JP2018154730A - Ultraviolet-excitation fluorescence sheet and ultraviolet-excitation fluorescence ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultraviolet-excitation fluorescence sheet having excellent water resistance, print quality, and writing quality, using UV-C as an excitation source, and having excellent fluorescence properties, and an ultraviolet-excitation fluorescence ink, using UV-C as an excitation source, and having excellent fluorescence properties.SOLUTION: An ultraviolet-excitation fluorescence sheet has an inorganic substance powder A containing an inorganic phosphor that emits fluorescence having a peak in a wavelength of 400-700 nm, using UV-C in a wavelength of 200-280 nm as an excitation source and a thermoplastic resin. The inorganic phosphor contains calcium carbonate A of 90 mass% or more; the inorganic phosphor contains at least one or more kinds of metal selected from the group consisting of Ag, Al, Au, Bi, Cd, Cr, Cu, Ga, In, Mn, Mo, Pb, Sn, Sr, Ti, Tl, Zn, Zr, and rare earth metal of 0.1 ppm or more and 10 mass% or less; the calcium carbonate A contains calcite-type calcium carbonate of 90 mass% or more; and the inorganic phosphor has a volume average particle size Dof 0.1-50 μm.SELECTED DRAWING: None

Description

  The present invention relates to an ultraviolet excited fluorescent sheet and an ultraviolet excited fluorescent ink. The present invention relates to an ultraviolet-excited fluorescent sheet and an ultraviolet-excited fluorescent ink that generate fluorescence having a peak at a wavelength of 400 to 700 nm using ultraviolet light in a specific wavelength range, specifically, UV-C having a wavelength of 200 to 280 nm as an excitation source. About.

The market for environmentally friendly sheets that reduce the use of water and petroleum resources, such as paper that consumes less water and paper pulp, and plastics that reduce oil-derived components, is expected to expand.
As a sheet having excellent environmental properties capable of reducing the use of water and petroleum resources, a sheet containing an inorganic substance powder and a thermoplastic resin can be cited as a candidate (see Patent Document 1).
A sheet containing an inorganic substance powder and a thermoplastic resin is superior in water resistance as compared to a sheet prepared using water or paper pulp. In addition, it is expected to be excellent in printability and writing performance compared to plastic.
If such a sheet is difficult to confirm with visible light but has an identification function that can be visualized with special light, it can be expected to expand new fields of use, such as restricting unauthorized manufacturing in various fields (Patent Documents) 2).

General markings for confirmation by display can be easily duplicated and are insufficient for the regulation of unauthorized manufacturing. It can also cause physical or chemical damage and impair the appearance.
Although it is difficult to confirm with visible light, it is required to regulate unauthorized manufacturing by visualizing with special light. In general, it is also necessary to mark the product with a method that cannot be confirmed, and to take traceability of the product.
For such uses, for example, fluorescent whitening agents such as fluorescent whitening agents are used, but they are not intended for foods, but foods are marked with fluorescent whitening agents. Are restricted due to food hygiene problems. Marking in a way that is free of food sanitation problems will help expand the field of use.

  It is confirmed that the baked scallop shell pulverized powder generates fluorescence using UV-C as an excitation source, and a method for producing a phosphor using a scallop shell is proposed based on this finding (Patent Documents 3 to 5). reference).

Japanese Patent No. 5461614 Japanese Patent No. 3523067 JP 2004-359923 A Japanese Patent No. 5881964 JP 2013-201951 A

An object of this invention is to provide the ultraviolet excitation fluorescent sheet which is excellent in water resistance and the fluorescence characteristic which uses UV-C as an excitation source.
Another object of the present invention is to provide an ultraviolet-excited fluorescent ink having excellent fluorescence characteristics using UV-C as an excitation source.

  When producing an ultraviolet-excited fluorescent sheet containing a phosphor using a scallop shell fired body, the phosphor is mixed with the raw material for producing the sheet, or an ink containing the phosphor is prepared on the surface of the produced sheet. The phosphor is attached to the sheet surface by a method such as coating. It was clarified that the fluorescence characteristics deteriorated in any procedure.

In order to achieve the above object, the present invention provides an inorganic substance powder A and a thermoplastic resin containing an inorganic phosphor that emits fluorescence having a peak at a wavelength of 400 to 700 nm using UV-C having a wavelength of 200 to 280 nm as an excitation source. And
The inorganic phosphor contains 90% by mass or more of calcium carbonate A,
The inorganic phosphor is selected from the group consisting of Ag, Al, Au, Bi, Cd, Cr, Cu, Ga, In, Mn, Mo, Pb, Sn, Sr, Ti, Tl, Zn, Zr, and rare earth metals. Containing one or more metals of 0.1 ppm or more and 10% by mass or less,
The calcium carbonate A contains 90% by mass or more of calcite-type calcium carbonate,
The inorganic phosphor provides an ultraviolet-excited fluorescent sheet, wherein the volume average particle diameter D ₅₀ is 0.1 to ₅₀ μm.

  The inorganic phosphor may further contain 0.01% by mass or more in total of one or more elements selected from the group consisting of Fe, Na, Mg, P, S, and Sr. In this case, the content of the element is 10% by mass or less in total content with the metal.

  In the ultraviolet-excited fluorescent sheet of the present invention, the inorganic phosphor may contain 10% by mass or less of aragonite-type calcium carbonate.

  In the ultraviolet-excited fluorescent sheet of the present invention, the mass ratio of the inorganic substance powder A and the thermoplastic resin is preferably 45:55 to 82:18.

  In the ultraviolet-excited fluorescent sheet of the present invention, the inorganic substance powder A is one or more inorganic substance powders B selected from the group consisting of calcium carbonate B, clay, silica, titanium oxide, talc, kaolin, and aluminum hydroxide. May further be contained. In this case, the inorganic substance powder B is preferably 99.5% by mass or less in the inorganic substance powder A.

In the ultraviolet-excited fluorescent sheet of the present invention, the inorganic material powder B preferably has a volume average particle diameter D ₅₀ of 0.1 to 30 μm and a maximum particle diameter D _max of 50 μm or less.

  In the ultraviolet-excited fluorescent sheet of the present invention, the thermoplastic resin is an olefin resin such as polyethylene or polypropylene, a vinyl resin such as polystyrene or polyvinyl chloride, an acrylonitrile butadiene styrene (ABS) resin, a polyester resin such as polycarbonate or polyethylene terephthalate, One or more resins selected from the group consisting of methacrylic resins such as polymethyl methacrylate and fluororesins such as polytetrafluoroethylene are preferred.

  In the ultraviolet-excited fluorescent sheet of the present invention, the thermoplastic resin is more preferably one or more resins selected from the group consisting of polyethylene, polypropylene, polystyrene, and polyethylene terephthalate.

Further, the present invention uses 1 to 70% by mass of an inorganic phosphor that generates fluorescence having a peak at a wavelength of 400 to 700 nm using UV-C having a wavelength of 200 to 280 nm as an excitation source, and 30 to 99% by mass of a binder component. Contains,
The inorganic phosphor contains 90% by mass or more of calcium carbonate A,
The inorganic phosphor is selected from the group consisting of Ag, Al, Au, Bi, Cd, Cr, Cu, Ga, In, Mn, Mo, Pb, Sn, Sr, Ti, Tl, Zn, Zr, and rare earth metals. Containing one or more metals of 0.1 ppm or more and 10% by mass or less,
The calcium carbonate A contains 90% by mass or more of calcite-type calcium carbonate,
The inorganic phosphor provides an ultraviolet-excited fluorescent ink characterized in that a volume average particle diameter D ₅₀ is 0.1 to 30 μm.

  In the ultraviolet-excited fluorescent ink of the present invention, the inorganic phosphor contains at least 0.01% by mass in total of one or more elements selected from the group consisting of Fe, Na, Mg, P, S, and Sr. May be. In this case, the content of the element is 10% by mass or less in terms of the total content with the metal.

  In the ultraviolet-excited fluorescent ink of the present invention, the binder component is preferably a resin to which food can be added.

The ultraviolet-excited fluorescent sheet of the present invention is excellent in water resistance and has good fluorescence characteristics using UV-C as an excitation source.
The ultraviolet-excited fluorescent ink of the present invention has good fluorescence characteristics using UV-C as an excitation source, and an ultraviolet-excited fluorescent sheet can be produced by applying it to the surface of a sheet containing a thermoplastic resin.
According to the ultraviolet-excited fluorescent sheet of the present invention, it is possible to provide a sheet, a packaging container, and a member that are difficult to replicate and that can be used for regulation of unauthorized manufacturing and that have excellent water resistance.

  Hereinafter, the ultraviolet-excited fluorescent sheet and the ultraviolet-excited fluorescent ink of the present invention will be described.

Ultraviolet-excited fluorescent sheet The ultraviolet-excited fluorescent sheet of the present invention has an inorganic substance powder A and a thermoplastic resin.

(Inorganic substance powder A)
The inorganic substance powder A includes a specific inorganic phosphor that generates fluorescence having a peak at a wavelength of 400 to 700 nm using UV-C having a wavelength of 200 to 280 nm as an excitation source. Hereinafter, when described as fluorescence in this specification, fluorescence having a peak at a wavelength of 400 to 700 nm is shown.

(Inorganic phosphor)
Said inorganic fluorescent substance contains the calcium carbonate A which makes a base material, and the metal which makes a luminescent center.

An inorganic phosphor using calcium carbonate A as a base material has little decrease in fluorescence over time.
In the inorganic phosphor, the content of calcium carbonate A is 90% by mass or more, preferably 95% by mass or more, and more preferably 98% by mass or more.

There are three types of calcium carbonate having different crystal structures, specifically, three types of crystal structures: cubic to spindle calcite type, needle to columnar aragonite type, and spherical vaterite type. Although calcium carbonate A has a calcite type of 90% by mass or more. Calcium carbonate A may contain 10% by mass or less of aragonite type in addition to calcite type.
The crystal structure of calcium carbonate can be confirmed with an X-ray diffraction apparatus. Typical peaks of calcite-type powder diffraction are as follows: PDF (Powder Diffraction File) # 66-867, lattice spacing (dÅ) 3.0361 (Miller index (104) plane), 1.8757 (Miller index (116)) Surface), 2.2851 (Miller index (113) surface).
On the other hand, typical peaks of Aragonite-type powder diffraction are lattice spacing (dÅ) 3.397 (Miller index (111) plane), 2.702 (Miller index (012) plane), 1 from PDF # 41-1475. 9774 (Miller index (113) plane).

  Examples of the metal forming the emission center include Ag, Al, Au, Bi, Cd, Cr, Cu, Ga, In, Mn, Mo, Pb, Sn, Sr, Ti, Tl, Zn, Zr, and rare earth metals. . These metals may contain only 1 type and may contain 2 or more types. Among these metals, Cu, Mn, Sn, Ce, Tb, Er, Eu, and Tb are preferable because the fluorescence intensity using UV-C as an excitation source becomes strong, and Cu and Mn are more preferable.

The content of the metal forming the emission center is 0.1 ppm or more. If the content of the metal forming the emission center is less than 0.1 ppm, the fluorescence intensity using UV-C as the excitation source will be significantly weakened.
The metal forming the emission center can be contained in an amount of 10% by mass or less. However, when using a fired scallop shell as the inorganic phosphor, it is possible to use a metal derived from scallop shell as the ultraviolet-excited fluorescent sheet of the present invention. It is preferable from the viewpoint of safety when used for foodstuffs and pharmaceutical containers and packaging. When a metal derived from a scallop shell is used, the content of the metal forming the luminescent center is approximately 1000 ppm or less.
The content of the metal forming the luminescent center is preferably 0.1 to 10,000 ppm, more preferably 0.1 to 1000 ppm, further preferably 0.1 to 500 ppm, and particularly preferably 0.5 to 300 ppm.

In addition to calcium oxide A and the metal forming the emission center, the inorganic phosphor in the present invention may contain an element that may contribute to improvement of fluorescence characteristics using UV-C as an excitation source. Such elements include Fe, Na, Mg, P, S and Sr. These elements may contain only 1 type and may contain 2 or more types.
When these elements are contained, the total content may be 0.01% by mass or more. When these elements are contained, the total content with the metal forming the emission center is set to 10% by mass or less.
The total content of these elements is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass, further preferably 0.01 to 2% by mass, and particularly preferably 0.01 to 1% by mass. It is preferable.

As will be described in detail later, the ultraviolet-excited fluorescent sheet is produced by a method such as mixing an inorganic phosphor with a raw material for producing the sheet, or applying and adhering ink containing the inorganic phosphor to the surface of the produced sheet. In either case, if the particle size of the inorganic phosphor is too large, the sheet surface will be uneven, and the fluorescent properties may be deteriorated due to surface wear due to friction. Therefore, the sheet surface is preferably excellent in smoothness. In addition, when it is desired to make the surface rough for a design reason, the surface may have unevenness. In the latter case, there is a possibility that inconveniences such as blocking of nozzles used for ink application and uneven printing may occur.
On the other hand, if the particle diameter of the inorganic phosphor is too small, there is a possibility that inconveniences such as a decrease in the fluorescence intensity and a deterioration in the dispersibility of the inorganic phosphor due to aggregation or the like may occur.
The inorganic phosphor in the present invention has a volume average particle diameter D ₅₀ of 0.1 to ₅₀ μm. In the inorganic phosphor in the present invention, D ₅₀ is preferably from 0.1 to 30 μm, more preferably from 0.1 to ₂₀ μm, further preferably from 0.1 to 15 μm, particularly preferably from 0.1 to 10 μm.

The inorganic phosphor in the present invention can be obtained by firing a powder obtained by pulverizing scallop shells under predetermined conditions. The powder obtained by pulverizing scallop shells is calcined under predetermined conditions to obtain calcium carbonate mainly having a calcite type crystal structure. Moreover, the powder which grind | pulverized the scallop shell contains the metal which makes the luminescent center mentioned above as a trace metal derived from a raw material, and the element which may contribute to the improvement of the fluorescence characteristic which uses UV-C as an excitation source. Therefore, it is possible to generate fluorescence using UV-C as an excitation source without adding these metals and elements. The content of these trace metals in the powder obtained by pulverizing scallop shells can be measured by inductively coupled plasma (ICP) emission spectroscopy, atomic absorption photometry, ion chromatography, or the like.
In addition, since scallop shells have been edible as an existing additive, it can be regarded as safe to eat when not added.

Preparation procedure of inorganic phosphor After firing unfired scallop shell, which is a raw material, primary heat treatment for carbonization and ashing of organic substrate is performed. Here, the primary heat treatment condition is suitably 400 to 600 ° C. in the atmosphere, and a heat treatment furnace such as a muffle furnace is used. Then, it cools to room temperature vicinity and grind | pulverizes using the electric mill etc. of a grind blade rotation type.
Next, the scallop shell as a raw material is fired to perform a secondary heat treatment for obtaining the inorganic phosphor in the present invention. Here, the secondary heat treatment condition is preferably 800 to 900 ° C. in a CO ₂ atmosphere. The secondary heat treatment is performed using a heat treatment furnace such as a gas replacement tubular furnace. Here, after placing the sample in a tubular furnace, the pressure in the furnace is once lowered to 10 Pa or less before heating, and then CO ₂ gas having a purity of 99.5% or more is introduced until the pressure reaches 0.1 MPa, followed by heat treatment. It is preferable to perform heat treatment after replacing the inside of the furnace with CO ₂ gas. Then, it cools to room temperature vicinity, a sample is grind | pulverized using an agate mortar, and it classifies with a sieve (pore diameter about 100 micrometers), and obtains an inorganic fluorescent substance.

Since the inorganic phosphor obtained by the above procedure generally has a volume average particle diameter D ₅₀ of more than ₅₀ μm, when used for producing an ultraviolet-excited fluorescent sheet, the volume average particle diameter D ₅₀ is 0.1 to ₅₀ μm. It is necessary to grind so that it becomes.

  When producing an ultraviolet-excited fluorescent sheet containing a phosphor using a scallop shell fired body, the phosphor is mixed with a raw material for producing the sheet, an ink containing the phosphor is applied to the surface of the produced sheet, etc. There is a method such as attaching the phosphor to the sheet surface by the above method. It has been clarified that when an ultraviolet-excited fluorescent sheet is produced by these methods, it must be produced so that the fluorescent properties of the phosphor are not deteriorated.

At the time of pulverization of the inorganic phosphor, the fluorescence characteristics of the inorganic phosphor are deteriorated due to distortions in the crystal lattice caused by mechanical stress, leading to a decrease in crystallinity, and impurities being mixed. Therefore, it is necessary to grind so that the crystal structure of the inorganic phosphor does not change.
Examples of such a pulverization method include a pulverization method mainly using peel pulverization. For example, a multi-ring medium type wet ultra-fine pulverizer or a wet jet mill is used.
Further, in the pulverization after the primary heat treatment, after the volume average particle diameter D ₅₀ was pulverized so that 0.1 to 50 [mu] m, by selecting the conditions and procedures during the secondary heat treatment, the volume average particle diameter D ₅₀ You may obtain 0.1-50 micrometers inorganic fluorescent substance.
It is necessary to pay attention to the following points when the inorganic phosphor is pulverized.
(1) Avoid acidic solvents that dissolve calcium carbonate.
(2) Avoid high temperatures where calcium carbonate changes to calcium oxide. When it exceeds 600 ° C, it gradually changes to calcium oxide.

The inorganic substance powder A may be entirely composed of an inorganic phosphor, but may contain components other than the inorganic phosphor as necessary. That is, one or more inorganic substance powders B selected from the group consisting of calcium carbonate B, clay, silica, titanium oxide, talc, kaolin, and aluminum hydroxide may be further contained. Here, the calcium carbonate B is different from the calcium carbonate A constituting the inorganic phosphor. The difference between the two is as described below. Calcium carbonate A shows what was produced in the preparation procedure of the said inorganic fluorescent substance. On the other hand, calcium carbonate B is other calcium carbonate, which may be light calcium carbonate or heavy calcium carbonate, or calcium carbonate not containing calcite type, derived from a shell not subjected to the secondary heat treatment as described above. Calcium carbonate may be used.
From the viewpoint of fluorescence characteristics, the inorganic phosphor content in the inorganic substance powder A is preferably 0.5% by mass or more, more preferably 5% by mass or more, further preferably 10% by mass or more, and 50% by mass. % Or more is particularly preferable.

When the inorganic substance powder A contains the inorganic substance powder B, the inorganic substance powder B preferably has a volume average particle diameter D ₅₀ of 0.1 to 30 m, more preferably 0.1 to 25 μm, 20 μm is more preferable, and 0.1 to 15 μm is particularly preferable.

(Thermoplastic resin)
The thermoplastic resin is not particularly limited, but is olefin resin such as polyethylene and polypropylene, vinyl resin such as polystyrene and polyvinyl chloride, acrylonitrile butadiene styrene (ABS) resin, polyester resin such as polycarbonate and polyethylene terephthalate, and polymethyl methacrylate. It is preferable that it is 1 or more types of resin selected from the group which consists of methacrylic resins, such as, and fluororesins, such as polytetrafluoroethylene.
More preferably, the thermoplastic resin is at least one resin selected from the group consisting of polyethylene, polypropylene, polystyrene, and polyethylene terephthalate.
The thermoplastic resin is a polyethylene resin, and more preferably 60% by mass or more of the polyethylene resin is a high-density polyethylene resin having a melt mass flow rate of 0.02 to 1.2 g / 10 min.
The thermoplastic resin is made of a high density polyethylene resin, and 50% by mass to 100% by mass of the high density polyethylene resin has a melt mass flow rate of 0.02 to 0.5 g / 10 min. It is particularly preferred that the remainder of has a melt mass flow rate of 0.5 to 1.2 g / 10 min.

  The mass ratio of the inorganic substance powder A and the thermoplastic resin in the ultraviolet-excited fluorescent sheet of the present invention is preferably 45:55 to 82:18.

  The ultraviolet-excited fluorescent sheet of the present invention may contain auxiliary agents such as a lubricant, a fluidity improver, a dispersant, an antioxidant, an ultraviolet absorber, and a stabilizer in addition to the inorganic substance powder A and the thermoplastic resin. . Such adjuvants may contain one or more selected from the group consisting of fatty acids, metal soaps, aliphatic amides, and aliphatic esters of alcohols. When it contains an adjuvant, it is preferably 0.05% by mass to 5.0% by mass based on 100% by mass of the total amount of the inorganic substance powder A and the thermoplastic resin.

(Procedure for UV-excited fluorescent sheet)
The ultraviolet-excited fluorescent sheet of the present invention can be produced by the following procedure.

An inorganic substance powder A, a thermoplastic resin, and an auxiliary agent to be added as necessary are prepared, and these raw materials are blended at a predetermined blending ratio. This is put into an extrusion molding machine equipped with a biaxial screw and kneaded, and then extruded by a T-die method through a die and brought into contact with a roll to be formed into a sheet. Or after kneading | mixing and shape | molding intermediate bodies, such as a sheet | seat, a pellet, flakes, and a bead, it may throw into another shaping | molding machine etc. and shape | mold into a sheet form. Thus, the obtained sheet | seat is extended | stretched to the vertical direction, a horizontal direction, or both directions as needed. The raw materials are kneaded at a temperature equal to or higher than the melting point of the thermoplastic resin. The forming into a sheet shape and the stretching performed as necessary are performed at a temperature equal to or lower than the melting point of the thermoplastic resin.
Also in these procedures, attention is paid to the points (1) and (2) described when the inorganic phosphor is pulverized.

  In the above procedure, the inorganic substance powder A containing the inorganic phosphor was used. However, using the inorganic substance powder not containing the inorganic phosphor, that is, the inorganic substance powder B, a sheet was obtained in the same procedure as described above. Then, an ultraviolet-excited fluorescent ink described later may be applied to the surface of the sheet to form an ultraviolet-excited fluorescent sheet.

  Since the ultraviolet light emitting sheet of the present invention is excellent in water resistance, it can be used in places where there is a possibility of contact with water, such as outdoors, underwater, and bathrooms. In addition, because it has printability and writing properties, for example, it is a substitute for paper (printed materials such as posters, catalogs, stickers, tags, clothes, banknotes, etc.) and plastics (car parts, electrical appliance parts, building materials, etc.) Can be used as

  In the case of using a scallop shell fired body as the inorganic phosphor, it can be used for containers for packaging foods, drugs, cosmetics, and the like that need attention, and can be quality controlled and distributed. Various foods such as fresh foods, fruits and vegetables, eggs, processed foods, instant foods, dried foods, liquid foods, foods for storage, etc. are the target foods. Data such as date, harvest time, production place, production place, producer, production process, product information, quality information, logo, name, barcode, alphanumeric symbol, document, special symbol, storage, measuring instrument, etc. When linked to marking, quality control and distribution management can be performed. These notations give reliability to the distribution form of the product as a reliable display method of the route.

(UV-excited fluorescent ink)
The ultraviolet-excited fluorescent ink of the present invention contains the above inorganic phosphor and a binder component.

The inorganic phosphor in the ultraviolet excited fluorescent ink is basically the same as the inorganic phosphor in the ultraviolet excited fluorescent sheet. However, D _{50 of the} inorganic phosphor is 0.1 to 30 μm, and preferably 0.1 to ₂₀ μm.

As the binder component in the ultraviolet-excited fluorescent ink, a resin can be used, but a resin to which food can be added is preferable. As such resins, shellac resins, dammar resins, and copal resins are easy to use because of their solubility in alcohol solvents. In addition, water-based resins may be used, and carboxymethylcellulose, methylcellulose, crystalline cellulose, gelatin, casein, soybean protein, gum arabic cyclodextrin, etc. may be used in whole or in part depending on the solvent, but are not limited thereto. .
Among these resins, shellac is mentioned as a preferable resin from various aptitudes. The shellac used in the present invention is preferably an alcohol-soluble resin. This shellac has a function of increasing the viscosity of the ink by dissolving in alcohol, and functions as a good binder for the printing medium. Shellac is also a resin of a type that dissolves in a water / alcohol mixed solvent, and this type of shellac is preferred for emphasizing stability on the alkali side.

  The ultraviolet-excited fluorescent ink of the present invention contains 1 to 70% by mass of an inorganic phosphor and 30 to 99% by mass of a binder component.

  The ultraviolet-excited fluorescent ink of the present invention contains a solvent in addition to the inorganic phosphor and the binder component. As the solvent, use of ethanol is advantageous in terms of drying property. The ethanol used as the solvent is preferably fermented ethanol for food or denatured ethanol.

  In the ultraviolet-excited fluorescent ink of the present invention, propylene glycol can be added as necessary in the roles of adjusting the drying of the ink and adjusting the viscosity of the ink. Propylene glycol also has an effect of adjusting permeation depending on the substrate. Propylene glycol can be used in the range of 0 to 30% by mass in the ink, and the amount of propylene glycol is appropriately adjusted by adjusting appropriate penetration and drying to the printing material.

  The ultraviolet-excited fluorescent ink of the present invention may contain an emulsifier such as glycerin fatty acid ester, sucrose fatty acid ester, and lecithin.

  The ultraviolet-excited fluorescent ink of the present invention can be produced by measuring the above components according to the prescription, mixing and stirring, and then filtering with a membrane filter or the like. Mixing and stirring can be carried out by a high-speed disperser or emulsifier in addition to a stirrer equipped with a normal blade.

  The method for applying the ultraviolet-excited fluorescent ink of the present invention to the object is not particularly limited, and various application means such as a wire bar coater may be used, or the ink may be applied by inkjet. In order to improve applicability, the surface of the object may be made hydrophilic. In this case, for example, the target may be hydrophilized by plasma etching.

  Since the ultraviolet-excited fluorescent ink of the present invention has good fluorescence characteristics using UV-C as an excitation source, when a scallop shell fired body is used as an inorganic phosphor, duplication is difficult and unauthorized production is restricted. As with foods, drugs, cosmetics, etc., foods that require attention can be provided.

The present invention will be further described below using examples.
(Production of inorganic phosphor)
After washing the unfired scallop shell as a raw material, primary heat treatment was performed for the purpose of carbonization and ashing of the organic substrate. Here, the primary heat treatment was performed at 500 ° C. for 2 hours in the atmosphere using an electric muffle furnace. Then, it cools to room temperature vicinity and grind | pulverizes using the electric mill of a grinding blade rotation type.
Next, the scallop shell as a raw material was fired, and a secondary heat treatment for obtaining the inorganic phosphor in the present invention was performed. The secondary heat treatment was performed using a gas displacement electric tubular furnace. Here, after putting the sample in a tubular furnace, the pressure in the furnace is once lowered to about 10 Pa before heating, and then CO ₂ gas having a purity of 99.5% or more is introduced until the pressure reaches 0.1 MPa (atmospheric pressure). did. When the inside of the furnace was replaced with CO ₂ gas, it was calcined at 875 ° C. for 1 hour in a CO ₂ atmosphere. Then, it cooled to near room temperature, the sample was grind | pulverized using the agate mortar, and classified with the sieve (opening diameter of about 100 micrometers), and the inorganic fluorescent substance A was obtained.

  The inorganic phosphor A obtained by the above procedure was pulverized by the following two methods.

(1) Pulverization was performed using a multi-ring medium type ultrafine pulverizer (manufactured by Nara Machinery Co., Ltd.). Pure water was used as a dispersion medium for the slurry, and the solid concentration was pulverized for 3 hours at 30% by mass to obtain an inorganic phosphor B having a volume average particle diameter D ₅₀ of 5 μm.

(2) Grinding was performed using a ball mill. Pure water was used as a dispersion medium for the slurry, zirconia balls were added at a solid concentration of 30% by mass, and the mixture was pulverized for 4 hours to obtain an inorganic phosphor C having a volume average particle diameter D ₅₀ of 5 μm.

Incidentally, the inorganic phosphor B, the volume average particle diameter D ₅₀ of C was measured by a laser diffraction type particle size distribution measuring method. Specifically, the following procedure was performed.
A laser diffraction / scattering type particle size distribution measuring device (manufactured by Microtrack, model: HR-A) was used. Pure water was used as the powder dispersion. When aggregation was observed in the powder, it was dispersed by applying ultrasonic waves. The measurement conditions were as follows: particle permeability was permeated, particle refractive index was 1.66, particle shape was non-spherical, measurement time was 30 seconds, and the volume average particle diameter D ₅₀ was obtained from the average data. .

The calcium carbonate content in the inorganic phosphors B and C obtained by the above procedure was quantified according to the purity test of JIS K8617 calcium carbonate (reagent). Specifically, the following procedure was performed.
A 1 g sample is weighed to the order of 0.1 mg with an electronic balance and dried at 105 ° C. for 2 hours with an atmospheric pressure constant temperature dryer. After allowing to cool to room temperature with a desiccator, 0.5 g from the dry residue is weighed to the order of 0.1 mg, put into a 500-mL volumetric flask, 3 ml of hydrochloric acid (2 + 1) is gradually added and dissolved, and water is added to the marked line. From there, 25 ml is accurately taken with a whole pipette, neutralized with potassium hydroxide solution (100 g / l), and further 12 ml of potassium hydroxide solution (100 g / l) is added. 2-hydroxy-1- (2′-hydroxy-4′-sulfo-1′-naphthylazo) -3-naphthoic acid (NN) diluted powder was added, and 0.01 mol / l ethylenediaminetetraacetic acid dihydrogen disodium dihydrogen dihydrate Titrate with product (EDTA2Na) solution. The end point is the point at which the liquid color changes from red to blue. In this case, 1 ml of 0.01 mol / l EDTA2Na solution corresponds to 1.0009 mg of CaCO ₃ . From the measurement results, the calcium carbonate (CaCO ₃ ) content (% by mass) in the inorganic phosphors B and C was calculated. The results are as follows.
Calcium carbonate content in inorganic phosphor B: 99.7% by mass
Calcium carbonate content in inorganic phosphor C: 99.7% by mass
In addition, the quantitative method described in the food additive official document can also be used for fixed_quantity | quantitative_assay of calcium carbonate content in inorganic fluorescent substance. In this case, after the sample is dried, about 1 g of the sample is accurately weighed and gradually added to 10 ml of hydrochloric acid (1 + 3) to dissolve, and water is added to make exactly 100 ml to prepare a test solution. Accurately measure 10 ml of the test solution, add 50 ml of water, add 10 ml of potassium hydroxide solution (1 + 9), leave it for about 1 minute, add about 0.1 g of NN indicator, and immediately titrate with 0.05 mol / l EDTA solution. To do. The end point is when the reddish purple color of the liquid completely disappears and becomes blue. In this case, 1 ml of 0.05 mol / l EDTA solution corresponds to 5.004 mg of CaCO ₃ .

The content of trace metals in the inorganic phosphors B and C obtained by the above procedure was measured by atomic absorption spectrophotometry, ICP emission analysis, and barium sulfate gravimetry.
Inorganic phosphor B
0.015% by mass of Na (atomic absorption photometry)
Mg 0.062 mass% (ICP emission spectrometry)
P 0.032 mass% (ICP emission spectrometry)
S 0.030 mass% (barium sulfate weight method)
Mn 6.5 ppm (atomic absorption photometry)
Fe 1.7ppm (ICP emission spectrometry)
Cu 0.36ppm (atomic absorption photometry)
Zn 1.7 ppm (atomic absorption photometry)
Sr 0.113 mass% (ICP emission spectrometry)
Inorganic phosphor C
0.011% by mass of Na (atomic absorption photometry)
Mg 0.057 mass% (ICP emission spectrometry)
P 0.029 mass% (ICP emission spectrometry)
S 0.033 mass% (barium sulfate weight method)
Mn 4.8 ppm (atomic absorption photometry)
Fe 1.9ppm (ICP emission spectrometry)
Cu 0.40ppm (atomic absorption photometry)
Zn 2.1ppm (atomic absorption photometry)
Sr 0.154 mass% (ICP emission spectrometry)

The crystal structure of calcium carbonate in the inorganic phosphors B and C obtained by the above procedure was qualitatively and quantified using X-ray diffraction. Specifically, the following procedure was performed.
The crystal structure of calcium carbonate was measured using an X-ray diffractometer (manufactured by JEOL Ltd., model: JDX-8020). As the X-ray generation conditions, a Cu tube was used, and a CuKα ray (tube voltage 40 kV, tube current 25 mA) was used. The measurement range was a 2θ range of 15 to 90 degrees and a condition of 0.02 degrees × 5 sec. The proportion of calcite-type calcium carbonate was automatically quantified from the X-ray diffraction spectrum using the attached analysis software (generally Rietveld analysis). As a result, about 99% of the calcite-type calcium carbonate in the inorganic phosphor A, the inorganic phosphor B was 93% by mass, and the inorganic phosphor C was 61% by mass. By grinding, the surface of calcium carbonate became amorphous and calcite-type components decreased.
Qualitative evaluation of the crystal structure of calcium carbonate in the inorganic phosphors B and C can also be performed by vibrational spectroscopy.

The fluorescence spectra of the inorganic phosphors A, B, and C were measured by the following procedure.
Using a spectrofluorometer (manufactured by JASCO Corporation, model: FP-6600), the sample was placed in a powder sample cell and measured. The excitation light wavelength was set to the peak wavelength of the excitation spectrum (around 250 nm), and a wavelength range of 300 to 800 nm was measured at a data acquisition width of 1 nm and a scanning speed of 100 nm / min. As a result, the fluorescence intensity of the fluorescence band having a peak at a wavelength of 570 to 590 nm (fluorescence band of a wavelength of 580 nm) was 80% or more of the inorganic phosphor A, whereas the inorganic phosphor C was It was deteriorated to 10% of the inorganic phosphor A.

Next, the ultraviolet excitation fluorescent sheet was produced in the following procedures using inorganic fluorescent substance B and C.
High-density polyethylene resin (Mel mass flowlay is 1 g / 10 min) and inorganic phosphor B or inorganic phosphor C at a mass ratio of 30:70, and magnesium stearate is based on a total amount of 100 mass%. Mix to 3% by mass. The obtained mixed powder was kneaded at a temperature of 220 ° C. with a small biaxial kneading extruder, and then directly molded to prepare an ultraviolet-excited fluorescent sheet (average thickness: 200 μm). When the obtained UV-excited fluorescent sheet was irradiated with a UV-C UV lamp, the UV-excited fluorescent sheet produced using the inorganic phosphor B was clearly confirmed to emit white light. It was confirmed that the ultraviolet-excited fluorescent sheet produced using the inorganic phosphor C was very weak in its entirety and emitted white. The produced ultraviolet-excited fluorescent sheet was cut into an appropriate size, and the fluorescence intensity of a fluorescent band having a wavelength of 580 nm was confirmed using a fluorescence spectrophotometer in the same manner as described above. The excitation fluorescent sheet had an intensity of 1/5 or less of the ultraviolet excitation fluorescent sheet produced using the inorganic phosphor B.

Next, ultraviolet-excited fluorescent ink was prepared using inorganic phosphors B and C according to the following procedure.
Raw materials containing 30% by mass of inorganic phosphor B or inorganic phosphor C, 42% by mass of 50% shellac alcohol solution, 27% by mass of 95% alcohol and 1% by mass of glycerin fatty acid ester were mixed and dispersed. It filtered with a 20 micrometers filter and prepared the ultraviolet excitation fluorescent ink. The obtained UV-excited fluorescent ink is coated on a PET film with a coating rod so as to have a thickness of 20 μm, and is irradiated with a UV-C UV lamp. In the example, sufficient light emission was confirmed visually, but weak light emission was confirmed in the ultraviolet-excited fluorescent ink produced using the inorganic phosphor C. When the fluorescence intensity of the fluorescent band having a wavelength of 580 nm was confirmed using a fluorescence spectrophotometer in the same procedure as described above, the ultraviolet-excited fluorescent ink produced using the inorganic phosphor C was produced using the inorganic phosphor B. The intensity was 1/5 or less of the ultraviolet-excited fluorescent ink.

Claims (11)

Having an inorganic substance powder A containing an inorganic phosphor that generates fluorescence having a peak at a wavelength of 400 to 700 nm, and a thermoplastic resin, using UV-C of a wavelength of 200 to 280 nm as an excitation source;
The inorganic phosphor contains 90% by mass or more of calcium carbonate A,
The inorganic phosphor is selected from the group consisting of Ag, Al, Au, Bi, Cd, Cr, Cu, Ga, In, Mn, Mo, Pb, Sn, Sr, Ti, Tl, Zn, Zr, and rare earth metals. Containing at least 0.1 ppm and not more than 10% by weight of one or more metals
The calcium carbonate A contains 90% by mass or more of calcite-type calcium carbonate,
The inorganic phosphor is an ultraviolet-excited fluorescent sheet, wherein the volume average particle diameter D ₅₀ is 0.1 to ₅₀ μm.   The inorganic phosphor further contains one or more elements selected from the group consisting of Fe, Na, Mg, P, S, and Sr in a total of 0.01% by mass or more, and includes the element and the metal. The ultraviolet-excited fluorescent sheet according to claim 1, wherein the total content is 10% by mass or less.   The ultraviolet-excited fluorescent sheet according to claim 1 or 2, wherein the inorganic phosphor contains 10% by mass or less of aragonite-type calcium carbonate.   The ultraviolet-excited fluorescent sheet according to any one of claims 1 to 3, wherein a mass ratio of the inorganic substance powder A and the thermoplastic resin is 45:55 to 82:18.   The inorganic substance powder A further contains one or more kinds of inorganic substance powder B selected from the group consisting of calcium carbonate B, clay, silica, titanium oxide, talc, kaolin, and aluminum hydroxide, and the inorganic substance powder The ultraviolet-excited fluorescent sheet according to any one of claims 1 to 4, wherein B is 99.5% by mass or less in the inorganic substance powder A. 6. The ultraviolet-excited fluorescent sheet according to claim 1, wherein the inorganic substance powder B has a volume average particle diameter D ₅₀ of 0.1 to 30 μm and a maximum particle diameter D _max of 50 μm or less.   The thermoplastic resin is an olefin resin such as polyethylene or polypropylene, a vinyl resin such as polystyrene or polyvinyl chloride, an acrylonitrile butadiene styrene (ABS) resin, a polyester resin such as polycarbonate or polyethylene terephthalate, a methacryl resin such as polymethyl methacrylate, The ultraviolet-excited fluorescent sheet according to claim 1, which is at least one resin selected from the group consisting of fluorine resins such as polytetrafluoroethylene.   The ultraviolet-excited fluorescent sheet according to claim 7, wherein the thermoplastic resin is at least one resin selected from the group consisting of polyethylene, polypropylene, polystyrene, and polyethylene terephthalate. Using UV-C having a wavelength of 200 to 280 nm as an excitation source, containing 1 to 70% by mass of an inorganic phosphor that generates fluorescence having a peak at a wavelength of 400 to 700 nm, and 30 to 99% by mass of a binder component,
The inorganic phosphor contains 90% by mass or more of calcium carbonate A,
The inorganic phosphor is selected from the group consisting of Ag, Al, Au, Bi, Cd, Cr, Cu, Ga, In, Mn, Mo, Pb, Sn, Sr, Ti, Tl, Zn, Zr, and rare earth metals. Containing at least 0.1 ppm and not more than 10% by weight of one or more metals
The calcium carbonate A contains 90% by mass or more of calcite-type calcium carbonate,
The inorganic phosphor has a volume average particle diameter D ₅₀ of 0.1 to 30 μm, and is an ultraviolet excitation fluorescent ink.   The inorganic phosphor further contains one or more elements selected from the group consisting of Fe, Na, Mg, P, S, and Sr in a total of 0.01% by mass or more, and includes the element and the metal. The ultraviolet-excited fluorescent ink according to claim 9, which has a total content of 10% by mass or less.   The ultraviolet-excited fluorescent ink according to claim 9 or 10, wherein the binder component is a resin to which food can be added.