Ozone indicator

Abstract

To provide an ozone indicator for simply determining the progress of sterilization treatment and the like.SOLUTION: An ozone indicator comprises a base material 11, and a sensitive portion 12 and a comparison portion 13 on a surface of the base material. The sensitive portion is composed of a plurality of discoloration portions 15a, ..., and 15h, which are formed of a coloring matter whose observation color is changed by ozone gas exposure, are arranged so as not to overlap each other, and have different speeds of observation color change by ozone gas. The comparison portion is composed of a plurality of index portions 16a, ..., and 16h, which are arranged in contact with one discoloration portion so as to clarify a relation with the discoloration portion and in which the observation color when the observation color change of the discoloration portion is substantially stopped is printed. In the ozone indicator, a CT value when each discoloration portion is changed to the observation color of the index portion in contact with the discoloration portion is described in the vicinity of the discoloration portion, and the plurality of discoloration portions are arranged in ascending order from one side of the base material to the other side on the basis of the CT value in each vicinity.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an ozone indicator for easily checking the progress of treatments such as sterilization, decomposition of harmful substances, decolorization, and deodorization using ozone gas. [Background technology]

[0002] In recent years, there have been notable global epidemics of infectious diseases, including the Spanish flu, Ebola hemorrhagic fever, acquired immune deficiency syndrome (AIDS), severe acute respiratory syndrome (SARS), and the novel coronavirus (COVID-19), even in humans. In response to these trends, the importance of sterilizing waiting rooms in hospitals and private clinics, treatment rooms where many unwell people stay even for a short time, and examination spaces has also increased in Japan.

[0003] Chlorine, hydrogen peroxide (gas), and ozone gas are known as gases with a sterilizing effect. However, chlorine gas is highly toxic and needs to be detoxified before being released into the outside world, and hydrogen peroxide gas requires a non-small device to gasify hydrogen peroxide water. Unlike these, which require careful handling and require full-scale related equipment, ozone gas can be generated with a small portable device and has the characteristic of being decomposed into oxygen in a short time and leaving no trace. In addition, ozone gas is known to have the effect of attenuating the activity of the new coronavirus, which is currently likely to re-emerge (Non-Patent Document 1). As such, ozone gas is easier to handle on a small scale than chlorine gas and hydrogen peroxide gas, and is therefore excellent for sterilizing living spaces in hospitals and private clinics and medical instruments used there.

[0004] Incidentally, it is widely known that the progress of a sterilization process using ozone gas can be evaluated by the CT value, which is the product of the ozone gas concentration (ppm) in the treatment environment and the time (minutes) of the sterilization process (for example, Non-Patent Document 2). The CT value is obtained by an ozone gas concentration meter and a management device that calculates the CT value from the measured ozone gas concentration, and the calculated CT value can also be displayed on the management device (Patent Document 1).

[0005] However, when ozone gas is used to maintain poorly ventilated X-ray rooms, etc., at 0.05 ppm or less (the ACGIH (American Conference of Governmental Industrial Hygienists) permissible concentration for 8 hours of heavy work) during working hours, or when ozone gas is used to sterilize living spaces, etc., on days off when there are no medical examinations, etc. as a matter of custom, strict management of CT values ​​using an ozone gas concentration meter and management device may not be necessary. Even in such preventive ozone gas sterilization treatment that does not require strict CT value management, it is important from the perspective of management to occasionally check the actual extent of sterilization treatment while the ozone generator is in operation. Therefore, it is desirable to obtain information by some simple means that ozone is being supplied and sterilization treatment is "actually continuing (CT value is increasing smoothly)".

[0006] Regarding the determination of the end of a sterilization process using ozone gas, an ozone indicator has been proposed that indicates the reached CT value using a color change of a coloring agent as an index (Patent Document 2). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2011-019825 A [Patent Document 2] Patent Publication No. 2022-122597 [Non-patent literature]

[0008] [Non-Patent Document 1] (World's first) Inactivation of the new coronavirus by ozone confirmed, February 14, 2020, Nara Medical University, MBT Consortium (Internet, URL: http: / / www.naramed-u.ac.jp / university / kenkyu-sangakukan / oshirase / r2nendo / documents / press_2.pdf) [Non-Patent Document 2] Report on ozone gas disinfection in bedding laundry operations, January 19, 2007, Ministry of Health, Labor and Welfare, Bedding Laundry Specialist Committee (Internet, URL: http: / / www.mhlw.go.jp / shingi / 2007 / 01 / s0119-7.html) Summary of the Invention [Problem to be solved by the invention]

[0009] The ozone indicator proposed in Patent Document 2 is for visually and easily evaluating whether or not the sterilization process has been performed properly as intended after the sterilization process or the like is completed. This ozone indicator is placed in a place where there is a concern that ozone gas may remain in the space where the sterilization process or the like is performed, or in a place away from an ozone gas concentration meter, and is used to determine whether or not the intended CT value has been reached even in such a place. Such an indicator is not suitable for determining whether or not the sterilization process using ozone is actually continuing.

[0010] The present invention has been made in consideration of the above problems, and has an object to provide an indicator for easily judging the progress of a sterilization process or the like. [Means for solving the problem]

[0011] The ozone indicator according to the present invention has a sheet-like substrate, and a sensitive part and a comparative part formed on the surface of the substrate. The sensitive part is composed of a plurality of discoloration parts, each of which is formed of a pigment whose observed color changes when exposed to ozone gas, and which are arranged without overlapping with each other and whose observed color changes at different speeds due to ozone gas. Here, "the speed of observed color change due to ozone gas" refers to the degree of observed color change with an increase in CT value. "Observed color" means "the sensory appearance of color due to the interrelationship between hue, saturation, and brightness (the three attributes of color)."

[0012] The comparison section is composed of a plurality of indicator sections which are arranged near or in contact with the discolored section so that the relationship of each discolored section to the other discolored sections can be seen by printing the observed color when the change in the observed color of the discolored section due to ozone gas has almost finished.

[0013] In the ozone indicator, the CT value (numerical value) when the observed color of each discolored part due to ozone gas changes to the observed color of the indicator part nearby or in contact with it is written on the discolored part or near the indicator part, and multiple discolored parts are arranged in ascending order based on the CT value of each neighborhood from one side to the other side of the substrate surface. The "sheet-like" substrate here refers to a substrate with a large surface area compared to its thickness, and includes materials that are not flexible.

[0014] Another ozone indicator according to the present invention has a sheet-like substrate, and a sensitive portion, a comparative portion, and a reference portion formed on the surface of the substrate. The sensitive portion is made of a dye whose observed color changes when exposed to ozone gas, and is composed of a plurality of discoloration portions arranged so as not to overlap each other and differing in the speed at which the observed color changes due to ozone gas. The comparative portion is made of a plurality of indicator portions arranged near or in contact with each discoloration portion so that the relationship between each discoloration portion and the other discoloration portions can be seen compared to the other discoloration portions, and the observed color when the change in the observed color of the discoloration portion due to ozone gas is almost completed is expressed by printing.

[0015] The reference portion is arranged near or in contact with each discoloration portion or indicator portion related to the discoloration portion so that the discoloration portion and its relationship to the indicator portion can be seen in comparison with other discoloration portions or other indicator portions, and is composed of a plurality of reference color portions in which the observed color of the discoloration portion before exposure to ozone gas is expressed by printing.

[0016] On the ozone indicator, the CT value (numerical value) when each discolored area changes due to ozone gas to the observed color of the indicator area nearby or in contact with it is written near the discolored area, the indicator area, or the reference color area, and the multiple discolored areas are arranged in ascending order from one side of the substrate surface to the other based on the CT values ​​of their respective vicinity.

[0017] The dye that changes the observed color is bromophenol blue or Coomassie brilliant blue, and sodium thiosulfate is used to form the discolored areas so that the speeds at which the discolored areas change the observed color differ from one another. Food dyes may be used as the dye that changes the observed color, and different food dyes may be used for each discolored area so that the speeds at which the discolored areas change the observed color differ from one another. Two different food dyes may be used to form any of the discolored areas.

[0018] Another ozone indicator according to the present invention has a sheet-like substrate, and a sensitive portion, a comparative portion, and a reference portion formed on the surface of the substrate. The sensitive portion is made of food dyes of two colors each having different fading rates when exposed to ozone gas, and is composed of a plurality of discoloration portions arranged so as not to overlap each other and each of which exhibits different rates of observed color change due to ozone gas.

[0019] The comparison section is composed of a plurality of indicator sections arranged near or in contact with each discolored section so that the relationship between each discolored section and the corresponding indicator section can be seen compared to other discolored sections, and the observed color when the exposure of the discolored section to the ozone gas results in a different specific CT value is expressed by printing.The reference section is composed of a plurality of reference color sections arranged near or in contact with each discolored section or indicator section related to the discolored section so that the relationship between the discolored section and the corresponding indicator section can be seen compared to other discolored sections or other indicator sections, and the observed color of the discolored section before exposure to ozone gas is expressed by printing.

[0020] This ozone indicator has a specific CT value (numerical value) written near the discolored area, the indicator area, or the reference color area when each discolored area changes due to ozone gas to the observed color of the indicator area nearby or in contact with it, and the multiple discolored areas are arranged in ascending order from one side of the substrate surface to the other based on the specific CT values ​​of their respective neighborhoods.

[0021] It is preferable that the comparison portion of the ozone indicator is protected with a resin film having resistance to ozone gas. Effect of the Invention

[0022] According to the present invention, it is possible to provide an ozone indicator for easily determining whether a sterilization process or the like is proceeding smoothly. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram showing an outline of an ozone indicator 1. As shown in FIG. [Diagram 2] FIG. 2 is a front view of a test device for examining the degree of discoloration of a sample due to exposure to ozone. [Diagram 3] FIG. 3 is a plan view of the test apparatus. [Figure 4] FIG. 4 is a diagram showing the concept of extracting a portion for color reduction measurement from a sample. [Diagram 5] FIG. 5 shows the relationship between the CT value and the color density retention rate for food dyes that fade quickly. [Figure 6] FIG. 6 shows the relationship between the CT value and the color density remaining rate for the group of food dyes with moderate fading. [Figure 7] FIG. 7 shows the relationship between the CT value and the color density retention rate for the slow-fading food dye group. [Figure 8] FIG. 8 is a diagram showing the change in observed color of the ozone indicator during exposure to ozone gas. [Figure 9] FIG. 9 is a diagram showing an outline of an ozone indicator suitable for carrying out sterilization treatment at a low ozone gas concentration for one week or more. [Figure 10] FIG. 10 is a schematic diagram of an ozone indicator that uses two different colored food dyes in the sensing portion. [Figure 11] FIG. 11 is a schematic diagram of another type of ozone indicator using two different colored food dyes as the sensitive part. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In this document, "observed color" means "the sensory appearance of a color based on the interrelationships of hue, saturation, and lightness (the three attributes of color)."

[0025] Fig. 1 is a diagram showing an overview of an ozone indicator 1. The ozone indicator 1 has a substrate 11, a sensitive part 12, and a comparison part 13. The substrate 11 is the basic part of the ozone indicator 1, and is formed of a slightly elongated rectangular sheet of cardboard or a general-purpose resin such as polypropylene or polystyrene. The substrate 11 is a horizontally long rectangle in Fig. 1, and the surface on which the sensitive part 12 and the comparison part 13 are formed is white or a color of high brightness.

[0026] The sensitive part 12 is composed of a plurality of discoloration parts 15a, 15b, 15c, 15d, 15e, 15f, 15g, 15h that fade with ozone gas. The discoloration parts 15a,...,15h are all rectangular in shape, with the length longer than the width. The discoloration parts 15a,...,15h are arranged in the longitudinal direction of the substrate 11 at approximately equal intervals with the short sides of the rectangles aligned in the longitudinal direction of the substrate 11. The discoloration parts 15a,...,15h are arranged in the order of the leftmost one whose discoloration is almost complete with the smallest CT value (high sensitivity), and the rightmost one whose discoloration is almost complete with the larger CT value (low sensitivity). The method of forming the discoloration parts 15a,...,15h will be described later.

[0027] The discolored portions 15a,...,15h all fade (change color) to different degrees as the CT value increases. The CT value at which the progress of the discoloration (fading) of each of the discolored portions 15a,...,15h is approximately completed is printed below the discolored portions 15a,...,15h. The printed CT values ​​in Fig. 1 are numerical values ​​with good divisions, but regardless of the divisions, the CT numerical value at which the fading of each of the discolored portions 15a,...,15h is approximately completed is printed.

[0028] The comparison section 13 is composed of a plurality of indicator sections 16a, 16b, 16c, 16d, 16e, 16f, 16g, and 16h printed on the substrate 11. The indicator sections 16a,...,16h are all rectangular in shape, and the width is the same as that of the discolored sections 15a,...,15h, but the length is longer than the width. The indicator sections 16a,...,16h are all bordered by thin black lines, and each is disposed on the substrate 11 with its longitudinal end in contact with an end of a different discolored section 15a,...,15h. Each indicator section 16a,...,16h is printed in an observation color when the progress of discoloration (fading) of the discolored section 15a,...,15h it contacts underneath has substantially stopped. The printing location of the CT value (numeric value) on the ozone indicator 1 is not limited to the printing location shown in FIG. 1, so long as it is clear to which of the discolored portions 15a, . . . , 15h or indicator portions 16a, . . . , 16h the numerical value relates to.

[0029] The comparison section 13 is printed using an inkjet printer. The comparison section 13 is covered and protected with a non-glare film (non-glossy film) made of ozone gas resistant materials such as polyethylene, polypropylene, or nylon so that the printing ink does not come into direct contact with ozone gas. The comparison section 13 can also be printed using a laser printer or offset printing. For printing the comparison section 13, a printing method and ink that cause little change in observed color over time are selected.

[0030] The ozone indicator 1 is placed in a sterilization space to which ozone gas is supplied, and the discolored portions 15a,...,15h complete fading in order from left to right as the sterilization process progresses (the CT value increases in the ozone gas process). Whether or not the discolored portions 15a,...,15h have completed fading is determined by whether or not the observed color of the discolored portion (any of 15a,...,15h) that is visually noted is approximately the same as the observed color of the indicator portion 16a,...,16h directly above it. In other words, if they are the same, it is determined that the process with ozone gas has been performed up to the value (CT value) below the discolored portion 15a,...,15h.

[0031] Next, the sensitive part 12 of the ozone indicator 1 will be described in more detail. Bromophenol blue (hereinafter sometimes abbreviated as "BPB") and Coomassie brilliant blue (hereinafter sometimes abbreviated as "CBB") disclosed in JP 2022-122597 A can be used as colorants that fade with an increase in the CT value in the sensitive part 12, and food dyes can also be used. The sensitive part 12 is formed by, for example, preparing a base solution using BPB as a colorant, applying this to a hydrophilic film, and naturally drying it. The base solution is obtained by dissolving BPB as a colorant in 0.025 mol / L phosphate buffer solution (pH 6.8) so that the concentration is 0.02%. Here, "%" indicating the component ratio means "% by weight" unless otherwise specified.

[0032] BPB is a special grade reagent sold by Fujifilm Wako Pure Chemical Industries, Ltd. 0.025 mol / L phosphate buffer is prepared using neutral phosphate standard solution (pH 6.86) from pH standard solution set 101-S in the LAQUA (registered trademark) series sold by Horiba, Ltd. Coomassie brilliant blue can also be used as a coloring agent in the base solution, just like BPB.

[0033] The hydrophilic membrane used in the sensitive part 12 is made of polyvinylidene fluoride resin (hereinafter referred to as "PVDF"), and a membrane filter (registered trademark "Durapore") with a pore size of 5.0 μm and a diameter of 47 mm manufactured by Merck is used. The appearance of the sensitive part 12 using BPB obtained by natural drying is blue-purple with blue accents.

[0034] The multiple discolored areas 15a, 15h due to BPB in the sensitive part 12 are formed by changing the amount of sodium thiosulfate added when preparing each base solution. The sensitivity to ozone gas can be varied by adding or not adding sodium thiosulfate and the amount of sodium thiosulfate added. Since CBB is a low-sensitivity colorant that fades at a larger CT value than BPB, it is also possible to form the discolored areas 15a, 15h by using BPB and CBB separately and further changing the amount of sodium thiosulfate added.

[0035] A base solution is prepared using food dye, the observed color of which changes with ozone gas, as the coloring dye, and discolored parts 15a,...,15h can be formed. Next, assuming a case in which food dye is used for sensitive part 12, the sensitivity of various food dyes to ozone gas, that is, the degree of fading with an increase in CT value, was examined. The examination was carried out using a sealed test device 2 for ozone gas exposure testing.

[0036] Fig. 2 is a front view of the test equipment 2, and Fig. 3 is a plan view of the test equipment 2. The test equipment 2 consists of a container 21, an ozone generator 22, a humidifier 23, a thermometer, a hygrometer 24, an ozone concentration meter 25, and a CT value recorder. The container 21 is a hollow rectangular box, and the top is closed with a removable lid 26. The container 21 is made of transparent polyvinyl chloride resin so that the inside can be easily observed from the outside.

[0037] The ozone generator 22 is a known stationary ozone gas generator incorporating an ozone lamp (ultraviolet lamp) and a forced circulation fan. The device vibrates the water by applying an AC voltage of 100 V to it, and generates ultrasonic waves that generate mist from the water, which is then discharged to the outside from discharge port 27. The hygrometer 24 is a device that measures and displays the humidity inside the container 21. The hygrometer 24 is housed in the container 21.

[0038] The ozone concentration meter 25 is a known device that is installed in the container 21 and measures the ozone gas concentration in the container 21. The ozone concentration meter 25 has a control unit (not shown) on the outside, and the control unit digitizes the measured ozone concentration and transmits it to a CT value recording device. The sample stage 28 in Figures 2 and 3 is for placing a sample 29 prepared using an edible coloring.

[0039] The CT value recorder calculates the increment of the CT value (=ozone concentration x interval time) from the ozone concentration transmitted from the ozone concentration meter 25 and the transmission interval (time), integrates this increment from the time when the decomposition process started, and displays the integrated value on the display device. A personal computer is used as the CT value recorder.

[0040] Sample 29 was prepared as follows. First, a food coloring was dissolved in 0.025 mol / L phosphate buffer (pH 6.8) to a concentration of 0.02% to prepare a "base solution." The 0.025 mol / L phosphate buffer was prepared using the neutral phosphate standard solution (pH 6.86) from the pH standard solution set 101-S in the LAQUA (registered trademark) series sold by Horiba, Ltd., as described above.

[0041] Sample 29 was obtained by dropping the base solution onto a hydrophilic membrane made of polyvinylidene fluoride resin (hereinafter referred to as "PVDF") and allowing it to dry naturally (standing indoors). The PVDF hydrophilic membrane used was a membrane filter (registered trademark "Durapore") with a pore size of 5.0 μm and a diameter of 47 mm manufactured by the same Merck as mentioned above.

[0042] In the fading test of the sample 29 by ozone gas, the sample 29 was placed on the sample stage 28, and the operation of the ozone generator 12 was controlled by the control part of the ozone concentration meter 25 so that the measurement value of the ozone concentration meter 25 became a predetermined concentration (5 ppm or 30 ppm). The temperature of the air conditioner in the room where the test device 2 was installed was set so that the temperature inside the container 21 was kept at 20°C, and it was periodically confirmed by a thermocouple inserted inside the container 21 that the temperature inside the container 21 was within this range.

[0043] The ozone gas exposure test was performed using three samples 29 prepared with the same food coloring, and the final CT value at which the ozone gas exposure test was terminated was changed for the same food coloring. In the case of a CT value of 0, the prepared sample 29 was used as it was to measure the observed color (color density).

[0044] FIG. 4 is a diagram showing the concept of extracting a portion for color reduction measurement from a sample 29. The sample 29 exposed to ozone gas up to a specified CT value is placed on a filter paper 32. The filter paper 32 used is qualitative filter paper No. 2 manufactured by Advantech. The sample 29 placed on the filter paper 32 is photographed under standardized conditions with a digital camera fixed to a stand under fluorescent lighting. "Standardized conditions" means the same (standardized) conditions in terms of the camera, the distance between the camera and the subject, the brightness of the shooting environment, the number of pixels for shooting, the shooting sensitivity, the aperture value, the shutter speed, the white balance, etc.

[0045] The entire filter paper 32 including the sample 29 is photographed, and the image data is imported into a computer, and the color density of the sample 29 is calculated using the analysis software ImageJ1.52v (downloadable from URL: https: / / imagej.jaleco.com / ).

[0046] On the PC, the imported image is decomposed into the three primary colors (RGB) of light using ImageJ1.52v, and the density of the element of interest (one of red, green, or blue (hereafter referred to as "RGB")) is calculated for a portion 33 of the sample 29 and a portion 34 of the filter paper 32 of the same area. The image decomposed into the three RGB elements is monochrome, with only light and dark, and the "density" that is calculated is actually the "lightness" of the element of interest.

[0047] Therefore, the "color density" described later is the value obtained by subtracting the "density" value of the filter paper 32 from the "density" value of the sample 29 for the color element of interest. Note that each value of the "color density" described later is the value obtained by multiplying the value obtained by the method described above (using ImageJ1.52v) by "-1."

[0048] Table 1 shows the color density for each RGB element when samples were prepared using commercially available food colorings. The color density for each RGB element in Table 1 was measured by photographing Sample 29 prepared using each food coloring with a digital camera without exposing it to ozone gas and using ImageJ1.52v.

[0049] [Table 1]

[0050] The food dyes shown in Table 1 were used as follows: (a) Food coloring test control solution set A sold by Tokyo Chemical Industry Co., Ltd. The following food dyes are each provided as 0.1% solutions in water:

[0051] (A-1) Food Red No. 2 (Amaranth) (A-2) Food Red No. 3 (Erythrosine) (A-3) Food Red No. 40 (Allura Red AC) (A-4) Food Red No. 102 (New Coccin) (A-5) Food Red No. 104 (Phloxine) (A-6) Food Red No. 105 (Rose Bengal) (A-7) Food Red No. 106 (Acid Red) (A-8) Food Yellow No. 4 (Tartrazine) (A-9) Food Yellow No. 5 (Sunset Yellow FCF) (A-10) Food Green No. 3 (Fast Green FCF) (A-11) Food Color Blue No. 1 (Brilliant Blue FCF) (A-12) Food Blue No. 2 (indigo carmine) (b) Food coloring test control solution set B sold by Tokyo Chemical Industry Co., Ltd. The following food dyes are each provided as 0.1% solutions in water:

[0052] (B-3) Ponceau R (formerly Food Red No. 101) (B-4) Eosin (formerly Food Red No. 103) (B-5) Naphthol Yellow S (formerly Food Yellow No. 1) (B-6) Light Green SF Yellow (formerly Food Green No. 2) (B-7) Orange I (formerly Food Orange No. 1) (B-8) Orange II (B-9) Multi-light yellow (B-10) Uranine (B-11) Guinea Green B (formerly Food Green No. 1) (B-12) Brilliant Milling Green (B-13) Azure Blue VX (B-14) Acid Violet 6B (formerly Food Purple No. 1) (c) (B-1) New Coccin (Red No. 1): Fujifilm Wako Pure Chemical (B-2) Tartrazine (Yellow No. 4): Fujifilm Wako Pure Chemical Table 2 shows the relationship between the CT value and the residual rate of color density of each representative color of food coloring when samples prepared using each food coloring in Table 1 as a coloring agent are exposed to ozone gas. Here, the "representative color of food coloring" refers to any of the RGB colors (shaded in Table 1) that have the largest value for each food coloring in Table 1.

[0053] [Table 2]

[0054] 5 to 7 are diagrams showing the relationship between the CT value and the residual rate of color density when sample 29 prepared using each food coloring shown in Table 1 is exposed to ozone gas using test device 2. The "color density" from which the residual rate is calculated in Figs. 5 to 7 is the color element (representative food coloring color) with the largest value for each food coloring in Table 1.

[0055] Here, the "residual rate" of color density is the value calculated by "color density (after exposure to ozone gas) ÷ color density at CT value 0 (not exposed to ozone gas) × 100," with the value before exposure to ozone gas being 100% and the color density at 0 being 0%. The reason why the residual rate of color density in Figures 5 and 6 is a negative value is because the color density value calculated by multiplying the value calculated by the method using ImageJ1.52v by "-1" was less than 0.

[0056] The food dyes in Table 1 can be classified into three groups based on their sensitivity to fading due to exposure to ozone gas. One is the "fast fading group" shown in Figure 5, where the CT value is less than 800 and the residual rate is 10% or less. Next, there is the "moderately fast fading rate group" shown in Figure 6, with CT values ​​between 800 and 2600 and a survival rate of 10% or less, and the "slow fading rate group" shown in Figure 7, with CT values ​​of 2600 or more and a survival rate of 10% or less.

[0057] The "fading speed" refers to the degree of progress of fading with an increase in the CT value in exposure to ozone gas, and "fast fading speed" is sometimes expressed as "good fading sensitivity." By combining these three groups of food dyes with different fading sensitivity, it is possible to configure the sensitive part 12 in the ozone indicator 1, which is made up of "multiple discoloration parts 15a,...,15h with different CT values ​​at which fading is approximately limited (approximately completed)."

[0058] FIG. 8 is a diagram showing the change in observed color of the ozone indicator 1 during exposure to ozone gas. FIG. 8(a) shows the ozone indicator 1 before exposure to ozone. FIG. 8(b) and FIG. 8(c) show the progress of fading of each discolored portion 15a,...,15h with an increase in CT value. The discolored portion 15a,...,15h, which has a small corresponding printed CT value (numerical value) (high fading sensitivity), is arranged on the far left, and the discolored portions 15b,...,15h, which have larger CT values ​​and are almost completely faded (low fading sensitivity), are arranged on the right. The food coloring used for each discolored portion 15a,...,15h is determined with reference to Table 2 and FIG. 5 to FIG. 7.

[0059] After the ozone indicator 1 placed in the ozone gas atmosphere starts to be exposed to ozone gas, the difference in observed color (sensory appearance of color) between the indicator parts 16a, 16b associated with the discolored parts 15a, 15b corresponding to small CT values ​​in order from the right to the left becomes small or disappears. From the ozone indicator 1 in the state shown in Figure 8(b), it can be seen by visual observation that the CT value in the ozone exposure process is greater than 500 and less than 2000.

[0060] For example, if the waiting room of a private practice doctor is sterilized with ozone gas at a concentration of 0.5 ppm from the time the clinic closes on Saturday afternoon until the clinic opens on Monday, if the ozone indicator 1 placed in the waiting room is as shown in Figure 8(b) at the time the clinic opens, the ozone indicator 1 indicates that the sterilization process has been carried out for longer than 16.7 hours and shorter than 66.8 hours (2.7 days). If the ozone generator is still operating when the clinic opens, it can be determined that the sterilization process of the waiting room continued normally during the closure. When the sterilization process using ozone gas is carried out for a longer period during the Bon holiday, the ozone indicator 1 will finish fading to the discolored part 15d, which has a lower fading sensitivity. If the target ozone gas concentration to be maintained during the sterilization process is 0.5 ppm and the ozone indicator 1 is in the state shown in Figure 8(c) at the end of the holiday, it can be visually determined that the sterilization process has been carried out for at least 2.7 days.

[0061] FIG. 9 is a diagram showing an outline of an ozone indicator 1B suitable for performing sterilization treatment continuously for one week or more at a low ozone gas concentration. The ozone indicator 1B has a substrate 11, a sensitive part 12, and a comparison part 13. The sensitive part 12 is composed of a plurality of discoloration parts 15a, 15b, 15c, 15d, 15e, 15f that fade with ozone gas. The comparison part 13 is composed of a plurality of indicator parts 16a, 16b, 16c, 16d, 16e, 16f printed on the substrate 11. The discoloration parts 15a, . . . , 15f and the indicator parts 16a, . . . , 16f in the ozone indicator 1B are the same as those in the ozone indicator 1, except for the CT value at which the fading of the discoloration parts 15a, . . . , 15f is almost completed.

[0062] "When sterilization treatment is performed continuously for one week or more with low ozone gas concentration" refers to the case where waiting rooms of hospitals are sterilized constantly with ozone gas of less than 0.1 ppm concentration, which is the permissible concentration in the working environment set by the Japan Society for Occupational Health. 24 hours and 48 hours after placing the ozone indicator 1B shown in FIG. 9(a) in a waiting room filled with low concentration ozone gas, its appearance changes to (b) and (c) in FIG. 9, respectively. Discolored portion 15 The discoloration of the discolored portion 15a and the discolored portion 15b is adjusted so that the discoloration is almost completed at CT values ​​of 120 and 240, respectively. A CT value of 120 is the value when exposed to an ozone gas concentration of 0.09 to 0.85 ppm for 24 hours.

[0063] A hospital staff member who visually confirms that the ozone indicator 1B is in the state of Fig. 9(b) on the first day and in the state of Fig. 9(c) on the next day can determine that the sterilization treatment using ozone gas is continuing. In this way, the ozone indicator 1 can easily determine whether the sterilization treatment using ozone gas is continuing smoothly without relying on an ozone concentration meter, a CT value integrating device, etc.

[0064] Any one or all of the discoloring parts 15a, ···, 15h can use two different edible pigments described in Table 2 as colorants in one basic solution. Combinations of two different edible pigments with similar fading speeds or different fading speeds due to ozone gas can be adopted.

[0065] Figure 10 is a diagram showing an overview of the ozone indicator 1C using two different edible pigments in the sensing part 12. (a) in Figure 10 shows the state before ozone exposure, (b) shows the state where 500 < CT value < 2000 after the start of ozone exposure, and (c) shows the state where 2000 < CT value < 4000 after the start of ozone exposure. The ozone indicator 1C has a reference part 14C further added to the ozone indicator 1 shown in Figure 1. The reference parts 14C are all rectangles of the same shape, and are each composed of a plurality of basic color parts 17Ca, 17Cb, 17Cc, 17Cd, 17Ce, 17Cf, 17Cg, 17Ch corresponding to the discoloring parts 15a, ···, 15h respectively. Each of the basic color parts 17Ca, ···, 17Ch is arranged on the base material 11 in a state where the upper side is in contact with the lower side of the corresponding discoloring part 15a, ···, 15h.

[0066] Each of the basic color parts 17Ca, ···, 17Ch is printed with the observed color before the corresponding discoloring part 15a, ···, 15h fades due to ozone gas, and is coated with a non - glare film so that the observed color does not change during ozone gas exposure. The individual correspondence between the discoloring part, the indicator part, and the basic color part means that, for example, if the discoloring part 15a is due to a certain edible pigment or the like, the indicator part 16a is printed with the observed color when the fading of this discoloring part 15a is substantially completed, and the basic color part 17Ca is printed with the observed color of the discoloring part 15a before fading due to ozone exposure, which is such an interrelationship.

[0067] In the discolored portion formed by the combination of two different colored food dyes with different fading sensitivities, the influence of the food dye with poor fading sensitivity becomes greater as fading by ozone gas progresses. In such a discolored portion (assumed to be discolored portion 15c), the hue changes due to fading of one of the food dyes with good fading sensitivity during the fading process by ozone gas. In this case, the hue of this discolored portion 15c can be easily compared visually with the corresponding reference color portion 17Cc showing the hue before fading and the indicator portion 16c showing the hue after fading is completed. If the discolored portion 15c of the ozone indicator 1C in FIG. 10(b) during the ozone gas exposure process is approximately the same as the hue of the basic color portion 17Cc at the time of observation, it can be visually determined that the CT value is 1000 or more. If the hue of discolored portion 15c is different from the hue of basic color portion 17Cc, it is possible to visually determine how close its hue is to the hue of basic color portion 17Cc, and thereby determine whether the CT value is close to 1000 or a little further away.

[0068] FIG. 11 is a diagram showing the outline of another form of ozone indicator 1D in which two different colored food dyes are used in the sensitive part. The ozone indicator 1D comprises a substrate 11, a sensitive part 12, a comparison part 13D and a reference part 14C. The substrate 11, the sensitive part 12 and the reference part 14C are substantially the same in configuration as those in the ozone indicator 1C. The comparison parts 13 of the ozone indicators 1, 1B and 1C are all printed in the hue (observed color) of the sensitive part 12 in which fading has been almost completed, whereas the comparison part 13D of the ozone indicator 1D is printed in the hue (observed color) of the sensitive part 12 (discolored part 15a, The CT value printed corresponding to each discoloration portion 15a,...,15h is the specific CT value at which the hue of one of the two food dyes with the lower fading sensitivity becomes stronger than the hue of the other of the two food dyes.

[0069] A discolored area formed with a single color of food dye does not show a large change in hue during the discoloration process caused by ozone gas (there is no discontinuous observed color change during the discoloration process), so the indicator is printed in the observed color when the discolored area is almost completely faded. On the other hand, a discolored area formed with two colors of food dyes with different fading sensitivities shows a large change in hue during the discoloration process caused by ozone gas, so even if the indicator is printed in the observed color that is the hue of the discolored area after the change, it is possible to determine whether the discolored area is the same as the indicator.

[0070] In this document, the term "observed color" has a broader meaning than general color tone (the way a color appears based on its saturation and lightness), and refers to "the way a color appears based on the three attributes of color: hue, saturation, and lightness."

[0071] In the above-mentioned embodiment, all of the discoloration parts 15a,...,15h in the ozone indicator 1,1C may be formed with two different colors of food dyes, or only the discoloration parts that fade at a specific CT value that is particularly important for ozone gas processing and the CT values ​​before and after that may be formed with two colors of food dyes. BPB, CBB, and food dyes can be used as colorants for the basic liquid for forming the discoloration parts 15a,...,15h. As long as it is easy to determine the discoloration parts 15a,...,15h, indicator parts 16a,...,16h, and (in the ozone indicator 1C) basic color parts 17Ca,...,17Ch that are individually related to each other, the shape and arrangement of the sensitive part 12, the comparison part 13, and the reference part 14C in the ozone indicator 1,1C can be arbitrarily changed according to the shape of the base material 11, etc. This also applies to the printing location of the printed CT value (numerical value).

[0072] In the case of the ozone indicator 1C, "the color change portion, the indicator portion, and the reference color portion that are individually related" refers to, for example, the relationship between the color change portion 15a, the indicator portion 16a, and the reference color portion 17Ca. Also, the arrangement that "makes it easy to distinguish the color change portion, the indicator portion, and the reference color portion that are individually related" refers to an arrangement in which the color change portion 15a is clustered or close to each other so that a person looking at the ozone indicator 1C can determine that the color change portion 15a is more strongly related to the indicator portion 16a and the reference color portion 17Ca than the other indicator portions 16b, . . . , 16h and the other reference color portions 17Cb, . . . , 17C.

[0073] Additionally, the individual configurations or overall structure, shape, dimensions, number, materials, etc. of the ozone indicators 1, 1B, 1C and the ozone indicators 1, 1B, 1C can be modified appropriately in accordance with the spirit of the present invention. [Industrial Applicability]

[0074] INDUSTRIAL APPLICABILITY The present invention can be used to simply determine whether a sterilization process using ozone gas or the like is continuing smoothly. [Explanation of symbols]

[0075] 1,1B,1C,1D Ozone Indicator 11 Base material 12 Sensory section 13 Comparison section 14C Reference section 15a, 15b, 15c, 15d, 15e, 15f, 15g, 15h Discolored area 16a,16b,16c,16d,16e,16f,16g,16h Indicator section 16Da,16Db,16Dc,16Dd,16De,16Df,16Dg,16Dh Indicator part 17Ca,17Cb,17Cc,17Cd,17Ce,17Cf,17Cg,17Ch Basic color part

Claims

1. A sheet-like substrate; A sensitive part and a comparative part formed on the surface of the substrate, the sensitive portion is made of a dye whose observed color changes when exposed to ozone gas, and is arranged so as not to overlap with each other, and is composed of a plurality of color-changing portions whose observed color changes at different speeds due to the ozone gas; the comparison section is composed of a plurality of indicator sections arranged near or in contact with each of the discolored sections so that the relationship of each of the discolored sections to the corresponding discolored sections can be seen by comparison with the other discolored sections, and which represent by printing an observed color when the change in observed color of the discolored section due to the ozone gas has almost finished; a CT value (numerical value) when the observation color of each of the discolored parts is changed by the ozone gas to the observation color of the indicator part adjacent thereto or in contact therewith is written in the vicinity of the discolored part or the indicator part; The plurality of discolored portions are arranged in ascending order based on the CT values ​​of the respective neighboring portions from one side to the other side of the substrate surface.

1. An ozone indicator comprising:

2. A sheet-like substrate; A sensitive part, a comparative part and a reference part formed on a surface of the substrate, the sensitive portion is made of a dye whose observed color changes when exposed to ozone gas, and is arranged so as not to overlap with each other, and is composed of a plurality of color-changing portions whose observed color changes at different speeds due to the ozone gas; the comparison section is composed of a plurality of indicator sections arranged in the vicinity or contacting the respective discolored sections so that the relationship between each of the discolored sections and the respective discolored sections can be understood by comparing the respective discolored sections with the other discolored sections, and the indicator sections represent by printing the observed color of the respective discolored sections when the change in the observed color of the respective discolored sections due to the ozone gas has almost finished; the reference portion is arranged in the vicinity of or in contact with each of the discolored portions or the indicator portions related to the discolored portions so that the relationship between the discolored portion and the indicator portion can be seen in comparison with other discolored portions or other indicator portions, and is composed of a plurality of reference color portions on which the observed color of the discolored portion before exposure to the ozone gas is expressed by printing; a CT value (numerical value) when the observed color of each of the discolored portions is changed by the ozone gas to the observed color of the indicator portion adjacent thereto or in contact therewith is written near the discolored portion, the indicator portion, or the reference color portion; The plurality of discolored portions are arranged in ascending order based on the CT values ​​of the respective neighboring portions from one side to the other side of the substrate surface.

1. An ozone indicator comprising:

3. A sheet-like substrate; A sensitive part, a comparative part and a reference part formed on a surface of the substrate, the sensitive part is made of food dyes of two colors each having a different color fading rate when exposed to ozone gas, and is arranged so as not to overlap with each other, and is composed of a plurality of color-changing parts each having a different speed of change in observed color when exposed to ozone gas, the comparison section is composed of a plurality of indicator sections arranged in the vicinity or contacting the respective discolored sections so that the relationship between each of the discolored sections and the respective discolored sections can be understood in comparison with the other discolored sections, and the indicator sections are printed with observed colors when the exposure of the respective discolored sections to the ozone gas results in different specific CT values, The reference portion is disposed in the vicinity of or in contact with each of the discolored portions or the indicator portions related to the discolored portions so that the discolored portions and their relationship with the indicator portions can be seen in comparison with other discolored portions or other indicator portions, and the discolored portions before exposure to ozone gas are The color sensor is constituted by a plurality of reference color portions in which the observed colors are expressed by printing, the specific CT value (numerical value) when each of the discolored portions is changed by the ozone gas to the observed color of the indicator portion adjacent thereto or in contact therewith is written near the discolored portion, the indicator portion, or the reference color portion; The plurality of discolored portions are arranged in ascending order based on the specific CT value of each of the adjacent portions from one side of the substrate surface to the other side.

1. An ozone indicator comprising:

4. the dye whose observed color changes is bromophenol blue or Coomassie brilliant blue, Sodium thiosulfate was used to form the discolored areas in order to differentiate the speed of color change observed in the discolored areas.

3. An ozone indicator according to claim 1 or 2.

5. The dye whose observed color changes is a food dye, A different food dye was used for each of the discolored areas to make the observed color change speeds of the discolored areas different from each other.

3. An ozone indicator according to claim 1 or 2.

6. Two different food colors were used in either or both of the discolored areas.

6. An ozone indicator according to claim 5.

7. The comparison portion was protected with a resin film having ozone gas resistance.

4. An ozone indicator according to claim 1.

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