JPH11140360A - Ink composition for ozone detection and ozone indicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink compsn. which can detect ozone easily and conveniently without fail by compounding an anthraquinone dye having at least one kind of amino group selected from prim- and sec-amino groups with a cationic surfactant of a quaternary ammonium salt type. SOLUTION: Alkyltrimethylammonium salts and dialkyldimethylammonium salts are esp. pref. cationic surfactants of quaternary ammonium salt types. Though this compsn. can be used as it is, it may be supported by a substrate, by coating or impregnation, before being used. This compsn. is suitably used as a color changing layer of an ozone indicator. The indicator is prepd. by forming a color changing layer comprising the ink compsn. for ozone detection and a color nonchanging layer comprising an ink not changing in color by ozone on a substrate so that at least a part of the color changing layer is exposed to an ozone atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition for detecting ozone and an ozone indicator using the composition.

[0002]

2. Description of the Related Art Ozone is used for disinfection and disinfection of foods, instruments and the like, or for disinfection, disinfection and deodorization in a certain atmosphere such as an operating room of a hospital because of its excellent disinfecting property. . On the other hand, ozone is extremely toxic and affects the human body, so its allowable concentration is limited. On the other hand, in photochemical smog forecasting, the concentration of oxidants in the atmosphere is an important factor.

[0003] In order to monitor the ozone concentration, various detection methods have been developed. As a conventional ozone (oxidant) detection method, color change due to the reaction of the following formula (1) is mainly used.

[0004]

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As a detection method utilizing this principle, for example, a method of introducing a gas containing ozone into a potassium iodide solution and optically measuring the degree of discoloration in proportion to the amount of iodine generated by a colorimeter, or Conventionally, a method using a simple type of detector tube, a method using potassium iodide-starch paper, and the like have been known.

However, in the above-mentioned optical measurement method, the apparatus itself is very expensive, and there are problems in terms of cost and operation, particularly when measuring a plurality of locations. Also, detector tubes are simpler than optical methods, but still expensive.
Moreover, it is necessary to manually or automatically aspirate the oxidant every time the measurement is performed. Potassium iodide-starch paper is inexpensive and simple, but it is practically unusable for detecting low concentrations of oxidants below a few hundred ppb due to low sensitivity.

[0007] In this regard, an ozone detecting element containing a triphenylmethane-based leuco compound and an acid stabilizer has been proposed (JP-A-62-291564). In this method, ozone is detected by utilizing a coloring phenomenon caused by oxidation of a dye leuco body. According to this technique, it is possible to detect ozone in a dry state without requiring an operation such as wetting with moisture.

[0008]

However, in the above-mentioned prior art, the triphenylmethane-based leuco itself is easily oxidized in the air, so that it is necessary to add a specific amount of acid and stabilizer as essential components. There is still room for improvement in terms of simplicity, storage stability (stability), accuracy and the like.

As described above, in any of the conventional techniques, a method for easily and reliably detecting ozone has not yet been developed.

Accordingly, it is a main object of the present invention to provide a material capable of detecting ozone more easily and reliably.

[0011]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the problems of the prior art, and as a result, have found that an ink composition containing a specific component has a function of effectively detecting ozone. Finally, the present invention has been completed.

That is, the present invention provides an ink composition for detecting ozone containing an anthraquinone dye having at least one primary amino group and a secondary amino group and a quaternary ammonium salt type cationic surfactant. It relates to things.

Further, the present invention has at least one color-change layer made of the above-described ink composition for detecting ozone on a substrate, and at least one non-color-change layer made of an ink that does not change color with ozone, and The present invention relates to an ozone indicator, wherein a color-changing layer and a non-color-changing layer are formed so that a part or the whole of at least one color-changing layer is exposed to an ozone atmosphere.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The anthraquinone dye used in the present invention is not particularly limited as long as it has anthraquinone as a basic skeleton and has at least one amino group of a primary amino group and a secondary amino group. A system disperse dye or the like can also be used. The amino group may have two or more, and these may be the same or different from each other. Such anthraquinone dyes include, for example, 1,4-
Diaminoanthraquinone (CIDisperse Violet 1),
1-amino-4-hydroxy-2-methoxyanthraquinone (CIDisperse Red 4), 1-amino-4-methylaminoanthraquinone (CIDisperse Violet 4),
1,4-diamino-2-methoxyanthraquinone (CI
Disperse Red 11), 1-amino-2-methylanthraquinone (CIDisperseOrange 11), 1-amino-4-
Hydroxyanthraquinone (CIDisperse Red15),
1,4,5,8-tetraaminoanthraquinone (CIDi
sperse Blue 1), 1,4-diamino-5-nitroanthraquinone (CIDisperse Violet 8) and the like (dye numbers in parentheses). In addition, CISol
vent Blue 14, CISolvent Blue 63, CISolvent Viol
et 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, CIAci
d Blue 80, CIAcid Violet 43, CIAcid Violet48,
CIAcid Red 81, CIAcid Red 83, CIReactive Blu
Dyes known as e4, CIReactiveBlue 19, CIDisperse Blue 7, etc. can also be used. These anthraquinone dyes can be used alone or in combination of two or more. Among these anthraquinone dyes, CI Disperse Blue 7, CI Disperse Violet 1 and the like are preferable. In the present invention, by changing the type (molecular structure, etc.) of these anthraquinone dyes,
It is also possible to control the detection sensitivity of ozone.

The quaternary ammonium salt type cationic surfactant (hereinafter also simply referred to as "cationic surfactant") is not particularly limited, and usually an alkyl ammonium salt can be used. Can also be used. These can be used alone or in combination of two or more. In the present invention, a better discoloration effect can be obtained by using these cationic surfactants in combination with the anthraquinone dye.

Among these cationic surfactants, alkyltrimethylammonium salts, dialkyldimethylammonium salts and the like are preferred. More specifically, coconut alkyltrimethylammonium chloride, tallowalkyltrimethylammonium chloride, behenyltrimethylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, lauryltrimethylammonium chloride, octadecyltrimethylammonium chloride, dioctyldimethylammonium chloride, dioctyldimethylammonium chloride Examples thereof include stearyl dimethyl ammonium and alkylbenzyl dimethyl ammonium chloride, and lauryl trimethyl ammonium chloride is particularly preferable.

The ink composition of the present invention can be used as long as it contains the above-mentioned anthraquinone dye and a cationic surfactant. If necessary, a known binder such as a resin binder, an extender and a solvent may be used. Components used in the ink composition can be appropriately blended.

The resin binder may be appropriately selected according to the type of the base material and the like. For example, a known resin component used in an ink composition for writing or printing can be used as it is. Specifically, for example, maleic acid resin,
Examples include amide resins, ketone resins, alkylphenol resins, rosin-modified resins, polyvinyl butyral, polyvinyl pyrrolidone, and cellulose resins.

The extender is not particularly restricted but includes, for example, bentonite, activated clay, aluminum oxide, silica gel and the like. In addition, a material known as a known extender can be used. Among them, porous ones are preferred, and silica gel is more preferred. By adding these extenders, the detection sensitivity can be adjusted mainly.

The solvent which can be used in the present invention is usually
Any solvent can be used as long as it is a solvent used for ink compositions for printing, writing and the like. For example, various solvents such as alcohols, esters, ethers, ketones, and hydrocarbons can be used, and they may be appropriately selected according to the solubility of the dye and resin binder to be used.

The proportion when all of these are blended may be appropriately set according to the type and use of the anthraquinone dye and the cationic surfactant to be used, but usually the anthraquinone dye in the ink composition of the present invention is usually used. 0.05-1
0% by weight (preferably 0.1 to 1% by weight), and 0.2 to 30% by weight (preferably 0.5 to 1) of a cationic surfactant.
0% by weight), and may be adjusted with a resin binder of 50% by weight or less (preferably 5 to 35% by weight), an extender of 1 to 30% by weight (preferably 2 to 20% by weight), and the like.

In this case, when the amount of the anthraquinone dye is less than 0.05% by weight, the color development becomes insufficient, the color difference before and after the color change is difficult to distinguish, and when the amount exceeds 10% by weight, the color change may become unclear. There is. If the amount of the resin binder is too small, the adhesiveness to the substrate becomes insufficient when the ink composition of the present invention is used by printing on the substrate,
If it exceeds 50% by weight, good printability cannot be obtained. When the amount of the cationic surfactant is less than 0.2% by weight, a sufficient discoloration effect (color difference) may not be obtained,
If it exceeds 0% by weight, it may hinder the formation of a coating film. Also, when the amount of the extender is too large, good printability cannot be obtained. Therefore, if each component is blended within the above range, especially when used by printing on a substrate, color development, discoloration, and the like become clear, and more favorable printability and adhesion can be obtained. .

These components may be simultaneously or sequentially mixed and uniformly mixed using a known stirrer such as a homogenizer or a dissolver. For example, an anthraquinone-based dye, a cationic surfactant, a resin-based binder, an extender, and the like may be mixed in a solvent in order, followed by mixing and stirring.

The ink composition of the present invention can be used as it is, but it can also be used by being supported on a substrate by coating or impregnating the ink composition on the substrate as necessary. The substrate is not particularly limited, and can be applied to any of, for example, paper, woody materials, plastics, metals and alloys, ceramics, cement and concrete, or a composite material thereof,
What is necessary is just to select suitably according to a use etc.

In particular, the ink composition for detecting ozone of the present invention can be suitably used for an ozone indicator using the ink composition for a color changing layer. That is, the ozone indicator of the present invention comprises at least one color-change layer composed of the above-described ink composition for detecting ozone and at least one non-color-change layer composed of an ink that does not change color with ozone.
And a color-changing layer and a non-color-changing layer are formed such that a part or all of at least one color-changing layer is exposed to an ozone atmosphere.

The substrate used in the ozone indicator of the present invention is not particularly limited as long as a color-changing layer or a non-color-changing layer can be formed, and the same materials as those described above can be used.

On the other hand, any ink can be used for the non-color-changing layer in the ozone indicator of the present invention as long as the color does not change with ozone. Commercially available ordinary color inks can also be used as such inks. For example, a water-based ink, an oil-based ink, a solventless ink, and the like can be used. In the case of printing, known letterpress ink, gravure ink, screen ink, offset ink and the like can be appropriately used depending on the printing method. These inks may be used alone or as a mixture of two or more. Further, the ink in the non-color-change layer may contain components (for example, a resin-based binder, a filler, a solvent, and the like) blended in a known ink composition.

The formation of the color-changing layer and the non-color-changing layer in the present invention can be carried out by using a known printing method such as silk screen printing, gravure printing, offset printing, letterpress printing, or flexographic printing using each ink. The order of printing the color-change layer and the non-color-change layer is not particularly limited, and may be appropriately selected according to the design to be printed.

In the ozone indicator of the present invention, the color-changing layer and the non-color-changing layer may be formed one by one, or a plurality of layers may be laminated. Further, color-change layers or non-color-change layers may be laminated. In this case, the discoloration layers may have the same composition or different compositions. Similarly, the non-color-changing layers may have the same composition or different compositions.

Further, the color-change layer and the non-color-change layer may be formed on the entire surface of the substrate or each layer, or may be formed partially. In these cases, in the present invention, the color-change layer and the non-color-change layer are formed such that a part or all of at least one color-change layer is exposed to an ozone atmosphere, particularly in order to secure the color-change of the color-change layer.

In the present invention, as long as the presence of ozone can be identified, the color-change layer and the non-color-change layer are formed so that the color difference between the color-change layer and the non-color-change layer can be identified only by the color change of the color-change layer. For the first time, it can be formed such that no color difference occurs between the color-change layer and the non-color-change layer. In particular, it is preferable to form the color-changing layer and the non-color-changing layer so that the color difference between the color-changing layer and the non-color-changing layer can be identified only after the color has changed.

When the color difference can be identified, the color-changing layer and the non-color-changing layer may be formed so that at least one of characters, designs and symbols can be identified only by the color change of the color-changing layer. In the present invention, the letters, symbols and symbols include all information that signals discoloration (ie, the presence of ozone). These characters and the like may be appropriately designed according to the purpose of use and the like.

Further, the color-change layer and the non-color-change layer before the color change may be different from each other. In particular, both colors are substantially the same, and the color difference (contrast) between the color-change layer and the non-color-change layer only after the color change. You may make it identifiable.

In the ozone indicator of the present invention, a color-changing layer and a non-color-changing layer may be formed so that the color-changing layer and the non-color-changing layer do not overlap. Thereby, the amount of ink used can be saved.

Further, in the present invention, a color-change layer or a non-color-change layer may be further formed on at least one of the color-change layer and the non-color-change layer. For example, a layer in which a color-change layer and a non-color-change layer are formed so that the color-change layer and the non-color-change layer do not overlap (“color-change layer-
If a color-changing layer having another design is formed on the non-color-changing layer, the boundary between the color-changing layer and the non-color-changing layer in the color-non-color-changing layer can be made substantially indistinguishable. Appearance can be achieved.

[0036]

(1) The ink composition for detecting ozone of the present invention discolors or loses its color even in a substantially dry state when it comes into contact with ozone, and the presence of ozone can be easily detected with the naked eye. Excellent in detection accuracy (selectivity), sensitivity, stability, etc. In particular, since a quaternary ammonium salt type cationic surfactant is added together, more excellent discoloration can be obtained, and lower concentration ozone can be reliably detected. Depending on the conditions, ozone having a low concentration of, for example, 0.03 ppm can be detected.

Further, in the composition of the present invention, the detection sensitivity, the discoloration speed and the like can be freely controlled by changing the kind and the mixing ratio of components such as anthraquinone dyes.

The ink composition of the present invention can be used as an ink for printing, writing, and stamping by blending a resin binder and the like, and used in a state of being applied on a base material such as paper or film. be able to. For this reason, for example, if several kinds of coating films of the ink composition of the present invention that change color or lose color at a certain ozone concentration are formed on a substrate, they can be used as a simple ozone indicator.

(2) The ozone indicator of the present invention comprises:
Since it is composed of a combination of a specific color-changing layer and a non-color-changing layer, it is possible to reliably identify the color change and thereby easily detect the presence of ozone. Also,
If the entire configuration is, for example, a sheet shape or a plate shape, space can be saved, and flexibility can be given by selecting a base material, so that it can be installed anywhere.

Moreover, by appropriately combining the color-changing layer and the non-color-changing layer, it is possible to represent patterns, characters, symbols, and the like according to the purpose of use, and it is possible to impart excellent design properties, so that it can be applied to a wide range of applications. can do.

In particular, since the ozone indicator of the present invention uses an ozone detecting ink composition containing a quaternary ammonium salt type cationic surfactant as an essential component as a color-changing layer, it is in a substantially dry state. Even when it reacts effectively with ozone, it changes color and has excellent detection accuracy (selectivity),
It exhibits sensitivity, stability, etc., and can easily detect the presence of ozone with the naked eye. Further, the detection sensitivity, the discoloration speed, and the like can be freely controlled by changing the types and mixing ratios of the components such as the cationic surfactant and the extender, and the ozone concentration can be quantitatively detected.

[0042]

EXAMPLES Examples and comparative examples are shown below to further clarify the features of the present invention.

Example 1 0.20 parts by weight of an anthraquinone-based disperse dye (“Miketone Fast Red Violet R” manufactured by Mitsui Toatsu Chemicals, Inc.)
7.35 parts by weight of ethyl cellulose resin ("Ethocel 10" manufactured by Dow Chemical Company) as a resin binder, 9.80 parts by weight of silica gel ("Aerosil R-972" manufactured by Nippon Aerosil Co., Ltd.), and coconut chloride as a cationic surfactant Alkyltrimethylammonium (“CA-215
1.96 parts by weight of "0" manufactured by NIKKOL Co., Ltd.) and 80.69 parts by weight of ethyl cellosolve ("Siphosol MG" manufactured by Nippon Shokubai Co., Ltd.) as a solvent were uniformly mixed with a stirrer to prepare an ink composition of the present invention.

Example 2 Lauryltrimethylammonium chloride ("Coatamine 24P" manufactured by Kao Corporation) 1.96 as a cationic surfactant
An ink composition of the present invention was prepared in the same manner as in Example 1 except that parts by weight were used.

Comparative Example 1 An ink composition was prepared in the same manner as in Example 1 except that no cationic surfactant was used. However, the solvent ethyl cellosolve was replenished by the amount of the cationic surfactant to make the solvent 82.65 parts by weight.

Example 3 0.24 parts by weight of an anthraquinone-based disperse dye ("Miketone Fast Turquoise Blue" manufactured by Mitsui Toatsu Chemicals) and an ethylcellulose-based resin ("Ethocel 10" manufactured by Dow Chemical Company) as a resin binder. 15 parts by weight, silica gel (“Aerosil R-972” manufactured by Nippon Aerosil Co., Ltd.) 1
2.20 parts by weight of hexadecyltrimethylammonium chloride (“Cation PB-4”) as a cationic surfactant
0 "2.44 parts by weight of Nippon Yushi Co., Ltd. and ethyl cellosolve as solvent (" Seafozol MG "manufactured by Nippon Shokubai Co., Ltd.) 7
5.97 parts by weight were uniformly mixed with a stirrer to prepare an ink composition of the present invention.

Comparative Example 2 An ink composition was prepared in the same manner as in Example 1 except that no cationic surfactant was used. However, the solvent ethyl cellosolve was replenished by the amount of the cationic surfactant to make the solvent 78.41 parts by weight.

Test Example 1 The discoloration of each ink composition obtained in Examples 1 to 3 and Comparative Examples 1 and 2 was examined.

Each ink composition was printed on Kent paper by silk screen printing (150 mesh). When the obtained printed matter was exposed to an atmosphere of ozone at 0.3 ppm for about 15 minutes, the printed color was faded or erased. The discolored state after discoloration was examined based on the color difference (ΔE) from before exposure (before discoloration). Table 1 shows the results.

[0050]

[Table 1]

From the results shown in Table 1, it can be seen that the color differences are small in Comparative Examples 1 and 2, and the color residue after discoloration is large, whereas in Examples 1 to 3, the color difference is large and the color residue is small. This shows that the ink composition of the present invention can reliably detect even when the ozone concentration is as low as 0.3 ppm.

Example 4 An ozone indicator was produced using the ink composition for ozone detection prepared in Example 1. On the other hand, a normal color ink used in the non-discoloring layer was toned. White ink "Conch 061
-A "60.6 parts by weight, purple ink" 082-A "6.1
By weight, 33.3 parts by weight of a medium ink "MEDIUM" (both made by "Sericol JM series (mat type)" manufactured by Teikoku Ink) were mixed to obtain a normal color ink (light purple).

The character design “deodorized (nuclear character)” shown in FIG. 1 was printed on Kent paper by silk screen printing (150 mesh) using an ink for detecting ozone to form a discoloration layer. Next, the character design “deodorized” shown in FIG. 2 using a normal color ink so as not to overlap with the discoloration layer.
Was printed by silk screen printing (300 mesh) to form a non-discoloring layer, and a light purple indicator was obtained over the entire surface. In the present invention, whichever of the designs shown in FIGS. 1 and 2 is used as the ozone detection ink or the ordinary color ink. In addition, the order of printing both designs may be first.

When the obtained indicator was left in an ozone atmosphere (ozone concentration: about 0.3 ppm) for about 15 minutes, only the discolored layer consisting of the above-mentioned "deodorized (nuclear character)" was decolorized, and the color difference was not obtained until the indicator was changed. "Deodorized" of non-discoloring layer
Characters can now be identified as light purple characters.

[Brief description of the drawings]

FIG. 1 is a diagram showing a design printed using an ozone detection ink in Example 4.

FIG. 2 is a diagram showing a design printed using a normal color ink in Example 4.

Claims (10)

[Claims] 1. An ink composition for detecting ozone, comprising an anthraquinone dye having at least one amino group of a primary amino group and a secondary amino group, and a quaternary ammonium salt type cationic surfactant. 2. The ozone detecting ink composition according to claim 1, wherein the quaternary ammonium salt type cationic surfactant is an alkyltrimethylammonium salt. 3. The ozone detecting ink composition according to claim 1, further comprising a filler. 4. The ink composition for detecting ozone according to claim 1, further comprising a resin binder. 5. A color-change layer comprising the ink composition for detecting ozone according to claim 1 and at least one non-color-change layer comprising an ink which does not change color with ozone on a substrate. And an ozone indicator, wherein a color-changing layer and a non-color-changing layer are formed such that a part or all of at least one color-changing layer is exposed to an ozone atmosphere. 6. The ozone indicator according to claim 5, wherein the color-changing layer and the non-color-changing layer are formed so that the color difference between the color-changing layer and the non-color-changing layer can be identified only after the color-changing layer has changed color. 7. The ozone indicator according to claim 5, wherein a color-changing layer and a non-color-changing layer are formed so that at least one of characters, designs and symbols can be identified only after the color-changing layer has changed color. 8. The ozone indicator according to claim 6, wherein the color-change layer and the non-color-change layer before color change have substantially the same color. 9. The ozone indicator according to claim 5, wherein a color-changing layer and a non-color-changing layer are formed so that the color-changing layer and the non-color-changing layer do not overlap. 10. The ozone indicator according to claim 5, wherein a color-changing layer or a non-color-changing layer is further formed on at least one of the color-changing layer and the non-color-changing layer.