WO2015068282A1

WO2015068282A1 - Infrared-absorptive inkjet printing ink

Info

Publication number: WO2015068282A1
Application number: PCT/JP2013/080328
Authority: WO
Inventors: 文人小林; 芝岡　良昭; 博昭島根; 渉吉住; 正太川▲崎▼
Original assignee: 共同印刷株式会社
Priority date: 2013-11-08
Filing date: 2013-11-08
Publication date: 2015-05-14

Abstract

Provided is an infrared-absorptive inkjet printing ink including antimony-doped tin oxide, and a vehicle. The antimony-doped tin oxide includes tin oxide and antimony oxide, and satisfies (a) and/or (b): (a) the half-value width (∆2θ) of a peak in the vicinity of 2θ=27˚ obtained from an X-ray diffraction measurement is not more than 0.30; and/or (b) the antimony oxide content is 0.5-10.0 wt% using the weight of the antimony-doped tin oxide as a reference, and the degree of crystallization, i.e. a value obtained by dividing, by the half-value width (∆2θ), the peak value of the peak in the vicinity of 2θ=27˚ obtained from the X-ray diffraction measurement, is at least 58427.

Description

Infrared absorbing ink jet printing ink

The present invention relates to an infrared absorbing ink jet printing ink, and more particularly to an infrared absorbing ink jet printing ink for preventing counterfeiting.

It has been studied to partially perform inkjet printing on bills, securities, etc. using infrared absorbing inkjet printing ink.

Infrared absorbing ink jet printing ink is configured by adding an infrared absorbing agent to commonly used ink jet printing ink.

As infrared absorbers, infrared absorbing organic materials such as cyanine compounds and phthalocyanine compounds; or infrared absorbing inorganic materials such as carbon black, tungsten oxide, and lead oxide are known.

For example, Patent Document 1 discloses infrared absorbing organic materials such as polymethine compounds, cyanine compounds, phthalocyanine compounds, counterion conjugates of benzenedithiol metal complex anions and cyanine dye cations as infrared absorbers; and Infrared absorbing inorganic materials such as composite tungsten oxide, tin oxide, indium oxide, indium tin oxide (ITO) have been described.

Patent Document 2 describes an ink jet printing ink containing an organic sulfur metal complex compound as an infrared absorber.

Further, Patent Document 3 describes an ultraviolet curable ink jet printing ink containing antimony-containing tin oxide as an infrared absorber for tracking or authenticating an object.

JP2012-121170A JP 2008-291072 A International Publication No. 2007/044106

However, inkjet printing inks containing an infrared absorbing organic material as an infrared absorber can be formulated with various colors because of the variety of colors of this material, but the problem is that the weather resistance of the ink is low. Has been pointed out.

On the other hand, ink-jet printing inks using carbon black as an infrared absorbing inorganic material have better weather resistance than inks containing infrared absorbing organic materials, but carbon black is a pigment having a dark color tone. The color of was limited to black or low brightness. For this reason, when carbon black was used as an infrared absorbing inorganic material, it was not possible to prepare an ink jet printing ink having a variety of colors by mixing with a pigment or dye having another color. In particular, it was impossible to prepare light-colored, particularly light-colored, light-colored inkjet printing inks. Even if a white pigment such as titanium oxide or zinc oxide is added to increase the brightness of an inkjet printing ink containing carbon black, the white pigment has the property of reflecting infrared rays, so that the ink absorbs infrared rays. As a result, the function as an anti-counterfeit ink is adversely affected.

Ink jet printing inks containing metal oxides such as tungsten oxide and lead oxide as infrared absorbing inorganic materials have high transparency but weak infrared absorbing effect, and sufficient infrared absorbing effect is obtained when ink or printed matter is formed. There is a problem that can not be.

Among metal oxides, indium tin oxide (ITO) is known for its relatively high absorption effect. However, since indium is a rare metal, the cost of ITO is high.

Among metal oxides, antimony tin oxide (ATO) is excellent in transparency and weather resistance, but regulations of each industry (for example, chemical substance release and transfer notification system (PRTR), toy safety standards, etc.) Therefore, it has been desired to reduce the amount of antimony. Further, since antimony is also a rare metal, it has been desired to reduce the amount of antimony contained in ATO and thereby reduce the production cost of the ATO-containing ink.

In this connection, there was room for study on the amount of antimony oxide contained in the conventional antimony-containing tin oxide. In addition, no detailed investigation has been made on conventional ink jet printing inks containing antimony-containing tin oxide.

Therefore, the present invention provides an inkjet printing ink for preventing counterfeiting that is excellent in infrared absorption, transparency, weather resistance, safety and cost, and can exhibit a variety of colors in combination with colorants of various colors. The purpose is to do.

In order to solve the above problems, the present invention adopts the following solutions:
[1] An infrared absorbing ink jet printing ink comprising antimony-doped tin oxide and a vehicle,
The antimony-doped tin oxide contains tin oxide and antimony oxide and satisfies the following (a) and / or (b):
(A) The half width (Δ2θ) of a peak around 2θ = 27 ° obtained by X-ray diffraction measurement is 0.30 or less; and / or (b) the content of the antimony oxide is the antimony dope A value obtained by dividing the peak value of the peak around 2θ = 27 ° obtained by X-ray diffraction measurement by the half-value width (Δ2θ), based on the weight of tin oxide, from 0.5 to 10.0% by weight. The degree of crystallinity is 58427 or more.
Inkjet printing ink.
[2] The infrared-absorbing inkjet printing ink according to [1], which is used for preventing forgery.
[3] The infrared-absorbing inkjet printing ink according to [1] or [2], wherein, in (a), the half width (Δ2θ) is 0.21 or less.
[4] In (b), the content of the antimony oxide is 2.8 to 9.3 wt% based on the weight of the antimony-doped tin oxide, according to [1] or [2] Infrared absorbing ink jet printing ink.
[5] The infrared-absorbing inkjet printing ink according to [1] or [2], wherein the crystallinity is 78020 or more.
[6] The infrared-absorbing inkjet printing ink according to any one of [1] to [5], wherein the antimony-doped tin oxide has an average particle size of 500 nm or less.
[7] The infrared-absorbing inkjet printing ink according to any one of [1] to [6], wherein the inkjet printing ink is a solvent-containing ink or an ultraviolet curable ink.
[8] The infrared-absorbing inkjet printing ink according to any one of [1] to [7], further comprising an auxiliary agent.
[9] The infrared-absorbing inkjet printing ink according to any one of [1] to [8], further including a colorant.
[10] A method for obtaining a printed matter by ink jet printing using the infrared absorbing ink jet printing ink according to any one of [1] to [9].
[11] A printed matter comprising a printing part printed with the infrared absorbing ink jet printing ink according to any one of [1] to [9].

The antimony-doped tin oxide pigment used in the present invention is an inorganic pigment and hardly deteriorates due to light such as ultraviolet rays. Therefore, according to the present invention, an inkjet printing ink having high weather resistance and infrared absorption is obtained. Can do.

Further, the inkjet printing ink of the present invention containing an antimony-doped tin oxide pigment has a high brightness and exhibits a light white color. Therefore, when mixed with other colorants, it can provide various colors, particularly bright colors. it can. That is, according to the present invention, it is possible to produce a light-colored infrared-absorbing ink jet printing ink that could not be realized by a conventional infrared-absorbing inorganic material such as carbon black, and therefore, the anti-counterfeiting effect and the design were excellent. Printed matter such as banknotes, securities, and cards can be produced.

Moreover, the production cost of antimony-doped tin oxide pigments is lower than that of tin-doped indium oxide pigments. Furthermore, according to the present invention, an antimony-doped tin oxide pigment having a lower content of antimony oxide than conventional antimony-doped tin oxide pigments can be used in ink jet printing inks. Therefore, according to the present invention, it is possible to provide an anti-counterfeit oil-based inkjet printing ink excellent in economic efficiency while complying with safety regulations regarding the amount of antimony used in a wide range of industries.

FIG. 1 is a process diagram showing one embodiment of the method of the present invention for producing antimony-doped tin oxide. FIG. 2 (A) is a diagram showing the results of X-ray diffraction of antimony-doped tin oxide of Example 1 (antimony oxide content: 0.7% by weight, with aerated firing / cooling), and FIG. FIG. 4 is a graph showing the results of X-ray diffraction of antimony-doped tin oxide of Example 2 (antimony oxide content: 2.8% by weight, with aerated firing / cooling). FIG. 3 (A) is a diagram showing the results of X-ray diffraction of antimony-doped tin oxide of Example 3 (antimony oxide content: 5.3% by weight, with aerated firing / cooling), and FIG. FIG. 6 is a graph showing the results of X-ray diffraction by antimony-doped tin oxide of Example 4 (antimony oxide content: 9.3 wt%, with aerated firing / cooling). FIG. 4 (A) shows the X-ray diffraction pattern of antimony-doped tin oxide of Example 5 (ventilated and cooled by commercial cooling, cooling rate of 200 [° C./hour] or more, antimony oxide content 2.7% by weight). FIG. 4 (B) shows the results, and FIG. 4 (B) shows antimony-doped tin oxide of Example 6 (commercially manufactured product by air firing and cooling, cooling rate of less than 200 [° C./hour], antimony oxide content 2.7 wt. %) Shows the result of X-ray diffraction. FIG. 5 is a diagram showing the results of X-ray diffraction of antimony-doped tin oxide of Example 7 (aerated firing / cooling of a mixture of metastannic acid and antimony trioxide, antimony oxide content 4.2% by weight). 6A is a diagram showing the results of X-ray diffraction of antimony-doped tin oxide of Comparative Example 1 (antimony oxide content: 9.9% by weight, commercially available product), and FIG. 6B is a comparative example. It is a figure which shows the result of the X-ray diffraction of antimony dope tin oxide 2 (antimony oxide content rate 2.8 weight%, aeration baking and no cooling). FIG. 7 is a conceptual diagram schematically showing a method for calculating the crystallinity. FIG. 8 is a graph showing the influence of the antimony oxide content rate on the reflectance at a wavelength of 200 nm to 2500 nm. FIG. 9 is a graph showing the influence of the ventilation firing process on the reflectance at a wavelength of 200 nm to 2500 nm and an antimony oxide content of 2.7 to 2.8% by weight. FIG. 10 is a graph showing the influence of the air-fired process on the reflectance and antimony content of a commercially available antimony-doped tin oxide material at a wavelength of 200 nm to 2500 nm. FIG. 11 is a graph showing the influence of the aeration firing process on the reflectance of a mixture of metastannic acid and antimony trioxide at a wavelength of 200 nm to 2500 nm. FIG. 12 is a graph showing the reflectance of indigo / red / yellow (CMY) process ink at wavelengths of 350 nm to 1500 nm.

<Inkjet printing ink>
The ink of the present invention includes antimony-doped tin oxide and a vehicle. In addition, the ink of the present invention can be used to prevent forgery of printed matter by utilizing the infrared absorptivity of antimony-doped tin oxide.

The inks of the present invention are roughly classified into solvent-containing inks and ultraviolet curable inks according to the type of printing machine used for inkjet printing.

The solvent-containing ink is an ink containing a solvent, and is sometimes called liquid ink. The solvent-containing ink can be used, for example, in a piezo method, a thermal method, a continuous method, or the like. In this connection, the solvent-containing ink of the present invention can be used as an organic solvent-containing ink or a water-based ink depending on the type of solvent.

Here, the organic solvent-containing ink is an ink containing an organic solvent or a non-volatile solvent, but it may not contain water substantially. “Substantially free of water” means that the content of water in the ink is 0% by mass, or that the ink inevitably contains 1% by mass or less of water. In addition, the organic solvent-containing ink is sometimes called oil-based ink in the field of ink jet printing.

On the other hand, the water-based ink is an ink containing water as a solvent, and may contain an organic solvent. In general, the water-based ink can be used for home inkjet printers and the like. Furthermore, the water-based ink preferably contains a resin such as a water-soluble resin, a colloidal dispersion resin, and an emulsion resin in addition to water.

Furthermore, ultraviolet curable ink (hereinafter abbreviated as “UV ink”) is an ink that can be cured by photopolymerization of a vehicle component. In general, the UV ink contains a photopolymerizable resin, a photopolymerization initiator, and the like. Also, UV ink may be used for the piezo method, thermal method, continuous method, and the like. Since UV ink is excellent in quick-drying property, it is preferable to use it for industrial inkjet printing, high-speed inkjet printing, etc., for example.

If desired, an ink having the characteristics of both a solvent-containing ink and a UV ink (hereinafter abbreviated as “oil-based / UV combined ink”) may be used as the ink of the present invention.

Further, the ink of the present invention may contain not only antimony-doped tin oxide and vehicle but also auxiliary agents and / or colorants. By controlling the type and content of the vehicle and / or auxiliary agent in the ink, the dispersibility of the antimony-doped tin oxide or the colorant, the drying property of the ink, the weather resistance and the solvent resistance are controlled during ink jet printing. be able to.

The antimony-doped tin oxide, vehicle, auxiliary agent and colorant contained in the ink of the present invention will be described below.

[Antimony-doped tin oxide]
Antimony-doped tin oxide is a substance in which tin oxide is doped with antimony. The antimony-doped tin oxide may be in the form of a pigment containing tin oxide and antimony oxide.

The antimony-doped tin oxide of the present invention contains tin oxide and antimony oxide. The content of antimony oxide is about 0.5% by weight or more, about 1.0% by weight or more, about 1.5% by weight or more, about 2.0% by weight or more based on the weight of antimony-doped tin oxide. The content is preferably 2.5% by weight or more, or about 2.8% by weight or more, and the content thereof is about 10.0% by weight or less, about 9.5% by weight or less, and about 9.3% by weight. Or less, about 8.0% or less, about 7.0% or less, about 6.0% or less, about 5.5% or less, about 5.0% or less, about 4.0% or less, It is preferably about 3.5% by weight or less, or about 3.0% by weight or less. The content of antimony oxide is about 2.5 to about 9.3 wt%, about 2.8 to about 9.3 wt%, and about 2.8 to about 5 based on the weight of antimony-doped tin oxide. More preferably, it is 0.5 wt%, or about 2.8 to about 3.5 wt%.

Conventional antimony-doped tin oxide needs to contain more than 10% by weight of antimony oxide in order to obtain a transparent conductive material having sufficient conductivity. On the other hand, the antimony dope tin oxide of this invention can reduce the usage-amount of an antimony oxide compared with the conventional antimony dope tin oxide as above-mentioned.

However, antimony oxide is considered to play a role of absorbing infrared rays by entering into the crystal lattice of tin oxide, so if the amount used is simply reduced, the infrared absorption effect is reduced accordingly. Will do.

Therefore, the antimony-doped tin oxide of the present invention has a half-value width (Δ2θ) near 2θ = 27 ° obtained by X-ray diffraction measurement of 0.35 or less in order to suppress a decrease in infrared absorption effect, In addition, the degree of crystallinity, which is a value obtained by dividing the peak value of a peak around 2θ = 27 ° obtained by X-ray diffraction measurement by the half width (Δ2θ), is 18092 or more.

The infrared absorption effect is an effect that occurs when antimony oxide is dissolved (enters) into the crystal lattice of tin oxide, which is the main component. That is, when manufacturing antimony-doped tin oxide, antimony oxide is contained in tin oxide as the main component.

Therefore, when antimony oxide is appropriately dissolved in the crystal lattice of tin oxide, the antimony-doped tin oxide of the present invention has an antimony oxide content in the antimony-doped tin oxide by appropriately maintaining the crystal structure. Even if it is a very small amount (for example, at least 0.5% by weight), an infrared absorption effect can be exhibited. At this time, for example, in the X-ray diffraction measurement, a sharp peak is observed in the vicinity of 2θ = 27 °.

On the other hand, for example, when antimony oxide not dissolved in the tin oxide crystal lattice is present as an impurity as in conventional antimony-doped tin oxide, it is considered that the impurity did not contribute to the infrared absorption effect.

In this case, the portion of antimony oxide that does not contribute to the infrared absorption effect remains as a waste material (impurity). For this reason, when manufacturing antimony dope tin oxide, the usage-amount of antimony oxide has increased more than necessary. Therefore, the inventors of the present invention have conducted research on this impurity, and as a result, the half-value width (Δ2θ) of antimony-doped tin oxide is wide and / or the crystallinity (the crystallization of the whole material when the material is crystallized). When the ratio of the portion is low, antimony oxide as an impurity increases. On the other hand, when the half width (Δ2θ) is narrow and / or the degree of crystallinity is high, antimony oxide as an impurity decreases. I found it.

In addition, examples of means for improving the crystallinity of antimony-doped tin oxide while removing antimony oxide as an impurity include aeration firing described later and vaporization purification described later.

Therefore, the present invention provides an antimony-doped tin oxide having a narrowed half width (Δ2θ) and / or an increased crystallinity in order to minimize the amount of antimony oxide used. In this respect, when the half width (Δ2θ) is narrowed or the crystallinity is increased, impurities are reduced, and antimony oxide can be effectively dissolved and the infrared absorption effect can be improved. .

Therefore, in the X-ray diffraction measurement, by adjusting the half width (Δ2θ) near 2θ = 27 ° to 0.35 or less and / or adjusting the crystallinity near 2θ = 27 ° to 18092 or more, Even if the amount of antimony used is suppressed, a sufficient infrared absorption effect can be exhibited.

In this specification, when measuring X-ray diffraction, a commercially available X-ray diffractometer may be used to select an arbitrary scan speed, but the number of integrations is set to one.

In the antimony-doped tin oxide of the present invention, the half width (Δ2θ) near 2θ = 27 ° is 0.30 or less, 0 in order to sufficiently exhibit the infrared absorption effect while reducing the amount of antimony oxide used. .25 or less, 0.21 or less, 0.20 or less, or 0.19 or less is preferable.

Further, it is preferable that the antimony-doped tin oxide of the present invention has a crystallinity around 2θ = 27 ° of 58427 or more, particularly 78020 or more.

When the crystallinity of antimony-doped tin oxide is 58427 or more, particularly 78020 or more, impurities can be further reduced, and antimony oxide can be effectively solid-solved to further improve the infrared absorption effect. Therefore, according to the present invention, the infrared absorption effect can be sufficiently exhibited while reducing the amount of antimony oxide used.

The antimony-doped tin oxide is dissolved in a varnish containing an acrylic polymer and silicone, applied to a substrate, dried, and a solid content weight ratio of antimony-doped tin oxide having a thickness of 70 μm and about 11.6% by weight. When the solar reflectance of this coating film is measured according to JIS K5602 when a coating film having a thickness of 380 is formed, the average reflectance in the wavelength range of 780 to 1100 nm is subtracted from the average reflectance in the wavelength range of 380 to 780 nm. The obtained value is preferably about 3.00% or more.

In this connection, if the value obtained by subtracting the average reflectance in the wavelength region of 780 to 1100 nm from the average reflectance in the wavelength region of 380 to 780 nm is 3.00% or more, the antimony-doped tin oxide Visible light absorption is relatively low, that is, the visible light transparency of antimony-doped tin oxide is relatively high. Therefore, antimony-doped tin oxide can be used in a wide range of applications without being restricted by the color exhibited by antimony-doped tin oxide.

The value obtained by subtracting the average reflectance in the wavelength range of 780 to 1100 nm from the average reflectance in the wavelength range of 380 to 780 nm is about 4.80% or more, or about 4.85% or more. And more preferably about 99% or less, about 90% or less, or about 80% or less.

The infrared absorbing pigment used in the present invention may be an infrared absorbing pigment made of the above antimony-doped tin oxide.

According to the infrared absorbing pigment used in the present invention, the action and effect of the antimony-doped tin oxide described above can be realized by the infrared absorbing pigment. For this reason, while reducing the usage-amount of antimony oxide, the infrared absorption effect can fully be exhibited, and the high quality infrared absorption pigment which followed the predetermined safety standard etc. can be provided.

The printed matter of the present invention is a printed matter comprising a printing part printed with the above infrared absorbing ink.

According to the printed matter of the present invention, since the above-described infrared absorbing ink is used to provide a printing unit on which characters, figures, and the like are printed, the printed matter has a sufficient effect of absorbing infrared rays while reducing the amount of antimony oxide used. be able to. In addition to providing high-quality printed materials, it is possible to provide printed materials that are environmentally friendly.

The printed matter of the present invention has a peak reflectance value of 28.776% or less in the infrared wavelength region of 780 to 1100 nm when the solid content weight ratio of the antimony-doped tin oxide contained in the printed part is 11.6% by weight. It is preferable that

Thus, by using a printed matter having a low infrared reflectance, it is possible to reduce the antimony oxide contained in the printing portion and to sufficiently exhibit the infrared absorption effect.

The antimony-doped tin oxide of the present invention can be produced, for example, by the following method.

[Method for producing antimony-doped tin oxide]
The method for producing antimony-doped tin oxide of the present invention includes an aeration firing step of firing the antimony-doped tin oxide raw material under aeration.

In the present invention, aeration firing or cooling is performed not only by firing or cooling while circulating a firing or cooling atmosphere, but also by firing or cooling in an open space (hereinafter also referred to as “open system”) that does not block outside air. Including.

The method for producing antimony-doped tin oxide of the present invention can narrow the half-value width of antimony-doped tin oxide from that of the conventional product and / or increase the crystallinity of antimony-doped tin oxide than that of the conventional product.

The method for producing antimony-doped tin oxide of the present invention comprises producing an antimony-doped tin oxide capable of sufficiently exhibiting the infrared absorption effect while reducing the amount of antimony oxide used by including an aeration firing step. Can do.

In the present specification, the “antimony-doped tin oxide raw material” is a raw material that becomes the antimony-doped tin oxide of the present invention by aeration firing, for example, a raw material that satisfies at least one of the following (i) to (v):
(I) a mixture of a tin compound and an antimony compound;
(Ii) a product obtained by firing the mixture of (i) above in a closed system (closed space that blocks outside air);
(Iii) a product obtained by cooling the product of (ii) above in a closed system;
(Iv) a crude antimony-doped tin oxide obtained by a coprecipitation firing method using a tin compound and an antimony compound as raw materials; and (v) a half width (Δ2θ) near 2θ = 27 ° obtained by X-ray diffraction measurement, The crystallinity, which is a value exceeding 0.35 and / or the peak value of the peak around 2θ = 27 ° obtained by X-ray diffraction measurement, divided by the half width (Δ2θ) is less than 18092 Some crude antimony-doped tin oxide.

As apparent from the above (ii) and (iii), since the firing process and the cooling process are conventionally performed in a closed system, in the conventional antimony-doped tin oxide, antimony oxide that is not solid-solved in the crystal lattice of tin oxide is present. Despite being present as an impurity and not contributing to the infrared absorption effect, it was antimony-doped tin oxide with a large amount of antimony oxide.

Therefore, the inventors of the present invention have found that the removal of excess antimony oxide can be achieved by performing an aeration firing process and a subsequent cooling process. The antimony-doped tin oxide obtained by the production method of the present invention has a narrow half-value width and / or a high crystallinity, which is considered to be caused by a small amount of impurity antimony oxide. . On the other hand, if extra antimony oxide is present in the antimony-doped tin oxide, it is considered that X-rays are scattered during measurement by X-ray diffraction and the peak is lowered.

In the present specification, a method for producing antimony-doped tin oxide including at least an aeration firing step and a subsequent aeration cooling step is referred to as a “vaporization purification method”.

In addition, for the antimony oxide solid-solved in the crystal lattice, the production method of the present invention can appropriately maintain the crystal structure while removing a part thereof by the aeration firing step, so that a high infrared ray Absorption effect can be maintained. For this reason, a high infrared absorption effect can be obtained while reducing the amount of antimony oxide used by passing through the aeration firing step.

Examples of the “tin compound” include metastannic acid, sodium stannate trihydrate, niobium tritin, fenbutane oxide, tin oxide, and tin hydride.

Examples of the “antimony compound” include antimony oxide, indium antimonide, and stibine.

If desired, the method for producing antimony-doped tin oxide of the present invention may include the following steps after the aeration firing step:
A ventilation cooling step of cooling the obtained antimony-doped tin oxide under ventilation; and / or a cooling step of cooling the obtained antimony-doped tin oxide at a cooling rate of 200 [° C./hour] or more.

The aeration cooling process can be performed, for example, by sending air into the furnace (specifically, it is possible to set the number of hours and how many times it is cooled by setting the cooling device).

If the time required for the hermetic cooling process (so-called natural cooling) is 10 hours, the air cooling process may be performed in an earlier time (for example, about 5 hours). For this reason, the ventilation cooling process is more actively cooling than natural cooling.

In the ventilation cooling process or the simple cooling process, the cooling rate is preferably 200 [° C./hour] or more, 215 [° C./hour] or more, or 216 [° C./hour] or more.

Moreover, it is preferable that the manufacturing method of the antimony dope tin oxide of this invention includes the following mixing processes and a closed baking process before a ventilation baking process:
A mixing step of mixing a tin compound and an antimony compound to obtain a mixture; and a closed baking step of firing the mixture in a closed system to obtain an antimony-doped tin oxide raw material.

Furthermore, the method for producing antimony-doped tin oxide of the present invention preferably includes a closed cooling step of cooling the antimony-doped tin oxide raw material in a closed system between the closed baking step and the aeration baking step.

The antimony-doped tin oxide raw material satisfying the above (i) to (iii) can be obtained by the mixing step, the closed firing step, and the closed cooling step, respectively.

Each process of the manufacturing method of the antimony dope tin oxide which concerns on one Embodiment of this invention is demonstrated below with reference to FIG.

[Raw material mixing step: Step S100]
In this step, a tin compound and an antimony compound as raw materials for antimony-doped tin oxide are mixed. Specifically, powdered metastannic acid (H ₂ SnO ₃ ) and powdered antimony trioxide (Sb ₂ O ₃ ) are mixed. The proportions of blending are “metastannic acid (H ₂ SnO ₃ ) = 90 wt%, antimony trioxide (Sb ₂ O ₃ ) = 10 wt%”, and the mixture is pulverized and mixed with a ball mill using water as a medium. The content of antimony trioxide is preferably 10% by weight, but may be about 5 to 20% by weight.

[First drying step: Step S102]
In this step, the material mixed in the previous raw material mixing step (step S100) is dried at 320 ° C. Thereby, the water used when mixing materials in the previous raw material mixing step (step S100) can be removed.

[First grinding step: Step S104]
In this step, the material dried in the first drying step (step S102) is pulverized. Specifically, the dried material is pulverized into a powder by a fine pulverizer.

[Closed firing process: Step S106]
In this step, the material pulverized in the first pulverization step (step S104) is baked. Specifically, the material pulverized in the first pulverization step (step S104) is fired at 1000 to 1300 ° C. for 1 hour or longer in a closed system. In the closed baking process, since baking is performed in a closed system, the content of antimony oxide (solid solution ratio) is maintained at about 10% by weight.

[Closed cooling process: Step S107]
In this step, the material fired in the previous closed firing step (step S106) is cooled. Specifically, cooling is started simultaneously with the end of the closed firing step, and the fired material is cooled in a closed system. Thereby, an antimony-doped tin oxide raw material in which tin (Sn) and antimony (Sb) are combined is generated. The antimony-doped tin oxide raw material is generated through a closed firing process (step S106) and a closed cooling process (step S107). In addition, although natural cooling may be sufficient as cooling, you may cool the baked material under ventilation similarly to the ventilation cooling process mentioned later.

[First fine grinding step: Step S108]
If desired, this step may be performed to pulverize the material cooled in the previous closed cooling step (step S107). Specifically, the fired material can be pulverized using a bead mill while using water as a medium until the particle diameter (median diameter in the laser diffraction scattering method) reaches about 100 nm. In the case where this process is omitted, the process may be continuously performed in the apparatus used in the process before this process (for example, step S106, step S107, etc.).

[Second drying step: Step S110]
If desired, this step may be performed, and the material pulverized in the first pulverization step (step S108) may be dried by heating to 320 ° C. Thereby, the water used when the material is pulverized in the first fine pulverization step (step S108) can be removed. In the case where this process is omitted, the process may be continuously performed in the apparatus used in the process before this process (for example, step S106, step S107, etc.).

[Second grinding step: Step S112]
If desired, this step may be performed to pulverize the material dried in the second drying step (step S110). Specifically, the dried material can be pulverized with a fine pulverizer. In the case where this process is omitted, the process may be continuously performed in the apparatus used in the process before this process (for example, step S106, step S107, etc.).

[Ventilation firing process: Step S114]
In this step, the material pulverized in the second pulverization step (step S112) is baked. Specifically, the material pulverized in the second pulverization step (step S112) is fired in a furnace under ventilation (a state in which ventilation is maintained inside the furnace). In this step, the firing temperature may be 1000 ° C. or more, 1050 ° C. or more, 1100 ° C. or more, or 1150 ° C. or more, and the firing temperature may be 1300 ° C. or less, 1250 ° C. or less, or 1200 ° C. or less. In this step, the firing time may be 1 hour or more, 2 hours or more, 3 hours or more, 4 hours or more, 5 hours or more, 6 hours or more, 7 hours or more, or 8 hours or more. It may be 12 hours or less, 11 hours or less, 10 hours or less, or 9 hours or less. By this aeration firing process, the antimony-doped tin oxide raw material produced by the closed firing process is fired again under ventilation. In the aeration firing process, since the firing is performed under ventilation, excess antimony oxide in tin oxide (SnO ₂ ) can be vaporized and eliminated. The final content of antimony oxide (solid solution ratio) is about 0.5 to 10.0% by weight.

[Ventilation cooling step: Step S116]
In this step, the antimony-doped tin oxide fired in the previous aeration firing step (step S114) is cooled under ventilation.

Specifically, cooling is started simultaneously with the end of the aeration firing process, and the temperature in the firing furnace is set to room temperature (for example, about 20 to 25 ° C.) within 300 minutes. Cooling. The aeration cooling step is performed under aeration.

In addition, when performing the vaporization refinement | purification method in embodiment, an aeration cooling process (step S116) can be performed after an aeration baking process (step S114).

[Second fine grinding step: Step S118]
In this process, the purified material cooled in the previous air cooling process (step S116) is pulverized. Specifically, using water as a medium, the purified material is pulverized using a bead mill until the particle size (median diameter in the laser diffraction scattering method) becomes about 100 nm.

[Washing process: Step S120]
In this step, the impurities of the material whose particle size has been adjusted in the second fine pulverization step (step S118) are removed by washing with water. Impurities are minute amounts of electrolyte (for example, sodium (Na), potassium (K), etc.) contained in the raw material, and whether or not the impurities are sufficiently removed can be confirmed by conductivity.

[Third drying step: Step S122]
In this step, the material cleaned in the previous cleaning step (step S120) is dried by heating to 145 ° C. Thereby, while being able to remove the water used when wash | cleaning material by the previous washing | cleaning process (step S120), the material after washing | cleaning can be dried.

[Finish grinding process: Step S124]
In this step, the material dried in the third drying step (step S122) is pulverized. Specifically, the dried material is pulverized with a fine pulverizer so that the particle diameter (median diameter by laser diffraction scattering method) is about several tens of nm to 100 μm.

And the antimony dope tin oxide of this invention is manufactured by passing through each said process.

[Vehicle]
The vehicle is a medium in which antimony-doped tin oxide and / or a colorant is dispersed and adhered to a substrate.

The ink of the present invention may contain a known vehicle component used for printing. Since the ink of the present invention can be formed as a solvent-containing ink or a UV ink, a vehicle suitable for the solvent-containing ink and a vehicle suitable for the UV ink will be described below.

(Vehicle suitable for solvent-containing ink)
Vehicles suitable for the solvent-containing ink are roughly classified into organic solvent-containing ink vehicles and water-based ink vehicles, and these vehicles will be described below.

"Vehicle for organic solvent-containing ink"
As a vehicle suitable for the organic solvent-containing ink, for example, a resin, an organic solvent, or the like can be used alone or in combination. The resin and organic solvent will be described below.

〔resin〕
Depending on the desired ink properties such as adhesion to the substrate, drying properties, heat resistance, gloss, dispersibility of antimony-doped tin oxide or colorant, organic solvent-containing inks are known to be used for printing These resins may be included.

Examples of the resin include vinyl resins such as vinyl chloride and vinyl acetate, acrylic resins, acrylamide resins, alkyd resins, styrene resins, polyester resins, polyurethane resins, silicone resins, fluorine resins, epoxy resins, phenoxy resins, polyolefin resins, and phenols. Resin, novolac resin, rosin modified phenolic resin, petroleum resin, polyvinylpyrrolidone resin, amino resin such as melamine, benzoguanamine, polyamide resin, polyester polyamide resin, cellulose diacetate, cellulose triacetate, nitrocellulose, cellulose nitrate, cellulose propionate, Cellulose ester resins such as cellulose acetate butyrate, methyl cellulose, ethyl cellulose, benzyl cellulose, trimethyl cellulose, Ann cellulose, carboxymethyl cellulose, carboxyethyl cellulose, cellulose ether resin, such as amino ethyl cellulose, silicone resins, terpene resins, and the like of these modified resins. These resins may be used alone or in combination of two or more. Furthermore, a copolymer resin obtained by copolymerizing a plurality of monomers constituting these resins may be used. These resins may be the same as the dispersant described later.

Among these resins, vinyl resin, acrylic resin, alkyd resin, polyester resin, polyurethane resin, silicone resin, fluororesin, epoxy resin, phenoxy resin, polyolefin resin, phenol resin are used for piezo ink jet printing. , Novolak resins, rosin-modified phenolic resins, amino resins such as melamine and benzoguanamine, polyamide resins, polyester polyamide resins, cellulose diacetate, cellulose triacetate, nitrocellulose, cellulose nitrate, cellulose propionate, cellulose acetate butyrate, etc. , Methylcellulose, ethylcellulose, benzylcellulose, trimethylcellulose, cyanethylcellulose, carboxymethylcellulose Scan, carboxyethyl cellulose, cellulose ether resin, such as amino ethyl cellulose, vinyl acetate copolymer resins are preferable.

Further, as the resin used for thermal ink jet printing, alkyd resin, acrylic resin, acrylic resin, acrylamide resin, polyvinyl pyrrolidone resin and the like are preferable.

Furthermore, as a resin used for continuous ink jet, a resin that is soluble in the organic solvent used and has good compatibility with the conductivity imparting agent described later may be used. Include acrylic resin, styrene / acrylic copolymer resin, silicone resin, phenolic resin, terpene / phenolic resin, epoxy resin, modified epoxy resin, polyester resin, cellulose resin (for example, nitrocellulose), vinyl chloride / Vinyl acetate copolymer resins, petroleum resins, rosin esters and the like are preferable.

〔Organic solvent〕
Select the solvent used in the ink of the present invention in consideration of the boiling point of the solvent, the compatibility of the solvent and the resin, the compatibility of the solvent and the auxiliary agent, the drying property of the ink, the permeability to the printing medium, etc. Good.

Examples of organic solvents include alcohols (eg, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol). , Octyl alcohol, nonyl alcohol, decyl alcohol, cyclohexanol, benzyl alcohol, diacetone alcohol, etc.); polyhydric alcohols (eg, ethylene glycol, diethylene glycol, trimethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene) Glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexa Diol, pentanediol, glycerin, hexanetriol, thiodiglycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,2- pentanediol, 1,2-hexanediol, 1 Ether solvents (for example, ethyl ether, butyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol) Monoethyl ether, etc.); ester solvents (eg, ethyl formate, methyl acetate, propyl acetate, phenyl acetate, ethylene glycol monoethyl) Ether acetate, propylene glycol monoethyl ether acetate, etc.); hydrocarbon solvents (eg, hexane, octane, cyclopentane, benzene, toluene, xylol, etc.); halogenated hydrocarbon solvents (eg, carbon tetrachloride, trichloroethylene, tetra) Chloroethane, dichlorobenzene, etc.); ketone solvents (eg, acetone, methyl ethyl ketone, methyl propyl ketone, methyl amyl ketone, cyclohexanone, etc.); amines (eg, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N— Ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethylene Amides (for example, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, etc.); heterocycles (for example, 2-pyrrolidone, N-methyl- 2-pyrrolidone, cyclohexyl pyrrolidone, 2-oxazolidone etc.); sulfoxides (eg dimethyl sulfoxide etc.); lactones (eg γ-butyrolactone etc.); sulfones (eg sulfolane etc.); urea; pyridine; acetonitrile; mineral Examples include oil.

Among these organic solvents, alcohols, polyhydric alcohols, ethers, amines, amides, heterocyclics, sulfoxides, sulfones, urea, acetonitrile are used as organic solvents for piezo ink jet printing. Acetone and the like are preferable.

Further, as the organic solvent used for thermal ink jet printing, alcohols, particularly alkyl alcohols having 1 to 10 carbon atoms, hydrocarbon solvents, ethers, ketones, esters and the like are preferable.

Furthermore, as the organic solvent used in the continuous ink jet, an organic solvent having excellent compatibility with the resin used and / or the conductivity imparting agent described later may be used. In order to improve the drying property, methyl ethyl ketone, methanol or ethanol is preferable.

"Vehicle suitable for water-based ink"
A suitable vehicle for water-based ink includes water. The vehicle suitable for the water-based ink may contain an organic solvent, a resin, or the like alone or in combination. The water, organic solvent and resin will be described below.

〔water〕
Water is an essential component of water-based ink. Water can form an aqueous dispersion with antimony-doped tin oxide, resin, organic solvent, colorant, adjuvant and the like. Further, by using water as the vehicle, it is possible to suppress the risk of fire, the toxicity of organic solvents, the amount of hydrocarbon emissions, and the amount of residual organic solvent in the coating film during printing.

Examples of water used as a vehicle for water-based ink include pure water, deionized water, distilled water, drinking water, tap water, seawater, groundwater, agricultural water, industrial water, soft water, hard water, light water, and heavy water. It is done.

〔Organic solvent〕
Organic solvents described as vehicles suitable for organic solvent-containing inks may be added to the aqueous ink. When using a mixture of water and an organic solvent, it is preferable to determine the type and content of the organic solvent in consideration of the flash point of the mixture, the combustion duration, volatility, and the like. In general, an alcohol solvent such as ethanol, isopropyl alcohol, ethylene glycol, diethylene glycol or the like is used in combination with water.

〔resin〕
Resins described as vehicles suitable for organic solvent-containing inks may be added to the water-based ink.

Also, the resin contained in the water-based ink plays a different role during ink jet printing and after ink jet printing. Specifically, the resin contained in the water-based ink disperses antimony-doped tin oxide in water at the time of inkjet printing, whereas after ink-jet printing, the antimony-doped tin oxide is fixed to the substrate to be printed on the water. Prevent elution. Therefore, the resin contained in the water-based ink is preferably in the form of a water-soluble resin, a colloidal dispersion resin, or an emulsion resin. These forms will be described below.

Water-soluble resin is a resin that can be dissolved in water to form an aqueous solution. Therefore, the structure of the water-soluble resin is preferably designed so as to have a hydrophilic portion. In that case, the resin having a hydrophilic portion is a nonionic resin having a hydrophilic group such as a hydroxyl group, an ether group, or an amide group; a hydrophilic group such as a carboxyl group, a sulfonic acid group, or a phosphate ester group is added to ammonia or an amine. An anionic resin neutralized with an alkaline substance such as a cation resin or a cationic resin in which a hydrophilic group such as a primary, secondary, tertiary or quaternary amine group is neutralized with an acid such as acetic acid. .

For example, when the anionic resin is dried, the alkaline substance used for neutralization volatilizes with water, so that the resin before neutralization remains in the dried coating film. Further, when the cationic resin is dried, the acid used for neutralization is volatilized with water, so that the resin before neutralization remains in the dried coating film.

For example, when a resin described as a vehicle suitable for an organic solvent-containing ink has low water solubility, a hydrophilic portion is incorporated into the resin so that the resin becomes a nonionic, anionic or cationic resin, and the resin The resin may be made aqueous. In general, an aqueous dispersion of an aqueous resin is transparent.

The colloidal dispersion resin is a resin dispersion in which the resin is dispersed in a colloidal form in water. In general, a colloidal dispersion resin is a so-called semi-dissolved state in which a lipophilic portion of the resin is surrounded by a hydrophilic portion in water. Therefore, the resin in the colloidal dispersion is stably dispersed by Brownian motion.

Generally, colloidal dispersion resins have a resin particle size of about 0.01 μm to about 0.1 μm. In addition, the colloidal dispersion resin has an intermediate property between the water-soluble resin and the emulsion resin, and therefore has an excellent balance between printability and physical properties of the coating film.

For example, a colloidal dispersion resin is obtained by ionizing a part of a resin in the same manner as an anionic or cationic resin when polymerization is performed in an aqueous solution containing an emulsifier such as a surfactant. It is also preferable to obtain a colloidal dispersion resin by using alcohol together with water during polymerization.

As the colloidal dispersion resin, for example, an aqueous dispersion such as urethane resin or acrylic resin can be used.

Emulsion resin is a resin dispersion obtained by polymerization in an aqueous solution in which an emulsifier such as a surfactant is present. In the emulsion resin, the resin in the dispersion is generally in the form of particles, and is stably dispersed in the aqueous solution by electrical repulsion between the particles. In general, an emulsion resin has a resin particle size of about 0.1 μm to about 1 μm in water when emulsion polymerization is employed, and has a resin particle size of about 1 μm to about 10 μm in water when suspension polymerization is employed. The emulsion resin is generally cloudy.

Generally, an emulsion resin can increase the solid content of an ink as compared with a water-soluble resin, and thus it is easy to control drying properties and physical properties of a coating film. Moreover, as an emulsion resin, water dispersions, such as a urethane resin and an acrylic resin, can be used, for example.

The resins listed above can be used alone or in combination of two or more as a vehicle suitable for aqueous ink.

(Vehicle suitable for UV ink)
Examples of the vehicle suitable for the UV ink include photopolymerizable resins such as monomers, oligomers, and binder polymers; photopolymerization initiators and the like. A monomer and an oligomer, a binder polymer, and a photoinitiator are demonstrated below.

[Monomer / Oligomer]
The monomer may be a compound having an ethylenically unsaturated bond conventionally used for photopolymerization. Moreover, an oligomer is obtained by oligomerizing the compound which has an ethylenically unsaturated bond.

Oligomers are resins that govern the basic physical properties of UV ink. On the other hand, the monomer mainly acts as a diluent and can be used to adjust properties such as ink viscosity, curability and adhesion.

Examples of compounds having an ethylenically unsaturated bond include (meth) acrylic acid compounds; maleic acid compounds; urethane-based, epoxy-based, polyester-based, polyol-based, vegetable oil-based compounds and the like. Examples include compounds having a heavy bond.

Specifically, a monofunctional acrylate and / or a bifunctional acrylate may be used as the compound having an ethylenically unsaturated bond.

Examples of monofunctional acrylates include caprolactone acrylate, isodecyl acrylate, isooctyl acrylate, isomyristyl acrylate, isostearyl acrylate, 2-ethylhexyl-diglycol diacrylate, 2-hydroxybutyl acrylate, and 2-acryloyloxyethyl hexahydro. Phthalic acid, neopentylglycol acrylic acid benzoate, isoamyl acrylate, lauryl acrylate, stearyl acrylate, butoxyethyl acrylate, ethoxy-diethylene glycol acrylate, methoxy-triethylene glycol acrylate, methoxy-polyethylene glycol acrylate, methoxydipropylene glycol acrylate, Phenoxyethyl acrylate, pheno Si-polyethylene glycol acrylate, nonylphenol ethylene oxide adduct acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl -Succinic acid, 2-acryloyloxyethyl-phthalic acid, 2-acryloyloxyethyl-2-hydroxyethyl-phthalic acid and the like.

Examples of the bifunctional acrylate include hydroxypivalate neopentyl glycol diacrylate, alkoxylated hexanediol diacrylate, polytetramethylene glycol diacrylate, trimethylolpropane acrylate benzoate, diethylene glycol diacrylate, triethylene glycol diacrylate, Tetraethylene glycol diacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (600) diacrylate, neopentyl glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butane Diol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonane Over diacrylate, dimethylol - diacrylate, and bisphenol A diacrylate.

Furthermore, as the oligomer, it is preferable to use an oligomer such as urethane acrylate, polyester acrylate, epoxy acrylate, silicon acrylate, polybutadiene acrylate, or the like.

[Binder polymer]
The binder polymer is a resin that can fix the colorant to the printing material. The weight average molecular weight of the binder polymer is preferably about 1000 to about 3,000,000.

Examples of the binder polymer include polyester, diallyl phthalate polymer, poly (meth) acrylic acid, poly (meth) acrylic ester, polyester-melamine polymer, styrene- (meth) acrylic acid copolymer, styrene- (meth) acrylic acid- Alkyl (meth) acrylate copolymer, styrene-maleic acid copolymer, styrene-maleic acid-alkyl (meth) acrylate copolymer, styrene-maleic acid half ester copolymer, vinylnaphthalene- (meth) acrylic acid copolymer, vinylnaphthalene-maleic acid copolymer, And salts thereof.

The monomers, oligomers and binder polymers listed above can be used alone or in combination of two or more.

(Photopolymerization initiator)
The photopolymerization initiator is a compound that generates radicals such as active oxygen when irradiated with ultraviolet rays. The UV ink of the present invention may contain a known photopolymerization initiator used for printing.

Examples of the photopolymerization initiator include, but are not limited to, acetophenone, α-aminoacetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, 2-hydroxy-2-methyl-1-phenylpropane -1-one, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-methylpropyl) ) Ketone, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propane-1- ON, 2-benzyl-2-dimethylamino-1- (4-mol Acetophenones such as linophenyl) -butanone; beizoin, beizoin methyl ether, benzoin ethyl ether, benzoin-n-propyl ether, beizoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, benzoin dimethyl ketal, benzoin per Benzoins such as oxides; acyl phosphine oxides such as 2,4,6-trimethoxybenzoin diphenylphosphine oxide; benzyl and methylphenyl-glyoxyesters; benzophenone, methyl-4-phenylbenzophenone, o-benzoylbenzoate, 2 -Chlorobenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenyls Benzophenones such as luffide, acrylic-benzophenone, 3,3'4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 3,3'-dimethyl-4-methoxybenzophenone; 2-methylthioxanthone, 2-isopropylthioxanthone Thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone; aminobenzophenones such as Michler ketone, 4,4′-diethylaminobenzophenone; tetramethylthiuram mono Sulfide; Azobisisobutyronitrile; Di-tert-butyl peroxide; 10-butyl-2-chloroacridone; 2-ethylanthraquinone; 9,10-phenanthrenequinone; Quinones; and titanocene and the like.

Further, a photopolymerization initiation assistant such as ethyl 4-dimethylaminobenzoate or isoamyl 4-dimethylaminobenzoate may be used in combination with the photopolymerization initiator.

The resin, monomer, oligomer or binder polymer described above in the section of vehicle suitable for solvent-containing ink and vehicle suitable for UV ink is grafted, self-dispersed or encapsulated with antimony-doped tin oxide or colorant. Can be used to

[Adjuvant]
The ink of the present invention may contain a known auxiliary agent used for printing. As an auxiliary agent, for example, a dispersant, a conductivity imparting agent, an antifoaming agent, a water solubilizer, a penetrating agent, a drying inhibitor, a pH adjuster, an antiseptic / antifungal agent, an oxygen scavenger, an extender pigment, and a crosslinking agent And other additives. These adjuvants will be described below.

[Dispersant]
The dispersant is an auxiliary agent for improving the leveling property, stability, and dispersibility of the ink. Specifically, the dispersant improves the wetting of the antimony-doped tin oxide or colorant by the vehicle component, or adsorbs the antimony-doped tin oxide or colorant to the vehicle component and / or disperses in the ink. It can be used to prevent reagglomeration of the antimony doped tin oxide or colorant.

Examples of the dispersant include a low molecular dispersant, a polymer dispersant, a pigment derivative, and a coupling agent.

The low molecular weight dispersant is a low molecular weight substance having a portion having high orientation or adsorptivity to antimony-doped tin oxide or a colorant and a portion having high affinity with a vehicle, and is also called a surfactant or a wetting agent.

Examples of the low molecular weight dispersant include soap, α-sulfo fatty acid ester salt (MES), alkylbenzene sulfonate (ABS), linear alkylbenzene sulfonate (LAS), alkyl sulfate (AS), and alkyl ether sulfate. Anionic compounds such as salts (AES) and alkylsulfuric acid triethanolamine; cationic compounds such as alkyltrimethylammonium salts, dialkyldimethylammonium chloride and alkylpyridinium chloride; amphoteric compounds such as amino acids, alkylcarboxybetaines, sulfobetaines and lecithins; Nonionic compounds such as fatty acid diethanolamide, polyoxyethylene alkyl ether (AE), and polyoxyethylene alkyl phenyl ether (APE) are exemplified.

The polymer dispersant is a high molecular weight substance having an anchor group adsorbed on the surface of antimony-doped tin oxide or a colorant and a barrier group that exhibits a steric hindrance effect in the vehicle. In general, since a plurality of anchor groups can be easily incorporated into a polymer dispersant, the polymer dispersant can be adsorbed at multiple points with antimony-doped tin oxide or a colorant. In addition, since the polymer dispersant has a higher barrier group than the low molecular dispersant, the dispersion stability of the antimony-doped tin oxide or the colorant is improved.

As the polymer dispersant, a polymer having a portion corresponding to an anchor group and a barrier group may be arbitrarily used. For example, it is preferable to use a non-aqueous polymer dispersant such as a partial alkyl ester of polyacrylic acid or a polyalkylene polyamine for the organic solvent-containing ink. Water-based inks include naphthalene sulfonate formalin condensate, polystyrene sulfonate, polyacrylate, copolymer salts of vinyl compounds and carboxylic acid-containing monomers, and water-based polymers such as carboxymethyl cellulose. It is preferred to use a dispersant.

The pigment derivative is obtained by introducing a polar group such as a carboxyl group, a sulfone group, or a tertiary amino group into the pigment skeleton. The pigment skeleton portion of the pigment derivative is easily adsorbed with the corresponding pigment, while the introduced polar group is excellent in affinity with the vehicle or other dispersant.

The pigment derivative can be synthesized by a known method according to the skeleton of the pigment contained in the ink of the present invention. For example, dialkylaminomethylene copper phthalocyanine, amine salt copper phthalocyanine, and the like are used to form inks that contain phthalocyanine as a colorant.

The coupling agent is a material that adsorbs to the surface of the antimony-doped tin oxide or the colorant or chemically bonds to improve the adhesion between the antimony-doped tin oxide or the colorant and the vehicle. Examples of the coupling agent include a silane coupling agent and a titanate coupling agent.

The silane coupling agent is an organosilicon compound having in its molecule an organic functional group that reacts with an organic material and a hydrolyzable group that reacts with an inorganic material. In general, examples of the organic functional group include a vinyl group, an epoxy group, a methacryloxy group, and an amino group, and examples of the hydrolyzable group include an alkoxy group, a chloro group, and an acetoxy group.

Since the hydrolyzable group is bonded to the antimony-doped tin oxide or the colorant and the organic functional group has affinity or reactivity with the vehicle component, the silane coupling agent is an antimony-doped tin oxide or the colorant and the vehicle. Adhesiveness with a component can be improved.

For example, when the hydrolyzable group is an alkoxy group such as a methoxy group or an ethoxy group, a silanol group obtained by hydrolysis of the alkoxy group self-condenses or reacts with a hydroxyl group of a component other than a silane coupling agent. To do. Therefore, the silane coupling agent is preferably used for improving the dispersibility of a colorant having a hydroxyl group on the surface (for example, an inorganic pigment containing glass, silica, alumina, etc.).

Specifically, examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3 -Glycidoxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane , 3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane, and the like.

The titanate coupling agent is an organic titanium compound having in its molecule an organic functional group that reacts with an organic material and a hydrolyzable group that reacts with an inorganic material. Also, the organic functional groups and hydrolyzable groups described for the silane coupling agent can be incorporated into the titanate coupling agent.

Generally, since the titanate coupling agent has low solubility in water, it is preferable to use the titanate coupling agent by dissolving it in an organic solvent.

[Conductivity imparting agent]
The conductivity imparting agent is an additive that imparts conductivity to the ink. The ink of the present invention may contain a conductivity imparting agent known in the printing field.

Examples of the conductivity imparting agent include alkali metal salts such as lithium, sodium and potassium; alkaline earth metal salts such as magnesium and calcium; and simple ammonium salts or quaternary ammonium salts. These salts are halogenated compounds (eg chloride, bromide, iodide, fluoride, etc.), perchlorate, nitrate, thiocyanate, formate, acetate, sulfate, sulfonate, propionate , Trifluoroacetate, triflate (trifluoro-methanesulfonate), hexafluorophosphate (eg potassium hexafluorophosphate), hexafluoro-antimonate, tetrafluoroborate, picrate and It may be a carboxylate or the like.

The conductivity imparting agents listed above can be used alone or in combination of two or more. The conductivity imparting agent is preferably used in continuous ink jet printing.

[Defoamer]
An antifoaming agent is an auxiliary agent used to suppress the generation of bubbles in the ink or to reduce bubbles generated in the ink. For example, antifoaming agents can be used during ink manufacture, storage, circulation, transfer or printing.

Also, since the surface tension of water is high, a vehicle suitable for water-based ink is more likely to foam than a vehicle suitable for ink containing an organic solvent. Therefore, it is preferable to add an antifoaming agent to the water-based ink in order to suppress foaming of the water-based ink.

As the antifoaming agent, for example, silicone compounds, polysiloxanes, polyglycols, polyalkoxy compounds and the like can be used alone or in combination.

Specifically, examples of the antifoaming agent include BYK (registered trademark) -019, BYK (registered trademark) -022, BYK (registered trademark) -024, and BYK (registered trademark) -065 manufactured by Byk-Chemie. , And BYK®-088; Surfinol DF-37, Surfinol DF-75, Surfinol DF-110D, and Surfinol DF-210 manufactured by Nissin Chemical Industry; US Air Products and Examples include EnviroGem (registered trademark) AE03 manufactured by Chemicals, Inc., and FAMEX 835 commercially available from Evonik-Tego-Chemie, Germany.

[Water-solubilizing agent]
The water-solubilizing agent is an auxiliary agent for making the antimony-doped tin oxide, the colorant, or the vehicle component water-soluble, and is generally used in the production of water-based inks.

As a water-soluble agent suitable for antimony-doped tin oxide or colorant, among the above-mentioned dispersants, a portion having high orientation or adsorptivity to antimony-doped tin oxide or colorant in the molecule, and affinity with water Those having a high portion may be used.

The water-solubilizing agent for making the vehicle component water-soluble may be an emulsifier such as a surfactant as described for the colloidal dispersion resin or the emulsion resin.

(Penetration agent)
The penetrating agent is an additive for causing ink to penetrate into the printing medium and fixing it. Generally, penetrants are used to improve the wettability and penetrability of ink with respect to a printing medium, and are classified into a printing medium dissolving type, a surface tension reducing type, and an evaporation combined type.

The printing medium-dissolving penetrant is a penetrant having a property of dissolving the surface of the printing medium. Examples of the printing medium-dissolving penetrant include potassium hydroxide.

The surface tension reducing penetrant is a penetrant having the property of reducing the surface tension of the ink. As the surface tension reducing penetrant, the above-described surfactants or organic solvents can be used.

The evaporation combined type penetrant is a penetrant that lowers the ink surface tension and suppresses ink bleeding by evaporation. The evaporation combined use type penetrant is typified by a water-soluble organic solvent having a relatively low boiling point, and may be, for example, ethanol or isopropanol.

[Drying inhibitor]
The anti-drying agent is an additive for preventing clogging of a nozzle of a printing machine head. In general, the anti-drying agent may be a hygroscopic compound. Examples of the drying inhibitor include diethylene glycol, polyethylene glycol, glycerin, N-methyl-2-pyrrolidone and the like.

[PH adjuster]
The pH adjuster is an additive for controlling the pH of the ink within a predetermined range. Examples of the pH adjuster include inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; organic acids such as acetic acid and benzoic acid; hydroxides such as sodium hydroxide and potassium hydroxide; halides such as ammonium chloride; sodium sulfate and the like. Sulfate such as potassium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, etc .; phosphates such as sodium hydrogen phosphate and sodium dihydrogen phosphate; organic acid salts such as ammonium acetate and sodium benzoate; tributylamine, And organic amines such as triethanolamine.

From the viewpoint of ink ejection stability and storage stability, a pH adjuster having a buffering action is preferable, and potassium hydrogen carbonate or potassium carbonate is more preferable. Further, from the viewpoint of the storage stability of the ink, the pH of the ink obtained by adding the pH adjuster is preferably 6 to 10, and more preferably 7 to 10.

[Preservatives and fungicides]
An antiseptic or fungicide is an additive for suppressing the generation or growth of microorganisms in the ink. In general, preservatives or fungicides can suppress the growth of microorganisms in the ink, and prevent a decrease in pH of the ink, sedimentation of contents in the ink, discoloration of the ink, clogging of the nozzle, and the like.

Examples of the antiseptic or fungicide include sodium benzoate, potassium sorbitanate, thiabendazole, benzimidazole, siabendazole, thiazosulfamide, pyridine thiol oxide, and the like. Further, it is preferable to contain a preservative or a fungicide in the water-based ink.

[Oxygen scavenger]
An oxygen scavenger is an additive used to remove dissolved oxygen in the ink. Examples of the oxygen scavenger include organic oxygen scavengers such as ascorbic acid, catechol, erythorbic acid, pyrogallol, hydroquinone, reducing sugars, and tannic acid; and organic acid salts such as sodium ascorbate.

[External pigment]
The extender pigment is a pigment used to adjust the viscosity of the ink, and has a low refractive index and low coloring power. Therefore, the extender pigment is preferably used when the viscosity of the ink is high and wiping is difficult. The ink of the present invention may contain a known extender pigment used for printing.

Examples of extender pigments include barium sulfate, calcium carbonate, calcium sulfate, kaolin, talc, silica, corn starch, titanium dioxide, and mixtures thereof.

[Crosslinking agent]
The crosslinking agent is an auxiliary agent necessary for chemically bonding a plurality of substances, and is also called a gelling agent or a curing agent. For example, for cross-linking, the chain polymer changes to a shaded structure; the formation of a urethane bond by the reaction of an isocyanate group and a hydroxyl group; the formation of a secondary amine by the reaction of a primary amine and an epoxy group, followed by a secondary amine And reaction of epoxy group.

Generally, as a crosslinking agent, a polyisocyanate compound, a polyol compound, an epoxy compound, an amine compound, an oxazoline compound, a formalin compound, a divinyl compound, a melamine compound, or the like can be used alone or in combination.

Specifically, as the crosslinking agent, for example, isocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, tetramethylxylylene diisocyanate, polymethylene polyphenyl polyisocyanate; trimethylolpropane-tris-β -Aziridine compounds such as N-aziridinylpropionate and pentaerythritol propane-tris-β-N-aziridinylpropionate; epoxy compounds such as glycerol polyglycidyl ether and trimethylolpropane polyglycidyl ether; aluminum triiso Propoxide, mono-sec-butoxyaluminum diisopropoxide, aluminum tri-sec-butoxide, ethyl acetate Aluminum alcoholates such as cetoacetate aluminum diisopropoxide and aluminum trisethylacetoacetate; aluminum chelate compounds; metal soaps such as aluminum stearate and aluminum octoate; oligomers or chelate compounds of metal soaps; bentonite and the like.

[Other additives]
In the ink of the present invention, a drying retarder; an antioxidant; an anti-reduction agent; a leveling agent; an anti-set-off agent; a drying oil / semi-drying oil; an oxidation polymerization catalyst; a wax; a nonionic surfactant, etc. A surfactant, a sensitizer, a heat stabilizer, a polymerization inhibitor, an ultraviolet absorber, a light stabilizer, and the like.

The adjuvants listed above can be used alone or in combination of two or more.

[Colorant]
A colorant is a component that colors ink. The ink of the present invention may contain a known colorant used for printing. Examples of the colorant include inorganic pigments, organic pigments, dyes, organic pigments for toners, and the like.

Examples of inorganic pigments include chrome yellow, zinc yellow, bitumen, barium sulfate, cadmium red, titanium oxide, zinc white, alumina white, calcium carbonate, ultramarine, graphite, aluminum powder, bengara, barium ferrite, copper and zinc alloy. Examples thereof include powder, glass powder, and carbon black.

Examples of organic pigments include soluble azo pigments such as β-naphthol pigments, β-oxynaphthoic acid pigments, β-oxynaphthoic acid anilide pigments, acetoacetate anilide pigments, and pyrazolone pigments; β-naphthol pigments Insoluble azo pigments such as pigments, β-oxynaphthoic acid anilide pigments, acetoacetanilide monoazos, acetoacetanilide disazos, pyrazolone pigments; copper phthalocyanine blue, halogenated (eg chlorine or brominated) copper phthalocyanine blue, Phthalocyanine pigments such as sulfonated copper phthalocyanine blue and metal-free phthalocyanine; quinacridone pigments, dioxazine pigments, selenium pigments (pyrantron, anthrone, indanthrone, anthrapyrimidine, flavantron, thioindigo, anthraquinone , Perinone, perylene, etc.), isoindolinone pigments, metal complex pigments, polycyclic or heterocyclic pigments such as quinophthalone pigments.

Examples of the dye include azo dyes, complex salts of azo dyes and chromium, anthraquinone dyes, indigo dyes, phthalocyanine dyes, xanthene dyes, thiazine dyes, and the like. Moreover, it is preferable to mix | blend dye with water-based ink from a soluble viewpoint with respect to water.

Here, the organic pigment includes a lake pigment. In general, a lake pigment is obtained by dyeing a dye on an inorganic pigment or extender, and the lake pigment also has water insolubility according to the water insolubility of the inorganic pigment or extender. Examples of lake pigments include the fanal (FANAL (registered trademark)) color series available from BASF.

The organic dye for toner is an organic dye that can be contained in the toner, and has charging properties in addition to the general characteristics of the colorant. As the organic pigment for toner, a dye or an organic pigment may be used, but a dye is preferred from the viewpoint of transparency and coloring power.

In addition, it is also preferable to use a dye and a pigment which are recognized by the names of “CI solvent dye” and “CI pigment” in the color index (Color Index International) dispersed in a vehicle.

Examples of “CI solvent dye” include C.I. I. Solvent black 27 or 29, C.I. I. Solvent black 7, C.I. I. Solvent black 35 or 45, C.I. I. Solvent blue 70, C.I. I. And solvent red 124. Examples of “CI pigment” include Pigment Blue 60, Pigment Blue 15 and the like.

Furthermore, in addition to the colorant described above, other functional materials such as functional pigments and functional dyes may be blended in the ink of the present invention. Here, the functional material may be inorganic or organic, and may be an additive that imparts functionality to the ink of the present invention.

Examples of functional materials include chromic materials, magnetic pigments, ultraviolet absorbers, optically variable materials, pearl pigments, and the like. In general, a chromic material is a material that develops a color in response to energy such as light, heat, electricity, and fades when the energy is blocked or lost. Examples of the chromic material include fluorescent pigments, excited luminescent pigments, temperature-sensitive color changing materials, photochromic materials, and stress luminescent materials.

The colorants listed above can be used alone or in combination of two or more.

<Composition, viscosity and pH of infrared absorbing ink jet printing ink>
The ink of the present invention may have a solids content of about 40 wt% or less, about 30 wt% or less, about 20 wt% or less, about 10 wt% or less, or about 5 wt% or less. It may be 0.005% or more, about 0.01% or more, about 0.05% or more, or about 0.1% or more.

In the case of the solvent-containing ink used in the piezo method, the mixing ratio of each component contained in the infrared-absorbing inkjet printing ink is about 80% by weight or more, or about 90% by weight or more, and about 99.995 wt% or less, about 95 wt% or less, or about 91 wt% or less, the colorant is 0 to about 10 wt%, or 0 to about 6 wt% or less, and the adjuvant is 0 to About 10% by weight and antimony doped tin oxide is about 0.005-10% by weight, or about 0.005-6% by weight. In this case, the weight ratio of the solvent to the resin in the vehicle may be about 9 or more, and the weight ratio may be about 90 or less.

The viscosity of the solvent-containing ink used in the piezo method is preferably about 5.0 mPa · s or less, or about 4.0 mPa · s or less at a temperature of about 20 to 25 ° C. It is preferably about 1 mPa · s or more, or about 2 mPa · s or more.

In the case of the solvent-containing ink used in the thermal method, the proportion of each component contained in the infrared-absorbing inkjet printing ink is about 40% by weight or more, or about 50% by weight or more, and about 99% by weight or less, about 90% by weight or less, about 80% by weight or less, about 70% by weight or less, or about 60% by weight or less, the colorant is 0 to about 50% by weight, and the adjuvant is 0 About 10% by weight and antimony-doped tin oxide is about 1-50% by weight. In this case, it is not necessary to use a resin as the vehicle. Also, when using a resin as the vehicle, the weight ratio of solvent to resin in the vehicle may be about 4 or more, or about 9.9 or more, and this weight ratio is about 99 or less, about 90 or less, or about It may be 40 or less.

The viscosity of the solvent-containing ink used in the thermal method is preferably about 30 mPa · s or less, or about 20 mPa · s or less at a temperature of about 20 ° C., and the viscosity is about 0.3 mPa · s. It is preferable that it is above or about 1 mPa · s or more.

In the case of the solvent-containing ink used in the continuous method, the mixing ratio of each component contained in the infrared-absorbing inkjet printing ink is about 30% by weight or more, about 40% by weight or more, or about 50% by weight. % By weight or more and about 99% by weight or less, about 90% by weight or less, about 80% by weight or less, or about 70% by weight or less, the colorant is 0 to about 20% by weight, and the adjuvant is 0 to about 10% by weight, and antimony-doped tin oxide is about 1 to 20% by weight. In this case, the weight ratio of the solvent to the resin in the vehicle may be about 0.75 or more, or about 2.4 or more, and the weight ratio is about 9500 or less, about 5000 or less, or about 3000 or less. It's okay. Further, the solvent-containing ink used in the continuous method preferably contains about 0.1 to 20% by weight of an auxiliary agent, and more preferably contains a conductivity imparting agent as an auxiliary agent.

The viscosity of the solvent-containing ink used in the continuous method is preferably about 5 mPa · s or less, or about 4 mPa · s or less at a temperature of about 60 ° C., and the viscosity is about 2 mPa · s. It is preferable that the pressure is at least about 2.5 mPa · s.

When preparing a solvent-containing ink used in various inkjet methods as a water-based ink, the pH of the water-based ink is preferably about 6 or more, or about 7 or more, and this pH is about 10 or less. Or about 9 or less.

In the case of UV inks used in various ink jet methods, the blending ratio of each component contained in the infrared absorbing ink jet printing ink is about 50% by weight or more, about 60% by weight or more, and about 99.995 wt% or less, the colorant is 0 to about 20 wt%, the adjuvant is 0 to about 10 wt%, and the antimony-doped tin oxide is about 0.005 wt% or more, Or about 0.1% by weight or more and about 30% by weight or less, about 20% by weight or less, about 10% by weight or less, or about 6% by weight or less.

In the case of UV ink, the content of the monomer, oligomer and photopolymerization initiator in the vehicle is about 30 to 70% by weight of monomer, about 20 to 60% by weight of oligomer, and The photopolymerization initiator is about 3 to 10% by weight.

Further, the viscosity of the UV ink is preferably about 15 mPa · s or less, or about 10 mPa · s or less at a temperature of about 60 ° C., and the viscosity is about 1 mPa · s or more, or about 2 mPa · s. The above is preferable.

<Ink production method>
The ink of the present invention can be obtained by dispersing antimony-doped tin oxide in a vehicle together with an auxiliary and / or a colorant as desired.

One aspect of the method for producing the ink of the present invention includes the following steps:
(1a) a blending step of blending antimony-doped tin oxide and / or colorant with a vehicle, optionally with adjuvant, to obtain a blend;
(1b) a premixing step of premixing the formulation to obtain a mill base;
(1c) a kneading step for kneading the mill base to obtain a rough ink;
(1d) an adjustment step in which an antimony-doped tin oxide, a colorant, a vehicle and / or an auxiliary agent are added to the crude ink to obtain an ink;
(1e) a polishing step of kneading the ink again to finish the ink; and (1f) a filling step of filling the container with the ink.

Step (1a) can be performed by mixing antimony-doped tin oxide and / or colorant into the vehicle in a container such as a mixing tank, using a mixer such as a dissolver, a single screw mixer, or a twin screw mixer. When the antimony-doped tin oxide or colorant is a dried solid or powder, the scattering of the antimony-doped tin oxide or colorant can be prevented by step (1a).

Step (1b) is performed to uniformly pulverize the antimony-doped tin oxide and / or colorant, wet it with the vehicle and uniformly disperse it in the vehicle before kneading the formulation. Although step (1b) may be omitted, if step (1b) is performed, subsequent step (1c) can be efficiently advanced. Step (1b) can be performed by a mixer such as a single screw mixer or a twin screw mixer.

Step (1c) is performed to achieve a higher degree of wetting and dispersion of antimony-doped tin oxide and / or colorant compared to step (1b). Further, the particle diameter of the dispersed material in the vehicle can be made uniform by the step (1c).

Step (1c) can be performed by a kneading machine (ink mill) such as a three roller mill, a bead mill, a ball mill, a sand grinder, or an attritor. For example, when a three-roller mill is used, the mill base becomes a thin film when passing through the roll, so that coarse ink can be deaerated. In addition, when a three-roller mill is used, coarse particles remain on the first roller, so that the dispersed substance can be classified. The bead mill is suitable for producing an ink having a relatively low viscosity, such as an ink-jet printing ink such as an organic solvent-containing ink, an aqueous ink, and a UV ink.

Step (1d) is performed to add antimony-doped tin oxide, colorant, vehicle and / or adjuvant to the crude ink to adjust the final composition, viscosity, color tone or dryness of the ink. Step (1d) can be performed by a mixer such as a single screw mixer or a twin screw mixer. Note that step (1d) may be omitted.

Each component contained in the ink of the present invention can be finally adjusted to a desired blending ratio by steps (1a) and / or (1d). Therefore, antimony-doped tin oxide may be added to the vehicle in at least one of steps (1a) and (1d). Further, when preparing an ink containing antimony-doped tin oxide and not containing a colorant, it is not necessary to use a colorant in step (1a) or (1d).

Step (1e) is performed to remove bubbles or foreign matters from the ink so that the ink can be used. Step (1e) can be performed with a meat mill such as a two-roller mill or a three-roller mill.

Step (1f) is performed to fill a container such as a can, a bottle, or a packaging bag with ink. In general, step (1f) can be performed by a metering and filling device provided in the grinder.

In the above embodiment, an inkjet printing ink can be manufactured. When preparing an oil-based / UV combined ink, it is possible to use both a vehicle suitable for solvent-containing ink and a vehicle suitable for UV ink as the vehicle, and to add an auxiliary agent suitable for both.

Another embodiment of the method for producing the ink of the present invention includes the following steps:
(2a) a flushing step to flash the colorant and vehicle and optionally antimony-doped tin oxide and adjuvants to obtain a mill base;
(2b) a kneading step for kneading the mill base to obtain a rough ink;
(2c) an adjusting step for obtaining an ink by adding antimony-doped tin oxide, a colorant, a vehicle and / or an auxiliary agent to the crude ink;
(2d) a polishing step in which the ink is kneaded again to finish the ink; and (2e) a filling step in which the container is filled with the ink.

Step (2a) is performed to omit the step of drying the colorant and the above steps (1a) and (1b) when the colorant contains water. In step (2a), flushing refers to an operation of transferring the colorant from the aqueous phase to the vehicle phase by kneading the water-containing colorant with the vehicle. Step (2a) can be performed by a flasher such as a kneader.

Steps (2b) to (2e) can be performed in the same manner as steps (1c) to (1f), respectively.

<Particle size of antimony-doped tin oxide and colorant in infrared absorbing ink jet printing ink>
The average particle diameter of the antimony-doped tin oxide in the infrared-absorbing inkjet printing ink is 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 80 nm or less, 60 nm or less in consideration of the suitability of the ink for inkjet printing. , 40 nm or less, 20 nm or less, 15 nm or less, 10 nm or less, or 5 nm or less, and the average particle diameter may be 1 nm or more, or 2 nm or more. The average particle diameter refers to the median diameter of the laser diffraction / scattering method.

The means for adjusting the average particle size of antimony-doped tin oxide in the ink to be in the range of 1 nm to 500 nm is not limited, but means for pulverizing antimony-doped tin oxide during the production of antimony-doped tin oxide, and inkjet printing This is considered to be a combination with means for dispersing antimony-doped tin oxide in the vehicle during the production of the ink. For example, the antimony-doped tin oxide is sufficiently pulverized by the step S118 or S124. Further, the antimony-doped tin oxide is sufficiently dispersed in the vehicle by the above steps (1b), (1c), (2a) or (2b).

In addition, the maximum particle size of the antimony-doped tin oxide in the infrared-absorbing inkjet printing ink is preferably 1 μm or less, 900 nm or less, or 800 nm or less from the viewpoint of preventing clogging of the head of the inkjet printer. The maximum particle size can be measured by a laser diffraction / scattering method.

Like antimony-doped tin oxide, the average particle size of the colorant in the infrared-absorbing inkjet printing ink is also preferably 500 nm or less, 300 nm or less, 100 nm or less, 60 nm or less, 20 nm or less, 10 nm or less, or 5 nm or less, The average particle diameter is preferably 1 nm or more, or 2 nm or more. Furthermore, the maximum particle size of the colorant in the infrared-absorbing inkjet printing ink is also preferably 1 μm or less, 900 nm or less, or 800 nm or less.

<Inkjet printing>
Using the ink of the present invention, a printed matter can be obtained by ink jet printing. Ink jet printing is a printing method in which ink is ejected as ink droplets from a nozzle and deposited on a printing medium.

Inkjet printing does not use a plate, does not apply pressure to the substrate, and the nozzle and the substrate do not contact each other, so printing is faster without damaging the substrate compared to printing methods that use plates. It can be performed.

Examples of the substrate to be used for inkjet printing include paper such as inkjet printing paper, fabric, clothing, glass, metal, resin products, inorganic materials such as ceramics, wallpaper, flooring, and labels.

Generally, in an ink jet printer, the method of ejecting ink from a nozzle is roughly divided into a continuous method and an on-demand method.

The continuous method is a method for electrically controlling the flight trajectory of the ink liquid by continuously discharging the ink liquid. In general, the continuous method is employed for industrial inkjet printing. For example, the continuous method is used for printing on a package (for example, production date, product number, etc.), creating a document such as an invoice.

In a continuous type printing machine, ink continuously pushed out from a nozzle by a pump is turned into fine droplets by an ultrasonic oscillator. The droplets are charged by the electrode, and the trajectory is bent by the deflection electrode as necessary, and reach the printing medium. At this time, the ink that has not been bent by the deflection electrode is sucked into the recovery port, returned to the ink tank, and can be reused.

In the continuous method, since the ink of the present invention can be pushed out by increasing the pressure of the pump, the ink of the present invention can be easily printed even when the ink of the present invention has a relatively high viscosity. In addition, since the ink of the present invention can be continuously extruded, the ink of the present invention can be easily printed even when the ink of the present invention contains a volatile solvent or is quick-drying.

On the other hand, the on-demand method is a method for discharging a necessary amount of ink at the time of printing. In general, the on-demand method is adopted for household or industrial inkjet printing. On-demand printing machines use the capillary action of ink to eject ink and supply it to the substrate, so that the ink of the present invention can be easily obtained even when the ink of the present invention has a relatively low viscosity. Can be printed.

In the on-demand method, an accumulation body (also referred to as “head”) of a plurality of nozzles for ejecting ink may be used. For example, on-demand ink jet printing can be performed by moving the print medium by moving the print head or by moving the print head according to the movement of the print medium.

Generally, the on-demand method is roughly classified into a piezo method, a thermal method, and an electrostatic induction method, depending on a method in which ink is pressurized and ejected.

The piezo method uses a piezo element that deforms when a voltage is applied. In an ink chamber provided with a piezo element, the piezo element is distorted to reduce the volume of the ink chamber, whereby ink can be ejected from the nozzle. Further, the piezo method is classified into a push type, a bend type, and a shear type according to the form of deformation of the piezo element.

For example, the piezo method is used for printing with a home inkjet printer, creation of a banner, wallpaper printing, clothing printing, and the like. In the piezo method, inks such as organic solvent-containing ink, water-based ink, and UV ink can be used.

In the piezo method, heat is not used for ink ejection and control, so the head can be made relatively hot. Therefore, even when the ink of the present invention has a relatively high viscosity, it can be easily printed by a piezo method.

The thermal method is a method in which ink is ejected by the pressure of bubbles generated by heating an ink chamber including a heat-generating member and vaporizing the ink. The heating of the exothermic member can be performed, for example, by attaching a heater to at least a part of an ink chamber such as a fine tube. For example, the thermal method is used for printing on a paper medium.

Since the ink is heated in the thermal method, an ink that is hardly deteriorated by heat, such as water-based ink, can be easily printed by the thermal method. In addition, since the thermal method is hardly affected by physical means and mechanical means, it is easy to achieve high-speed printing or high-density printed matter.

The electrostatic induction method is a method in which a voltage is applied between the ink and the printing medium to discharge the ink electrostatically. The electrostatic induction method is easy to control the amount of ink discharged, so it is excellent in forming a thin film and can reduce the amount of ink waste liquid.

The ink of the present invention can be printed by any of the methods described above.

Usually, when ink-jet printing is performed, black ink, cyan ink, magenta ink, yellow ink, special color ink, and the like are used. Here, when only the antimony-doped tin oxide used in the present invention is dispersed in the vehicle, the dispersion has a high brightness and a light white color. Therefore, the ink of the present invention may be used as any color ink, but is formed as indigo ink, red ink, yellow ink or spot color ink, or mixed with indigo process ink, red process ink or yellow process ink. It is preferred that

<Printed matter>
The ink of the present invention has infrared absorptivity. Therefore, when the printed matter obtained by printing the ink of the present invention on the substrate is observed with an infrared light detector such as an infrared camera, the portion on which the ink of the present invention is printed absorbs infrared rays, Since it is displayed blacker than the portion of, the infrared absorption contrast can be detected. For example, the authenticity of the printed matter can be determined by comparing a predetermined infrared absorption contrast with an infrared absorption contrast of the observation target.

<Preparation of antimony-doped tin oxide>
The materials used are as follows:
Metastannic acid: Metastannic acid manufactured by Nippon Chemical Industry Co., Ltd. Antimony trioxide: PATOX-CF (registered trademark; manufactured by Nippon Seiko Co., Ltd.)
Antimony-doped tin oxide raw material (commercially available): ELCOM (registered trademark) P-specialized product manufactured by JGC Catalysts & Chemicals Co., Ltd. (antimony oxide content: 9.9% by weight, no air firing, no air cooling)

The used firing furnace is a shuttle-type firing furnace with a cooling device (manufactured by Tsuji Electric Furnace).

[Example 1]
Steps 100-124 were performed as described in FIG. 1 using 118.8 g of metastannic acid and 1 g of antimony trioxide.

Specifically, as described in Table 1 below, a method including a mixing step (S100), a closed firing step (S106), a closed cooling step (S107), an aeration firing step (S114), and an aeration cooling step (S116). Thus, antimony-doped tin oxide having an antimony oxide content of 0.7% by weight was obtained.

The aerated firing step (S114) was performed for about 8 hours with the temperature in the aerated furnace set to about 1100 ° C. The aeration cooling step (S116) was performed at a cooling rate of about 200 [° C./hour] or more.

[Examples 2 to 7 and Comparative Examples 1 and 2]
Examples 2 to 7 and Comparative Examples 1 and 2 were performed as described in Table 1 below. For Examples 2 to 4, the content of antimony oxide in the obtained antimony-doped tin oxide was changed by changing the weight of metastannic acid and antimony trioxide and / or the time of the aeration firing step (S114). I let you.

On the other hand, in Comparative Example 2, the mixing step (S100), the closed firing step (S106), and the closed cooling step (S107) were performed in the same manner as in Example 1, but the aeration firing step (S114) and the aeration cooling step (S116). ), A product having the same antimony oxide content as in Example 2 was obtained.

In Comparative Example 1, a commercially available antimony-doped tin oxide raw material was prepared. On the other hand, in Example 5 and 6, the commercial item of the comparative example 1 was used for the ventilation baking process (S114) and the ventilation cooling process (S116). The cooling rate in the ventilation cooling step (S116) was 200 [° C./h] or more in Example 5, and less than 200 [° C./h] in Example 6.

In Example 7, a simple mixture of metastannic acid and antimony trioxide was subjected to an aeration firing step (S114) and an aeration cooling step (S116).

[Method for measuring content of antimony oxide in product]
The content of antimony oxide in the product is measured by an order analysis method using a fluorescent X-ray analyzer RIX-1000 (manufactured by Rigaku Corporation). Moreover, as measurement conditions, the measurement is performed using antimony-doped tin oxide as a powder. The powder is measured under the condition that the particle diameter (median diameter by laser diffraction scattering method) is 120 nm.

[X-ray diffraction measurement of product]
And X-ray diffraction was performed about each product of the Example and the comparative example, and the value of crystallinity was computed from the measurement result.

As shown in Table 1, FIGS. 2 to 5 are diagrams showing the results of X-ray diffraction by the antimony-doped tin oxide of the example, and FIG. 6 is a diagram showing the results of X-ray diffraction of the comparative example. In each figure, the vertical axis indicates “intensity (CPS)” of reflected light when X-rays are irradiated, and the horizontal axis indicates “2θ (deg)”.

[CPS]
Here, “CPS (Count Per Second)” indicates the amount of reflected photons per second when the measurement object is irradiated with X-rays, and can also be regarded as the intensity (level) of reflected light. .

[2θ]
Further, “2θ” indicates an irradiation angle when the measurement object is irradiated with X-rays. The reason for “2θ” is that if the angle (incident angle) for irradiating X-rays is θ, the reflection angle is also θ, and the sum of the incident angle and the reflection angle is 2θ. It is.

[Calculation method of crystallinity]
The degree of crystallinity is calculated based on the measurement result of X-ray diffraction (XRD). The equipment used and the measurement conditions are as follows.
(1) Equipment used: Rigaku Corporation MultiFlex (X-ray diffractometer)
(2) Measurement conditions:
Scan speed: 4.0 ° / min.
Radiation source: 40 kV, 30 mA
Integration count: 1 time

For example, the graph of FIG. 2 (B) is a graph showing the result of X-ray diffraction by antimony-doped tin oxide of Example 2. In the antimony-doped tin oxide of Example 2, points where the intensity of reflected light greatly increases (points where the waveform rises) are generated at a plurality of locations.

Specifically, a point near “2θ = 27 °”, a point near “2θ = 34 °”, a point near “2θ = 38 °”, a point near “2θ = 52 °”, “2θ = 55 ° ”And a point near“ 2θ = 58 ° ”.
Then, the crystallinity is calculated using the measured values of 2θ (deg) and intensity (CPS) at the point where the intensity of the reflected light is the highest among the points where the intensity of the reflected light increases. The point where the intensity of reflected light is the highest in antimony-doped tin oxide is a point near “2θ = 27 °”.

FIG. 7 is a conceptual diagram schematically showing a method for calculating the crystallinity.
The crystallinity indicates the ratio of the crystallized portion with respect to the entire material when the material is crystallized, and is defined here as crystallinity = CPS / Δ2θ (half-value width). That is, the crystallinity is defined by a numerical value at a point near 2θ = 27 °. Thereby, the crystallinity can be calculated from the measurement result of X-ray diffraction (XRD). In the illustrated graph, the peak of the waveform is larger and the tip of the waveform becomes sharper as the crystal structure is regular and there are no impurities.

[CPS]
Since CPS is the intensity (level) of reflected light, it has a waveform height in the illustrated example.

[Δ2θ]
Further, Δ2θ is the width of the half width corresponding to a half value of the maximum value (peak value) of CPS obtained by the X-ray diffraction measurement (in FIG. 7, the length A1 is the same as the length A2. Length).

For this reason, the larger the CPS value (the higher the peak of the waveform), the larger the crystallinity value. Further, the smaller the value of Δ2θ (the narrower the half width), the larger the crystallinity value.

Here, when X-rays are applied to the material to be inspected, there are an angle at which the reflected light is generated and an angle at which the reflected light is not generated depending on the angle at which the X-ray is applied. The angle at which the reflected light is generated is constant depending on the material. If the material is the same, the rising or falling tendency of the waveform is almost the same. In the present embodiment, since antimony-doped tin oxide, which is the same material, is used in each example and each comparative example, the position of 2θ at which the CPS value is maximum is unified as “2θ = 27 °”. .

For Examples 1 to 7 and Comparative Examples 1 and 2, the full width at half maximum (Δ2θ) near 2θ = 27 °, the intensity (CPS) near 2θ = 27 °, the crystallinity (CPS / Δ2θ), and the X-ray diffraction graph The drawing numbers are shown in Table 1 below.

2A is a graph showing the result of X-ray diffraction by the antimony-doped tin oxide of Example 1. FIG. The antimony-doped tin oxide of Example 1 has the highest reflected light intensity at a point near “2θ = 27 °”, and the maximum value of CPS is about 12,000. Also regarding Δ2θ, the width of the bottom part of the waveform where the CPS value reaches a peak is almost the same as that in Examples 2 to 4 described above. Therefore, Example 1 is considered to have sufficient crystallinity as antimony-doped tin oxide. However, since the content of antimony oxide is 0.7% by weight and the amount of antimony oxide dissolved in the crystal lattice of tin oxide is small, the infrared absorption effect is considered to be lower than those of Examples 2 to 4. It is done.

3 (A) and 3 (B) are graphs showing the results of X-ray diffraction using antimony-doped tin oxide of Examples 3 and 4, respectively. Even in the antimony-doped tin oxides of Examples 3 and 4, the point where the intensity of the reflected light is the highest is a point near “2θ = 27 °”.

4A and 4B are graphs showing the results of X-ray diffraction by antimony-doped tin oxide of Examples 5 and 6, respectively, and the graph of FIG. 5 is the antimony of Example 7. It is a graph which shows the result of the X-ray diffraction by dope tin oxide. Even in the antimony-doped tin oxides of Examples 5 to 7, the point where the intensity of the reflected light is the highest is a point in the vicinity of “2θ = 27 °”.

In each of the antimony-doped tin oxides of Examples 2 to 4, the maximum value of CPS is about 15000, and the waveform appearing at the point where the intensity of the reflected light is the highest is sharp and the width of the skirt portion is narrow. It has a sharp waveform.

The graph of FIG. 6 (A) is a graph showing the result of X-ray diffraction by the commercially available product of Comparative Example 1. In the commercially available product of Comparative Example 1, the intensity of reflected light is highest at a point in the vicinity of “2θ = 27 °”, but the CPS value is extremely small compared to those of Examples 1 to 7 above ( About 2000). As for Δ2θ, the width of the bottom part of the waveform at which the CPS value reaches its peak is wider than those of the above-described Examples 1 to 7. This is considered to be caused by a large amount of impurities because it is antimony-doped tin oxide produced without using a vaporization purification method.

The graph of FIG. 6 (B) is a graph showing the result of X-ray diffraction by the product of Comparative Example 2. In the product of Comparative Example 2, the intensity of reflected light is highest at a point in the vicinity of “2θ = 27 °”, but the CPS value is smaller than those in Examples 1 to 7 (CPS = 6860.0). As for Δ2θ, the width of the bottom part of the waveform at which the CPS value reaches its peak is wider than those of the above-described Examples 1 to 7. This is considered to be caused by a large amount of impurities because it is antimony-doped tin oxide manufactured without using the above-described vaporization purification method. This can also be seen from the fact that the crystallinity of Comparative Example 2 is lower than that of Example 2 even though Comparative Example 2 has the same antimony oxide content as Example 2.

[Measurement of infrared absorption effect]
The infrared absorption effect was measured by measuring the light reflectance using a spectrophotometer. The equipment used, the measurement conditions, and the measurement method are as follows.

(1) Equipment used: Spectrophotometer V570 manufactured by JASCO Corporation
(2) Sample preparation conditions: 95 parts of acrylic / silicone varnish (Aqueous Cefcote # 800 Clear manufactured by Urethane Giken Co., Ltd.) is added with 5 parts of the infrared absorbing pigments of Examples and Comparative Examples, and a planetary dispersion mill is used. An infrared-absorbing ink is prepared by dispersing and coated with a film applicator on a PET film having a thickness of 200 μm, dried, and a printed part having a thickness of 70 μm is formed in a dried state. It was created.
(3) Measuring method: A standard white plate was attached to the back of the coated film, and the reflectance in the wavelength range of 200 to 2500 nm was measured. In addition, about the infrared absorption pigment of an Example and a comparative example, all are measuring by making a particle size (median diameter in a laser diffraction scattering method) into 120 nm.
Further, the reflectance of the standard white plate was set as a standard value of about 100%.
In addition, the said measuring method is based on "How to obtain | require the solar reflectance of a coating film". Moreover, about the solid content weight ratio (pigment ratio) of the infrared rays absorption pigment contained in a printing part, it calculates as follows. The acrylic / silicone varnish described in the above (2) includes a solid content such as a resin and a solvent that volatilizes and disappears when dried. Since the acrylic / silicone varnish solids weight ratio is 40% by weight, the acrylic / silicone varnish solids content is 38 parts, the infrared absorbing pigment is 5 parts, and the infrared absorbing pigment solids weight ratio is 11.6. % By weight. The remaining 88.4% by weight is resin and / or other additives.

For Examples 1 to 7 and Comparative Examples 1 and 2, the relationship between the wavelength of 200 nm to 2500 nm and the reflectance is shown in FIGS. 8 to 11, and the average reflectance in the wavelength range of 380 nm to 780 nm and / or 780 to 1100 nm, Table 1 below shows the maximum reflectivity and the wavelength indicating the maximum reflectivity.

FIG. 8 shows that antimony-doped tin oxide in which antimony oxide is dissolved in the crystal lattice of tin oxide has an infrared absorption effect.

In the near infrared region (wavelength region of 780 to 1100 nm) used for general authenticity determination, it is desirable that the infrared absorption effect is high, and the solid content of the antimony-doped tin oxide pigment, which is a particularly general printing condition, is desirable. When the weight ratio is 11.6% by weight and the reflectance is 30% or less, when a printed matter is observed with an authenticity determination device such as an infrared camera, a printed part containing antimony-doped tin oxide and other parts The difference is large and 10 out of 10 people can be distinguished, so it is easy to use for authenticity determination and is preferred. In this connection, as shown in FIG. 8, Examples 2 to 4 having an antimony oxide content of 2.8% by weight or more maintain a reflectance of 30% or less in that region.

From FIG. 9, even if it has an antimony oxide content of 2.7 to 2.8% by weight, the comparative example 2 that has not undergone the aeration firing process is compared with the examples 2, 5 and 6 that have undergone the aeration firing process. It is clear that the infrared absorption effect is low. That is, the aeration firing process can improve the crystallinity of the antimony-doped tin oxide, thereby improving the infrared absorption effect. This is supported by comparing the crystallinity of Examples 2, 5, and 6 and Comparative Example 2 in Table 1 below.

Further, Examples 5 and 6 were performed under substantially the same conditions except for the cooling rate in the aeration cooling step (S116). However, as shown in Table 1 below, Example 5 performed at a cooling rate of 200 [° C./hour] or higher was more than Example 6 performed at a cooling rate of less than 200 [° C./hour]. The half width (Δ2θ) is narrow and the degree of crystallinity is high. In this connection, even if a small amount of antimony oxide dissolved in the crystal lattice is removed together with excess antimony oxide not dissolved in the crystal lattice of tin oxide by aeration baking, By actively cooling after firing, it is expected that the crystal lattice will be maintained. Therefore, it is considered that adjusting the cooling rate to 200 [° C./hour] or more in the ventilation cooling step contributes to the improvement in crystallinity of the antimony-doped tin oxide.

From FIG. 10, even if it is a commercially available antimony-doped tin oxide pigment (Comparative Example 1) having an antimony oxide content of 9.9% by weight, a sufficient infrared absorption effect can be obtained through the aeration firing process. It can be seen that the antimony-doped tin oxide (Example 5) has an antimony oxide content of 2.7% by weight. That is, excess antimony oxide that is not dissolved in the crystal lattice (that is, impurities that do not contribute to the infrared absorption effect) can be removed by the aeration firing process.

From FIG. 11, even if the closed firing step and the closed cooling step are omitted, that is, only the mixing step, the aeration firing step and the aeration cooling step are performed, an antimony-doped tin oxide having a sufficient infrared absorption effect can be obtained. I understand.

Here, when comparing Examples 1 to 7 with respect to Table 1 below, Examples 1 to 6 have an average reflectance in the visible light wavelength range (380 nm to 780 nm) and an infrared wavelength range (780 to 1100 nm) than Example 7. ) The average reflectance difference is large. Therefore, it can be seen that the antimony-doped tin oxides of Examples 1 to 6 can be used in a wide range of applications without being restricted by the color exhibited by antimony-doped tin oxide as compared with the antimony-doped tin oxide of Example 7. .

Therefore, by producing antimony-doped tin oxide using an aerated firing process, the crystallinity can be improved with the minimum content of antimony oxide, and antimony-doped tin oxide having a sufficient infrared absorption effect is produced. can do.

In addition, the obtained antimony-doped tin oxide has an antimony oxide content of 9.3 wt% or less and an antimony oxide tin oxide having a content of 9.9 wt% is substantially equal to or higher than that. Infrared absorption effect is obtained.

<Preparation of inkjet printing ink>
[Preparation of solvent-containing ink for continuous method]
The following materials were stirred and uniformly dissolved in a sealed container and then filtered to obtain a solvent-containing ink for continuous use:
Solvent: 41 parts by weight pure ethylal and 42 parts by weight denatured ethanol;
Resin: phenol resin 10 parts by weight;
Pigment: 5 parts by weight of infrared absorbing pigment of Example 2; and conductivity imparting agent: 2 parts by weight of potassium hexafluorophosphate

[Production of solvent-containing ink for piezo method]
Using a mixer, 1-propanol, isopropanol and 1-hexanol were mixed at a weight ratio of 1-propanol: isopropanol: 1-hexanol = 9: 5: 5 to obtain a mixed organic solvent.

10 parts by weight of the infrared absorbing pigment of Example 2, 88 parts by weight of the mixed organic solvent, and 2 parts by weight of a dispersant (“Floren DOPA-33” modified acrylic copolymer (manufactured by Kyoeisha Chemical Co., Ltd.)) were dispersed with a sand mill. Infrared absorbing pigment dispersion was obtained.

76 parts by weight of the mixed organic solvent, 4 parts by weight of styrene-acrylic resin, and 20 parts by weight of the infrared-absorbing pigment dispersion are stirred and uniformly dissolved in a closed container, and then filtered to obtain a piezo method. A solvent-containing ink was obtained.

[Preparation of solvent-containing ink for thermal method]
The following materials were stirred and uniformly dissolved in a sealed container, and then filtered to obtain a solvent-containing ink for the thermal method:
Solvent: 10 parts by weight of ethylene glycol, 10 parts by weight of diethylene glycol, and 76 parts by weight of water; and pigment: 4 parts by weight of the infrared absorbing pigment of Example 2

[Preparation of UV ink for piezo method]
The following materials were stirred and uniformly dissolved in a closed container, and then filtered through a membrane filter to obtain a UV ink for piezo method:
resin:
Monomer: SR238 (1,6 hexanediol diacrylate manufactured by Sartomer Japan Co., Ltd.) 55 parts by weight; and oligomer: CN981 (aliphatic urethane acrylate oligomer Sartomer Japan Co., Ltd. manufactured) 32 parts by weight;
Photopolymerization initiator: Darocur 1173 (2-hydroxy-2-methyl-1-phenyl-propan-1-one, manufactured by Ciba Japan Ltd.) 10 parts by weight;
Pigment: Infrared absorbing pigment of Example 2 2 parts by weight; and Dispersant: Florene DOPA-33 (modified acrylic copolymer, manufactured by Kyoeisha Chemical Co., Ltd.) 1 part by weight

[Infrared absorption effect of inkjet printing ink]
The solvent-containing ink for the continuous method obtained above is printed on high-quality paper (Shiraoi high-quality paper, manufactured by Nippon Paper Industries Co., Ltd.) using an inkjet printer (Excel MVP opaque made by Videojet Technologies), and dried to obtain printed matter I. Obtained.

The solvent-containing ink for the piezo method obtained above is used on high-quality paper (Shiraoi fine-quality paper, Nippon Paper Industries) on an inkjet printer ("Roll Jet" manufactured by Tritech Co., Ltd. and "KM512M head" manufactured by Konica Minolta Co., Ltd.) ) And dried to obtain Print II.

The solvent-containing ink for thermal method obtained above was printed on high-quality paper (Shiraoi fine-quality paper, manufactured by Nippon Paper Industries Co., Ltd.) with a thermal ink jet printer (Videojet Technologies VJ8510), and dried to obtain printed matter III .

Using the piezo method UV ink obtained above with a inkjet printer ("Roll Jet" manufactured by Tritech Co., Ltd. and "KM512M head" manufactured by Konica Minolta Co., Ltd.) And dried to obtain a printed matter IV.

When the printed materials I to IV were observed using an infrared camera (Dino-Lite Pro manufactured by ANMO), the printed surface of the infrared absorbing ink appeared black because it absorbed infrared light, whereas infrared absorbing. The non-ink-printed surface (eg, the base paper portion, the general process ink print portion, etc.) appeared white because it transmitted or reflected infrared light.

[Relationship between color tone of inkjet printing ink and infrared absorptivity]
The following substrates and inks were prepared:
Base material: General paper (OK Prince fine quality 90 kg)
Process ink (3 colors):
Indigo (C): Super Tech GT Series Indigo (T & K TOKA Co., Ltd.)
Crimson (M): Super Tech GT Series Crimson (T & K TOKA Co., Ltd.)
Yellow (Y): Super Tech GT Series Yellow (manufactured by T & K TOKA Corporation)

According to the following print sample preparation conditions, the above three color process inks were respectively printed on the substrate to obtain three types of print samples corresponding to the respective colors:
(Print sample preparation conditions)
Printing machine: Offset printing machine RI tester (manufactured by IHI Machine System Co., Ltd.)
Ink volume: 0.125cc
Ink film thickness: about 1 μm

The light reflectance of three types of printed samples was measured according to the following measurement conditions:
(Measurement condition)
Measuring device: UV-visible spectrophotometer U-4000 (manufactured by Hitachi, Ltd.)
Measurement item: Reflectance (%)
Measurement wavelength: 350-2500 nm

FIG. 12 shows the reflectance in the wavelength range of 350 to 1500 nm for the indigo (C), red (M), and yellow (Y) process inks.

FIG. 12 is a graph showing the reflectance of a printed matter obtained by offset printing of CMY process inks. However, as long as the colorant concentration, the film thickness, and the measurement conditions are uniform, the reflectance of the printed matter obtained by inkjet printing is considered to be the same as the reflectance of the printed matter obtained by offset printing. Therefore, by combining the reflectance graph of the CMY process ink shown in FIG. 12 and the reflectance graphs of Examples 1 to 7 shown in FIGS. 8 to 11, the inkjet printing ink of the present invention can be used as a general color ink. Predict the relationship between color tone and infrared absorption when used.

For example, in FIG. 12, the red and yellow process inks do not absorb light in the infrared wavelength region (780 to 1100 nm). On the other hand, in the reflectance graphs of Examples 1 to 7 shown in FIGS. 8 to 11, since the average reflectance in the infrared wavelength region is lower than the average reflectance in the visible light wavelength region (380 nm to 780 nm), it is higher than that of visible light. Infrared light is also considered to be absorbed. Therefore, when the antimony-doped tin oxide used in the present invention is contained in the red or yellow ink, or the ink jet printing ink of the present invention is used as the red or yellow ink, the ink is not affected without affecting the color tone of the red or yellow. It can be seen that infrared absorptivity can be provided.

From FIG. 12, it can also be considered that the indigo process ink slightly absorbs light in the infrared wavelength region (780 to 1100 nm). However, in FIGS. 8 to 11, compared with the ratio of the infrared absorbing inks of Examples 1 to 7 to absorb infrared light, the ratio of the indigo process ink to absorb infrared light is so low that it does not need to be taken into consideration. Therefore, even if the antimony-doped tin oxide used in the present invention is contained in the indigo ink or the ink jet printing ink of the present invention is used as the indigo ink, the ink absorbs infrared rays without affecting the indigo color tone. It can be seen that sex can be imparted.

Furthermore, the infrared absorbing ink containing antimony-doped tin oxide obtained in Examples 1 to 7 and containing no colorant does not correspond to black, indigo, red or yellow ink. In this connection, the infrared absorbing ink containing antimony-doped tin oxide obtained in Examples 1 to 7 and containing no colorant has a high brightness and a light white color. The influence on the color tone of yellow ink is considered to be small. Therefore, the infrared absorbing ink containing antimony-doped tin oxide obtained in Examples 1 to 7 and containing no colorant can be grasped as a special color ink or functional ink suitable for inkjet printing. In that case, the reflectance graphs of Examples 1 to 7 shown in FIGS. 8 to 11 can be regarded as graphs representing the light reflection characteristics of the special color ink of the present invention.

The present invention can be implemented with various modifications or replacements without being limited to the above-described embodiments and examples. In addition, it should be understood that any of the configurations and materials described in the above-described embodiments and examples are preferable examples and can be implemented by appropriately modifying them.

Claims

An infrared absorbing ink jet printing ink comprising antimony-doped tin oxide and a vehicle,
The antimony-doped tin oxide contains tin oxide and antimony oxide and satisfies the following (a) and / or (b):
(A) The half width (Δ2θ) of a peak around 2θ = 27 ° obtained by X-ray diffraction measurement is 0.30 or less; and / or (b) the content of the antimony oxide is the antimony dope A value obtained by dividing the peak value of the peak around 2θ = 27 ° obtained by X-ray diffraction measurement by the half-value width (Δ2θ), based on the weight of tin oxide, from 0.5 to 10.0% by weight. The degree of crystallinity is 58427 or more.
Inkjet printing ink.
The infrared-absorbing inkjet printing ink according to claim 1, which is used for preventing counterfeiting.
3. The infrared-absorbing inkjet printing ink according to claim 1, wherein in (a), the half width (Δ2θ) is 0.21 or less.
The infrared-absorbing inkjet printing according to claim 1 or 2, wherein in (b), the content of the antimony oxide is 2.8 to 9.3 wt% based on the weight of the antimony-doped tin oxide. ink.
The infrared-absorbing inkjet printing ink according to claim 1 or 2, wherein the crystallinity is 78020 or more.
The infrared-absorbing inkjet printing ink according to any one of claims 1 to 5, wherein the antimony-doped tin oxide has an average particle size of 500 nm or less.
The infrared-absorbing ink-jet printing ink according to any one of claims 1 to 6, wherein the ink-jet printing ink is a solvent-containing ink or an ultraviolet curable ink.
The infrared-absorbing inkjet printing ink according to any one of claims 1 to 7, further comprising an auxiliary agent.
The infrared-absorbing inkjet printing ink according to any one of claims 1 to 8, further comprising a colorant.
A method for obtaining a printed matter by ink jet printing using the infrared absorbing ink jet printing ink according to any one of claims 1 to 9.
A printed matter comprising a printing part printed with the infrared-absorbing inkjet printing ink according to any one of claims 1 to 9.