 8]
A color printing step of printing a color image on a heat-expanding layer provided on one surface of the heat-expandable sheet is provided.
The step of forming the photothermal conversion layer on one surface of the heat-expandable sheet and the color printing step are performed at the same time.
The method for manufacturing a modeled object according to Appendix 7, characterized in that.
[Appendix 9]
A color printing step of printing a color image on a heat-expanding layer provided on one surface of the heat-expandable sheet is provided.
The color printing step is performed before the step of forming the photothermal conversion layer on one surface of the heat-expandable sheet.
The method for manufacturing a modeled object according to Appendix 7, characterized in that.

10 ... Ink, 20 ... Thermally expandable sheet, 21 ... Substrate, 22 ... Thermal expansion layer, 23 ... Ink receiving layer, 41 ... Front side photothermal conversion layer, 42 ... -Color ink layer, 43 ... backside photothermal conversion layer, 50 ... stereoscopic image forming system, 51 ... control unit, 52 ... printing unit, 52a, 53a ... carry-in section, 52b, 53b.・ ・ Discharge part, 53 ・ ・ ・ Expansion unit, 54 ・ ・ ・ Display unit, 55 ・ ・ ・ Top plate, 60 ・ ・ ・ Frame, 61 ・ ・ ・ Side plate, 62 ・ ・ ・ Connecting beam, 71 ・ ・ ・Carriage, 72 ... Print head, 73, 73e, 73c, 73m, 73y ... Ink cartridge, 74 ... Guide rail, 75 ... Drive belt, 75m ... Motor, 76 ... Flexible communication Cable, 77 ... Frame, 78 ... Platen, 79a ... Paper feed roller pair, 79b ... Paper output roller pair

Claims (10)

An ink for forming a pattern of a photothermal conversion layer applied to the heating so as to overlap the thermal expansion layer that expands by a predetermined heating.
It contains a tungsten oxide or a hexaborylated metal compound as an inorganic infrared absorber having a higher absorbance in at least one of the infrared regions as compared with the visible light region.
By the heat the tungsten-based oxide in a predetermined ink-receiving layer formed so as to overlap the expansion layer or the hexaboride metal compound is acceptance, the thermal expansion layer which is formed with the heating the coverage by the ink-receiving layer with respect to the surface irregularities while is maintained, the ink-receiving layer of the tungsten-based oxide or the hexaboride metal compound is receiving portion, denatured in the photothermal conversion layer ,
Ink characterized by that. The tungsten-based oxide and the hexaborometal compound are contained as the inorganic infrared absorber.
The ink according to claim 1. The inorganic infrared absorber is contained in a proportion of 20% by weight to 0.10% by weight.
The ink according to claim 1 or 2, wherein the ink is characterized by the above. The ink receiving layer contains porous silica or polyvinyl alcohol.
The ink according to any one of claims 1 to 3, wherein the ink is characterized by the above. An ink containing a tungsten oxide or a hexaborometal compound as an inorganic infrared absorber having a higher absorbance in at least one of the infrared regions than in the visible light region is formed so as to overlap the thermal expansion layer. The surface of the thermal expansion layer formed by heating by printing on the ink receiving layer with a predetermined coating means and allowing the tungsten oxide or the hexaborometal compound to be received by the ink receiving layer. while to maintain the coverage by the ink-receiving layer with respect to irregularities, an ink-receiving layer of the ink is printed area, Ru denatured in the light-to-heat conversion layer,
A printing device characterized by that. An ink containing a tungsten oxide or a hexaborometal compound as an inorganic infrared absorber having a higher absorbance in at least one of the infrared regions than in the visible light region is formed so as to overlap the thermal expansion layer. By printing on the ink receiving layer and allowing the ink receiving layer to receive the tungsten oxide or the hexaborometal compound, the surface irregularities of the thermally expanded layer formed by heating are dealt with. while to maintain the coverage by the ink-receiving layer, an ink-receiving layer of the ink is printed area, Ru denatured in the light-to-heat conversion layer,
A printing method characterized by that. A method for manufacturing a modeled object by expanding at least a part of a thermal expansion layer using a photothermal conversion layer.
An ink containing a tungsten oxide or a hexaborometal compound as an inorganic infrared absorber having a higher absorbance in at least one of the infrared regions than in the visible light region is formed so as to overlap the thermal expansion layer. By printing on the ink receiving layer and allowing the ink receiving layer to receive the tungsten oxide or the hexaborometal compound, the surface irregularities of the thermally expanded layer formed by heating are dealt with. the remains were maintained coverage by the ink-receiving layer, an ink-receiving layer of the ink is printed area comprises the photothermal conversion layer forming step of Ru denatured in the light-to-heat conversion layer,
A method for manufacturing a modeled object, which is characterized in that. By printing color ink on the ink receiving layer and allowing the color ink to be received by the ink receiving layer, the ink receiving layer in the region where the color ink is printed is a color layer having a color corresponding to the color ink. Equipped with a color layer forming step to form
In the photothermal conversion layer forming step, the ink is printed on the ink receiving layer as the color layer to allow the tungsten oxide or the hexaborometal compound to be received by the color layer, thereby producing the ink. A color layer in the printed area is formed on the photothermal conversion layer in which the tint of the color layer is maintained.
The method for manufacturing a modeled object according to claim 7, characterized in that. By printing a color ink on the ink receiving layer as the photothermal conversion layer and allowing the color ink to be received by the photothermal conversion layer, the photothermal conversion layer in the region where the color ink is printed corresponds to the color ink. A color layer forming step for forming a color layer having a similar color is provided.
The method for manufacturing a modeled object according to claim 7, characterized in that. The photothermal conversion layer forming step and the color layer forming step are continuously carried out for each predetermined unit region.
The method for manufacturing a modeled object according to claim 8 or 9.