JPWO2019054478A1 - Near-infrared curable ink composition, near-infrared curable film, their manufacturing method, and stereolithography - Google Patents

Abstract

A near-infrared curable ink composition, a near-infrared curable film, and the near-infrared curable ink composition containing composite tungsten oxide fine particles having sufficient near-infrared absorption ability and excellent adhesion to a substrate. The stereolithography method used is provided. A near-infrared curable ink composition containing a composite tungsten oxide having a near-infrared absorbing ability and an uncured thermocurable resin, wherein the composite tungsten oxide contains a hexagonal crystal structure, and the composite tungsten The lattice constants of the oxide are 7.3850 Å or more and 7.4186 Å or less on the a-axis, 7.5600 Å or more and 7.6240 Å or less on the c-axis, and the average particle size of the composite tungsten oxide is 100 nm or less. Provided is a photomolding method using a cured film and the near-infrared ray curable ink composition.

Description

The present invention relates to a near-infrared curable ink composition, a near-infrared curable film, a method for producing them, and a stereolithography method.

The ultraviolet curable paint, which is cured using ultraviolet rays, can be printed without heating. For this reason, in recent years, it has become widely known as an environmentally friendly paint, and for example, proposals and disclosures as described in Patent Documents 1 to 6 have been made.

However, according to the study by the present inventors, when a composition that undergoes radical polymerization by ultraviolet irradiation is used as an ultraviolet curable ink or paint, the presence of oxygen inhibits the polymerization (curing). On the other hand, when a composition in which cationic polymerization is carried out by irradiation with ultraviolet rays is used, there is a problem that a strong acid is generated during the polymerization.
Further, in order to enhance the light resistance of the printed surface and the coated surface, an ultraviolet absorber is generally added to the printed surface and the coated surface. However, when an ultraviolet absorber is added to an ultraviolet curable ink or paint, there is a problem that curing by ultraviolet irradiation is hindered.

In order to solve the above-mentioned problems, Patent Documents 7 and 8 propose near-infrared curable compositions that are cured by irradiation with near-infrared rays instead of ultraviolet rays.
Further, in Patent Document 9, the applicant discloses a near-infrared curable ink composition containing a composite tungsten oxide.

Japanese Unexamined Patent Publication No. 7-100433 Japanese Patent No. 3354122 Japanese Patent No. 5267854 Japanese Patent No. 5626648 Japanese Patent No. 3494399 Japanese Unexamined Patent Publication No. 2004-18716 Japanese Patent No. 50444733 JP 2015-131928 International Publication No. 2017/047736

However, according to further studies by the present inventors, all of the near-infrared curable compositions described in Patent Documents 7 and 8 have a problem that the near-infrared absorption characteristics are not sufficient.
On the other hand, the market demand for near-infrared curable compositions is increasing. For example, even with a near-infrared curable ink composition containing a composite tungsten oxide or a near-infrared curable film described in Patent Document 9, the market demand for improved adhesion to a base material should be continuously satisfied. Was thought to be difficult.

The present invention has been made under the above-mentioned circumstances, and the problem to be solved is that the present invention is provided on a predetermined base material and adheres to the base material when cured by irradiating with near infrared rays. A near-infrared curable ink composition excellent in the above, a near-infrared curable film obtained by curing the near-infrared curable ink composition, a method for producing them, and the near-infrared curable ink composition were used. The purpose is to provide an optical modeling method.

As a result of research conducted by the present inventors in order to solve the above-mentioned problems, the near-infrared absorbing ability of the composite tungsten oxide fine particles is enhanced, and heat is generated when the near-infrared curable ink composition is irradiated with near-infrared rays. I came up with the idea that increasing the amount is effective. Then, by increasing the calorific value, it was possible to increase the degree of curing of the ink composition and improve the adhesion to the base material.

That is, the first invention for solving the above-mentioned problems is
A near-infrared curable ink composition containing composite tungsten oxide fine particles having a near-infrared absorbing ability and an uncured thermosetting resin.
The composite tungsten oxide fine particles are composite tungsten oxide fine particles containing a hexagonal crystal structure.
The lattice constant of the composite tungsten oxide fine particles is 7.3850 Å or more and 7.4186 Å or less on the a-axis, and 7.5600 Å or more and 7.6240 Å or less on the c-axis.
It is a near-infrared curable ink composition characterized in that the average particle diameter of the composite tungsten oxide fine particles is 100 nm or less.
The second invention is
The near infrared ray according to the first invention, wherein the lattice constant of the composite tungsten oxide fine particles is 7.4031 Å or more and 7.4111 Å or less on the a-axis and 7.5891 Å or more and 7.6240 Å or less on the c-axis. It is a curable ink composition.
The third invention is
The near-infrared curable ink composition according to the first or second invention, wherein the composite tungsten oxide fine particles have an average particle diameter of 10 nm or more and 100 nm or less.
The fourth invention is
The near-infrared curable ink composition according to any one of the first to third inventions, wherein the composite tungsten oxide fine particles have a crystallite diameter of 10 nm or more and 100 nm or less.
The fifth invention is
Further, the near-infrared curable ink composition according to any one of the first to fourth inventions, which comprises a dispersant.
The sixth invention is
Further, the near-infrared curable ink composition according to any one of the first to fifth inventions, which comprises a solvent.
The seventh invention is
The composite tungsten oxide is a general formula M _x W _{y Oz} (M element is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh. , Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te , Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, Yb, one or more elements, W is tungsten, O is oxygen, 0.001 ≦ x The near-infrared curable ink composition according to any one of the first to sixth inventions, which is described in (/ y ≦ 1, 2.0 ≦ z / y ≦ 3.0). is there.
The eighth invention is
The near-infrared curable ink composition according to a seventh invention, wherein the composite tungsten oxide is composed of a composite tungsten oxide in which the M element is one or more selected from Cs and Rb. is there.
The ninth invention is
A first feature is that at least a part of the surface of the composite tungsten oxide fine particles is covered with a surface coating film containing at least one element selected from Si, Ti, Zr, and Al. The near-infrared curable ink composition according to any one of the first to eighth inventions.
The tenth invention is
The near-infrared curable ink composition according to a ninth aspect of the invention, wherein the surface coating film contains oxygen atoms.
The eleventh invention is
Further, the near-infrared curable ink composition according to any one of the first to tenth inventions, which comprises any one or more selected from organic pigments, inorganic pigments and dyes.
The twelfth invention is
A near-infrared ray curable film according to any one of the first to eleventh inventions, wherein the near-infrared ray curable ink composition is cured by being irradiated with near infrared rays.
The thirteenth invention is
A light characterized by applying the near-infrared ray curable ink composition according to any one of the first to eleventh inventions onto a substrate to form a coating material, and irradiating the coating material with near infrared rays to cure the coating material. It is a modeling method.
The fourteenth invention is
A method for producing a near-infrared curable ink composition containing composite tungsten oxide fine particles having near-infrared absorbing ability, an uncured thermosetting resin, a dispersant, and a solvent.
The composite tungsten oxide fine particles are composite tungsten oxide fine particles containing a hexagonal crystal structure.
The composite tungsten oxide fine particles were produced so that their lattice constants were in the range of 7.3850 Å or more and 7.4186 Å or less and the c-axis was 7.5600 Å or more and 7.6240 Å or less.
A method for producing a near-infrared curable ink composition, which comprises performing a pulverization / dispersion treatment step of making the average particle diameter 100 nm or less while maintaining the range of the lattice constant in the composite tungsten oxide fine particles.
The fifteenth invention is
The composite tungsten oxide is a general formula MxWyOz (M element is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd. , Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V , Mo, Ta, Re, Be, Hf, Os, Bi, I, Yb, one or more elements, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1, 2 The method for producing a near-infrared curable ink composition according to the fourteenth invention, which is described in (0 ≦ z / y ≦ 3.0).
The sixteenth invention is
The near infrared ray according to any one of the 14th to 15th inventions, wherein the composite tungsten oxide is composed of a composite tungsten oxide in which the M element is one or more selected from Cs and Rb. This is a method for producing a curable ink composition.
The seventeenth invention is
The 14th to 16th, characterized in that at least a part of the surface of the composite tungsten oxide fine particles is coated with a surface coating film containing at least one element of Si, Ti, Zr, and Al. Is a method for producing a near-infrared curable ink composition according to any one of the inventions.
The eighteenth invention is
The method for producing a near-infrared curable ink composition according to the seventeenth invention, wherein the surface coating film contains oxygen atoms.
The nineteenth invention
Further, according to the method for producing a near-infrared curable ink composition according to any one of the 14th to 18th inventions, which comprises containing any one or more selected from organic pigments, inorganic pigments and dyes. is there.

The near-infrared curable ink composition according to the present invention has excellent adhesion to a substrate and is industrially useful.

It is a device conceptual diagram of one Embodiment of the high frequency thermal plasma reactor used for manufacturing the composite tungsten oxide fine particle which concerns on this invention.

Hereinafter, the near-infrared ray curable ink according to the present invention and the stereolithography method using the same will be described in detail in the order of [1] near infrared ray curable ink composition, [2] near infrared ray curable film and stereolithography method. ..

[1] Near-infrared curable ink composition The near-infrared curable ink composition according to the present invention comprises composite tungsten oxide fine particles having near-infrared absorbing ability, an uncured thermosetting resin, and other components if desired. And include. Therefore, hereinafter, [a] composite tungsten oxide fine particles, [b] method for synthesizing composite tungsten oxide fine particles, [c] uncured thermosetting resin, [d] other components, and [e] near-infrared curable ink. The composition will be described in this order.

[A] Composite Tungsten Oxide Fine Particles The near-infrared absorbing fine particles used in the near-infrared curable ink composition include composite tungsten oxide fine particles, carbon black powder, and tin-added indium oxide (described as "ITO" in the present invention. In some cases.) Powder is possible. However, when carbon black powder is used as the near-infrared absorbing fine particles, the degree of freedom in selecting the color of the near-infrared curable ink composition is reduced because the powder is black. On the other hand, when ITO powder is used as the near-infrared absorbing fine particles, the curability of the near-infrared curable ink composition cannot be exhibited unless a large amount of the powder is added. Therefore, if a large amount of the ITO powder is added, there arises a problem that the powder added in a large amount affects the color tone of the near-infrared curable ink composition.

In a near-infrared cured film containing near-infrared absorbing fine particles, coloring caused by the near-infrared absorbing fine particles is not preferable. Therefore, in the present invention, the composite tungsten oxide that does not cause coloring caused by the fine particles as near-infrared absorbing fine particles is not preferable. I came up with the idea of containing fine particles.
By making the composite tungsten oxide into near-infrared absorbing fine particles, free electrons are generated in the composite tungsten oxide, and the absorption characteristics derived from free electrons are exhibited in the near-infrared region. As a result, the composite tungsten oxide fine particles are effective as near-infrared absorbing fine particles having a wavelength of around 1000 nm.

The composite tungsten oxide fine particles according to the present invention are composite tungsten oxide fine particles having near-infrared absorption characteristics and containing a hexagonal crystal structure, and have a lattice constant of 7.3850 Å or more and 7.4186 Å or less. The c-axis is 7.5600 Å or more and 7.6240 Å or less.
Further, in the composite tungsten oxide fine particles according to the present invention, the value of [c-axis lattice constant / a-axis lattice constant] is preferably 1.0221 or more and 1.0289 or less.
Hereinafter, regarding the composite tungsten oxide fine particles according to the present invention, (1) crystal structure and lattice constant, (2) particle diameter and crystallite diameter, (3) composition of composite tungsten oxide fine particles, and (4) composite tungsten oxide. Surface coating of fine particles (5) Summary will be described in this order.

(1) Crystal structure and lattice constant The composite tungsten oxide fine particles according to the present invention have a tetragonal or cubic tungsten bronze structure in addition to the hexagonal crystal, and any structure can be used as a near-infrared absorbing material. It is valid. However, the absorption position in the near-infrared region tends to change depending on the crystal structure of the composite tungsten oxide fine particles. That is, the absorption position in the near-infrared region tends to move to the longer wavelength side when the tetragonal crystal is than the cubic crystal, and to move to the longer wavelength side when the tetragonal crystal is than the tetragonal crystal. In addition, along with the fluctuation of the absorption position, the absorption of light in the visible light region is the least in the hexagonal crystal, followed by the tetragonal crystal, and the cubic crystal is the largest among them.

From the above findings, it is most preferable to use hexagonal tungsten bronze for applications in which light in the visible light region is more transmitted and light in the near infrared region is absorbed more. When the composite tungsten oxide fine particles have a hexagonal crystal structure, the transmittance of the fine particles in the visible light region is improved, and the absorption in the near infrared region is improved. In this hexagonal crystal structure, _six octahedrons formed in WO ₆ units are assembled to form a hexagonal void (tunnel), and M element is arranged in the void to form one unit. A large number of these one unit are assembled to form a hexagonal crystal structure.

In order to obtain the effect of improving the transmission in the visible light region and improving the absorption in the near infrared region according to the present invention, a unit structure (octahedron formed in WO ₆ units) is formed in the composite tungsten oxide fine particles. A hexagonal void is formed by aggregating six of them, and the structure in which the M element is arranged in the void) may be included.
When the cation of the M element is added to the hexagonal void and exists, the absorption in the near infrared region is improved. Here, in general, when the M element having a large ionic radius is added, the hexagonal crystal is formed, and specifically, one or more kinds selected from Cs, Rb, K, Tl, Ba, and In are added. It is preferable that hexagonal crystals are easily formed.
Further, in the composite tungsten oxide fine particles to which one or more of these M elements having a large ionic radius selected from Cs and Rb are added, both absorption in the near infrared region and transmission in the visible light region can be achieved. ..
When two or more types of M elements are selected, one of them is selected from Cs, Rb, K, Tl, Ba, and In, and the rest is selected from one or more elements constituting the M element. Can also be hexagonal.

In the case of Cs tungsten oxide fine particles in which Cs is selected as the M element, the lattice constant is preferably 7.4031 Å or more and 7.4186 Å or less, and the c axis is 7.5750 Å or more and 7.6240 Å or less. Preferably, the a-axis is 7.4031 Å or more and 7.4111 Å or less, and the c-axis is 7.5891 Å or more and 7.6240 Å or less.
In the case of Rb tungsten oxide fine particles in which Rb is selected as the M element, the lattice constant is preferably 7.3850 Å or more and 7.3950 Å or less, and the c-axis is 7.5600 Å or more and 7.5700 Å or less.
In the case of CsRb tungsten oxide fine particles in which Cs and Rb are selected as the M element, the lattice constants of the CsRb tungsten oxide fine particles are that the a-axis is 7.3850 Å or more and 7.4186 Å or less, and the c-axis is 7.5600 Å or more and 7.6240 Å or less. preferable.
However, the M element is not limited to the above Cs and Rb. Even if the M element is an element other than Cs or Rb, it may be present as an added M element in the hexagonal void formed in WO ₆ units.

When the composite tungsten oxide fine particles having a hexagonal crystal structure according to the present invention are represented by the general formula MxWyOz, and the composite tungsten oxide fine particles have a uniform crystal structure, the amount of the added M element added is 0. 001 ≦ x / y ≦ 1, preferably 0.2 ≦ x / y ≦ 0.5, more preferably 0.20 ≦ x / y ≦ 0.37, and most preferably x / y = 0.33. This is because it was theoretically considered that the added M element is arranged in all the hexagonal voids by setting x / y = 0.33 when z / y = 3. Typical examples include Cs _0.33 WO ₃ , Cs _0.03 Rb _0.30 WO ₃ , Rb _0.33 WO ₃ , K _0.33 WO ₃ , and Ba _0.33 WO _3. ..

Here, the present inventors have repeated research on measures for further improving the near-infrared absorption function of the composite tungsten oxide fine particles, and have come up with a configuration for further increasing the amount of free electrons contained.
That is, as a measure for increasing the amount of free electrons, the idea was to apply mechanical treatment to the composite tungsten oxide fine particles to impart appropriate strain and deformation to the contained hexagonal crystals. It is considered that in the hexagonal crystal to which the appropriate strain and deformation are applied, the overlapping state of the electron orbits in the atoms constituting the crystallite structure changes, and the amount of free electrons increases.

Based on the above idea, the present inventors produce a composite tungsten oxide fine particle dispersion from the composite tungsten oxide particles produced in the firing step of "[b] Synthesis method of composite tungsten oxide fine particles" described later. In the dispersion step, the composite tungsten oxide particles are crushed under predetermined conditions to impart strain and deformation to the crystal structure, increase the amount of free electrons, and have a near-infrared absorption function of the composite tungsten oxide fine particles. Was studied to further improve.

Then, from this research, the particles of the composite tungsten oxide produced through the firing step were examined by focusing on each particle. Then, it was found that the lattice constant and the composition of the constituent elements were varied among the particles.
As a result of further research, it is desirable that the lattice constant of the finally obtained composite tungsten oxide fine particles is within a predetermined range, despite the variation in the lattice constant and the composition of constituent elements among the particles. It was found that it exhibits optical characteristics.

Based on the above findings, the present inventors further measured the a-axis and c-axis, which are lattice constants in the crystal structure of the composite tungsten oxide fine particles, to determine the distortion and deformation of the crystal structure of the fine particles. While grasping the degree, we studied the optical characteristics exhibited by the fine particles.
As a result of the research, when the a-axis is 7.3850 Å or more and 7.4186 Å or less and the c-axis is 7.5600 Å or more and 7.6240 Å or less in the hexagonal composite tungsten oxide fine particles, the fine particles have a wavelength of 350 nm or more. It was found that the composite tungsten oxide fine particles have a maximum value in the range of 600 nm, a light transmittance having a minimum value in the wavelength range of 800 nm to 2100 nm, and exhibit an excellent near-infrared absorption effect. ..

Further, in the hexagonal composite tungsten oxide fine particles having an a-axis of 7.3850 Å or more and 7.4186 Å or less and a c-axis of 7.5600 Å or more and 7.6240 Å or less of the composite tungsten oxide fine particles according to the present invention, the M element. Especially when the value of x / y indicating the addition amount is in the range of 0.001 ≦ x / y ≦ 1, preferably in the range of 0.20 ≦ x / y ≦ 0.37, it is particularly excellent. It was also found that it exerts an infrared absorption effect.

It was also found that the composite tungsten oxide fine particles are preferably a single crystal having an amorphous phase volume ratio of 50% or less.
When the composite tungsten oxide fine particles are single crystals having an amorphous phase volume ratio of 50% or less, the crystallite diameter can be 10 nm or more and 100 nm or less while maintaining the lattice constant within the above-mentioned predetermined range. It is considered that excellent optical characteristics can be exhibited.

It should be noted that the fact that the composite tungsten oxide fine particles are single crystals is confirmed by the fact that no crystal grain boundaries are observed inside each fine particle and only uniform plaids are observed in an electron microscope image by a transmission electron microscope or the like. can do. In addition, the fact that the volume ratio of the amorphous phase in the composite tungsten oxide fine particles is 50% or less means that uniform plaids are observed in the entire fine particles and most of the plaids are unclear in the transmission electron microscope image. It can be confirmed from the fact that it is not done.
Further, since the amorphous phase is often present on the outer peripheral portion of each fine particle, it is often possible to calculate the volume ratio of the amorphous phase by paying attention to the outer peripheral portion of each fine particle. For example, in a spherical composite tungsten oxide fine particle, when an amorphous phase having unclear lattice stripes exists in a layer on the outer peripheral portion of the fine particle, if the thickness is 10% or less of the average particle diameter, the composite tungsten oxidation The volume ratio of the amorphous phase in the fine particles is 50% or less.

On the other hand, when the composite tungsten oxide fine particles are dispersed in a matrix of a solid medium such as a resin constituting the composite tungsten oxide fine particle dispersion, crystals are formed from the average particle size of the dispersed composite tungsten oxide fine particles. If the value obtained by subtracting the child diameter is 20% or less of the average particle size, it can be said that the composite tungsten oxide fine particles are single crystals having an amorphous phase volume ratio of 50% or less.

From the above, the value obtained by subtracting the crystallite diameter from the average particle size of the composite tungsten oxide fine particles dispersed in the composite tungsten oxide fine particle dispersion is 20% or less of the value of the average particle size. It is preferable to appropriately adjust the synthesis step, the pulverization step, and the dispersion step of the composite tungsten oxide fine particles according to the manufacturing equipment.
The crystal structure and lattice constant of the composite tungsten oxide fine particles are measured by X-ray diffraction of the composite tungsten oxide fine particles obtained by removing the solvent of the dispersion liquid for forming a near-infrared absorber. The a-axis length and c-axis length can be calculated as lattice constants by specifying the crystal structure to be obtained and using the Rietveld method.

(2) Particle Diameter and Crystalline Diameter The composite tungsten oxide fine particles according to the present invention have an average particle diameter of 100 nm or less. From the viewpoint of exhibiting more excellent infrared absorption characteristics, the average particle size is preferably 10 nm or more and 100 nm or less, more preferably 10 nm or more and 80 nm or less, and further preferably 10 nm or more and 60 nm or less. When the average particle size is in the range of 10 nm or more and 60 nm or less, the best infrared absorption characteristics are exhibited.
Here, the average particle size is a value of the diameter of each non-aggregated composite tungsten oxide fine particles, and is the average particle size of the composite tungsten oxide fine particles contained in the composite tungsten oxide fine particle dispersion described later. ..
On the other hand, the average particle size does not include the diameter of the aggregates of the composite tungsten oxide fine particles, and is different from the dispersed particle size.

The average particle size is calculated from the electron microscope image of the composite tungsten oxide fine particles.
The average particle size of the composite tungsten oxide fine particles contained in the composite tungsten oxide fine particle dispersion is determined from the transmission electron microscope image of the thinned sample of the composite tungsten oxide fine particle dispersion taken out by cross-sectional processing. It can be obtained by measuring the diameters of 100 particles using an image processing device and calculating the average value thereof. A microtome, a cross-section polisher, a focused ion beam (FIB) device, or the like can be used for cross-section processing for taking out the sliced sample. The average particle size of the composite tungsten oxide fine particles contained in the composite tungsten oxide fine particle dispersion is an average value of the particle sizes of the composite tungsten oxide fine particles dispersed in the solid medium which is a matrix.

Further, from the viewpoint of exhibiting excellent infrared absorption characteristics, the crystallite diameter of the composite tungsten oxide fine particles is preferably 10 nm or more and 100 nm or less, more preferably 10 nm or more and 80 nm or less, and further preferably 10 nm or more and 60 nm or less. .. This is because the best infrared absorption characteristics are exhibited when the crystallite diameter is in the range of 10 nm or more and 60 nm or less.

The lattice constants and crystallite diameters of the composite tungsten oxide fine particles contained in the composite tungsten oxide fine particle dispersion obtained after undergoing the crushing treatment, the crushing treatment, or the dispersion treatment described later are the composite tungsten oxide fine particle dispersion. It is also maintained in the composite tungsten oxide fine particles obtained by removing the volatile components from the liquid and the composite tungsten oxide fine particles contained in the composite tungsten oxide fine particle dispersion obtained from the composite tungsten oxide fine particle dispersion. ..
As a result, the effect of the present invention is also exhibited in the composite tungsten oxide fine particle dispersion liquid and the composite tungsten oxide fine particle dispersion containing the composite tungsten oxide fine particles according to the present invention.

(3) Composition of Composite Tungsten Oxide Fine Particles The composite tungsten oxide fine particles according to the present invention have the general formula MxWyOz (where M is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr. , Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F , P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, Yb, one or more elements, W is tungsten, O is preferably oxygen, which is a composite tungsten oxide fine particle represented by 0.001 ≦ x / y ≦ 1, 2.0 ≦ z / y ≦ 3.0).

The composite tungsten oxide fine particles represented by the general formula MxWyOz will be described.
The M elements, x, y, z and their crystal structures in the general formula MxWyOz are closely related to the free electron density of the composite tungsten oxide fine particles and have a great influence on the near infrared absorption characteristics.

Generally, since there are no effective free electrons in tungsten trioxide (WO ₃ ), the near-infrared absorption characteristic is low.
Here, the present inventors have added M element (however, M element is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, to the tungsten oxide. Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Add one or more elements selected from Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, Yb) to form a composite tungsten oxide. Then, free electrons are generated in the composite tungsten oxide, and absorption characteristics derived from free electrons are exhibited in the near infrared region, which makes it effective as a near infrared absorbing material having a wavelength of around 1000 nm, and the composite tungsten. It has been found that oxides maintain a chemically stable state and are effective as a near-infrared absorbing material having excellent weather resistance. Further, the M element is preferably Cs, Rb, K, Tl, Ba, In, and among them, when the M element is Cs, Rb, the composite tungsten oxide tends to have a hexagonal structure. As a result, it has been found that it is particularly preferable for the reason described later because it transmits visible light, absorbs near infrared rays and converts it into heat. When two or more types of M elements are selected, one of them is selected from Cs, Rb, K, Tl, Ba, and In, and the rest is selected from one or more elements constituting the M element. It may be hexagonal.

Here, the findings of the present inventors regarding the value of x indicating the amount of M element added will be described.
When the value of x / y is 0.001 or more, a sufficient amount of free electrons are generated and the desired near-infrared absorption characteristic can be obtained. Then, as the amount of M element added increases, the amount of free electrons supplied increases and the near-infrared absorption characteristic also increases, but the effect is saturated when the value of x / y is about 1. Further, when the value of x / y is 1 or less, it is preferable because it is possible to avoid the formation of an impurity phase in the composite tungsten fine particles.

Next, the present inventors' findings on the value of z indicating the control of the amount of oxygen will be described.
In the composite tungsten oxide fine particles represented by the general formula MxWyOz, the value of z / y is preferably 2.0 ≦ z / y ≦ 3.0, more preferably 2.2 ≦ z / y ≦ 3. It is 0, more preferably 2.6 ≦ z / y ≦ 3.0, and most preferably 2.7 ≦ z / y ≦ 3.0. When the value of z / y is 2.0 or more, it is possible to avoid the appearance of a crystal phase of WO ₂ other than the intended one in the composite tungsten oxide, and the chemical stability as a material can be improved. This is because it can be obtained and can be applied as an effective infrared absorbing material. On the other hand, when the value of z / y is 3.0 or less, a required amount of free electrons are generated in the tungsten oxide, and the material becomes an efficient infrared absorbing material.

(4) Surface Coating Film of Composite Tungsten Oxide Fine Particles At least a part of the surface of the composite tungsten oxide fine particles is selected from silicon, zirconium, titanium, and aluminum in order to improve the weather resistance of the composite tungsten oxide fine particles. It is also preferable to coat with a surface coating film containing one or more kinds of elements. These surface coating films are basically transparent, and their addition does not reduce the visible light transmittance. The coating method is not particularly limited, but the surface of the composite tungsten oxide fine particles can be coated by adding a metal alkoxide containing the above element to a solution in which the composite tungsten oxide fine particles are dispersed. In this case, the surface coating film contains oxygen atoms, but it is more preferable that the surface coating film is composed of an oxide.

(5) Summary The lattice constant, average particle diameter, and crystallite diameter of the composite tungsten oxide fine particles described in detail above can be controlled by predetermined synthesis conditions. Specifically, in the thermal plasma method and the solid phase reaction method described later, the temperature (calcination temperature), the generation time (calcination time), the production atmosphere (calcination atmosphere), and the precursor raw material when the fine particles are produced It can be controlled by appropriately setting synthetic conditions such as morphology, annealing treatment after formation, and doping of impurity elements. On the other hand, the content of the volatile components of the composite tungsten oxide fine particles is controlled by appropriately setting the production conditions such as the storage method and storage atmosphere of the fine particles, the temperature at which the fine particle dispersion is dried, the drying time, and the drying method. It is possible. The content of the volatile components of the composite tungsten oxide fine particles does not depend on the crystal structure of the composite tungsten oxide fine particles or the synthesis method such as the thermal plasma method or the solid phase reaction described later.

[B] Method for synthesizing composite tungsten oxide fine particles The method for synthesizing composite tungsten oxide fine particles according to the present invention will be described.
Examples of the method for synthesizing the composite tungsten oxide fine particles according to the present invention include a thermal plasma method in which the starting material of the tungsten compound is charged into the thermal plasma, and a solid phase reaction method in which the starting material of the tungsten compound is heat-treated in a reducing gas atmosphere. Can be mentioned. The composite tungsten oxide fine particles synthesized by the thermal plasma method or the solid phase reaction method are subjected to dispersion treatment or pulverization / dispersion treatment.
Hereinafter, (1) thermal plasma method, (2) solid phase reaction method, and (3) synthesized composite tungsten oxide fine particles will be described in this order.

(1) Thermal plasma method The thermal plasma method will be described in the order of (i) raw materials used in the thermal plasma method, and (ii) thermal plasma method and its conditions.

(I) Raw materials used in the thermal plasma method When synthesizing the composite tungsten oxide fine particles according to the present invention by the thermal plasma method, a mixed powder of a tungsten compound and an M element compound can be used as a raw material.
The tungsten compound, tungstic acid (H 2 _{WO 4),} ammonium tungstate, tungsten hexachloride, hydrates of tungsten to tungsten hexachloride dissolved in alcohol by adding water to evaporate the solvent after the hydrolysis, It is preferable that it is one or more selected from.

Further, as the M element compound, it is preferable to use one or more selected from M element oxides, hydroxides, nitrates, sulfates, chlorides and carbonates.
The ratio of the M element to the W element of the aqueous solution containing the above-mentioned tungsten compound and the above-mentioned M element compound is MxWyOz (however, M is the M element, W is tungsten, O is oxygen, 0.001 ≦ x /. Wet mixing is performed so that the ratio of the M element and the W element of y ≦ 1.0 and 2.0 ≦ z / y ≦ 3.0) is obtained. Then, by drying the obtained mixed solution, a mixed powder of the M element compound and the tungsten compound is obtained. The mixed powder can be used as a raw material for the thermal plasma method.

Further, the composite tungsten oxide obtained by firing the mixed powder in the first step under the atmosphere of an inert gas alone or a mixed gas of an inert gas and a reducing gas is used as a raw material for the thermal plasma method. You can also do it. In addition, the first stage is fired in a mixed gas atmosphere of an inert gas and a reducing gas, and the first stage fired product is fired in a second stage in an inert gas atmosphere. The composite tungsten oxide obtained by step calcination can also be used as a raw material for the thermal plasma method.

(Ii) Thermal plasma method and its conditions The thermal plasma used in the present invention is, for example, any of DC arc plasma, high frequency plasma, microwave plasma, low frequency AC plasma, or a superposition of these plasmas, or , Plasma generated by an electric method in which a magnetic field is applied to DC plasma, plasma generated by irradiation with a high-power laser, and plasma generated by a high-power electron beam or an ion beam can be applied. However, regardless of which thermal plasma is used, it is a thermal plasma having a high temperature portion of 1000 to 15000 K, and in particular, a plasma capable of controlling the generation time of fine particles is preferable.

The raw material supplied into the thermal plasma having the high temperature portion evaporates instantly in the high temperature portion. Then, the evaporated raw material is condensed in the process of reaching the plasma tail flame portion and is rapidly cooled and solidified outside the plasma flame to generate composite tungsten oxide fine particles.

The synthesis method will be described with reference to FIG. 1 by taking the case of using a high-frequency plasma reactor as an example.
First, the inside of the reaction system composed of the inside of the water-cooled quartz double tube and the inside of the reaction vessel 6 is evacuated to about 0.1 Pa (about 0.001 Torr) by the vacuum exhaust device. After evacuating the inside of the reaction system, the inside of the reaction system is filled with argon gas to prepare an argon gas flow system at 1 atm.
Then, as a plasma gas in the reaction vessel, any gas selected from argon gas, a mixed gas of argon and helium (Ar-He mixed gas), or a mixed gas of argon and nitrogen (Ar-N ₂ mixed gas). Is introduced from the plasma gas supply nozzle 4 at a flow rate of 30 to 45 L / min. On the other hand, an Ar—He mixed gas is introduced from the sheath gas supply nozzle 3 at a flow rate of 60 to 70 L / min as a sheath gas to flow immediately outside the plasma region.
Then, an alternating current is applied to the high frequency coil 2 to generate a thermal plasma 1 by a high frequency electromagnetic field (frequency 4 MHz). At this time, the high frequency power is set to 30 to 40 kW.

Further, from the powder supply nozzle 5, a mixed powder of the M element compound and the tungsten compound obtained by the above synthesis method or a composite tungsten oxide is supplied from a gas supply device with an argon gas of 6 to 98 L / min as a carrier. As a gas, it is introduced into a thermal plasma at a supply rate of 25 to 50 g / min and reacted for a predetermined time. After the reaction, the generated composite tungsten oxide fine particles pass through the suction tube 7 and are deposited on the filter 8, so that they are recovered.
The carrier gas flow rate and the raw material supply rate have a great influence on the production time of fine particles. Therefore, it is preferable that the carrier gas flow rate is 6 L / min or more and 9 L / min or less, and the raw material supply rate is 25 to 50 g / min.

Further, it is preferable that the plasma gas flow rate is 30 L / min or more and 45 L / min or less, and the sheath gas flow rate is 60 L / min or more and 70 L / min or less. The plasma gas has a function of maintaining a thermal plasma region having a high temperature portion of 1000 to 15000 K, and the sheath gas has a function of cooling the inner wall surface of the quartz torch in the reaction vessel and preventing the quartz torch from melting. At the same time, since the plasma gas and the sheath gas affect the shape of the plasma region, the flow rate of these gases is an important parameter for controlling the shape of the plasma region. As the flow rate of plasma gas and sheath gas is increased, the shape of the plasma region extends in the gas flow direction, and the temperature gradient of the plasma tail flame portion becomes gentler. Therefore, the generation time of the generated fine particles is lengthened, and fine particles having good crystallinity are generated. become able to.

When the composite tungsten oxide obtained by the thermal plasma method has a crystallite diameter of more than 200 nm, or the composite tungsten oxide fine particle dispersion obtained from the composite tungsten oxide obtained by the thermal plasma method. When the dispersed particle size of the tungsten oxide exceeds 200 nm, pulverization / dispersion treatment described later can be performed. When synthesizing a composite tungsten oxide by the thermal plasma method, the plasma conditions and the subsequent pulverization / dispersion treatment conditions are appropriately selected, and the average particle size, crystallite size, and lattice constant of the composite tungsten oxide are a-axis. The effect of the present invention is exhibited by defining the pulverization conditions (fine particle conditions) to which the length and the c-axis length can be imparted.

(2) Solid-phase reaction method The solid-phase reaction method will be described in the order of (i) raw materials used in the solid-phase reaction method, and (ii) firing and its conditions in the solid-phase reaction method.

(I) Raw materials used in the solid phase reaction method When synthesizing the composite tungsten oxide fine particles according to the present invention by the solid phase reaction method, a tungsten compound and an M element compound are used as raw materials.
The tungsten compound is a hydrate of tungsten obtained by adding water to tungsten hexachloride dissolved in tungstic acid (H ₂ WO ₄ ), ammonium tungstate, tungsten hexachloride, or alcohol, hydrolyzing the mixture, and then evaporating the solvent. It is preferable that it is one or more selected from.
In addition, a general formula MxWyOz (where M is one or more elements selected from Cs, Rb, K, Tl, Ba, and In, 0.001 ≦ x / y ≦ 1, 2. The M element compounds used in the production of raw materials for the composite tungsten oxide fine particles represented by 0 ≦ z / y ≦ 3.0) include oxides, hydroxides, nitrates, sulfates, chlorides, and carbonates of M elements. , And more than one selected from.

Further, a compound containing one or more impurity elements selected from Si, Al, and Zr (may be referred to as "impurity element compound" in the present invention) may be contained as a raw material. The impurity element compound does not react with the composite tungsten compound in the subsequent firing step, suppresses crystal growth of the composite tungsten oxide, and functions to prevent crystal coarsening. The compound containing an impurity element is preferably one or more selected from oxides, hydroxides, nitrates, sulfates, chlorides, and carbonates, and colloidal silica and colloidal alumina having a particle size of 500 nm or less are particularly preferable. preferable.

The ratio of the M element to the W element of the tungsten compound and the aqueous solution containing the M element compound is MxWyOz (where M is the M element, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦. Wet mixing is performed so that the ratio of M element and W element is 1.0, 2.0 ≦ z / y ≦ 3.0). When the impurity element compound is contained as a raw material, wet mixing is performed so that the impurity element compound is 0.5% by mass or less. Then, by drying the obtained mixed solution, a mixed powder of the M element compound and the tungsten compound, or a mixed powder of the M element compound containing the impurity element compound and the tungsten compound can be obtained.

(Ii) Firing in the solid phase reaction method and its conditions A mixed powder of an M element compound and a tungsten compound produced by the wet mixing, or a mixed powder of an M element compound containing an impurity element compound and a tungsten compound is not used. It is fired in one step in a gas atmosphere of the active gas alone or a mixed gas of the inert gas and the reducing gas. The calcination temperature is preferably close to the temperature at which the composite tungsten oxide fine particles start to crystallize, specifically, the calcination temperature is preferably 1000 ° C. or lower, more preferably 800 ° C. or lower, and 800 ° C. or lower and 500 ° C. The above temperature range is more preferable.

The reducing gas is not particularly limited, but H ₂ is preferable. When H ₂ is used as the reducing gas, its concentration may be appropriately selected according to the firing temperature and the quantity of the starting raw material, and is not particularly limited. For example, it is 20% by volume or less, preferably 10% by volume or less, and more preferably 7% by volume or less. This is because if the concentration of the reducing gas is 20% by volume or less, it is possible to avoid the formation of WO ₂ having no solar radiation absorption function due to rapid reduction. At this time, by controlling the firing conditions, the average particle diameter, crystallite diameter, lattice constant a-axis length and c-axis length of the composite tungsten oxide fine particles according to the present invention can be set to predetermined values.
However, in the synthesis of the composite tungsten oxide fine particles, tungsten trioxide may be used instead of the tungsten compound.

(3) Synthesized composite tungsten oxide fine particles When the composite tungsten oxide fine particle dispersion liquid described later is prepared using the composite tungsten oxide fine particles obtained by the synthetic method by the thermal plasma method or the solid phase reaction method, the said When the dispersed particle size of the fine particles contained in the dispersion liquid exceeds 200 nm, it may be pulverized and dispersed in the step of producing the composite tungsten oxide fine particle dispersion liquid described later. Then, if the values of the average particle diameter, crystallite diameter, a-axis length and c-axis length of the lattice constants of the composite tungsten oxide fine particles obtained through the pulverization / dispersion treatment can realize the range of the present invention, the present invention The composite tungsten oxide fine particle dispersion obtained from the composite tungsten oxide fine particles and the dispersion liquid thereof according to the present invention can realize excellent near-infrared absorption characteristics.

As described above, the composite tungsten oxide fine particles according to the present invention have an average particle diameter of 100 nm or less.
Here, when the average particle size of the composite tungsten oxide fine particles obtained by the method described in "[b] Method for synthesizing composite tungsten oxide fine particles" exceeds 100 nm, pulverization / dispersion treatment is performed to atomize the composite tungsten oxide fine particles. , The step of producing the composite tungsten oxide fine particle dispersion (crushing / dispersion treatment step) and the drying treatment of the manufactured composite tungsten oxide fine particle dispersion to remove volatile components (mostly solvents), The composite tungsten oxide fine particles according to the present invention can be produced.
Hereinafter, (i) pulverization / dispersion treatment step and (ii) drying step will be described in this order.

(I) Grinding / dispersion processing process,
In the step of crushing / dispersing the composite tungsten oxide fine particles, the composite tungsten oxide fine particles are put into a monomer of a thermosetting resin in an appropriate uncured state or an appropriate solvent described later together with a dispersant described later. This is a step of uniformly dispersing the particles without aggregating them.
In the pulverization / dispersion treatment step, the average particle size of the composite tungsten oxide fine particles can be 100 nm or less, preferably 10 nm or more and 100 nm or less, and the a-axis is preferably 7.3850 Å or more in terms of the lattice constant of the crystal. The value of 7.4186 Å or less, c-axis 7.5600 Å or more and 7.6240 Å or less, and more preferably [c-axis lattice constant / a-axis lattice constant] can be guaranteed in the range of 1.0221 or more and 1.0289 or less. That is.

Specific examples thereof include a pulverization / dispersion treatment method for a predetermined time using an apparatus such as a bead mill, a ball mill, a sand mill, a paint shaker, and an ultrasonic homogenizer. Among them, crushing and dispersing with a medium stirring mill such as a bead mill, a ball mill, a sand mill, and a paint shaker using a medium medium such as beads, balls, and Otawa sand is to obtain a desired average particle size and dispersed particle size. It is preferable because the time required is short.

By crushing and dispersing using a medium stirring mill, the composite tungsten oxide fine particles are dispersed in the dispersion liquid, and at the same time, the composite tungsten oxide fine particles collide with each other and the medium media collides with the fine particles to form fine particles. Then, the composite tungsten oxide fine particles can be made into finer particles and dispersed (that is, they are pulverized and dispersed).
By the mechanical dispersion treatment step using these equipment, the composite tungsten oxide fine particles are dispersed in the solvent, and at the same time, the composite tungsten oxide particles are made into fine particles due to collisions between the composite tungsten oxide particles, and the composite tungsten oxide particles are formed. Distortion or deformation is applied to the contained hexagonal crystal structure, the overlapping state of electron orbits in the atoms constituting the crystallite structure changes, and the amount of free electrons progresses.

It should be noted that the fine particles of the composite tungsten oxide particles and the fluctuations in the a-axis length and the c-axis length, which are the lattice constants in the hexagonal crystal structure, differ depending on the equipment constants of the pulverizer. Therefore, a pulverizer capable of imparting the above-mentioned predetermined average particle diameter, crystallite diameter, lattice constant a-axis length and c-axis length to the composite tungsten oxide fine particles by performing a test pulverization in advance, pulverization conditions. It is important to ask for.

The state of the composite tungsten oxide fine particle dispersion liquid can be confirmed by measuring the dispersed state of the composite tungsten oxide fine particles when the tungsten oxide fine particles are dispersed in a solvent. For example, the composite tungsten oxide fine particles according to the present invention can be confirmed by sampling a sample from the fine particles and a liquid existing in an aggregated state of the fine particles in a solvent and measuring with various commercially available particle size distribution meters. it can. As the particle size distribution meter, for example, a known measuring device such as ELS-8000 manufactured by Otsuka Electronics Co., Ltd. based on the dynamic light scattering method can be used.
The dispersed particle size of the composite tungsten oxide fine particles according to the present invention is preferably 200 nm or less, and more preferably 10 nm or more and 200 nm or less.

Since the near-infrared absorbing component containing the composite tungsten oxide fine particles according to the present invention largely absorbs light in the near-infrared region, particularly in the vicinity of a wavelength of 900 to 2200 nm, the transmitted color tone in the visible light is bluish to greenish. May be. On the other hand, if the dispersed particle size of the composite tungsten oxide fine particles contained in the infrared ray absorbing layer is 1 to 200 nm, light in the visible light region having a wavelength of 380 nm to 780 nm is not scattered by geometric scattering or me scattering. This is because the infrared ray absorbing layer reduces the color development due to light scattering and can increase the visible light transmittance. Further, in the Rayleigh scattering region, the scattered light is reduced in proportion to the sixth power of the particle size, so that the scattering is reduced and the transparency is improved as the dispersed particle size is reduced. Therefore, when the dispersed particle diameter is 200 nm or less, the scattered light becomes very small and the transparency is further increased, which is preferable.

From the above, if the dispersed particle size of the fine particles is made smaller than 200 nm, transparency can be ensured, so that the near-infrared curable ink composition can be easily colored. When the transparency is emphasized, the dispersed particle size is preferably 150 nm or less, more preferably 100 nm or less. On the other hand, if the dispersed particle size is 10 nm or more, industrial production is easy.

Here, the dispersed particle size of the composite tungsten oxide fine particles in the composite tungsten oxide fine particle dispersion liquid will be briefly described. The dispersed particle size of the composite tungsten oxide fine particles means the particle size of the single particles of the composite tungsten oxide fine particles dispersed in the solvent and the particles (aggregated particles) in which the composite tungsten oxide fine particles are aggregated. It can be measured with various commercially available particle size distribution meters. For example, a sample of the composite tungsten oxide fine particle dispersion can be taken, and the sample can be measured using ELS-8000 manufactured by Otsuka Electronics Co., Ltd. based on the dynamic light scattering method.

Further, the composite tungsten oxide fine particle dispersion liquid in which the content of the composite tungsten oxide fine particles obtained by the above synthesis method is 0.01% by mass or more and 80% by mass or less is excellent in liquid stability. When an appropriate liquid medium, dispersant, coupling agent, and surfactant are selected, gelation of the dispersion and sedimentation of particles do not occur for 6 months or more even when placed in a constant temperature bath at a temperature of 40 ° C. The dispersed particle size can be maintained in the range of 10 to 200 nm.

The dispersed particle size of the composite tungsten oxide fine particle dispersion liquid and the average particle size of the composite tungsten oxide fine particle dispersed in the composite tungsten oxide fine particle dispersion may be different. This is because even if the composite tungsten oxide fine particles are aggregated in the composite tungsten oxide fine particle dispersion, the composite tungsten oxide fine particles are processed when the composite tungsten oxide fine particle dispersion is processed into the composite tungsten oxide fine particle dispersion. This is because the aggregation is broken.

(Ii) Drying Step In the drying step, the composite tungsten oxide fine particle dispersion obtained in the above-mentioned pulverization / dispersion step is dried to remove volatile components in the dispersion, and the composite tungsten oxide according to the present invention is removed. It obtains fine particles.

As the drying treatment equipment, heating and / or depressurization is possible, and from the viewpoint of easy mixing and recovery of the fine particles, an air dryer, a universal mixer, a ribbon type mixer, a vacuum flow dryer, and a vibration flow dryer. Machines, freeze dryers, ribocorns, rotary kilns, spray dryers, parcon dryers, etc. are preferred, but not limited to these.

[C] Uncured Thermosetting Resin The uncured thermosetting resin according to the present invention is in an uncured liquid state at the time of the near-infrared curable ink composition, but when it is irradiated with near-infrared rays. Is a thermosetting resin that is cured by applying heat energy from composite tungsten oxide fine particles.

Specific examples of the uncured thermosetting resin include uncured epoxy resin, urethane resin, acrylic resin, urea resin, melamine resin, phenol resin, ester resin, polyimide resin, silicone resin, and unsaturated polyester resin. Cured resin can be mentioned.
The uncured thermosetting resin may contain monomers and oligomers that form a thermosetting resin by a curing reaction, and a known curing agent that is appropriately added. Further, a known curing accelerator may be added to the curing agent.

[D] Other Components The near-infrared curable ink composition according to the present invention further contains other components such as pigments, solvents, and dispersants, if desired.
Therefore, (1) pigments and dyes, (2) dispersants, and (3) solvents will be described in this order.

(1) Pigments and Dyes Known pigments can be used without particular limitation as pigments that can be used for coloring the near-infrared curable ink composition according to the present invention. Specifically, organic pigments such as insoluble pigments and rake pigments and inorganic pigments such as carbon black can be preferably used.
It is preferable that these pigments are present in a dispersed state in the near-infrared curable ink composition according to the present invention. As a method for dispersing these pigments, a known method can be used without particular limitation.

As described above, the insoluble pigment is not particularly limited, but for example, azo, azomethine, methine, diphenylmethane, triphenylmethane, quinacridone, anthraquinone, perylene, indigo, quinophthalone, isoindoline, isoindoline, azine, oxazine, Thiazine, dioxazine, thiazole, phthalocyanine, diketopyrrolopyrrole and the like are preferred insoluble pigments.

Here, the names of commercially available pigments that are preferably used are listed below.
Examples of pigments for magenta or red include C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 53: 1, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 139, C.I. I. Pigment Red 144, C.I. I. Pigment Red 149, C.I. I. Pigment Red 166, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 202, C.I. I. Pigment Red 222, C.I. I. Pigment Violet 19 and the like.

Examples of pigments for orange or yellow include C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 15: 3, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 128, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 138 and the like.

Examples of pigments for green or cyan include C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

Examples of black pigments include C.I. I. Pigment Black 1, C.I. I. Pigment Black 6, C.I. I. Pigment Black 7 and the like.

As described above, the inorganic pigment is not particularly limited, but carbon black, titanium dioxide, zinc sulfide, zinc oxide, zinc phosphate, mixed metal oxide phosphate, iron oxide, manganese oxide, chromium oxide, and ultramarin. , Nickel or chromium antimony titanium oxide, cobalt oxide, aluminum, aluminum oxide, silicon oxide, silicate, zirconium oxide, mixed oxide of cobalt and aluminum, molybdenum sulfide, rutile mixed phase pigment, rare earth sulfide, vanadic acid An extender pigment composed of bismuth, aluminum hydroxide, barium sulfate and the like are preferable inorganic pigments.

The dispersed particle size of the pigment in the dispersed state contained in the near-infrared curable ink composition according to the present invention is preferably 10 nm or more and 200 nm or less. This is because when the dispersed particle size of the pigment dispersion is 10 nm or more and 200 nm or less, the storage stability in the near-infrared curable ink composition is good.

The dye used in the present invention is not particularly limited, and either an oil-soluble dye or a water-soluble dye can be used, and a yellow dye, a magenta dye, a cyan dye, or the like can be preferably used.

Examples of the yellow dye include aryl or heteryl azo dyes having phenols, naphthols, anilines, pyrazolones, pyridones, and open-chain active methylene compounds as coupling components;
For example, an azomethin dye having an open chain type active methylene compound as a coupling component;
Methine dyes such as benzylidene dyes and monomethine oxonor dyes;
For example, there are quinone dyes such as naphthoquinone dyes and anthraquinone dyes. Examples of other dye types include quinophthalone dyes, nitro / nitroso dyes, acridine dyes, and acridinone dyes.
These dyes may be yellow only after a part of the chromophore is dissociated. In that case, the counter cation may be an alkali metal, an inorganic cation such as ammonium, or an organic cation such as pyridinium or a quaternary ammonium salt. Furthermore, it may be a polymer cation having them in a partial structure.

Magenta dyes include, for example, aryl or heteryl azo dyes having phenols, naphthols, and anilines as coupling components;
For example, an azomethine dye having pyrazolones and pyrazorotriazoles as coupling components;
For example, methine dyes such as allylidene dyes, styryl dyes, merocyanine dyes, oxonor dyes;
For example, carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene dyes;
For example, quinone dyes such as naphthoquinone, anthraquinone, anthrapyridone;
For example, condensed polycyclic dyes such as dioxazine dyes; etc. can be mentioned.
These dyes may exhibit magenta only after a part of the chromophore is dissociated. In that case, the counter cation may be an alkali metal or an inorganic cation such as ammonium. It may also be an organic cation such as pyridinium or quaternary ammonium salt. Furthermore, it may be a polymer cation having them in a partial structure.

Cyan dyes include azomethine dyes such as indoaniline dyes and indophenol dyes;
Polymethine dyes such as cyanine dyes, oxonor dyes, merocyanine dyes;
Carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene dyes;
Phthalocyanine dyes; anthraquinone dyes; for example, aryl or heteryl azo dyes having phenols, naphthols, anilines as coupling components, indigo and thioindigo dyes can be mentioned.
These dyes may exhibit cyan only after a part of the chromophore is dissociated. In that case, the counter cation may be an alkali metal, an inorganic cation such as ammonium, or an organic cation such as pyridinium or a quaternary ammonium salt. Further, it may be a polymer cation having them in a partial structure. In addition, black dyes such as polyazo dyes can also be used.

The water-soluble dye used in the present invention is not particularly limited, and direct dyes, acid dyes, edible dyes, basic dyes, reactive dyes, and the like can be preferably used.

Specific dye names that are preferably used as water-soluble dyes are listed below.
C. I. Direct Red 2, 4, 9, 23, 26, 31, 39, 62, 63, 72, 75, 76, 79, 80, 81, 83, 84, 89, 92, 95, 111, 173, 184, 207, 211, 212, 214, 218, 21, 223, 224, 225, 226, 227, 232, 233, 240, 241, 242, 243, 247,
C. I. Direct Violet 7, 9, 47, 48, 51, 66, 90, 93, 94, 95, 98, 100, 101,
C. I. Direct Yellow 8, 9, 11, 12, 27, 28, 29, 33, 35, 39, 41, 44, 50, 53, 58, 59, 68, 86, 87, 93, 95, 96, 98, 100, 106, 108, 109, 110, 130, 132, 142, 144, 161, 163,
C. I. Direct Blue 1, 10, 15, 22, 25, 55, 67, 68, 71, 76, 77, 78, 80, 84, 86, 87, 90, 98, 106, 108, 109, 151, 156, 158, 159, 160, 168, 189, 192, 193, 194, 199, 200, 201, 202, 203, 207, 211, 213, 214, 218, 225, 229, 236, 237, 244, 248, 249, 251, 252, 264, 270, 280, 288, 289, 291
C. I. Direct Black 9, 17, 19, 22, 32, 51, 56, 62, 69, 77, 80, 91, 94, 97, 108, 112, 113, 114, 117, 118, 121, 122, 125, 132, 146, 154, 166, 168, 173, 199,
C. I. Acid Red 35, 42, 52, 57, 62, 80, 82, 111, 114, 118, 119, 127, 128, 131, 143, 151, 154, 158, 249, 254, 257, 261, 263, 266, 289, 299, 301, 305, 336, 337, 361, 396, 397,
C. I. Acid Violet 5, 34, 43, 47, 48, 90, 103, 126,
C. I. Acid Yellow 17, 19, 23, 25, 39, 40, 42, 44, 49, 50, 61, 64, 76, 79, 110, 127, 135, 143, 151, 159, 169, 174, 190, 195, 196, 197, 199, 218, 219, 222, 227,
C. I. Acid Blue 9, 25, 40, 41, 62, 72, 76, 78, 80, 82, 92, 106, 112, 113, 120, 127: 1, 129, 138, 143, 175, 181, 205, 207, 220, 221, 230, 232, 247, 258, 260, 264, 271, 277, 278, 279, 280, 288, 290, 326,
C. I. Acid Black 7, 24, 29, 48, 52: 1, 172,
C. I. Reactive Red 3, 13, 17, 19, 21, 22, 23, 24, 29, 35, 37, 40, 41, 43, 45, 49, 55,
C. I. Reactive Violet 1,3,4,5,6,7,8,9,16,17,22,23,24,26,27,33,34,
C. I. Reactive Yellow 2,3,13,14,15,17,18,23,24,25,26,27,29,35,37,41,42,
C. I. Reactive Blue 2,3,5,8,10,13,14,15,17,18,19,21,25,26,27,28,29,38,
C. I. Reactive Black 4, 5, 8, 14, 21, 23, 26, 31, 32, 34,
C. I. Basic Red 12, 13, 14, 15, 18, 22, 23, 24, 25, 27, 29, 35, 36, 38, 39, 45, 46,
C. I. Basic Violet 1, 2, 3, 7, 10, 15, 16, 20, 21, 25, 27, 28, 35, 37, 39, 40, 48,
C. I. Basic Yellow 1,2,4,11,13,14,15,19,21,23,24,25,28,29,32,36,39,40,
C. I. Basic Blue 1,3,5,7,9,22,26,41,45,46,47,54,57,60,62,65,66,69,71,
C. I. Basic black 8, etc. can be mentioned.

The particle size of the pigment of the coloring material and the composite tungsten oxide fine particles contained in the near-infrared curable ink described above is preferably determined in consideration of the characteristics of the coating device of the near-infrared curable ink composition.
The near-infrared curable ink composition according to the present invention is a concept including the above-mentioned near-infrared curable ink composition containing no pigment or dye.

(2) Dispersant The composite tungsten oxide fine particles according to the present invention may be dispersed together with an appropriate dispersant in a monomer of a thermosetting resin in an appropriate uncured state or an appropriate solvent described later. This is because the composite tungsten oxide fine particles can be easily dispersed in the near-infrared curable ink by adding an appropriate dispersant, and it can be expected to suppress the variation in curing in the coating film of the near-infrared curable ink.

As the dispersant, a commercially available dispersant can be used as appropriate, but the molecular structure of the dispersant is a polyester-based, polyacrylic-based, polyurethane-based, polyamine-based, polycaptolactone-based, or polystyrene-based main chain. It is preferable that the functional group has an amino group, an epoxy group, a carboxyl group, a hydroxyl group, a sulfo group or the like. A dispersant having such a molecular structure is unlikely to deteriorate when the coating film of the near-infrared ray curable ink according to the present invention is intermittently irradiated with near infrared rays for several tens of seconds. Therefore, problems such as coloring due to the alteration do not occur.

For such dispersants,
SOLPERSE® (registered trademark) (same below) 3000, 5000, 9000, 11200, 12000, 13000, 13240, 13650, 13940, 16000, 17000, 18000, 20000, 21000, 24000SC, 24000GR, 26000, 27000, manufactured by Japan Lubrizol. , 28000, 31845, 32000, 32500, 32550, 32600, 33000, 33500, 34750, 35100, 35200, 36600, 37500, 38500, 39000, 41000, 41090, 53095, 55000, 56000, 71000, 76500, J180, J200, M387 etc;
SOLPLUS® (registered trademark) (same below) D510, D520, D530, D540, DP310, K500, L300, L400, R700, etc .;
Disperbyk® (registered trademark) manufactured by Big Chemie Japan (the same applies hereinafter) -101, 102, 103, 106, 107, 108, 109, 110, 111, 112, 116, 130, 140, 142, 145, 154, 161 162, 163, 164, 165, 166, 167, 168, 170, 171, 174, 180, 181, 182, 183, 184, 185, 190, 191, 192, 2000, 2001, 2009, 2020, 2025, 2050, 2070, 2095, 2096, 2150, 2151, 2152, 2155, 2163, 2164;
Anti-Terra® (same below) -U, 203, 204, etc .;
BYK® (registered trademark) -P104, P104S, P105, P9050, P9051, P9060, P9065, P9800, 051, 052, 053, 054, 055, 057, 063, 065, 066N, 067A, 077, 088, 141, 220S, 300, 302, 306, 307, 310, 315, 320, 322, 323, 325, 330, 331, 333, 337, 340, 345, 346, 347, 348, 350, 354, 355, 358N, 361N, 370, 375, 377, 378, 380N, 381, 392, 410, 425, 430, 1752, 4510, 6919, 9076, 9077, W909, W935, W940, W961, W966, W969, W972, W980, W985, W995, W996, W9010, Dynawet800, Silkean3700, UV3500, UV3510, UV3570, etc .;
EFKA® (registered trademark) 2020, 2025, 3030, 3031, 3236, 4008, 4009, 4010, 4015, 4046, 4047, 4060, 4080, 7462, 4020, 4050, 4055, manufactured by Fuka Adidebs. 4,300, 4310, 4320, 4400, 4401, 4402, 4403, 4300, 4320, 4330, 4340, 5066, 5220, 6220, 6225, 6230, 6700, 6780, 6782, 8503;
Made by BASF Japan, JONCRYL (registered trademark) (same below) 67, 678, 586, 611, 680, 682, 690, 819, -JDX5050, etc.;
Otsuka Chemical Co., Ltd., TERPLUS (registered trademark) (same below) MD1000, D 1180, D 1130, etc.
Ajinomoto Fine Techno Co., Ltd., Ajispar (registered trademark) (same below) PB-711, PB-821, PB-822, etc.;
Kusumoto Kasei Co., Ltd., Disparon (registered trademark) (same below) 1751N, 1831, 1850, 1860, 1934, DA-400N, DA-703-50, DA-325, DA-375, DA-550, DA-705, DA-725, DA-1401, DA-7301, DN-900, NS-5210, NVI-8514L, etc .;
UC-3000, UF-5022, UG-4010, UG-4035, UG-4070, etc. manufactured by Toagosei Co., Ltd., Alfon (registered trademark) (the same applies hereinafter).

(3) Solvent In the near-infrared curable ink composition according to the present invention, it is also preferable to use a solvent together with a monomer of a thermosetting resin in an uncured state.
In this case, as a solvent for the near-infrared curable ink composition, an epoxy group or the like that reacts with a monomer or oligomer of the thermosetting resin contained in the resin that is in an uncured state during the curing reaction of the thermosetting resin described later. It is also preferable to use a reactive organic solvent having the above functional groups.
By adding the solvent, the viscosity of the near-infrared curable ink composition can be appropriately adjusted. As a result, the coatability and the smoothness of the coating film can be easily ensured.

Examples of the solvent of the near-infrared curable ink composition according to the present invention include water, methanol, ethanol, propanol, butanol, isopropyl alcohol, isobutyl alcohol, diacetone alcohol and other alcohols, methyl ether, ethyl ether and propyl ether. Various organic solvents such as ethers such as ethers, esters, acetone, methyl ethyl ketone, diethyl ketone, cyclohexanone, inbutyl ketone and other ketones, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, polyethylene glycol and polypropylene glycol can be used. is there.

[E] Near-infrared curable ink composition As described above, the composite tungsten oxide fine particles according to the present invention are added to the uncured thermosetting resin, or the composite tungsten oxide fine particles according to the present invention are appropriately added. The near-infrared curable ink composition according to the present invention can be obtained by adding an uncured thermosetting resin after dispersing in a solvent. The near-infrared ray curable ink composition according to the present invention is provided on a predetermined base material and has excellent adhesion to the base material when cured by being irradiated with near infrared rays.
Then, the near-infrared ray curable ink composition according to the present invention is used as a conventional ink, and a predetermined amount is applied to the composition, which is then irradiated with near infrared rays to be cured and stacked to form a three-dimensional object described later. This is a near-infrared curable ink composition that is most suitable for the stereolithography method.

As described above, the solvent is removed from the near-infrared curable ink composition containing the composite tungsten oxide fine particles and containing the solvent, the dispersant, and the uncured thermosetting resin, or without using the solvent. It is also preferable to obtain a near-infrared curable ink composition containing composite tungsten oxide fine particles, a dispersant, and an uncured thermosetting resin.
The near-infrared curable ink composition containing the composite tungsten oxide fine particles, the dispersant, and the uncured thermosetting resin without using the solvent omits the step related to the volatilization of the solvent in the subsequent step. And the efficiency of the curing reaction is good.
On the other hand, the method for removing the solvent is not particularly limited, but a heat distillation method or the like with a reduced pressure operation can be used.

The amount of the composite tungsten oxide fine particles contained in the near-infrared curable ink according to the present invention may be appropriately added in an amount that allows the uncured thermosetting resin to be cured during the curing reaction. Therefore, the amount of the composite tungsten oxide fine particles per coating area of the near-infrared curable ink may be determined in consideration of the coating thickness of the near-infrared curable ink.

The method for dispersing the composite tungsten oxide fine particles in the solvent is not particularly limited, but it is preferable to use a wet medium mill. However, also at this time, a test dispersion is carried out in advance, and the average particle diameter is 100 nm or less, the lattice constant is 7.3850 Å or more and 7.4186 Å or less, and the c-axis is 7 in the composite tungsten oxide fine particles. A disperser and dispersion conditions capable of imparting 1.0221 or more and 1.0289 or less as the value of [c-axis lattice constant / a-axis lattice constant] of .5600 Å or more and 7.6240 Å or less are obtained. ..

[2] Near-infrared curable product and photomolding method Since the near-infrared curable ink according to the present invention has visible light transmission, a predetermined amount of the near-infrared curable ink composition is applied to obtain a coating film. By irradiating and curing near infrared rays, a near infrared ray cured film according to the present invention exhibiting excellent adhesion to a predetermined substrate can be obtained. Further, a colored film can be easily obtained by adding at least one kind of various pigments and dyes to the near-infrared curable ink. Since the colored film has almost no effect on the color due to the composite tungsten oxide fine particles, the colored film can be used as a color filter or the like of a liquid crystal display.

The reason for obtaining the above-mentioned excellent adhesion is that the composite tungsten oxide fine particles absorb the irradiated near infrared rays and generate heat, and the heat energy of the heat generation is the monomer contained in the uncured thermosetting resin. This is because a curing reaction of a thermosetting resin occurs by accelerating a reaction such as a polymerization reaction, a condensation reaction, or an addition reaction with an oligomer or the like. In addition, the solvent is volatilized by the heat generated by the composite tungsten oxide fine particles by irradiation with near infrared rays.
On the other hand, even if the near-infrared ray cured film according to the present invention is further irradiated with near-infrared ray, the cured film is not remelted. Since the near-infrared ray curable film according to the present invention contains a thermosetting resin obtained by curing an uncured thermosetting resin, it does not remelt even if the composite tungsten oxide fine particles generate heat due to irradiation with near infrared rays. is there.

This characteristic is the light that forms a three-dimensional object by repeatedly curing and stacking a predetermined amount of the near-infrared curable ink composition according to the present invention, applying the near-infrared curable ink and repeatedly irradiating the near-infrared ray. When applied to a modeling method, it is particularly effective in combination with the excellent adhesion to the substrate described above.
Of course, it is also preferable to apply a predetermined amount of the near-infrared ray curable ink composition according to the present invention on a substrate and irradiate the substrate with near infrared rays to cure the near infrared ray curable film according to the present invention.

The material of the base material used in the present invention is not particularly limited, and examples thereof include paper, PET, acrylic, urethane, polycarbonate, polyethylene, ethylene vinyl acetate copolymer, vinyl chloride, fluororesin, polyimide, polyacetal, polypropylene, nylon and the like. , Can be preferably used according to various purposes. In addition to paper and resin, glass can be preferably used.

As a method for curing the near-infrared ray curable ink composition according to the present invention, infrared irradiation is preferable, and near infrared irradiation is more preferable. Near infrared rays have a high energy density, and can efficiently apply the energy required for curing the resin in the ink composition.
It is also preferable to cure the near-infrared curable ink composition according to the present invention by combining infrared irradiation and an arbitrary method selected from known methods. For example, methods such as heating, blowing air, and irradiating electromagnetic waves may be used in combination with infrared irradiation.

In the present invention, infrared rays refer to electromagnetic waves having a wavelength in the range of 0.1 μm to 1 mm, near infrared rays refer to infrared rays having a wavelength of 0.75 to 4 μm, and far infrared rays refer to infrared rays having a wavelength of 4 to 1000 μm. .. The effect of the present invention can be obtained regardless of which infrared ray is generally called far infrared ray or near infrared ray is irradiated. However, when near infrared rays are irradiated, the thermosetting resin can be cured efficiently in a shorter time.

Further, in the present invention, the microwave refers to an electromagnetic wave having a wavelength in the range of 1 mm to 1 m.
The microwave to be irradiated preferably has a power of 200 to 1000 W. If the power is 200 W or more, the vaporization of the organic solvent remaining in the ink is promoted, and if it is 1000 W or less, the irradiation conditions are mild, and there is no possibility that the base material or the thermosetting resin is deteriorated.

The preferable infrared irradiation time for the near-infrared curable ink composition according to the present invention varies depending on the irradiation energy and wavelength, the composition of the near-infrared curable ink, and the amount of the near-infrared curable ink applied, but is generally 0. Irradiation for 1 second or longer is preferable. When the irradiation time is 0.1 seconds or more, it is possible to carry out infrared irradiation within a range within the above-mentioned preferable power. It is possible to sufficiently dry the solvent in the ink composition by lengthening the irradiation time, but the irradiation time may be within 30 seconds when printing or coating at high speed is taken into consideration. It is preferably within 10 seconds, more preferably within 10 seconds.

As the infrared radiation source, it may be obtained directly from a heat source, or an effective infrared radiation may be obtained from a heat medium interposed therebetween. For example, infrared rays can be obtained by heating a discharge lamp of mercury, xenon, cesium, sodium or the like, a carbon dioxide gas laser, or an electric resistor such as platinum, tungsten, nichrome or cantal. A halogen lamp is mentioned as a preferable radiation source. Halogen lamps have the advantages of good thermal efficiency and quick start-up.

The near-infrared curable ink composition according to the present invention may be irradiated with infrared rays from the near-infrared curable ink coating surface side or the back surface side. It is also preferable to irradiate from both sides at the same time, and it is also preferable to combine it with heating temperature drying or blast drying. Further, it is more preferable to use a condensing plate as needed. By combining these methods, it becomes possible to cure with infrared irradiation for a short time.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(1) Method for measuring crystal structure, method for calculating lattice constant and crystallite diameter As a sample to be measured for composite tungsten oxide fine particles, composite tungsten oxide obtained by removing a solvent from a dispersion liquid for forming a near-infrared absorber. Fine particles were used. Then, the X-ray diffraction pattern of the composite tungsten oxide fine particles is measured by a powder X-ray diffraction method (θ-2θ method) using a powder X-ray diffractometer (X'Pert-PRO / MPD manufactured by PANalytical Co., Ltd.). did. The crystal structure contained in the fine particles was specified from the obtained X-ray diffraction pattern, and the lattice constant and crystallite diameter were calculated using the Rietveld method.

(2) Dispersed particle size The dispersed particle size of the fine particles in the composite tungsten oxide fine particle dispersion is determined by using ELS-8000 manufactured by Otsuka Electronics Co., Ltd., observing the fluctuation of the scattered light of the laser, and using a dynamic light scattering method. The autocorrelation function was obtained by (photon correlation method), and the average particle size (fluodynamic diameter) was calculated by the Cumulant method.

(3) Evaluation of Hardened Film Containing Composite Tungsten Oxide Fine Particles A near-infrared ray curable ink composition is applied to a blue plate glass plate having a thickness of 3 mm, and the cured film containing the composite tungsten oxide fine particles is irradiated with near infrared rays. Made. The optical characteristics of the cured film were measured using a spectrophotometer U-4100 (manufactured by Hitachi, Ltd.). Visible light transmittance was measured according to JIS R 3106: 1998.

(4) Average particle size in the cured film containing the composite tungsten oxide fine particles The average particle size of the composite tungsten oxide fine particles dispersed in the near-infrared curable ink composition is the transmission electron in the cross section of the cured film described above. It was measured by observing a microscopic image. The transmission electron microscope image was observed using a transmission electron microscope (HF-2200 manufactured by Hitachi High-Technologies Corporation). The transmission electron microscope image was processed by an image processing apparatus, the particle size of 100 composite tungsten oxide fine particles was measured, and the average value was taken as the average particle size.

[Example 1]
A solution was obtained by dissolving 7.43 kg of cesium carbonate (Cs ₂ CO ₃ ) in 6.70 kg of water. The solution was added to 34.57 kg of tungstic acid (H ₂ WO ₄ ), sufficiently stirred and mixed, and then dried while stirring (the molar ratio of W to Cs is equivalent to 1: 0.33). The dried product was heated while supplying 5% by volume H ₂ gas using N ₂ gas as a carrier, and fired at a temperature of 800 ° C. for 5.5 hours, after which the supplied gas was switched to N ₂ gas only. , The temperature was lowered to room temperature to obtain composite tungsten oxide particles (hereinafter referred to as particles a).
20 parts by mass of particles a, 65 parts by mass of methyl isobutyl ketone, and 15 parts by mass of an acrylic dispersant were mixed to prepare a mixture. The mixture was loaded into a paint shaker (manufactured by Asada Iron Works Co., Ltd.) containing 0.3 mmφZrO ₂ beads, and pulverized and dispersed for 7 hours to make fine particles a (hereinafter referred to as fine particles a) fine particle dispersion liquid. (Hereinafter referred to as fine particle dispersion a) was obtained. At this time, 100 parts by mass of the mixture was pulverized and dispersed using 300 parts by mass of 0.3 mmφZrO ₂ beads.

Here, the dispersed particle size of the fine particles a in the fine particle dispersion a was measured by a particle size measuring device (ELS-8000 manufactured by Otsuka Electronics Co., Ltd.) based on a dynamic light scattering method and found to be 70 nm. Moreover, when the lattice constant of the fine particle a after removing the solvent from the fine particle dispersion a was measured, it was 7.4008 Å on the a-axis and 7.6122 Å on the c-axis. The crystallite diameter was 24 nm. Then, the crystal structure of the hexagonal crystal was confirmed.

25 parts by mass of the fine particle dispersion liquid a and 75 parts by mass of a thermosetting ink (MEG screen ink (Medium) manufactured by Teikoku Inks Manufacturing Co., Ltd.) containing a commercially available one-component type uncured thermosetting resin are mixed. A near-infrared curable ink (hereinafter referred to as ink A) according to Example 1 was prepared.
Ink A is applied onto a blue plate glass having a thickness of 3 mm using a bar coater (No. 10), and a line heater HYP-14N (output 980 W) manufactured by Hi-Beck Co., Ltd. is applied from the coated surface as an irradiation source of near infrared rays. The film was placed at a height of 5 cm and irradiated with near infrared rays for 10 seconds to obtain a cured film according to Example 1 (hereinafter referred to as cured film A).

The average particle size of the composite tungsten oxide fine particles dispersed in the cured film A was calculated by an image processing apparatus using a transmission electron microscope image and found to be 25 nm.

The adhesion of the cured film A was evaluated by the method shown below.
Make 100 square-shaped cuts using a cutter guide with a gap spacing of 1 mm, and attach a tape with a width of 18 mm (Cellotape (registered trademark) CT-18 manufactured by Nichiban Co., Ltd.) to the cut surface on the squares. After 20 kg of rollers were reciprocated 20 times to completely adhere, they were rapidly peeled off at a peeling angle of 180 degrees, and the number of peeled squares was counted.
The number of squares peeled off was 0.

Even if the cured film A was irradiated with near-infrared rays under the same conditions as those for curing the near-infrared-curable ink described above for 20 seconds, the cured film did not remelt.
The above results are shown in Tables 1 and 2.

[Example 2]
Tungstic acid and cesium carbonate were operated in the same manner as in Example 1 except that a predetermined amount was weighed so that the molar ratio of W and Cs was 1: 0.31, and Cs tungsten oxidation according to Example 2 was performed. Fine particles (hereinafter referred to as fine particles b) were obtained.
A dispersion liquid of the fine particles b (hereinafter referred to as a fine particle dispersion b) was obtained by the same operation as in Example 1 except that the fine particles b were used instead of the fine particles a.
Next, the near-infrared curable ink according to Example 2 (hereinafter referred to as ink B) is operated in the same manner as in Example 1 except that the fine particle dispersion liquid b is used instead of the fine particle dispersion liquid a. Was prepared.
An operation was carried out in the same manner as in Example 1 except that ink B was used instead of ink A to obtain a cured film according to Example 2 (hereinafter, referred to as cured film B).
The fine particle dispersion b and the cured film B were evaluated in the same manner as in Example 1. A hexagonal crystal structure was confirmed in the composite tungsten oxide fine particle sample.
The above results are shown in Tables 1 and 2.

[Example 3]
Tungstic acid and cesium carbonate were operated in the same manner as in Example 1 except that a predetermined amount was weighed so that the molar ratio of W and Cs was 1: 0.35, and Cs tungsten oxidation according to Example 3 was performed. Fine particles (hereinafter referred to as fine particles c) were obtained.
A dispersion liquid of the fine particles c (hereinafter referred to as a fine particle dispersion c) was obtained by the same operation as in Example 1 except that the fine particles c were used instead of the fine particles a.
Next, the near-infrared curable ink according to Example 3 (hereinafter referred to as ink C) is operated in the same manner as in Example 1 except that the fine particle dispersion liquid c is used instead of the fine particle dispersion liquid a. Was prepared.
An operation was carried out in the same manner as in Example 1 except that ink C was used instead of ink A to obtain a cured film according to Example 3 (hereinafter, referred to as cured film C).
The fine particle dispersion c and the cured film C were evaluated in the same manner as in Example 1. A hexagonal crystal structure was confirmed in the composite tungsten oxide fine particle sample.
The above results are shown in Tables 1 and 2.

[Example 4]
Tungstic acid and cesium carbonate were operated in the same manner as in Example 1 except that a predetermined amount was weighed so that the molar ratio of W and Cs was 1: 0.37, and Cs tungsten oxidation according to Example 3 was performed. Material fine particles (hereinafter referred to as fine particles d) were obtained.
A dispersion liquid of the fine particles d (hereinafter referred to as a particle dispersion d) was obtained by the same operation as in Example 1 except that the fine particles d were used instead of the fine particles a.
Next, the near-infrared curable ink according to Example 4 (hereinafter referred to as ink D) is operated in the same manner as in Example 1 except that the fine particle dispersion liquid d is used instead of the fine particle dispersion liquid a. Was prepared.
An operation was carried out in the same manner as in Example 1 except that ink D was used instead of ink A to obtain a cured film according to Example 4 (hereinafter, referred to as cured film D).
The fine particle dispersion d and the cured film D were evaluated in the same manner as in Example 1. A hexagonal crystal structure was confirmed in the composite tungsten oxide fine particle sample.
The above results are shown in Tables 1 and 2.

[Example 5]
Tungstic acid and cesium carbonate were operated in the same manner as in Example 1 except that a predetermined amount was weighed so that the molar ratio of W and Cs was 1: 0.21, and Cs tungsten oxidation according to Example 5 was performed. Fine particles (hereinafter referred to as fine particles e) were obtained.
A dispersion liquid of the fine particles e (hereinafter referred to as a fine particle dispersion e) was obtained by the same operation as in Example 1 except that the fine particles e were used instead of the fine particles a.
Next, the near-infrared curable ink according to Example 5 (hereinafter referred to as ink E) is operated in the same manner as in Example 1 except that the fine particle dispersion liquid e is used instead of the fine particle dispersion liquid a. Was prepared.
An operation was carried out in the same manner as in Example 1 except that ink E was used instead of ink A to obtain a cured film according to Example 5 (hereinafter, referred to as cured film E).
The fine particle dispersion e and the cured film E were evaluated in the same manner as in Example 1. A hexagonal crystal structure was confirmed in the composite tungsten oxide fine particle sample.
The above results are shown in Tables 1 and 2.

[Example 6]
Cs tungsten oxide fine particles according to Example 6 (hereinafter referred to as Example 6) in the same manner as in Example 1 except that the mixture was fired at a temperature of 550 ° C. for 9.0 hours while supplying 5% H ₂ gas using N ₂ gas as a carrier. , Described as fine particles f) were obtained.
A dispersion liquid of the fine particles f (hereinafter referred to as a fine particle dispersion f) was obtained by the same operation as in Example 1 except that the fine particles f were used instead of the fine particles a.
Next, the near-infrared curable ink according to Example 6 (hereinafter referred to as ink F) is operated in the same manner as in Example 1 except that the fine particle dispersion liquid f is used instead of the fine particle dispersion liquid a. Was prepared.
An operation was carried out in the same manner as in Example 1 except that ink F was used instead of ink A to obtain a cured film according to Example 6 (hereinafter, referred to as cured film F).
The fine particle dispersion f and the cured film F were evaluated in the same manner as in Example 1. A hexagonal crystal structure was confirmed in the composite tungsten oxide fine particle sample.
The above results are shown in Tables 1 and 2.

[Example 7]
The same operation as in Example 1 was performed except that 30 parts by mass of the fine particle dispersion liquid a and 70 parts by mass of a commercially available one-component type thermosetting ink were mixed, and the near-infrared curable ink according to Example 7 (hereinafter, Ink G) was prepared.
An operation was carried out in the same manner as in Example 1 except that ink G was used instead of ink A to obtain a cured film according to Example 7 (hereinafter, referred to as cured film G).
The cured film G was evaluated in the same manner as in Example 1.
The above results are shown in Tables 1 and 2.

[Example 8]
The near-infrared curable ink according to Example 8 is operated in the same manner as in Example 1 except that 35 parts by mass of the fine particle dispersion liquid a and 65 parts by mass of a commercially available one-component type thermosetting ink are mixed. , Ink G) was prepared.
An operation was carried out in the same manner as in Example 1 except that ink H was used instead of ink A to obtain a cured film according to Example 8 (hereinafter, referred to as cured film H).
The cured film H was evaluated in the same manner as in Example 1.
The above results are shown in Tables 1 and 2.

[Example 9]
The operation was the same as in Example 1 except that 25 parts by mass of the fine particle dispersion a, 37.5 parts by mass of an uncured bisphenol A type epoxy resin, and 37.5 parts by mass of a curing agent to which a curing accelerator was added were mixed. Then, the near-infrared curable ink (hereinafter referred to as ink I) according to Example 9 was prepared. The curing agent is a mixture of a phenol resin and imidazole (curing accelerator).
An operation was carried out in the same manner as in Example 1 except that ink I was used instead of ink A to obtain a cured film according to Example 9 (hereinafter referred to as cured film I).
The cured film I was evaluated in the same manner as in Example 1.
The above results are shown in Tables 1 and 2.

[Example 10]
20 parts by weight of the particles a, 65 parts by mass of methyl isobutyl ketone, and 15 parts by weight of the acrylic dispersant were mixed to prepare a mixture. The mixture was loaded into a paint shaker (manufactured by Asada Iron Works Co., Ltd.) containing 0.3 mmφZrO ₂ beads, and pulverized and dispersed for 20 minutes to obtain a fine particle dispersion liquid of fine particles a (hereinafter referred to as fine particle dispersion p). Obtained. At this time, 100 parts by mass of the mixture was pulverized and dispersed using 300 parts by mass of 0.3 mmφZrO ₂ beads.
A near-infrared curable ink (hereinafter referred to as ink P) according to Example 10 was prepared by operating in the same manner as in Example 1 except that the fine particle dispersion liquid p was used instead of the fine particle dispersion liquid a. ..
An operation was carried out in the same manner as in Example 1 except that ink P was used instead of ink A to obtain a cured film according to Example 3 (hereinafter, referred to as cured film P).
The fine particle dispersion p and the cured film P were evaluated in the same manner as in Example 1. A hexagonal crystal structure was confirmed in the composite tungsten oxide fine particle sample.
The above results are shown in Tables 1 and 2.

[Comparative Example 1]
Tungstic acid and cesium carbonate were operated in the same manner as in Example 1 except that a predetermined amount was weighed so that the molar ratio of W and Cs was 1: 0.15, and Cs tungsten oxidation according to Comparative Example 1 was performed. Fine particles (hereinafter referred to as fine particles j) were obtained.
A dispersion liquid of the fine particles j (hereinafter referred to as a fine particle dispersion j) was obtained in the same manner as in Example 1 except that the fine particles j were used instead of the fine particles a.
Next, the near-infrared curable ink according to Comparative Example 1 (hereinafter referred to as ink J) is operated in the same manner as in Example 1 except that the fine particle dispersion liquid j is used instead of the fine particle dispersion liquid a. Was prepared.
An operation was carried out in the same manner as in Example 1 except that ink J was used instead of ink A to obtain a cured film (hereinafter referred to as cured film J) according to Comparative Example 1.
The fine particle dispersion j and the cured film J were evaluated in the same manner as in Example 1.
The above results are shown in Tables 1 and 2.

[Comparative Example 2]
Tungstic acid and cesium carbonate were operated in the same manner as in Example 1 except that a predetermined amount was weighed so that the molar ratio of W and Cs was 1: 0.39, and Cs tungsten oxidation according to Comparative Example 2 was performed. Fine particles (hereinafter referred to as fine particles k) were obtained.
A dispersion liquid of the fine particles k (hereinafter referred to as a fine particle dispersion k) was obtained by the same operation as in Example 1 except that the fine particles k were used instead of the fine particles a.
Next, the near-infrared curable ink according to Comparative Example 2 (hereinafter referred to as ink K) is operated in the same manner as in Example 1 except that the fine particle dispersion liquid k is used instead of the fine particle dispersion liquid a. Was prepared.
An operation was carried out in the same manner as in Example 1 except that ink K was used instead of ink A to obtain a cured film (hereinafter, referred to as cured film K) according to Comparative Example 2.
The fine particle dispersion k and the cured film K were evaluated in the same manner as in Example 1.
The above results are shown in Tables 1 and 2.

[Comparative Example 3]
Tungstic acid and cesium carbonate were weighed in a predetermined amount so that the molar ratio of W and Cs was 1: 0.23, and calcined at a temperature of 400 ° C. for 5.5 hours in the same manner as in Example 1. By the operation, Cs tungsten oxide fine particles (hereinafter referred to as fine particles l) according to Comparative Example 3 were obtained.
Next, the near-infrared curable ink according to Comparative Example 3 (hereinafter referred to as ink L) is operated in the same manner as in Example 1 except that the fine particle dispersion liquid l is used instead of the fine particle dispersion liquid a. Was prepared.
An operation was carried out in the same manner as in Example 1 except that ink L was used instead of ink A to obtain a cured film (hereinafter, referred to as cured film L) according to Comparative Example 3.
In the same manner as in Example 1, the fine particle dispersion l and the cured film L were evaluated.
The above results are shown in Tables 1 and 2.

[Comparative Example 4]
Tungstic acid and cesium carbonate were weighed in a predetermined amount so that the molar ratio of W and Cs was 1: 0.23, and calcined at a temperature of 600 ° C. for 5.5 hours in the same manner as in Example 1. By the operation, Cs tungsten oxide fine particles (hereinafter referred to as fine particles m) according to Comparative Example 4 were obtained.
Next, 20 parts by mass of the fine particles m, 65 parts by mass of methyl isobutyl ketone, and 15 parts by mass of the acrylic dispersant were mixed to prepare a mixture. The mixture was loaded into a paint shaker (manufactured by Asada Iron Works Co., Ltd.) and dispersed for 10 minutes to obtain a dispersion liquid of fine particles m (hereinafter referred to as fine particle dispersion m).
The near-infrared curable ink (hereinafter referred to as ink M) according to Comparative Example 4 was prepared by operating in the same manner as in Example 1 except that the fine particle dispersion liquid m was used instead of the fine particle dispersion liquid a. ..
An operation was carried out in the same manner as in Example 1 except that ink M was used instead of ink A to obtain a cured film (hereinafter, referred to as cured film M) according to Comparative Example 4.
In the same manner as in Example 1, the fine particle dispersion m and the cured film M were evaluated.
The above results are shown in Tables 1 and 2.

[Comparative Example 5]
20 parts by mass of the fine particles a, 65 parts by mass of methyl isobutyl ketone, and 15 parts by mass of the acrylic dispersant are mixed to prepare a mixture. The mixture was loaded into a paint shaker (manufactured by Asada Iron Works Co., Ltd.) containing 0.3 mmφZrO ₂ beads and pulverized and dispersed for 50 hours to obtain a dispersion liquid of fine particles a (hereinafter referred to as fine particle dispersion n). It was. At this time, 100 parts by mass of the mixture was pulverized and dispersed using 300 parts by mass of 0.3 mmφZrO ₂ beads.
The near-infrared curable ink (hereinafter referred to as ink N) according to Comparative Example 5 was prepared by operating in the same manner as in Example 1 except that the fine particle dispersion liquid n was used instead of the fine particle dispersion liquid a. ..
An operation was carried out in the same manner as in Example 1 except that ink N was used instead of ink A to obtain a cured film (hereinafter, referred to as cured film N) according to Comparative Example 5.
The fine particle dispersion n and the cured film N were evaluated in the same manner as in Example 1.
The above results are shown in Tables 1 and 2.

[Comparative Example 6]
20 parts by mass of the fine particles m, 65 parts by mass of methyl isobutyl ketone, and 15 parts by mass of the acrylic dispersant were mixed to prepare a mixture. The mixture was loaded into a paint shaker containing 0.3 mmφZrO2 beads and pulverized and dispersed for 4 hours to obtain a dispersion liquid of fine particles m (hereinafter referred to as fine particle dispersion liquid o). At this time, 100 parts by mass of the mixture was pulverized and dispersed using 300 parts by mass of 0.3 mmφZrO ₂ beads.
The near-infrared curable ink (hereinafter referred to as ink O) according to Comparative Example 6 was prepared by operating in the same manner as in Example 1 except that the fine particle dispersion liquid o was used instead of the fine particle dispersion liquid a. ..
An operation was carried out in the same manner as in Example 1 except that ink O was used instead of ink A to obtain a cured film (hereinafter, referred to as cured film O) according to Comparative Example 6.
The fine particle dispersion o and the cured film O were evaluated in the same manner as in Example 1.
The above results are shown in Tables 1 and 2.

[Summary]
According to the results of Examples 1 to 10 and Comparative Examples 1 to 6 shown above, the cured films according to Examples 1 to 10 efficiently absorb light in the near infrared region and have good adhesion to the substrate. It was confirmed that it was expensive.
On the other hand, the cured films according to Comparative Examples 1 to 6 did not have sufficient near-infrared characteristics and had low adhesion to the substrate.

1 Thermal plasma 2 High frequency coil 3 Sheath gas supply nozzle 4 Plasma gas supply nozzle 5 Raw material powder supply nozzle 6 Reaction vessel 7 Suction tube 8 Filter

Claims (19)

A near-infrared curable ink composition containing composite tungsten oxide fine particles having a near-infrared absorbing ability and an uncured thermosetting resin.
The composite tungsten oxide fine particles are composite tungsten oxide fine particles containing a hexagonal crystal structure.
The lattice constant of the composite tungsten oxide fine particles is 7.3850 Å or more and 7.4186 Å or less on the a-axis, and 7.5600 Å or more and 7.6240 Å or less on the c-axis.
A near-infrared curable ink composition characterized in that the average particle size of the composite tungsten oxide fine particles is 100 nm or less. The near-infrared curing according to claim 1, wherein the lattice constant of the composite tungsten oxide fine particles is 7.4031 Å or more and 7.4111 Å or less on the a-axis and 7.5891 Å or more and 7.6240 Å or less on the c-axis. Mold ink composition. The near-infrared curable ink composition according to claim 1 or 2, wherein the composite tungsten oxide fine particles have an average particle diameter of 10 nm or more and 100 nm or less. The near-infrared curable ink composition according to any one of claims 1 to 3, wherein the composite tungsten oxide fine particles have a crystallite diameter of 10 nm or more and 100 nm or less. The near-infrared curable ink composition according to any one of claims 1 to 4, further comprising a dispersant. The near-infrared curable ink composition according to any one of claims 1 to 5, further comprising a solvent. The composite tungsten oxide is a general formula M _x W _{y Oz} (M element is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh. , Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te , Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I, Yb, one or more elements, W is tungsten, O is oxygen, 0.001 ≦ x The near-infrared curable ink composition according to any one of claims 1 to 6, wherein the composition is described in (/ y ≦ 1, 2.0 ≦ z / y ≦ 3.0). The near-infrared curable ink composition according to claim 7, wherein the composite tungsten oxide is composed of a composite tungsten oxide in which the M element is one or more selected from Cs and Rb. The claim is characterized in that at least a part of the surface of the composite tungsten oxide fine particles is covered with a surface coating film containing at least one element selected from Si, Ti, Zr, and Al. Item 2. The near-infrared curable ink composition according to any one of Items 1 to 8. The near-infrared curable ink composition according to claim 9, wherein the surface coating film contains oxygen atoms. The near-infrared curable ink composition according to any one of claims 1 to 10, further comprising any one or more selected from organic pigments, inorganic pigments, and dyes. A near-infrared curing film according to any one of claims 1 to 11, wherein the near-infrared curable ink composition is cured by being irradiated with near-infrared rays. A stereolithography method characterized by applying the near-infrared ray curable ink composition according to any one of claims 1 to 11 onto a substrate to form a coating material, and irradiating the coating material with near infrared rays to cure the coating material. .. A method for producing a near-infrared curable ink composition containing composite tungsten oxide fine particles having near-infrared absorbing ability, an uncured thermosetting resin, a dispersant, and a solvent.
The composite tungsten oxide fine particles are composite tungsten oxide fine particles containing a hexagonal crystal structure.
The composite tungsten oxide fine particles were produced so that their lattice constants were in the range of 7.3850 Å or more and 7.4186 Å or less and the c-axis was 7.5600 Å or more and 7.6240 Å or less.
A method for producing a near-infrared curable ink composition, which comprises performing a pulverization / dispersion treatment step of reducing the average particle diameter to 100 nm or less while maintaining the range of the lattice constant in the composite tungsten oxide fine particles. The composite tungsten oxide is a general formula MxWyOz (M element is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd. , Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V , Mo, Ta, Re, Be, Hf, Os, Bi, I, Yb, one or more elements, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1, 2 The method for producing a near-infrared curable ink composition according to claim 14, wherein the method is described in (0 ≦ z / y ≦ 3.0). The near-infrared curable type according to any one of claims 14 to 15, wherein the composite tungsten oxide is composed of a composite tungsten oxide in which the M element is one or more selected from Cs and Rb. A method for producing an ink composition. Claims 14 to 16 are characterized in that at least a part of the surface of the composite tungsten oxide fine particles is coated with a surface coating film containing at least one element of Si, Ti, Zr, and Al. The method for producing a near-infrared curable ink composition according to any one of. The method for producing a near-infrared curable ink composition according to claim 17, wherein the surface coating film contains oxygen atoms. The method for producing a near-infrared curable ink composition according to any one of claims 14 to 18, further comprising any one or more selected from organic pigments, inorganic pigments, and dyes.