Ozone detection ink composition, ozone indicator, and printed material

Abstract

To provide an ink composition for detecting ozone and an ozone indicator, which are capable of suppressing discoloration due to hydrogen peroxide gas.SOLUTION: There is provided an ink composition for detecting ozone containing a discoloration dye, a solvent, and a discoloration accelerator, further containing at least one selected from the group consisting of an alkylphenol resin, a terpene phenol resin, and nitrocellulose.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an ozone-detecting ink composition, an ozone indicator, and a printed matter.

Background Art

[0002] Ozone has an excellent sterilizing effect and is used for sterilization or disinfection of instruments and the like, or for sterilization, disinfection, or deodorization in a special atmosphere such as a hospital operating room. On the other hand, since ozone is extremely toxic and there is concern about its influence on the human body, there is a limit to the concentration used. In addition, in photochemical smog forecasting, the concentration of oxidants in the atmosphere is an important factor.

[0003] For this reason, various detection methods have been developed to monitor the ozone concentration. In Patent Document 1, an ozone indicator has been proposed as a means capable of easily detecting the presence of ozone.

[0004] However, the above ozone indicator has a problem that it also reacts and discolors with respect to hydrogen peroxide gas, which is used for sterilization in the same manner as ozone gas. Therefore, in the ozone indicator disclosed in Patent Document 1, there is a concern that even if sterilization with ozone gas is not performed, if hydrogen peroxide gas is present, it may be erroneously recognized that sterilization with ozone gas has been carried out. In addition, in a sterilizer having sterilization steps for both ozone gas and hydrogen peroxide gas, it is impossible to determine which gas caused the discoloration.

[0005] Thus, there is an urgent need for an ozone indicator that can more accurately determine the implementation of a sterilization operation with ozone gas.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

[0007] In view of the above circumstances, the object of the present invention is to provide an ozone detection ink composition and an ozone indicator in which discoloration caused by hydrogen peroxide gas is suppressed. [Means for solving the problem]

[0008] The inventors diligently conducted research to solve the above problems and found that discoloration caused by hydrogen peroxide gas can be suppressed by using an ozone detection ink composition containing at least one selected from the group consisting of alkylphenol resin, terpene phenol resin, and nitrocellulose. Based on this finding, the inventors conducted further research and completed the present invention.

[0009] In other words, the present invention provides the following ozone detection ink composition, ozone indicator, and printed material. Section 1. An ozone detection ink composition comprising a color-changing dye, a solvent, and a color-changing accelerator, Furthermore, an ozone detection ink composition characterized by containing at least one selected from the group consisting of alkylphenol resin, terpene phenol resin, and nitrocellulose. Section 2. The ozone detection ink composition according to item 1, wherein the color change accelerator comprises hydrophobic silica. Section 3. The ozone detection ink composition according to claim 1 or 2, wherein the total amount of the alkylphenol resin, the terpene phenol resin, and the nitrocellulose in 100% by mass of the ozone detection ink composition is 0.01 to 15% by mass. Section 4. An ozone detection ink composition according to any one of items 1 to 3, further comprising a non-discoloring dye. Section 5. An ozone indicator having a color-changing layer on a substrate containing the ozone detection ink composition described in any of items 1 to 4. Section 6. The ozone indicator according to item 5, further comprising a non-discoloring layer. Section 7. The ozone indicator according to item 5 or 6, further comprising an overcoat layer. Section 8. A printed material having a printed layer containing an ozone detection ink composition as described in any of items 1 to 4. [Effects of the Invention]

[0010] The ozone detection ink composition or ozone indicator according to the present invention, as described above, suppresses discoloration caused by hydrogen peroxide and can detect ozone gas more selectively. [Brief explanation of the drawing]

[0011] [Figure 1] (a) A schematic cross-sectional view of an embodiment of the protective structure for the discoloration layer. (b)(c) A schematic top view of an embodiment of the protective structure for the discoloration layer. [Figure 2] (a) A schematic cross-sectional view of another embodiment of the protective structure for the discoloration layer. (b) A schematic top view of another embodiment of the protective structure for the discoloration layer. [Figure 3] An explanatory diagram of an embodiment having a half-cut. [Figure 4] Diagram illustrating another embodiment having a half-cut. [Modes for carrying out the invention]

[0012] (1. Ink composition for ozone detection) The ozone detection ink composition of the present invention comprises a color-changing dye, a solvent, and a color-changing accelerator. In addition, the ozone detection ink composition of the present invention comprises at least one selected from the group consisting of alkylphenol resin, terpene phenol resin, and nitrocellulose.

[0013] (1.1. Discoloration Pigments) As the discoloring dye, known dyes employed in ozone-detecting ink compositions can be widely used without particular limitation. Specifically, methine-based, anthraquinone-based, oxazine-based, azo-based, thiazine-based, and triarylmethane-based dyes can be used. These may be used alone or in combination of two or more. However, among these, it is preferable to use methine-based dyes.

[0014] As the methine-based dye, any dye having a methine group may be used. Therefore, in the present invention, polymethine-based dyes, cyanine-based dyes, etc. are also included in the methine-based dyes. These can be appropriately adopted from known or commercially available methine - based dyes. Specifically, examples include C.I.Basic Red 12, C.I.Basic Red 13, C.I.Basic Red 14, C.I.Basic Red 15, C.I.Basic Red 27, C.I.Basic Red 35, C.I.Basic Red 36, C.I.Basic Red 37, C.I.Basic Red 45, C.I.Basic Red 48, C.I.Basic Yellow 11, C.I.Basic Yellow 12, C.I.Basic Yellow 13, C.I.Basic Yellow 14, C.I.Basic Yellow 21, C.I.Basic Yellow 22, C.I.Basic Yellow 23, C.I.Basic Yellow 24, C.I.Basic Violet 7, C.I.Basic Violet 15, C.I.Basic Violet 16, C.I.Basic Violet 20, C.I.Basic Violet 21, C.I.Basic Violet 39, C.I.Basic Blue 62, C.I.Basic Blue 63, etc. These can be used singly or in two or more kinds.

[0015] As the anthraquinone-based dye, it is not limited as long as it has an anthraquinone as the basic skeleton, and known anthraquinone-based disperse dyes and the like can also be used. Particularly, an anthraquinone-based dye having an amino group is preferable. More preferably, it is an anthraquinone-based dye having at least one kind of amino group selected from a primary amino group and a secondary amino group. In this case, each amino group may have two or more, and these may be the same or different from each other.

[0016] More specifically, for example, 1,4-diaminoanthraquinone (C.I.Disperse Violet 1), 1-amino-4-hydroxy-2-methylaminoanthraquinone (C.I.Disperse Red 4), 1-amino-4-methylaminoanthraquinone (C.I.Disperse Violet 4), 1,4-diamino-2-methoxyanthraquinone (C.I.Disperse Red 11), 1-amino-2-methylanthraquinone (C.I.Disperse Orange 11), 1-amino-4-hydroxyanthraquinone (C.I.Disperse Red 15), 1,4,5,8-tetraaminoanthraquinone (C.I.Disperse Blue 1), 1,4-diamino-5-nitroanthraquinone (C.I.Disperse Violet 8), etc. can be mentioned (the content in parentheses is the Color Index name).

[0017] Other dyes known as CISolvent Blue 14, CISolvent Blue 35, CISolvent Blue 63, CISolvent Violet 13, CISolvent Violet 14, CISolvent Red 52, CISolvent Red 114, CIVat Blue 21, CIVat Blue 30, CIVat Violet 15, CIVat Violet 17, CIVat Red 19, CIVat Red 28, CIAcid Blue 23, CIAcid Blue 80, CIAcid Violet 43, CIAcid Violet 48, CIAcid Red 81, CIAcid Red 83, CIReactive Blue 4, CIReactive Blue 19, CIDisperse Blue 7, etc., can also be used.

[0018] The oxazine-based dyes are not particularly limited as long as they have at least one oxazine ring as shown in formulas (I) to (III) below. For example, monooxazine-based dyes having one oxazine ring, dioxazine-based dyes having two oxazine rings, etc., are also included.

[0019] [ka]

[0020] Furthermore, any of the following can be used as the oxazine-based dye: a basic dye having at least one substituted or unsubstituted amino group as a chromatophore, or a chromium mordant having an OH group, COOH group, or the like as a substituent.

[0021] These oxazine dyes can be used individually or in combination of two or more. These can be publicly known or commercially available. More specifically, it is desirable to use oxazine dyes such as CI Basic Blue 3, CI Basic Blue 12, CI Basic Blue 6, CI Basic Blue 10, and CI Basic Blue 96, indicated by their color index names. CI Basic Blue 3 is particularly preferable.

[0022] Azo dyes are not limited to those having an azo group -N=N- as a chromophore. Examples include monoazo dyes, polyazo dyes, metal complex azo dyes, stilbene azo dyes, and thiazole azo dyes. More specifically, examples using color index names include CISolvent Red 1, CISolvent Red 3, CISolvent Red 23, CDisperse Red 13, CDisperse Red 52, CDisperse Violet 24, CDisperse Blue 44, CDisperse Red 58, CDisperse Red 88, CDisperse Yellow 23, CDisperse Orange 1, CDisperse Orange 5, and CISolvent Red 167:1. These can be used individually or in combination of two or more.

[0023] The thiazine-based dyes are not particularly limited and can be selected from publicly known or commercially available options. Examples include CIBasic Blue 9, CIBasic Blue 25, CIBasic Blue 24, CIBasic Blue 17, CIBasic Green 5, and CISolvent Blue 8. These can be used individually or in combination of two or more.

[0024] The triarylmethane dyes are not particularly limited, and known or commercially available dyes can be used. For example, CIBasic Blue 1, CIBasic Blue 26, CIBasic Blue 5, CIBasic Blue 8, CIBasic Green 1, CIBasic Red 9, CIBasic Violet 12, CIBasic Violet 14, CIBasic Violet 3, CISolvent Green 15, CISolvent Violet 8, etc. These can be used individually or in combination of two or more. Among these triarylmethane dyes, CISolvent Violet 8, CIBasic Green 1, CIBasic Red 9, CIBasic Blue 1, etc. can be suitably used.

[0025] The content of the color-changing dye in the ozone detection ink composition of the present invention is preferably 0.01 to 10% by mass, and more preferably 0.01 to 5% by mass, based on 100% by mass of the composition. By setting the content of the color-changing dye to 0.01% by mass or more, it becomes easier to confirm the color change of the indicator due to exposure to ozone.

[0026] (1.2. Solvents) The solvent is not particularly limited as long as it can dissolve the above-mentioned dye and binder resin, etc., and examples include water, alcohol or polyhydric alcohol-based, ether-based, ketone-based, and glycol ether-based solvents. These solvents can be appropriately selected according to the solubility of the color-changing dye, non-color-changing dye, color-changing accelerator, and oil-soluble resin used, and it is preferable that they have a suitable drying rate. Water, alcohol, glycol ether-based solvents are preferred as the above-mentioned solvents, and glycol ether-based solvents are particularly preferred. The above-mentioned solvents can be used one or more of the above-mentioned solvents.

[0027] The solvent content can be appropriately determined depending on the type of color-changing dye, non-color-changing dye, color-changing accelerator, and oil-soluble resin used, and is not particularly limited. It is preferably 30 to 99% by mass, and more preferably 40 to 95% by mass, of 100% by mass of the ozone detection ink composition. By setting the solvent content to 30% to 99% by mass or less, a composition with appropriate viscosity can be obtained, and the good printability of the composition can be obtained. The total amount of solids of each component in the entire composition is the amount obtained by subtracting the total amount of solvent from the total amount of the composition. In other words, the total amount of solids of each component in the entire composition is preferably 1 to 70% by mass, and more preferably 5 to 60% by mass, of 100% by mass of the composition of the present invention.

[0028] (1.3. Discoloration Accelerator) Examples of discoloration accelerators include surfactants (nonionic surfactants and / or cationic surfactants) and oxygen-containing additives. Such discoloration accelerators can be those disclosed in Japanese Patent Application Publication No. 2015-205995, for example, and are not particularly limited.

[0029] However, the color change accelerator used in the ozone detection ink composition of the present invention is preferably one that has a color change accelerating effect when exposed to ozone, and hydrophobic silica is particularly preferred.

[0030] A wide range of known hydrophobic silica can be used, and there are no particular limitations. Furthermore, hydrophobic silica may include silica powder that has been treated to make it hydrophobic with a hydrophobic agent.

[0031] Examples of hydrophobic agents that can be used include silicone oil, modified silicone oil, silicone resin, halosilane, silazane, and alkoxysilane.

[0032] Hydrophobic silica can also be readily used in general-purpose products available on the market. Examples of such products include Nipsil® SS-10, SS-40, SS-50 and SS-100 (Tosoh Silica Co., Ltd.), AEROSIL® R972, RX200 and RY200 (Nippon Aerosil Co., Ltd.), SIPERNAT® D10, D13 and D17 (Evonik Japan Co., Ltd.), TS-530, TS-610, TS-720 (Cabot Carbon Co., Ltd.), AEROSIL R202, R805 and R812 (Evonik Japan Co., Ltd.), REOLOSIL® MT-10, DM-10 and DM-20S (Tokuyama Corporation), and SYLOPHOBIC® 100, 702, 505 and 603 (Fuji Silicia Chemical Co., Ltd.).

[0033] Among these, it is preferable to use hydrophobic silica that has been hydrophobized with, for example, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysine, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, hexamethyldisilazane, etc. Among these, it is more preferable to use hydrophobic silica that has been hydrophobized with dimethyldichlorosilane.

[0034] The non-surface area of ​​the hydrophobic silica is 30 to 200 m². 2 A weight of 70-150 m is preferred. 2 Hydrophobic silica of / g is more preferable. The hydrophobic silicas mentioned above may be used individually or in combination of two or more types.

[0035] The amount of such discoloration accelerator used is preferably 0.1 to 30% by mass, and more preferably 1.0 to 20% by mass, per 100% by mass of the ozone detection ink composition of the present invention. By using 0.1% by mass or more of the discoloration accelerator in 100% by mass of the composition, the detection sensitivity of ozone can be improved. Furthermore, in order to obtain good fixation to the substrate when printing the composition of the present invention onto the substrate, it is preferable that the content of the discoloration accelerator in 100% by mass of the composition be 30% by mass or less.

[0036] (1.4. Alkylphenol resins, terpene phenol resins, and nitrocellulose) The composition of the present invention comprises an alkylphenol resin, a terpene phenol resin, or nitrocellulose. The inventors have found that alkylphenol resins, terpene phenol resins, and nitrocellulose have the effect of suppressing discoloration of ozone detection ink compositions caused by hydrogen peroxide gas. If alkylphenol resins, terpene phenol resins, or nitrocellulose are not included, discoloration caused by hydrogen peroxide gas will progress.

[0037] A wide range of known alkylphenol resins can be used, and there are no particular limitations. Specifically, examples include "Tamanol 1010R," "Tamanol 100S," "Tamanol 200N," "Tamanol 510," "Tamanol 521," "Tamanol 526," "Tamanol 586," and "Tamanol 7509" (all from Arakawa Chemical Industries, Ltd.), and "PR2500," "PR1501," and "PR1140" (all from Showa Denko Materials Co., Ltd.). These may be used individually or in combination of two or more.

[0038] However, among those mentioned above, by using a novolac-type alkylphenol resin, and more preferably a novolac-type alkylphenol resin with a softening point of 75 to 145°C, discoloration caused by hydrogen peroxide gas can be significantly suppressed. Examples of such alkylphenol resins include "Tamanol 100S", "Tamanol 200N", "Tamanol 510", and "Tamanol 7509".

[0039] A wide range of known terpene phenol resins can be used, and there are no particular limitations. Specifically, examples include "Tamanol 803L" and "Tamanol 901" (both from Arakawa Chemical Industries, Ltd.), "YP-90", "YP-90L", "YS Polystar S145", "YS Polystar #2100", "YS Polystar #2115", "YS Polystar #2130", "YS Polystar T80", "YS Polystar T100", "YS Polystar T115", "YS Polystar T130", "YS Polystar T145", "Mighty Ace G125", and "Mighty Ace G150" (all from Yasuhara Chemical Co., Ltd.). These may be used individually or in combination of two or more.

[0040] Furthermore, a wide range of known nitrocelluloses can be used, and there are no particular limitations. However, among the nitrocelluloses classified by combining nitrogen content L, H and symbols as specified in JIS-K6703 (1995), it is preferable to use H1 / 2, H1 / 4, H1 / 8, L1 / 8, L1 / 4, or L1 / 2. More specifically, as an example of H1 / 2 nitrocellulose, RS1 / 2 manufactured by KCNC Corporation can be given. These may be used individually or in combination of two or more.

[0041] Alkylphenol resins, terpene phenol resins, and nitrocellulose may be used individually or in combination of multiple types. In particular, using novolac-type alkylphenol resins or terpene phenol resins can yield a composition with excellent heat resistance. Whether using only one type or multiple types in combination, the total amount of alkylphenol resins, terpene phenol resins, and nitrocellulose used is preferably 0.01 to 15% by mass, and more preferably 1.0 to 10.0% by mass, per 100% by mass of the composition of the present invention.

[0042] (1.5. Binder resin) The composition of the present invention may optionally contain a binder resin. A wide range of known resins used in ink compositions for writing, printing, etc., can be used as the binder resin. Examples include maleic acid resins, ketone resins, polyvinyl butyral resins, cellulose resins (excluding nitrocellulose resins), acrylic resins, phenolic resins (excluding alkylphenol resins and terpene phenol resins), styrene maleic acid resins, styrene acrylic acid resins, polyester resins, polyamide resins, polyacrylonitrile resins, polyimide resins, polyvinylpyrrolidone resins, polyacrylamide resins, polyvinylimidazole resins, polyethyleneimine resins, amino resins, and the like. These may be used individually or in combination of two or more.

[0043] The binder resin content can be appropriately determined depending on the type of binder resin used, the type of color-changing pigment used, etc., but generally it is preferable to have about 0.5 to 50% by mass, more preferably about 1 to 35% by mass, and even more preferably 1 to 20% by mass, per 100% by mass of the ozone detection ink composition. By including 0.5% by mass or more of binder resin, sufficient fixation can be obtained when printing the ink composition of the present invention. Furthermore, by setting the amount of binder resin to 50% by mass or less, good handling properties can be obtained without the viscosity of the composition becoming excessive.

[0044] (1.6. Non-discoloring pigments) The composition of the present invention may further contain a non-color-changing dye.

[0045] In this specification, a non-color-changing pigment is defined as a pigment that does not fade or become colorless, or undergo any or almost no change in hue or lightness, due to ozone. Non-color-changing pigments are not particularly limited and include, for example, pigments and dyes. Examples of pigments include azo, phthalocyanine, perylene, and quinacridone pigments. Examples of dyes include azo, quinone, cyanine, phthalocyanine, and indigo dyes. Among these, the use of phthalocyanine dyes is preferred. From the viewpoint of visibility after discoloration, it is preferable to select a complementary color of the color-changing pigment. The non-color-changing pigment can be used one or more types.

[0046] When a non-color-changing dye is included, the color-changing and non-color-changing dyes are uniformly mixed in the composition, so the composition will no longer be colorless. For example, if the color-changing dye in the composition is blue and the non-color-changing dye is yellow, an indicator using this composition will initially be green and change to yellow over time. Furthermore, when a non-color-changing dye is included, it is preferable that the color of the indicator after color change is the color of the non-color-changing dye.

[0047] When a non-discoloring dye is added, a dispersion of about 10% by mass of the non-discoloring dye may be used. From the viewpoint of improving visibility, the content of the non-discoloring dye in 100% by mass of the ozone detection ink composition of the present invention is preferably 0.5 to 30% by mass, and more preferably 0.5 to 15% by mass.

[0048] (1.7. Additives) The composition of the present invention may further optionally contain additives, provided that they do not impair its effects or purpose. The additives are not particularly limited and include, for example, leveling agents, thickeners, and dispersants.

[0049] The leveling agent is not particularly limited, and examples include silicone oil.

[0050] Preferably, the thickening agent is one that can impart a thickening effect to the composition of the present invention and improve its applicability. Examples of thickening agents include silicate minerals and silicate compounds.

[0051] The dispersant is not particularly limited and includes, for example, polymeric dispersants (e.g., Solspers 41000, Solspers 45000, Solspers 54000, Solspers 66000 (all manufactured by Lubrizol)), surfactants, etc.

[0052] When adding the above-mentioned additives, the total content is not particularly limited, but it is preferably 0.01 to 10% by mass, and more preferably 0.01 to 5% by mass, of 100% by mass of the ozone detection ink composition of the present invention.

[0053] (2. Method for producing an ink composition for ozone detection) The method for preparing the composition of the present invention is not particularly limited, and for example, it can be prepared by mixing and stirring the above components by known methods.

[0054] (3. Ozone Indicator) The present invention further includes an invention relating to an ozone indicator for detecting exposure to ozone. The indicator has a color-changing layer comprising a substrate and an ozone-detecting ink composition, and optionally further comprises a non-color-changing layer, an overcoat layer, an adhesive layer, and a protective structure for the color-changing layer.

[0055] (3.1. Base material) The substrate is not particularly limited as long as it can form and support the discoloration layer. For example, metal or alloy materials (aluminum foil, stainless steel foil, tin foil, tin foil, etc.), plastics (polyester (various polyesters such as polyethylene terephthalate), cellophane, acetylcellulose, ethylcellulose, polyethylene, polypropylene, polyvinyl chloride, hydrochloric acid rubber, polystyrene, polycarbonate, polyvinyl alcohol, polyvinyl fluoride, polyamide, polyfluoroethylene, etc., films or molded articles), fibers (paper, wood materials, nonwoven fabrics, woven fabrics, other fiber sheets), inorganic materials (ceramics, glass, concrete, gypsum, etc.), and composite materials thereof can be used. The size of the substrate (length, width, thickness, etc.) can be set appropriately depending on the type of indicator.

[0056] (3.2. Discolored layer) The discoloration layer is formed from the composition of the present invention. Methods for forming the layer include, for example, forming a coating film of the composition of the present invention on a substrate. Specifically, it is preferable to form the discoloration layer by applying the composition of the present invention to a substrate and then drying it.

[0057] The method for applying the composition of the present invention onto a substrate is not particularly limited, and for example, known coating methods such as spin coating, slit coating, spray coating, and dip coating; known printing methods such as silkscreen printing, gravure printing, offset printing, letterpress printing, and flexographic printing can be used. In the present invention, the concept of coating also includes concepts other than coating, such as printing and immersion.

[0058] After applying the composition of the present invention, it is preferable to dry the coating film. The drying temperature is not particularly limited, but is preferably around 60 to 100°C.

[0059] Furthermore, since the discoloration layer is formed by applying the composition of the present invention onto a substrate and then drying it, there are no or very few solvents derived from the composition in the discoloration layer. The thickness of the discoloration layer in the indicator of the present invention is not particularly limited, but from the viewpoint of visibility and handling of printed materials, it is preferably about 500 nm to 2 mm, and more preferably about 1 to 100 μm.

[0060] (3.3. Non-discolored layer) The indicator of the present invention may also have a non-discoloring layer as a base layer to enhance the visibility of the discolored layer. The non-discoloring layer is not particularly limited as long as it does not affect the reaction between ozone and the discoloring pigment in the discolored layer, and can be formed by a composition containing pigments and / or dyes.

[0061] Examples of pigments include azo, phthalocyanine, perylene, and quinacridone pigments. Examples of dyes include azo, quinone, cyanine, phthalocyanine, and indigo dyes.

[0062] The composition for the non-discoloring layer may contain oil-soluble resins, fillers, solvents, etc., as needed. Examples of oil-soluble resins, fillers, and solvents include those described above, and each can be used individually or in combination of two or more.

[0063] The method for forming the non-discoloring layer is not particularly limited, and known coating methods, printing methods, etc., similar to those used for the discoloring layer, can be used. Furthermore, the thickness of the non-discoloring layer can be appropriately set depending on the type of indicator.

[0064] In the present invention, the discoloration layer and the non-discoloration layer may be combined in any way. For example, the discoloration layer and the non-discoloration layer may be formed so that the color difference between the discoloration layer and the non-discoloration layer can be identified only after the discoloration of the discoloration layer occurs, or they may be formed so that the color difference between the discoloration layer and the non-discoloration layer disappears only after the discoloration occurs. In the present invention, it is particularly preferable to form the discoloration layer and the non-discoloration layer so that the color difference between the discoloration layer and the non-discoloration layer can be identified only after the discoloration occurs.

[0065] To enable the identification of color differences, for example, the color-changing layer and the non-color-changing layer may be formed such that at least one of letters, patterns, and symbols appears only after the color-changing layer changes color. In this invention, the letters, patterns, and symbols encompass all information that indicates the color change. These letters, etc., may be designed appropriately according to the intended use.

[0066] Furthermore, the discolored layer and the non-discolored layer may be different colors before discoloration. Alternatively, they may be substantially the same color, and the color difference (contrast) between the discolored layer and the non-discolored layer may only become discernible after discoloration.

[0067] In the present invention, preferred embodiments of the layer configuration include, for example, (i) an indicator in which the discoloration layer is formed adjacent to one main surface of the substrate, and (ii) an indicator in which the non-discoloration layer and the discoloration layer are formed sequentially on the substrate, the non-discoloration layer being formed adjacent to the main surface of the substrate, and the discoloration layer being formed adjacent to the main surface of the non-discoloration layer.

[0068] (3.4. Overcoat layer) The indicator of the present invention may optionally have an overcoat layer. This overcoat layer is placed as the outermost layer of the indicator. Therefore, whether the substrate has only a discoloration layer or both a discoloration layer and a non-discoloration layer (for example, the layer configurations in (i) and (ii) above), the overcoat layer is formed adjacent to the discoloration layer and placed as the outermost layer of the indicator. By having this overcoat layer, it is possible to suppress direct contact of the discoloration layer of the indicator with the outside air and control the discoloration sensitivity of the indicator (further suppress the discoloration rate). Furthermore, the formation of the overcoat layer can also increase the coating strength of the discoloration layer.

[0069] The overcoat layer can be formed from a composition containing a resin. The resin is not particularly limited, but examples include those similar to the oil-soluble resins described above, and one or more types can be used. The thickness of the overcoat layer is not particularly limited, but from the viewpoint of handling printed materials, it is preferably about 500 nm to 2 mm, and more preferably about 1 to 100 μm.

[0070] The composition for the overcoat layer may contain solvents as needed. For example, the resin can be dissolved in a solvent before use. Examples of solvents include those mentioned above, and one or more types can be used.

[0071] The method for forming the overcoat layer is not particularly limited, and known coating methods, printing methods, etc., similar to those for the discoloration layer described above can be used.

[0072] (3.5. Adhesive layer) The indicator of the present invention may optionally have an adhesive layer on the back surface of the substrate (the side opposite to the surface where the discoloration layer is formed). By having an adhesive layer on the back surface of the substrate, the indicator of the present invention can be securely fixed to the object.

[0073] The components of the adhesive layer are not particularly limited, and examples include acrylic, urethane, and silicone-based materials. Furthermore, the thickness of the adhesive layer can be appropriately set depending on the type of indicator.

[0074] (3.6. Discoloration layer protection structure) The abrasion resistance of the discoloration layer described above is not necessarily high; for example, when stacking indicators together during storage, the discoloration layer may be damaged by friction. To avoid such damage to the discoloration layer, it is preferable to provide a discoloration layer protection structure.

[0075] As a first embodiment of such protective structure, it is preferable to provide a convex structure 11a with a height greater than or equal to the thickness of the discoloration layer (preferably 100% or more when the thickness of the discoloration layer is considered 100%; preferably 101% or more if the protective film described later is not provided), surrounding the discoloration layer 12 at one point (Figure 1(b)) or multiple points (Figure 1(c)), as shown in Figure 1, and further to provide a protective film 14 that adheres to the convex structure 11a and covers the discoloration layer 12. It is also preferable to provide a convex structure 11b, for example, a columnar structure, on top of the discoloration layer 12.

[0076] As a second embodiment of the discoloration layer protection structure, as shown in Figure 2, the convex structure 11a and the protective film 14 can be provided on the substrate 13 and the discoloration layer 12 via an adhesive layer 15. The adhesive layer can be made of, for example, glue or double-sided tape.

[0077] Here, as shown in Figures 2 and 3, a half-cut 16 is formed, and after removing the protective film 14 and the convex structure 11a (or only the protective film 14 as shown in Figure 4) from the indicator, the half-cut 16 is cut, and the removed portion is used as the indicator (Figures 3 and 4). By using the removed portion, excess materials such as adhesives are not brought into the sterilization device, and contamination inside the device can be prevented.

[0078] (4.Printed materials) The printed material of the present invention has a printed layer containing the ozone detection ink composition of the present invention. Examples of objects to which the composition of the present invention is printed include products that require product management. Products are not particularly limited, but examples include food products, pharmaceuticals, insecticides, dehumidifiers, deodorants, and other products with expiration dates.

[0079] If the composition of the present invention can be printed directly onto the product, it should be printed directly onto the product; if it cannot be printed directly onto the product, it should be printed on the product's outer packaging or the like.

[0080] Although embodiments of the present invention have been described above, the present invention is not limited in any way to these examples, and can be implemented in various forms without departing from the spirit of the invention. [Examples]

[0081] The embodiments of the present invention will be described in more detail below based on examples, but the present invention is not limited to these.

[0082] (Examples 1-22, Comparative Examples 1-4) Ozone detection ink compositions were prepared by mixing and stirring each raw material according to the compositions shown in the tables below (the unit of the amount of each component in the table is mass%). The obtained compositions were printed onto a polyethylene substrate using a screen printing machine, and the indicators were dried by leaving them in a constant temperature bath (70°C for 10 minutes).

[0083] (Color change confirmation test in response to ozone gas and hydrogen peroxide gas) The indicators for each example and comparative example were exposed to ozone gas and hydrogen peroxide gas. The treatment conditions were as follows: ozone gas was treated at a CT value (ozone gas concentration × exposure time) of 5,000 ppm·min, and hydrogen peroxide gas was treated at a CT value (hydrogen peroxide gas concentration × exposure time) of 50,000 ppm·min. The color change of the indicator after treatment was observed.

[0084] (Method for calculating color difference) The evaluation of indicator discoloration was performed by measuring the color tone of the indicator before and after treatment and calculating the color difference. Specifically, using a commercially available colorimeter, the color tone of each indicator was measured before and after treatment with ozone gas and hydrogen peroxide gas, thereby obtaining the values ​​of L* (representing lightness), a* (representing hue and saturation), and chromaticity a* and b* (representing hue and saturation) in the L*a*b* color space. Using these L*, a*, and b* values, the color difference ΔE*ab was calculated using the following formula (1). Formula 1

[0085] TIFF0007896858000002.tif8170

[0086] (Examples 1-7) When using methine-based dyes such as CI,Basic Red 14, anthraquinone-based dyes (CIDisperse Voilet 1), azo-based dyes (CIDisperse Red 58), or thiazine-based dyes (CIBasic Blue 9) as the color-changing pigments, and using tamanol 100S, a novolac-type alkylphenol resin, or nitrocellulose, RS1 / 2, the material changed color with ozone gas alone, but not with hydrogen peroxide gas (Table 1).

[0087] [Table 1]

[0088] (Examples 8-15) When using CI, Basic Red 14, a methine-based dye, as the color-changing pigment, and Tamanol 100S, a novolac-type alkylphenol resin, the color difference ΔE*ab for hydrogen peroxide gas was smaller than the color difference for ozone gas in the range of 0.01% to 10.0%, indicating that discoloration progressed less in response to hydrogen peroxide gas than to ozone gas. A larger ratio of the color difference ΔE*ab(O3) / ΔE*ab(H2O2) to the color difference for hydrogen peroxide gas ΔE*ab(O3) indicates a higher hydrogen peroxide suppression effect. Since a ratio of 3.4 or higher is generally visually discernible, it was evaluated as suppressing discoloration in response to hydrogen peroxide (△). A ratio of 4.1 or higher was evaluated as ○, and a ratio of 5.4 or higher was evaluated as ◎, indicating a remarkable effect (Table 2).

[0089] [Table 2]

[0090] (Examples 11, 16-19) The methine-based dye CI, Basic Red 14 was used as the color-changing pigment. Novolac-type alkylphenol resins such as Tamanol 100S and Tamanol 510, non-novolac-type alkylphenol resins such as Tamanol 526 and Tamanol 586, and the terpene phenol resin YP-90L were used. In all cases, the ΔE*ab(O3) / ΔE*ab(H2O2) ratio was 4.1 or higher (○ and ◎), indicating that no further color change occurred in response to hydrogen peroxide gas (Table 3).

[0091] (Heat resistance evaluation test) Using the indicators from Examples 11 and 16-19, untreated indicators were subjected to a heating test in a constant temperature bath at 130°C for 1 hour with ozone gas and hydrogen peroxide gas. The values ​​of L*, a*, and b* were measured before and after heating, and the color difference ΔE*ab was calculated. A color difference ΔE*ab of less than 20 was considered to indicate sufficient heat resistance. When novolac-type alkylphenol resin and terpene phenol resin were used, the color difference ΔE*ab before and after heating was small (20 or less), confirming good heat resistance.

[0092] [Table 3]

[0093] (Examples 20-22) Even when using CI,Basic Red 14, a methine-based dye, as the color-changing pigment, and using both Tamanol 100S, a novolac-type alkylphenol resin, and RS1 / 2, a nitrocellulose nitrate cotton, the ΔE*ab(O3) / ΔE*ab(H2O2) ratio was 5.4 or higher (◎), and no further color change occurred in response to hydrogen peroxide gas (Table 4).

[0094] [Table 4] [Explanation of Symbols]

[0095] 10 Indicators 11 Convex structure 11a Convex structure 11b Convex structure 12 Discolored layer 13 Base material 14 Protective film 15 Adhesive layer 16 Half Cut

Claims

1. An ozone detection ink composition comprising a color-changing dye, a solvent, and a color-changing accelerator, Furthermore, an ozone detection ink composition characterized by containing a novolac-type alkylphenol resin or a terpene phenol resin having a softening point of 75 to 145°C.

2. The ozone detection ink composition according to claim 1, wherein the color change accelerator contains hydrophobic silica.

3. The ozone detection ink composition according to claim 1 or 2, wherein the total amount of the novolac-type alkylphenol resin and the terpene phenol resin in 100% by mass of the ozone detection ink composition is 0.01 to 15% by mass.

4. The ozone detection ink composition according to claim 1 or 2, further comprising a non-discoloring dye.

5. An ozone indicator having a color-changing layer on a substrate containing the ozone detection ink composition described in claim 1 or 2.

6. The ozone indicator according to claim 5, further comprising a non-discoloring layer.

7. The ozone indicator according to claim 5, further comprising an overcoat layer.

8. A printed article having a printed layer containing the ozone detection ink composition according to claim 1 or 2.

Images