JP2016155903A - Photochromic brilliant ink and printed matter of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel brilliant ink and a printed matter of the ink useful as an anticounterfeit measure.SOLUTION: A photochromic brilliant ink is provided, including a photochromic brilliant pigment and a vehicle. A printed matter (100) is provided, which has a brilliant printed part (10) printed with the above ink on a substrate (1).SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ink containing a bright pigment having photochromic properties and a printed matter thereof. In particular, the present invention relates to an ink containing a bright pigment having a high weather resistance, a high light response speed, and a high photochromic property, which is useful for determining the authenticity of a printed matter, and the printed matter thereof.

  A photochromic pigment is a pigment having an effect of changing its color when exposed to ultraviolet rays or the like, and is generally used for an optical recording material, a light control glass or the like.

  Research has also been conducted on the use of photochromic pigments as anti-counterfeiting colorants, taking advantage of the property of changing color when exposed to ultraviolet rays. In this case, the medium printed using the photochromic pigment is irradiated with ultraviolet rays at the time of delivery, and authenticity is determined based on whether or not the color has changed. Although this anti-counterfeiting technology can determine the authenticity with a simple device, it is generally a non-public measure that does not know whether anti-counterfeiting measures are taken, and is called a covert technology.

  Regarding such a photochromic pigment, Patent Document 1 discloses an organic photochromic pigment, and Patent Document 2 discloses an inorganic photochromic pigment.

  A luster pigment, so-called pearl pigment, is a pigment that artificially expresses pearl luster. Such pigments have a flip-flop effect (brightness) that varies in brightness depending on the viewing direction, which gives pearl luster. Usually, pigments with titanium oxide coated on scale-like mica (titanium mica pigment) are used and reflected at the boundary between a layer of titanium oxide or the like with a high refractive index, mica with a low refractive index, and the surrounding medium. The shining light brings the glitter.

  Locations printed with ink containing glitter pigment (hereinafter referred to as “brilliant ink”) cannot be duplicated on a color copier, so glitter pigments should be used as anti-counterfeiting colorants. Can do. Such anti-counterfeiting technology is a publicly-known anti-counterfeiting measure that enables everyone to clearly determine the authenticity of an object, and is called overt technology.

Japanese Patent No. 4568042 JP 2013-043332 A

  However, in recent years, such glitter pigments are also commercially available for toys, cosmetics, and the like, and are generally easily available. Therefore, although the glitter ink is still difficult to reproduce the printed matter with a color copier, the effect is decreasing as a counterfeit prevention measure.

  Therefore, as a more advanced forgery prevention measure, it is conceivable to take a forgery prevention measure combining the covert technique and the overt technique. However, it has been difficult to obtain an ink having both glitter and photochromic properties and a printed product thereof. That is, in this case, since it is necessary to include both the luster pigment and the photochromic pigment in the ink, there arises a problem that the content of the pigment increases and the printability deteriorates. It is also difficult to further include other pigments in the ink.

  Accordingly, an object of the present invention is to provide a novel glitter ink and printed matter thereof that are further useful as a countermeasure against forgery.

The inventors have found that the present invention having the following embodiments is extremely effective:
<< Aspect 1 >>
A photochromic glittering ink comprising a glittering pigment having a photochromic property and a vehicle.
<< Aspect 2 >>
The photochromic glitter pigment is supported on mica and titanium mica including a titanium oxide-containing layer covering the mica, and on the surface of the mica and / or inside or on the surface of the titanium oxide-containing layer. The ink according to aspect 1, comprising a photochromic activator.
<< Aspect 3 >>
The aspect in which the photochromic activator includes a metal or a metal compound selected from the group consisting of iron, chromium, copper, nickel, manganese, cobalt, and molybdenum, and oxides, nitrides, halides, and salts thereof. 2. The ink according to 2.
<< Aspect 4 >>
The ink according to aspect 2 or 3, wherein the photochromic activator contains iron oxide.
<< Aspect 5 >>
The ink according to any one of aspects 2 to 4, wherein an average particle size of the photochromic activator is less than 0.7 μm.
<< Aspect 6 >>
The ink according to aspect 5, wherein the photochromic activator is iron oxide fine particles having an average particle size of 0.2 μm or less.
<< Aspect 7 >>
When the ink containing 20 parts by weight of the pigment and 80 parts by weight of the vehicle having a solid content of 20% by weight is printed on a white background of Kent paper using a 100 mesh silk screen printing plate, a rubber squeegee and a silk printing stand. The E value measured after being placed in a dark place for 12 hours and the E value after being taken out after being placed in a dark place for 12 hours and irradiated with ultraviolet rays having a wavelength of 365 nm at an intensity of 5 mW / cm ² for 10 seconds from the closest distance. The ink according to any one of aspects 1 to 6, wherein ΔE which is a difference indicates 3 or more.
<< Aspect 8 >>
The ink according to any one of aspects 1 to 7, which is used for preventing counterfeiting.
<< Aspect 9 >>
Printed matter provided with a glittering printing part printed with the ink according to any one of aspects 1 to 8 on a substrate.
<< Aspect 10 >>
The printed matter according to aspect 9, which is a bill, a securities, an official document, a ticket, a cash voucher, a card, or a label for authenticity determination.

  The glitter ink of the present invention is useful not only as a counterfeit prevention measure by the overt technique, but also as a counterfeit prevention measure by the covert technique.

  That is, since the glittering ink of the present invention can impart photochromic properties, the printed portion printed using the ink changes color by receiving ultraviolet rays or the like. Therefore, for securities and the like printed using the glitter ink of the present invention, authenticity can be determined on the spot by irradiating with ultraviolet rays or the like at the time of delivery. For counterfeiters, since it is considered that anti-counterfeiting measures have been taken on printed matter when glitter ink is used, further anti-counterfeiting measures have been taken by providing photochromic properties to this glitter ink. It is unexpected. Therefore, it can be said that the glittering ink of the present invention is extremely useful for preventing forgery of printed matter.

  In addition, since anti-counterfeiting measures are taken with both the covert technique and the overt technique, it has been difficult to obtain a printed matter having both glitter and photochromic properties. That is, in this case, since it is necessary to include both the luster pigment and the photochromic pigment in the ink, there arises a problem that the content of the pigment increases and the printability deteriorates. It is also difficult to further include other pigments in the ink.

  On the other hand, the glitter ink of the present invention uses a pigment having both photochromic properties and glitter. Therefore, it is possible to reduce the amount of pigment contained in the ink, and printing is easy even if other pigments are further included. Has the advantage of being.

(A) Illustrated before and after light irradiation of the printed material of one embodiment of the present invention. (B) Illustrated before and after light irradiation of a printed matter having a normal glitter printing portion. The light irradiation of the printed matter of 1 aspect of this invention is illustrated. Here, the printing part by photochromic glitter ink and the printing part by normal glitter ink are printed by tapping. It is a figure which shows the relationship between ultraviolet irradiation time and (DELTA) E of the printing part using the ink of this invention and the comparative ink. It is a figure which shows the relationship between the particle size of the photochromic activator (iron oxide) contained in the pigment in ink, and the reflectance of a printing part, when printing on a white background. It is a figure which shows the relationship between the particle size of the photochromic activator (iron oxide) contained in the pigment in ink, and the reflectance of a printing part, when printing on a black background.

  Hereinafter, embodiments of the present invention will be described in detail. Note that the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist of the present invention.

≪Photochromic glitter ink≫
The ink of the present invention contains a bright pigment having photochromic properties (hereinafter sometimes referred to as “photochromic bright pigment”). Further, the inks of the present invention include a vehicle and may further include adjuvants and colorants.

  The ink of the present invention may be an oxidation polymerization type ink (hereinafter referred to as “oil-based ink”), an ultraviolet curable ink (hereinafter referred to as “UV ink”), or an oil-based / ultraviolet curable type, depending on the type of vehicle component. As a combined ink (hereinafter referred to as “oil-based / UV combined ink”), it can be used in various printing methods.

  Oil-based inks are inks that can be cured by oxidative polymerization of vehicle components. In general, the oil-based ink includes a resin, a crosslinking agent or a drying accelerator, a drying oil or a semi-drying oil, a solvent, and the like.

  UV inks are inks that can be cured by photopolymerization of vehicle components. In general, the UV ink contains a resin, a photopolymerizable monomer or oligomer, a photopolymerization initiator and the like as a vehicle component, but does not contain a volatile component such as a solvent.

  The oil-based / UV combined ink is an ink having curing characteristics of both oil-based ink and UV ink.

  The ink of the present invention can be used as a water-based ink containing water as a main solvent or a solvent ink containing an organic solvent as a main solvent, depending on the type of solvent that can be used as a vehicle.

  The water-based ink is an ink containing water as a main solvent, but may contain an organic solvent. The solvent ink is an ink containing an organic solvent as a main solvent, but may be substantially free of water. “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.

  The ink of the present invention may be used as a general printing ink, for example, silk screen printing ink, gravure printing ink, intaglio printing ink, offset printing ink, letterpress printing ink, inkjet printing ink, flexographic printing ink, etc. it can. The intaglio printing ink can be used for press printing using a direct printing plate surface or an etching plate surface.

  The content of the photochromic glitter pigment in the ink is the total mass of the ink, regardless of the printing method, so that the printed matter including the printed part printed with the ink of the present invention can easily exhibit the glitter and photochromic properties. On the other hand, it is preferably about 5% by mass or more, about 10% by mass or more, or about 20% by mass or more, and about 50% by mass or less, about 40% by mass or less, or about 30% by mass or less. When the content is 5% by mass or more, the visibility of the printed part can be ensured. When the content is 50% by mass or less, the viscosity of the ink is ensured while ensuring the visibility of the printed part. Can be maintained in an appropriate range, and the problem of deterioration in printability or peeling of the printed image line portion can be suppressed.

  For example, the ink of the present invention can contain 45 to 90% by weight, preferably 70 to 90% by weight of a vehicle and 0 to 10% by weight of an auxiliary agent when printing by solvent-based gravure printing. The colorant other than the photochromic glitter pigment can be contained in an amount of 0 to 30% by weight, preferably 5 to 15% by weight. Further, when printing by water-based gravure printing, the vehicle can be contained in an amount of 50 to 90% by weight, preferably 70 to 90% by weight, and the auxiliary agent is 0 to 10% by weight, preferably 3 to 5% by weight. The colorant other than the photochromic glitter pigment can be contained in an amount of 0 to 30% by weight, preferably 5 to 15% by weight. In this case, the viscosity of the ink is 0.3 to 2.0 dPa · S, preferably 0.5 to 1.0 dPa · S, as measured with a Brookfield rotational viscometer.

  For example, the ink of the present invention can contain 50 to 90% by weight, preferably 70 to 80% by weight of a vehicle, and 0 to 10% by weight of an auxiliary agent, preferably when printing by flexographic printing. It can be contained at 3 to 5% by weight, and a colorant other than the photochromic glitter pigment can be contained at 0 to 30% by weight, preferably 5 to 15% by weight. In this case, the viscosity of the ink is 1.0 to 2.0 dPa · S, preferably 1.0 to 1.5 dPa · S, as measured with a Brookfield rotational viscometer.

  For example, the ink of the present invention can contain 50 to 90% by weight, preferably 70 to 80% by weight of a vehicle, and 0 to 5% by weight of an auxiliary agent when printing by silk screen printing as an oil-based ink. %, Preferably 3 to 5% by weight, and a colorant other than the photochromic glitter pigment can be contained in an amount of 0 to 35% by weight, preferably 5 to 15% by weight. Moreover, when printing by UV-ink printing by silk screen printing, the vehicle can be contained in an amount of 10 to 85% by weight, preferably 70 to 80% by weight, and the auxiliary agent is 0 to 5% by weight, preferably 3 to 3%. The colorant other than the photochromic glitter pigment can be contained in an amount of 0 to 50% by weight, preferably 5 to 15% by weight. Further, when printing by silk screen printing as an oil-based / UV combined ink, the oil-based ink and the UV ink vehicle may each be contained in an amount of 30 to 50% by weight, preferably 35 to 45% by weight, respectively. Auxiliaries can be contained in an amount of 0 to 5% by weight, preferably 3 to 5% by weight, and colorants other than the photochromic glitter pigment can be contained in an amount of 0 to 50% by weight, preferably 5 to 15% by weight. be able to. In this case, the viscosity of the ink is 20 to 100 dPa · S, preferably 80 to 100 dPa · S, as measured with a Brookfield rotational viscometer.

  For example, the ink of the present invention can contain 20 to 85% by weight, preferably 70 to 80% by weight of a vehicle and 2.1 to 80% of an auxiliary agent when printing by intaglio printing as an oil-based ink. The colorant other than the photochromic glitter pigment can be contained in an amount of 0 to 35% by weight, preferably 5 to 15% by weight. When printing by intaglio printing as UV ink, the vehicle can be contained in an amount of 30 to 99% by weight, preferably 70 to 80% by weight, and the auxiliary agent is 2.1 to 80% by weight, preferably 3%. The colorant other than the photochromic glitter pigment can be contained in an amount of 0 to 35% by weight, preferably 5 to 15% by weight. Furthermore, when printing by intaglio printing as an oil-based and UV combined ink, the oil-based ink vehicle and the UV ink vehicle are 5 to 50% by weight and 2 to 95% by weight, preferably 30 to 50% by weight, respectively. 50 to 70% by weight, auxiliary agents can be contained in an amount of 5 to 65% by weight, preferably 3 to 5% by weight, and coloring agents other than the photochromic glitter pigment can be contained in an amount of 0 to 35% by weight. Preferably it can contain 5 to 15weight%. In this case, the viscosity of the ink is 0.5 to 700 dPa · S, preferably 400 to 600 dPa · S, as measured with a cone plate viscometer.

  In addition to the photochromic glitter pigment and vehicle contained in the ink of the present invention, optional adjuvants and colorants are described below.

<Photochromic glitter pigment>
The photochromic glitter pigment contained in the ink of the present invention is not particularly limited as long as it has photochromic properties and glitter, and may be an organic pigment or an inorganic pigment. Examples of the inorganic pigment include pigments described in Japanese Patent No. 3507230.

  For example, the photochromic glitter pigment contained in the ink of the present invention is supported on mica titanium including mica and a titanium oxide-containing layer covering mica, and on the surface of mica and / or inside or on the surface of the titanium oxide-containing layer. A photochromic activator that is used. Preferably, the photochromic glitter pigment used in the present invention consists essentially of titanium mica and a photochromic activator. The photochromic glitter pigment used in the present invention is given glitter by, for example, titanium mica, and the photochromic nature is given by a photochromic activator.

Inorganic photochromic pigments have higher weather resistance than organic photochromic pigments, but have a low light response speed, change color slowly even when irradiated with light, and tend to have a small photochromic effect, that is, color change. is there. Surprisingly, however, the present inventors have found that a titanium mica-based glitter pigment achieves a high response speed and a photochromic effect by including a small particle size photochromic activator. Although not bound by theory, the following reasoning can be made as the cause. That is, it is considered that a lattice defect usually exists in the titanium oxide crystal, and an oxidation-reduction reaction occurs between the lattice defect and a metal ion doped in the crystal by irradiation with ultraviolet to low wavelength visible light. . For example, when iron ions are used as metal ions, the coloring mechanism is considered to darken by reducing Fe ^{3+ in} iron oxide to Fe ²⁺ . At this time, the finer particles of iron oxide are, It is considered that the redox reaction is likely to occur due to the large surface area.

  Therefore, the photochromic glitter pigment used in the preferred embodiment of the present invention has a small particle size of the photochromic activator. When the particle size of the photochromic activator is small, the color derived from the photochromic activator does not appear strongly. For example, even when iron oxide fine particles are used as the photochromic activator, the printed matter contains iron oxide. There is also an effect that the yellowish yellow color derived from it does not appear strongly.

  In addition, since the photochromic glitter pigment used in a preferred embodiment of the present invention has high glitter, it can give high design to printed matter and the like. Furthermore, in a preferred embodiment using a photochromic activator having a small particle size, since the color derived from the activator does not appear strongly, it is indistinguishable from the appearance of a normal bright pigment not mixed with an activator. The printing portion having the photochromic effect and the printing portion not having the photochromic effect can be separately printed. That is, when only a part of a certain character string is printed using the ink of the present invention and the remaining part is printed with a normal glitter ink, the appearance is indistinguishable, but the printed matter is irradiated with ultraviolet rays. Thus, it is possible to change the color of only a part of the character (the part printed using the ink of the present invention).

  For example, the photochromic glitter pigment used in a preferred embodiment of the present invention and a vinyl clear lacquer (solid content 25% by weight) are mixed at a weight ratio of 2: 8, and an applicator is used so that the dry film thickness is 10 μm. It was coated on the black ground of Kent paper (Concealment rate measuring paper, Motofuji). After being placed in a dark place at room temperature for 12 hours, when measured with a spectrometer (U-4000 type spectrophotometer, Hitachi High-Technologies Corporation), the wavelength of the coating film part is between 400 nm to 500 nm or 400 nm to The average reflectance of light between 450 nm is 45% or more, 50% or more, 55% or more, or 60% or more, and the average reflectance of light between 600 nm to 650 nm is 45% or less, 40% or less. Or 38% or less. Therefore, since the photochromic glitter pigment used in the preferred embodiment of the present invention has a relatively strong bluishness and a relatively weak redness, the pigment described in Japanese Patent No. 3507230 is oxidized when the light intensity is low. It is different in that it is supposed to exhibit iron-derived jaundice.

  The photochromic glittering pigment used in the present invention exhibits a high photochromic effect with respect to ultraviolet rays and its response speed, and the printed material is preferably 3 or more by UV irradiation for 10 seconds when measured by the method described in the examples. A ΔE of 5 or more, 8 or more, or 10 or more is shown. Further preferably, ΔE of 3 or more, 5 or more, 8 or more, or 10 or more is exhibited by UV irradiation for 5 seconds. Similarly, the printed material containing the photochromic glittering pigment used in the present invention preferably exhibits a ΔL of 5 or more, 8 or more, 10 or more, or 14 or more, more preferably 5 seconds of UV, when irradiated with UV for 10 seconds. Irradiation shows ΔL of 4 or more, 6 or more, or 8 or more.

  The photochromic glitter pigment used in the present invention may have a number average particle diameter of 1 μm or more, 3 μm or more, or 5 μm or more, or 50 μm or less, 30 μm or less, or 20 μm or less. Here, the average particle size is a value obtained by randomly selecting 100 particles from the SEM image and measuring the equivalent diameter obtained from the outer periphery of these particles as the particle size. Here, the equivalent diameter of a certain particle refers to the diameter of a perfect circle having an outer peripheral length equal to the outer peripheral length of the particle.

  Depending on the particle size and / or shape of the photochromic glitter pigment used, the pigment may not be properly transferred to the roll of an offset printing press, letterpress printing machine, etc. Large size pigments may not be suitable. Therefore, it is necessary to select the photochromic glitter pigment to be used according to the printing method.

<Photochromic luster pigment-titanium mica>
The photochromic glitter pigment used in the present invention preferably includes a glitter pigment having mica and a titanium oxide-containing layer covering the mica. This pigment has a structure in which a titanium dioxide layer is formed on the surface of fine flaky mica, and has pearly luster and various interference colors. As described in Japanese Patent Publication No. 43-25644, an aqueous solution of an inorganic salt of titanium (for example, titanyl sulfate) is hydrolyzed in the presence of mica to deposit hydrous titanium dioxide on the surface of mica as described in Japanese Patent Publication No. 43-25644. The method of hydrolyzing is mentioned. In this case, the produced mica titanium pigment exhibits various interference colors depending on the thickness of the titanium dioxide coating layer on the mica surface.

  The interference color emitted by titanium mica is determined by the thickness of the titanium oxide-containing layer laminated on the mica. That is, normally, mica titanium has reflected light on the surface of the titanium oxide-containing layer and the mica surface that is the boundary between the mica and the titanium oxide-containing layer, so the ratio of the titanium oxide-containing layer is adjusted to By adjusting the optical path difference of the reflected light on the respective surfaces, it is possible to adjust the interference light due to the interference action generated between the reflected lights in various colors.

  The proportion of the titanium oxide-containing layer in titanium mica is preferably 30% by weight or more, 35% by weight or more, 40% by weight or more, or 45% by weight or more, and 70% by weight or less, 65% by weight or less, 60 It is preferable that it is below wt% or below 55 wt%.

  As the crystal structure of titanium oxide, there are a rutile structure, a brookite structure and an anatase structure, but the titanium oxide in the mica titanium used in the present invention is anatase because it is relatively stable and has a high surface area and photoactivity. A mold is preferred.

  Luminous pigments containing anatase-type titanium oxide having interference colors include flamenco gold, flamenco orange, flamenco red, flamenco violet, flamenco blue, flamenco green, flamenco sparkle gold, flamenco sparkle red, flamenco sparkle blue, Flamenco sparkle green (BASF).

  The photochromic glitter pigment used in the present invention contains mica titanium, preferably 80% by weight or more, 85% by weight or more, 90% by weight or more, 95% by weight or more, or 97% by weight or more, preferably 99.95% by weight. % Or less, 99.90% by weight or less, or 99.70% by weight or less.

<Photochromic glitter pigment-photochromic activator>
As described above, the photochromic glitter pigment used in the present invention contains, for example, a photochromic activator in order to develop photochromic properties.

  Examples of the photochromic activator include fine particles of metal or metal compound selected from the group consisting of iron, chromium, copper, nickel, manganese, cobalt, and molybdenum, and oxides, nitrides, halides, and salts thereof. It is done. Examples of the salt include sulfate, nitrate, and acetate. Among these, it is particularly preferable to use fine iron oxide particles.

  Light scattering by such fine particles is mainly Rayleigh scattering, and the scattering intensity is proportional to the sixth power of the particle diameter. Therefore, as the particle size decreases, the scattering rapidly decreases and the transparency increases, and the color derived from the fine particles does not appear. In particular, the particle diameter is 1/3 to 1/4 or less of the wavelength of visible light, for example, 1/3 to 1/4 or less of the wavelength of 0.550 μm which is the central wavelength of visible light (that is, 0.20 μm or less or 0 .15 μm or less), the transparency is very high.

  In the pigment described in Japanese Patent No. 3507230, the metal of the photochromic activator is added to the mica titanium pigment, and the metal color of the activator appears as the object color. And when iron oxide is used as an activator, it is supposed that the light yellow intensity | strength derived from an iron oxide will be exhibited in the place where light intensity is weak. This means that light is strongly scattered by the fine particles of the photochromic activator. Therefore, the pigment described in Japanese Patent No. 3507230 uses a photochromic activator having a relatively large particle size. Specifically, it is considered that fine metal particles having an average particle diameter of 0.7 μm or more are used.

  Further, since the pigment described in Japanese Patent No. 3507230 reflects yellow to red light, it is considered that Mie scattering or geometric scattering is dominant, and particles having the same wavelength as the red wavelength. It is considered that activator particles having a diameter of 0.7 μm or more are used.

  On the other hand, the average particle size of the photochromic activator added to the photochromic glitter pigment used in the preferred embodiment of the present invention is preferably less than 0.70 μm, more preferably 0.69 μm or less, 0.6 μm or less. 0.5 μm or less, 0.4 μm or less, 0.39 μm or less, 0.3 μm or less, 0.2 μm or less, 0.19 μm or less, or 0.15 μm or less. Here, the average particle diameter of the photochromic activator is the number average particle diameter of the primary particles, and is determined as follows: First, the photochromic activator deposited on the photochromic glitter pigment surface by SEM is used. Search; Next, 100 primary particle photochromic activators are randomly selected from the SEM image, and the equivalent diameter determined from the outer periphery of these photochromic activators is measured as the particle size.

  When the average particle size of the photochromic activator is smaller than 0.7 μm, the response speed of the photochromic effect to the ultraviolet light in the photochromic glitter pigment is fast, and the color change ΔE due to the photochromic effect is also large. Further, since the color derived from the photochromic activator becomes light, there is little decrease in transmitted light, and the flip-flop effect is hardly lowered. On the other hand, when the average particle size of the photochromic activator is larger than 0.7 μm, the response speed of the photochromic effect to ultraviolet rays is slow, and the color change ΔE due to the photochromic effect is small. In addition, the color derived from the photochromic activator is darker than the pigment color, the transparency is lowered, and the flip-flop effect of the glitter pigment due to interference transmitted light is also lowered.

  When the amount of the photochromic activator is too large, the color change due to the photochromic effect is weakened. Therefore, the photochromic glitter pigment used in the preferred embodiment of the present invention is preferably a photochromic activator, preferably 10% by weight or less, or 5 Contains up to weight percent. In order to effectively exhibit a photochromic effect, the pigment used in the present invention contains a photochromic activator, preferably 0.05% by weight or more, 0.1% by weight or more, or 0.3% by weight or more. .

  Further, the photochromic glitter pigment used in a preferred embodiment of the present invention contains 0.05% by weight or more, preferably 0.10% by weight or more, 0.30% by weight of a photochromic activator having a particle size of less than 0.7 μm. % Or more, 0.50% by weight or more, 0.80% by weight or more, 1.0% by weight or more, 1.20% by weight or more, 1.50% by weight or more, or 2.0% by weight or more.

  Furthermore, the photochromic glitter pigment used in a preferred embodiment of the present invention is a photochromic activator having a particle size of 0.4 μm or less, 0.05 wt% or more, 0.10 wt% or more, 0.30 wt% or more, It is preferable to contain 0.50% by weight or more, 0.80% by weight or more, 1.0% by weight or more, 1.20% by weight or more, 1.50% by weight or more, or 2.0% by weight or more. The photochromic glitter pigment used in a preferred embodiment of the present invention contains 0.05% by weight or more of a photochromic activator of 0.2 μm or less, preferably 0.10% by weight or more, 0.30% by weight or more, and 0.0. It is preferable to contain 50% by weight or more, 0.80% by weight or more, 1.0% by weight or more, 1.20% by weight or more, 1.50% by weight or more, or 2.0% by weight or more.

  The photochromic glitter pigment used in a preferred embodiment of the present invention may contain particles of other metals or metal compounds in addition to the photochromic activator as long as the photochromic effect and / or flip-flop effect is not significantly impaired. The average particle size may be 0.7 μm or more.

  Specifically, as the photochromic activator, IPJ-226G having an average particle size of 0.07 μm, IPK-409G having an average particle size of 0.10 μm, IPK-426G having an average particle size of 0.11 μm, average IPJ-218H with a particle size of 0.07 μm, IPF-249H with an average particle size of 0.08 μm, IPK-409H with an average particle size of 0.10 μm, IPK-428H with an average particle size of 0.11 μm (all Toda Industries) Co., Ltd.) and iron oxide fine particles such as TRY-100P (Titanium Industry Co., Ltd.) having an average particle size of 0.10 μm.

<Photochromic glitter pigment-production method>
The photochromic glitter pigment used in the present invention can be produced by mixing the above-described mica titanium and photochromic activator, and firing the mixture. The mixture preferably contains a photochromic activator having an average particle size of less than 0.7 μm, but all the photochromic activators contained in the mixture need to be less than 0.7 μm. Absent.

  Moreover, baking is performed at 750 to 950 ° C. In such a temperature range, the obtained pigment exhibits suitable photochromic properties. Without being bound by theory, in such a temperature range, aggregation of the photochromic activator particles can be prevented, and the crystal structure of titanium oxide can be prevented from changing from anatase type to rutile type. This is considered to be possible.

<Vehicle>
The vehicle used in the ink of the present invention is a medium for transferring the photochromic glitter pigment to the printed material and fixing the photochromic glitter pigment to the printed material after printing. The vehicle used in the present invention may contain known vehicle components used for printing, such as resins, solvents, photopolymerization components, and the like.

  The solid content contained in the vehicle varies depending on the printing method, but may be, for example, 10% by weight or more, 15% by weight or more, or 20% by weight or more, and is 80% by weight or less, 60% by weight or less, 50% by weight. Or 30% by weight or less.

<Vehicle-Resin>
In embodiments of the present invention, known resins used for printing may be used as the vehicle. For example, a resin contained in oil-based ink or a resin contained in UV ink may be used.

  The resin may be a natural resin or a synthetic resin and may be a homopolymer or a copolymer. In order to ensure the viscosity of the oil-based ink, the resin is preferably solid. When the resin is used as a binder for UV ink, the resin preferably has a weight average molecular weight of about 1000 to about 3,000,000.

  Examples of natural resins include rosin, cocoon, shellac, and gilsonite.

  Synthetic resins include, for example, polyamide resin, two-component urethane resin, epoxy resin, acrylic resin, vinyl chloride resin, butyral resin, vinylidene chloride resin, styrene resin, rosin, phenol resin, modified alkyd resin, polyester resin, chlorine And maleic resins such as fluorinated polypropylene, petroleum resin, rosin-modified maleic resin, cyclized rubber, chlorinated rubber, and other synthetic resins and copolymers.

  Moreover, nitrocellulose and its derivative can also be mentioned as resin. Nitrocellulose is a nitrate ester of cellulose obtained by treating cellulose with a mixture of nitric acid and sulfuric acid, and is also called nitrified cotton or nitric acid fibrin. Nitrocellulose has different solubility in a solvent depending on the degree of nitrification, and has a different melt viscosity depending on the degree of polymerization.

  When the ink of the present invention is a water-based ink, the water-based ink may contain, for example, a water-soluble resin, a colloidal dispersion resin, an emulsion resin, and the like.

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

<Vehicle-Solvent>
Examples of the solvent include organic solvents, drying oils, semi-drying oils, mineral oils, water, and the like.

(Vehicle-solvent-organic solvent)
In consideration of various properties such as resin dissolving power, drying speed, viscosity, fluidity, wettability to printed material, presence of odor, influence on environment or human body, the ink of the present invention is suitable for printing. Known organic solvents used may be included. Further, in order to adjust various properties of the organic solvent, it is preferable to use not only one type of organic solvent but also a mixture of a plurality of types of organic solvents.

  Examples of the organic solvent include hydrocarbon solvents such as toluene, xylene, cyclohexane, n-hexane, n-heptane, and turpentine oil; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, acetic acid Ester solvents such as isobutyl, cellosolve acetate, acetic acid-ethylene glycol monomethyl ether, acetic acid-ethylene glycol monoethyl ether; alcohol solvents such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol; acetone, methyl ethyl ketone Ketone solvents such as methyl isobutyl ketone and cyclohexanone; methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethylene glycol monomethyl ether, ethylene glycol monoethyl ester Ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, ether-based solvents such as propylene glycol monomethyl ether acetate; other organic solvents such as tetrahydrofuran, and mixtures thereof.

(Vehicle-solvent-drying oil / semi-drying oil)
Dry oil and semi-dry oil are oil-based materials that are polymerized and hardened by air oxidation. Dry oil refers to vegetable oil or a component derived from vegetable oil having an iodine value of 130 or more. Semi-drying oil refers to vegetable oil or vegetable oil-derived component having an iodine value of 100 to 130.

  The drying oil or semi-drying oil listed above can be used alone or in combination of two or more.

(Vehicle-solvent-mineral oil)
Examples of the mineral oil include spindle oil, machine oil, white kerosene, and non-aromatic petroleum solvent. In particular, the mineral oil is preferably a non-aromatic petroleum solvent that is incompatible with water and has a boiling point of 180 ° C. or higher. The boiling point of the non-aromatic petroleum solvent is preferably 200 ° C. or higher. Examples of the non-aromatic petroleum solvent include n-dodecane mineral oil.

(Vehicle-solvent-water)
Water is an essential component of water-based ink. Water can form an aqueous dispersion together with a photochromic glitter pigment, optionally with a resin, an organic solvent, a drying oil, a semi-drying oil, a mineral oil, a photopolymerization component, a colorant, an auxiliary agent, and the like.

  Examples of water used as a water-based ink vehicle 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.

  The water content relative to the total amount of the solvent in the ink of the present invention may be 50% by weight or more, or 70% by weight or more in consideration of the balance of performance required for the water-based ink. It may be up to 85% by weight or 85% by weight.

<Vehicle-Photopolymerization component>
When used in the present invention, the photopolymerization component includes a monomer, an oligomer, a photopolymerization initiator, and the like.

(Vehicle-photopolymerization component-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 inks. 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.

  Among these, a compound having compatibility with a resin and having a highly lipophilic ethylenically unsaturated bond is preferable, for example, a compound having an ethylenically unsaturated bond having a long-chain alkyl group having 6 to 24 carbon atoms, A compound having an ethylenically unsaturated bond modified with polybutylene glycol, a compound having an ethylenically unsaturated bond modified with vegetable oil, and the like are preferable.

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

<Adjuvant>
The ink of the present invention may contain known auxiliary agents used in printing, such as dispersants, crosslinking agents, drying accelerators, waxes, extender pigments, and other additives.

<Auxiliary agent-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 photochromic glitter pigment and optionally the colorant by the vehicle component, or adsorbs the photochromic glitter pigment and optionally the colorant to the vehicle component and / or the ink. It can be used to prevent reagglomeration of the photochromic glitter pigment dispersed therein and optionally the colorant.

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

  A low molecular weight dispersant is a low molecular weight substance having a photochromic glitter pigment and optionally a portion having a high orientation or adsorptivity to a colorant, and a portion having a high affinity with a vehicle. be called.

  A polymeric dispersant is a high molecular weight material having a photochromic glitter pigment and optionally an anchor group adsorbed on the surface of the 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 perform multi-point adsorption with a photochromic glitter pigment and optionally a colorant. In addition, since the polymer dispersant has a higher barrier group than the low molecular dispersant, the dispersion stability of the photochromic glitter pigment and optionally the colorant is improved.

  The pigment derivative can be 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.

  A coupling agent is a material that adsorbs or chemically bonds to the surface of the photochromic glitter pigment and optionally the colorant to improve the adhesion between the photochromic glitter pigment and optionally the colorant and the vehicle. Examples of the coupling agent include silane coupling agents and titanate coupling agents.

  A 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 binds to the photochromic glitter pigment and optionally the colorant, and the organic functional group has affinity or reactivity with the vehicle component, the silane coupling agent is a photochromic glitter pigment and optionally The adhesion between the colorant and the vehicle component can be improved.

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

  In general, since titanate coupling agents have low solubility in water, it is preferable to use titanate coupling agents by dissolving them in an organic solvent.

<Auxiliary agent-crosslinking agent>
A crosslinker can be added to the vehicle to crosslink or gel the resin described above. 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.

<Auxiliary agent-Drying accelerator>
The drying accelerator is an auxiliary agent that accelerates drying by oxidative polymerization of the vehicle component. Specifically, the drying accelerator can promote curing of the surface and the inside of the ink film. As the drying accelerator, for example, a metal salt of an organic carboxylic acid, a metal salt of an inorganic acid, or the like can be used alone or in combination.

<Auxiliary agent-wax>
Wax is an auxiliary agent for preventing the printed surface from being scratched. Specifically, the wax can impart properties such as friction resistance, anti-blocking properties, slipperiness, and anti-scratch properties to the surface of the ink coating. The ink of the present invention may contain a known wax used for printing.

  Examples of the wax include natural waxes such as carnauba wax, wax, lanolin, montan wax, paraffin wax, microcrystalline wax; Fischer-Trops wax, polyethylene wax, polypropylene wax, polytetrafluoroethylene wax, polyamide wax, silicone compound Synthetic waxes such as; fluorinated products of synthetic waxes.

<Auxiliary agent-extender pigment>
The extender pigment is a pigment used for adjusting the viscosity of the ink, and has a low refractive index and a low coloring power. Accordingly, extender pigments are 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.

<Auxiliary agent-Antifoaming agent>
An antifoaming agent is an auxiliary agent used to suppress the generation of bubbles in the ink or reduce the bubbles generated in the ink. For example, antifoaming agents can be used during ink production, storage, circulation, transfer or printing.

  Further, 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, in order to suppress foaming of the water-based ink, it is preferable to add an antifoaming agent to 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.

<Auxiliary agent-Leveling agent>
A leveling agent is an additive which, when added to an ink, reduces the surface tension of the ink and improves the surface smoothness of the coating film. Examples of the leveling agent include silicone polymers, polyacrylate polymers, and polyvinyl ether polymers. Any polymer can be used to improve the leveling properties of the ink.

<Auxiliary agent-Other additives>
If desired, the ink of the present invention may contain a polymerization inhibitor such as phenothiazine, t-butylhydroxytoluene, etc .; a drying inhibitor; an antioxidant; a leveling aid; an anti-set-off agent; or a surfactant. It's okay.

<Colorant>
The colorant is a component that adds color to the ink. The ink of the present invention may contain a known colorant used for printing in addition to the photochromic glitter pigment. Examples of the colorant include inorganic pigments, organic pigments, dyes, organic pigments for toners, and the like.

  Furthermore, in addition to the photochromic glitter pigment and 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.

  Since the ink of the present invention can provide photochromic properties and glitter only with a single photochromic glitter pigment, the amount of the pigment contained in the ink can be made relatively small. As a result, other anti-counterfeiting materials, hue pigments, and the like can be further combined to provide a high anti-counterfeiting effect.

<Method for producing photochromic glitter ink>
In one embodiment of the method for producing the ink of the present invention, the ink can be obtained by mixing and dispersing optional components such as an auxiliary agent and a coloring agent in addition to the photochromic glitter pigment and the vehicle. it can. The mixing and dispersion of each component can be performed by a mixer such as a single-screw mixer and a twin-screw mixer;

  In this embodiment, the oil-based ink, UV ink, water-based ink or oil-based / UV combined ink of the present invention may be formed. When forming oil-based and UV combined inks, a photochromic glitter pigment, solvent and resin are mixed to obtain a mixture, to which a photopolymerizable monomer or oligomer is added and, if desired, additional vehicle, adjuvant or coloring An ink mill base is obtained by adding the agent and kneading and dispersing with a dispersing machine such as a bead mill or a three-roll mill. Furthermore, the oil-based / UV combined ink of the present invention can be obtained by adding a photopolymerization initiator to the mill base for ink and adding other materials as desired.

<Printed matter and printing method>
The photochromic glitter ink of the present invention can provide a printed matter having a printing part by being printed on a substrate. Therefore, the printed matter has a printed part printed with the ink of the present invention on the substrate.

  As the substrate, a paper substrate such as fine paper, coated paper, art paper, cast coated paper, foil paper, recycled paper, impregnated paper, variable information paper, etc .; film substrate such as polyester film, polyolefin film, Polystyrene film, vinyl chloride film, polyimide film, variable information film or the like; or a cloth substrate such as woven cloth or non-woven cloth may be used. The printed matter may be banknotes, securities, passports, official documents, tickets, cash vouchers, cards, labels for authenticity determination, and the like.

  Using the ink of the present invention, a printed matter can be obtained by a general printing method such as silk screen printing, gravure printing, intaglio printing, offset printing, letterpress printing, ink jet printing, flexographic printing and the like. Among these printing methods, silk screen printing, gravure printing, flexographic printing, or intaglio printing is preferable.

  In the case of printing by gravure printing or flexographic printing, since the film thickness formed per printing is relatively thin, it is preferable to overprint the ink of the present invention on the substrate by printing a plurality of times. In this respect, silk screen printing or intaglio printing, in which the printing film thickness is relatively thick, is preferable.

  Since the printing part printed with the ink of the present invention has not only glitter but also photochromic properties, the color changes when irradiated with ultraviolet rays or the like. For example, by irradiating the printed matter with ultraviolet rays, it is possible to determine whether the printed matter is a printed matter printed with the ink of the present invention.

  FIG. 1A illustrates a printed matter of the present invention, and FIG. 1B illustrates a printed matter using a normal glitter ink. The printed matter 100 of the present invention including the printed portion 10 with photochromic glitter ink changes color at the place 10 a irradiated with ultraviolet rays 2, but the printed matter 100 including only the printed portion 20 with ordinary glittering ink emits ultraviolet rays 2. Does not change color when irradiated.

  FIG. 2 exemplifies a printed matter 100 including a printing portion 10 using a photochromic glitter ink according to a preferred embodiment of the present invention. Here, the printing part 10 using photochromic glittering ink and the printing part 20 using ordinary glittering ink are indistinguishable visually, and printing with photochromic glittering ink discolored by irradiating with ultraviolet rays 2 is performed. Part 10a appears as a character.

  The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

<Production examples of each pigment>
Pigment for ink of Example 1:
Bright pigment with blue interference color (titanium mica) Flamenco (trademark) Blue 620C (mica / anatase type titanium oxide = 45/55 wt%) (BASF) 98.0 g and iron oxide fine particles IPJ-226G (average particle diameter) 0.07 μm) (Toda Kogyo Co., Ltd.) 2.0 g was stirred and mixed, and then baked at 850 ° C. for 2 hours using an electric furnace to obtain a pigment for ink of Example 1.

Pigment for ink of Example 2:
The iron oxide fine particles in Example 1 were changed to IPF-409H (average particle size 0.11 μm) (Toda Kogyo Co., Ltd.) to obtain a pigment for ink of Example 2.

Pigment for ink of Example 3:
The iron oxide fine particles in Example 1 were changed to LL-100P (average particle size 0.7 μm) (Titanium Industry Co., Ltd.) to obtain a pigment for ink of Example 3.

Pigment for ink of Example 4:
The iron oxide fine particles in Example 1 were changed to iron oxide fine particles having an average particle diameter of 1.5 μm (High-Purity Chemical Laboratory Co., Ltd.) to obtain the ink pigment of Example 4.

Pigment for ink of Comparative Example 1:
Only the titanium mica used in Example 1 without containing iron oxide fine particles was used as the pigment for the ink of Comparative Example 1.

Pigment for ink of Comparative Example 2:
A commonly used mica-titanium-based glitter pigment PEARL-GLAZE (trademark) MRB-100RF (mica / rutile titanium oxide) (Nippon Koken Kogyo Co., Ltd.) was used as a pigment for the ink of Comparative Example 2. .

<Examples of ink production>
20 parts by weight of a solvent containing xylene (vinyl standard solvent, Jujo Chemical Co., Ltd.) is added to 80 parts by weight of vinyl silk printing medium (vinyl ink H-type halftone, Jujo Chemical Co., Ltd.), and a mixer (Pony Mixer Co., Ltd.). The vehicle was obtained by stirring at Inoue Seisakusho.

  Further, 3 parts of a mixture of a silicone antifoaming agent (JA-750X, Jujo Chemical Co., Ltd.) and a silicone leveling agent (JA-200, Jujo Chemical Co., Ltd.) was added to the vehicle.

  80 parts by weight of this vehicle (solid content: about 20% by weight) and 20 parts by weight of the above-mentioned pigments were mixed to obtain silk screen printing inks of Examples 1-4 and Comparative Examples 1-2.

<Evaluation of photochromic properties>
The silk screen printing inks of Examples 1 to 4 and Comparative Examples 1 to 2 were applied to a 100 mesh silk screen printing plate (80 mm × 80 mm solid pattern), a rubber squeegee (9 mm × 50 mm × 200 mm, Teikoku Ink Manufacturing Co., Ltd.) and Using a silk printing stand, printing was performed on Kent paper (hiding ratio measurement paper, Motofuji).

This was dried at room temperature and then placed in the dark for 12 hours to obtain a sample of each printed matter. Immediately after taking out from the dark place, using a spectrocolorimeter Spectroeye (GretagMacbeth), the Lab value of each sample was measured, and the E value before ultraviolet irradiation was obtained. Similarly, each sample taken out from the dark place was irradiated with ultraviolet light having an intensity of 5 mW / cm ² from the closest distance for 0 to 90 seconds, and the Lab value of each sample was measured using a spectrocolorimeter Spectroeye (GretagMacbeth). Were measured to obtain E values at each irradiation time. The E value of each sample before ultraviolet irradiation was set as a reference E value, and the difference from the E value after ultraviolet irradiation was ΔE. In addition, in order to measure the intensity | strength using the ultraviolet lamp UVGL-25 (Funakoshi Co., Ltd.) with a wavelength of 365 nm as a light source, the ultraviolet intensity meter YK-35UV (LUTRON ELECTRONIC ENTERPRISE) was used.

  Table 1 shows the measured values of the printed materials with the inks of Examples 1 to 4 and Comparative Examples 1 to 2 before ultraviolet irradiation and 90 seconds after ultraviolet irradiation. Also, the transition of ΔE with respect to the ultraviolet irradiation time is shown in FIG.

  In Examples 1 to 4, when the ultraviolet rays were irradiated, the color change was large, and ΔE indicating a photochromic effect was high. On the other hand, in Comparative Examples 1 and 2, there was almost no color change.

  Further, from FIG. 3, when attention is paid to the response speed, it has been found that, for example, the ultraviolet irradiation time necessary for ΔE to be 5 varies greatly depending on the particle size of the photochromic activator. When considering use as a forgery prevention technique, since it is possible to determine authenticity instantly, it is preferable that the light (ultraviolet ray) response speed is high, and the inks of Examples 1 and 2 are particularly suitable for the application. I understand that. Moreover, since these inks use the inorganic pigment, they have high weather resistance.

<Evaluation of appearance (brightness)>
Comparative Example 1 (no activator), Example 1 (activator average particle size 0.07 μm), Example 3 (activator average particle size 0.7 μm), and Example 4 (activator average particle size) 1. Using each pigment used in 1.50 μm), make a coated material that can be evaluated in the same way as a printed material, and what kind of glitter it has by measuring the reflectance between 400 nm and 700 nm Evaluation was performed.

  2 g of each pigment and 8 g of clear lacquer vinyl chloride CH (solid content 25% by weight, Fujikura Applied Chemical Co., Ltd.) are mixed, and an applicator is used so that the dry film thickness is 10 μm. ). After placing it in the dark at room temperature for 12 hours, it was measured using a spectrometer (U-4000 spectrophotometer, Hitachi High-Technologies Corporation).

  Comparative Example 1 (no activator), Example 1 (activator average particle size 0.07 μm), Example 3 (activator average particle size 0.7 μm), and Example 4 (activator average particle size) For each pigment used in 1.50 μm), the result of the reflectance between 400 nm and 700 nm measured by coating on a white portion of Kent paper is shown in FIG. Similarly, FIG. 5 shows the results when the measurement was performed by coating the black background portion of Kent paper. In all of these examples, the glitter itself was present.

  As is clear from these results, the larger the average particle size of the activator, the lower the reflectance at 400 nm to 500 nm. Further, in FIG. 5, the pigment used in Example 1 and Comparative Example 1 has an average reflectance of 50% or more or exceeding 55% at 400 nm to 500 nm. Furthermore, in the pigment used in Example 1 and Comparative Example 1, the average reflectance at 600 nm to 650 nm is 45% or less or 40% or less. When the coated material was actually observed visually, the larger the average particle diameter was, the brighter the redness was.

  Moreover, the smaller the average particle size, the higher the reflectivity was as that of titanium mica containing no activator. Particularly, the pigment used in the ink of Example 1 and the pigment used in the ink of Comparative Example 1 have very similar reflectance waveforms. Since printed matter printed using such a pigment is indistinguishable in appearance, is the anti-counterfeiting provided by using the ink of the present invention and the mica titanium pigment used in producing the pigment? It is possible to easily give a printed matter that is difficult to understand.

  For example, when a part of the ink is printed with the ink of Example 1 or 2 and printed with the ink of Comparative Example 1 in the adjacent place, only a part of the glittering portion as shown in FIG. A printed matter exhibiting photochromic properties can also be obtained.

DESCRIPTION OF SYMBOLS 1 Base material 2 Light source 10 Printing part by photochromic glittering ink 10a Printing part in which photochromic effect appears 20 Printing part by normal glittering ink 100 Printed matter

Claims (10)

  A photochromic glittering ink comprising a glittering pigment having a photochromic property and a vehicle.   The photochromic glitter pigment is supported on mica and titanium mica including a titanium oxide-containing layer covering the mica, and on the surface of the mica and / or inside or on the surface of the titanium oxide-containing layer. The ink according to claim 1, comprising a photochromic activator.   The photochromic activator comprises a metal or metal compound selected from the group consisting of iron, chromium, copper, nickel, manganese, cobalt, and molybdenum, and oxides, nitrides, halides, and salts thereof. Item 3. The ink according to Item 2.   The ink according to claim 2 or 3, wherein the photochromic activator contains iron oxide.   The ink according to any one of claims 2 to 4, wherein an average particle size of the photochromic activator is less than 0.7 µm.   The ink according to claim 5, wherein the photochromic activator is iron oxide fine particles having an average particle diameter of 0.2 μm or less. When the ink containing 20 parts by weight of the pigment and 80 parts by weight of the vehicle having a solid content of 20% by weight is printed on a white background of Kent paper using a 100 mesh silk screen printing plate, a rubber squeegee and a silk printing stand. The E value measured after being placed in a dark place for 12 hours and the E value after being taken out after being placed in a dark place for 12 hours and irradiated with ultraviolet rays having a wavelength of 365 nm at an intensity of 5 mW / cm ² for 10 seconds from the closest distance. The ink according to any one of claims 1 to 6, wherein ΔE which is a difference indicates 3 or more.   The ink according to any one of claims 1 to 7, which is used for preventing forgery.   The printed matter provided with the glittering printing part printed with the ink as described in any one of Claims 1-8 on a base material.   The printed matter according to claim 9, which is a bill, a securities, an official document, a ticket, a cash voucher, a card, or a label for authenticity determination.