Carbon dioxide detection body

Abstract

A carbon dioxide detecting body obtained by impregnating an ink composition into a carrier, the ink composition containing a pH indicator, an alkali agent, a water retaining agent, a silver-based antibacterial agent, and water, the content of the silver-based antibacterial agent being 0.001 to 0.02 mass% in terms of silver with respect to the total amount of the carbon dioxide detecting body.

Description

Technical Field

[0001] This invention relates to carbon dioxide detectors. Background Technology

[0002] To preserve food, beverages, and pharmaceuticals that may spoil upon contact with oxygen, an inert gas that does not react with the contents is sealed into the packaging container. Carbon dioxide (carbonic acid) is widely used in this application.

[0003] In addition, carbon dioxide is also used to seal in the preservation of food, beverages, and medicines that may deteriorate in quality or lose their efficacy due to the release of carbon dioxide.

[0004] However, sometimes damage to the packaging container can reduce the concentration of carbon dioxide inside, leading to spoilage of the contents.

[0005] In particular, medications containing bicarbonate have the property of releasing carbon dioxide and losing their efficacy. Therefore, by packaging the container holding the bicarbonate-containing medication together with carbon dioxide in a gas-barrier packaging container, the release of carbon dioxide is prevented and the medication is preserved. However, due to defects in the packaging material itself, failures in sealing the contents, or impacts during handling in distribution or at home or hospital, pinholes or poor sealing may occur. Sometimes, the atmosphere of the gas-replacement packaging changes, causing the contents to deteriorate. In addition, it is possible for the medication to be distributed without noticing the change in atmosphere after gas-replacement packaging.

[0006] As a simple method to prevent this situation, an operation was carried out in which the detector for detecting carbon dioxide and the carbon dioxide were simultaneously sealed in a packaging container. The study was conducted to more easily and accurately confirm the presence of carbon dioxide.

[0007] For example, in Patent Document 1, a carbon dioxide detection reagent packaging with a breathable substrate is disclosed as a packaging for a detection reagent that requires no operation during use and does not require concern about the contents scattering.

[0008] In addition, in Patent Document 2, a carbon dioxide detector that changes color even in a low-concentration carbon dioxide atmosphere and can visually determine the generation of carbon dioxide is disclosed. This carbon dioxide detector is obtained by sealing a substrate impregnated with an alkaline aqueous solution into a small bag with a specific water vapor permeability. The alkaline aqueous solution contains a pH indicator and a water-retaining agent and is adjusted in such a way that the pH indicator shows an alkaline color.

[0009] Furthermore, in Patent Document 3, a carbon dioxide detection ink composition comprising a pH indicator, a binder, and a solvent is disclosed as a carbon dioxide detection ink composition that allows for easy visual confirmation of color changes.

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent Application Publication No. 2015-219084

[0013] Patent Document 2: Japanese Patent Application Publication No. 2008-224579

[0014] Patent Document 3: International Publication No. 2001 / 044385 Summary of the Invention

[0015] The problem the invention aims to solve

[0016] As mentioned above, examples of products preserved by sealing in carbon dioxide include food, beverages, and pharmaceuticals. Carbon dioxide detectors are also sealed in these products and their packaging containers. These products contain moisture, leading to problems such as mold growth in the carbon dioxide detector, reduced visibility, and difficulty in judging color changes in detectors using pH indicators. Furthermore, if anti-mold agents are used in the detector to prevent mold growth, pH changes or the effectiveness of the anti-mold treatment are affected by pH, thus impacting the colorimetric properties of the pH indicator. Therefore, it is desirable to have a carbon dioxide detector that uses a pH indicator and that inhibits the growth of mold, etc., even when used in food, beverages, pharmaceuticals, and other products, thereby not affecting color changes or visibility.

[0017] Therefore, the objective of this invention is to provide a carbon dioxide detector that can inhibit the growth of mold and the like, and has excellent visibility of color changes, enabling it to accurately detect changes in carbon dioxide concentration.

[0018] Solution for solving the problem

[0019] In view of the above-mentioned problems, the inventors conducted in-depth research and found that a carbon dioxide detector containing an ink composition of a pH indicator, an alkali agent, a water-retaining agent, a specific amount of silver-based antibacterial agent and water, which is impregnated into a carrier, can solve the aforementioned problems, thereby completing the present invention.

[0020] The present invention provides the following [1]~

[12] .

[0021] [1] A carbon dioxide detector is obtained by impregnating an ink composition into a carrier, wherein the ink composition contains a pH indicator, an alkali agent, a water-retaining agent, a silver-based antibacterial agent and water, wherein the content of the silver-based antibacterial agent, calculated in silver equivalents, is 0.001 to 0.02 by mass relative to the total amount of the carbon dioxide detector.

[0022] [2] According to the carbon dioxide detector described in [1] above, wherein the silver-based antibacterial agent is a silver-supported antibacterial agent formed by supporting silver ions on an antibacterial agent carrier, and the antibacterial agent carrier is selected from at least one of the groups consisting of silicate-based carriers and phosphate-based carriers.

[0023] [3] The carbon dioxide detector according to the above [1] or [2], wherein the pH indicator is m-cresol purple.

[0024] [4] The carbon dioxide detector according to any one of [1] to [3] above, wherein the water-retaining agent is selected from at least one of the group consisting of polyols, polyalkylene glycols, acrylic polymers and cellulose.

[0025] [5] The carbon dioxide detector according to any one of [1] to [4] above, wherein the mass ratio of water to the carrier (water / carrier) is 0.7 to 1.0.

[0026] [6] The carbon dioxide detector according to any one of [1] to [5] above, wherein the mass ratio of water to the water-retaining agent (water / water-retaining agent) is 1.2 to 1.9.

[0027] [7] The carbon dioxide detector according to any one of [1] to [6] above further comprises a spreading agent.

[0028] [8] The carbon dioxide detector according to the above [7], wherein the spreading agent is silicon dioxide.

[0029] [9] A carbon dioxide detector packaging body comprising a carbon dioxide detector as described in any one of [1] to [8] above and a packaging material containing the carbon dioxide detector.

[0030]

[10] A method for manufacturing a carbon dioxide detector, wherein an ink composition containing a pH indicator, an alkali, a water-retaining agent, a silver-based antibacterial agent and water is impregnated into a carrier, and then mixed with a spreading agent.

[0031]

[11] A carbon dioxide sealed packaging body, characterized in that a carbon dioxide detector or a carbon dioxide detector packaging body described in any one of [1] to [8] above or [9] above is disposed in an outer packaging body, wherein the outer packaging body is sealed with a gas containing carbon dioxide.

[0032]

[12] A method for preserving an infusion containing bicarbonate, wherein a carbon dioxide detector or a carbon dioxide detector package as described in any one of [1] to [8] above, or as described in [9] above, is disposed in an outer packaging body along with the infusion containing bicarbonate, the outer packaging body being sealed with a gas containing carbon dioxide.

[0033] The effects of the invention

[0034] According to the present invention, a carbon dioxide detector is provided that can inhibit the growth of mold and the like, and has excellent visibility of color changes, enabling accurate detection of changes in carbon dioxide concentration. Detailed Implementation

[0035] [Carbon Dioxide Detector]

[0036] A carbon dioxide detector is obtained by impregnating an ink composition into a carrier. The ink composition contains a pH indicator, an alkali agent, a water-retaining agent, a silver-based antibacterial agent, and water. The content of the silver-based antibacterial agent, calculated in silver equivalents, is 0.001 to 0.02% by mass relative to the total amount of the carbon dioxide detector.

[0037] It should be noted that, in this invention, when referred to simply as "carrier," it refers to the carrier of the ink impregnation composition, and the carrier containing silver ions in the silver-based antibacterial agent described later is called "antibacterial agent carrier."

[0038] <Ink Composition>

[0039] The ink composition contained in the carbon dioxide detector contains a pH indicator, an alkali, a water-retaining agent, a silver-based antibacterial agent, and water.

[0040] (pH indicator)

[0041] pH indicators are used for the detection of carbon dioxide. By utilizing the pH change achieved through a carbon dioxide-based base neutralization reaction, carbon dioxide can be clearly detected even in low concentration regions.

[0042] The pH indicator used in the carbon dioxide detector of the present invention is preferably an indicator that has a color-changing region in the neutral to alkaline range, more preferably an indicator that has a color-changing region in the pH range of 7.0 to 10.0, and even more preferably an indicator that has a color-changing region in the pH range of 7.2 to 9.6. Furthermore, an indicator that clearly changes color for easy identification is preferred. An indicator with high thermal stability that can be used even at high temperatures is also preferred.

[0043] Examples of pH indicators that exhibit color-changing properties in the neutral to alkaline range include phenol red, cresol red, curcumin, anthocyanin, α-naphtholphthalein, m-cresol purple, thymol blue, o-cresolphthalein, and phenolphthalein. These can be used individually or in combination of two or more. When combining two or more, it is preferable to combine substances that produce the same hue within the same system.

[0044] Among these, m-cresol purple is preferred as the pH indicator because the color-changing region is alkaline, changes from purple to yellow at pH 9.0, exhibits a large color change, and thus has high chemical stability.

[0045] The amount of pH indicator is preferably an amount that produces a noticeable color change that can be visually confirmed. In the ink composition, it is preferably 0.001 to 0.1% by mass, more preferably 0.005 to 0.05% by mass. In the carbon dioxide detector, it is preferably 0.0005 to 0.05% by mass, more preferably 0.001 to 0.01% by mass.

[0046] (Alkali)

[0047] Since a pH indicator is used to detect carbon dioxide, the ink composition used in the carbon dioxide detector of the present invention contains an alkaline agent.

[0048] The alkali agent is preferably a compound with high solubility in water.

[0049] Examples of alkaline agents include metal phosphate salts, metal hydroxide salts, metal silicate salts, metal sulfite salts, and metal carbonate salts, with metal phosphate salts and metal hydroxide salts being preferred, and metal phosphate salts being even more preferred.

[0050] Phosphate and hydroxide salts are preferred because they have particularly high solubility in water.

[0051] Examples of metal phosphate salts include alkali metal phosphates, with trisodium phosphate being a preferred choice.

[0052] Examples of metal hydroxide salts include alkali metal hydroxides, with sodium hydroxide and potassium hydroxide being preferred, and sodium hydroxide being more preferred.

[0053] Ideally, the amount of alkali is adjusted according to the pH of its aqueous solution, and in the ink composition, it is preferably 0.02 to 1.0% by mass, more preferably 0.1 to 0.5% by mass. Additionally, in the carbon dioxide detector, it is preferably 0.01 to 0.5% by mass, more preferably 0.05 to 0.2% by mass.

[0054] (Water-retaining agent)

[0055] To retain moisture, the ink composition used in the carbon dioxide detector of the present invention contains a water-retaining agent. The type of water-retaining agent is not particularly limited as long as it has the effect of reducing water activity when added to the carbon dioxide detector; however, the following water-retaining agents are preferred.

[0056] The water-retaining agent is preferably selected from at least one of the group consisting of polyols, polyalkylene glycols, acrylic polymers and cellulose, and more preferably polyols.

[0057] Examples of polyols include glycerol, ethylene glycol, and propylene glycol, with glycerol being the preferred choice.

[0058] Examples of polyalkylene glycols include polyethylene glycol.

[0059] Examples of acrylic polymers include polyacrylates and polyacrylates.

[0060] From the viewpoint of rapidly detecting carbon dioxide concentration and effectively reducing water activity, the amount of water-retaining agent in the ink composition is preferably 10-70% by mass, more preferably 20-60% by mass. Furthermore, in the carbon dioxide detector, it is preferably 5-50% by mass, more preferably 10-40% by mass.

[0061] (Silver-based antibacterial agents)

[0062] The ink composition used in the carbon dioxide detector of the present invention contains a silver-based antibacterial agent, and the content of the aforementioned silver-based antibacterial agent, calculated in silver equivalent to the total mass of the carbon dioxide detector, is 0.001 to 0.02 by mass.

[0063] By including the above-mentioned amount of silver-based antibacterial agent in the carbon dioxide detector of the present invention, a carbon dioxide detector can be made that can inhibit the growth of mold and the like, has excellent visibility of color changes, and can accurately detect changes in carbon dioxide concentration.

[0064] The aforementioned silver-based antibacterial agent is preferably a silver-supported antibacterial agent formed by loading silver ions onto an antibacterial agent carrier. It should be noted that the carrier in the silver-based antibacterial agent is called an "antibacterial agent carrier".

[0065] As carriers for antibacterial agents that carry the aforementioned silver ions, examples include silicate-based carriers and phosphate-based carriers, with at least one selected from the group consisting of silicate-based carriers and phosphate-based carriers, and more preferably silicate-based carriers.

[0066] Examples of silicate-based carriers include zeolite, magnesium aluminum silicate, and calcium silicate, with zeolite being the preferred choice.

[0067] Examples of phosphate-based carriers include zirconium phosphate and calcium phosphate, with zirconium phosphate being the preferred option.

[0068] Among these, the antibacterial agent carrier that carries the aforementioned silver ions is preferably selected from at least one of the group consisting of zeolite and zirconium phosphate, and from a safety point of view, zeolite is more preferred.

[0069] The silver ion content in the silver-based antibacterial agent is preferably 1-20% by mass, more preferably 1-15% by mass, even more preferably 1-10% by mass, and even more preferably 1-5% by mass, and even more preferably 2-3% by mass, relative to the total amount of the silver-based antibacterial agent.

[0070] The content of silver-based antibacterial agent in the carbon dioxide detector, expressed as silver, is 0.001 to 0.02% of the total mass of the carbon dioxide detector.

[0071] The content of silver-based antibacterial agent in the carbon dioxide detector relative to the total amount of carbon dioxide detector, calculated in silver equivalents, is preferably 0.0015~0.02% by mass, more preferably 0.0015~0.01% by mass, even more preferably 0.0015~0.009% by mass, even more preferably 0.002~0.006% by mass, even more preferably 0.002~0.005% by mass, even more preferably 0.002~0.004% by mass, and even more preferably 0.002~0.003% by mass.

[0072] More specifically, the content of silver-based antibacterial agent in the carbon dioxide detector, expressed in silver equivalents, is preferably 0.0010 to 0.020% by mass relative to the total amount of carbon dioxide detector.

[0073] The content of the silver-based antibacterial agent in the carbon dioxide detector, calculated in silver equivalents relative to the total amount of the carbon dioxide detector, is preferably 0.0015 to 0.020% by mass, more preferably 0.0015 to 0.010% by mass, even more preferably 0.0015 to 0.0090% by mass, even more preferably 0.0020 to 0.0060% by mass, even more preferably 0.0020 to 0.0050% by mass, even more preferably 0.0020 to 0.0040% by mass, and even more preferably 0.0020 to 0.0030% by mass.

[0074] If the silver-based antibacterial agent content in the carbon dioxide detector is within the aforementioned range, it can effectively inhibit the growth of mold and other microorganisms, resulting in a carbon dioxide detector with excellent visibility of color changes. Therefore, the obtained carbon dioxide detector can accurately detect changes in carbon dioxide concentration. In particular, even after long-term storage, the visibility of color changes remains excellent, enabling accurate detection of changes in carbon dioxide concentration. Furthermore, it tends to offer an excellent balance between cost and performance.

[0075] The amount of silver-based antibacterial agent relative to the total amount of the ink composition, calculated in silver equivalents, is preferably 0.002 to 0.04% by mass, more preferably 0.003 to 0.025% by mass, even more preferably 0.003 to 0.02% by mass, even more preferably 0.003 to 0.018% by mass, even more preferably 0.004 to 0.008% by mass, and even more preferably 0.004 to 0.007% by mass.

[0076] The amount of silver-based antibacterial agent relative to the total amount of carbon dioxide detector is preferably 0.005-2% by mass, more preferably 0.01-1% by mass, even more preferably 0.03-1% by mass, even more preferably 0.03-0.5% by mass, even more preferably 0.05-0.3% by mass, and even more preferably 0.05-0.2% by mass.

[0077] The amount of silver-based antibacterial agent relative to the total amount of ink composition is preferably 0.01 to 4% by mass, more preferably 0.02 to 2% by mass, even more preferably 0.05 to 2% by mass, even more preferably 0.05 to 1% by mass, even more preferably 0.1 to 0.5% by mass, and even more preferably 0.1 to 0.3% by mass.

[0078] If the amount of silver-based antibacterial agent is within the aforementioned range, it can effectively inhibit the growth of mold and other fungi, resulting in a carbon dioxide detector with excellent visibility of color changes. Therefore, the obtained carbon dioxide detector can accurately detect changes in carbon dioxide concentration. In particular, even after long-term storage, the visibility of color changes remains excellent, enabling accurate detection of changes in carbon dioxide concentration. Furthermore, it tends to offer an excellent balance between cost and performance.

[0079] (water)

[0080] From the viewpoint of rapidly detecting carbon dioxide concentration, the water content in the ink composition is preferably 40-75% by mass, more preferably 50-65% by mass. Furthermore, in the carbon dioxide detector, it is preferably 30-40% by mass, more preferably 30-38% by mass, even more preferably 32-38% by mass, and even more preferably 32-36% by mass.

[0081] From the viewpoint of rapidly detecting carbon dioxide concentration, the mass ratio of water to the aforementioned water-retaining agent (water / water-retaining agent) is preferably 1.0 to 2.0, more preferably 1.2 to 1.9. By setting the mass ratio of water to the aforementioned water-retaining agent within the aforementioned range, it is possible to obtain a carbon dioxide detector without unevenness during manufacturing. In particular, thorough mixing results in a uniform and particulate carbon dioxide detector.

[0082] Furthermore, from the viewpoint of rapidly detecting carbon dioxide concentration and improving flowability, the mass ratio of water to the carrier (water / carrier) is preferably 0.5 to 2.0, more preferably 0.7 to 1.0. By setting the mass ratio of water to the aforementioned carrier within the aforementioned range, color development is improved, and it is easier to fill into packaging materials.

[0083] <Carrier>

[0084] The carbon dioxide detector of the present invention is obtained by impregnating the aforementioned ink composition into a carrier. By impregnating into the carrier and forming it into a particulate shape, it has excellent flowability.

[0085] As a carrier, porous particles are preferred, and porous inorganic particles are more preferred.

[0086] Examples of porous inorganic particles include silica gel, diatomaceous earth, zeolite, and porous silicates, with porous silicates being the preferred choice.

[0087] Among porous silicates, magnesium aluminum silicate is preferred for its suitability for food and pharmaceutical applications.

[0088] In addition, the carrier is preferably colorless or white to make the color change more distinct. The pH of the carrier is preferably neutral to alkaline.

[0089] From the viewpoint of flowability and composability, the average particle size of the carrier is preferably 1~500μm, more preferably 100~300μm.

[0090] From the perspective of fluidity, the shape of the carrier is preferably spherical or approximately spherical, and more preferably spherical.

[0091] From the viewpoint of rapidly detecting carbon dioxide concentration and improving fluidity, the amount of carrier in the carbon dioxide detector is preferably 20 to 70% by mass, more preferably 30 to 60% by mass.

[0092] <Spreading agent>

[0093] From the viewpoint of maintaining the clarity of hue changes and improving fluidity, the carbon dioxide detector of the present invention preferably contains a spreading agent.

[0094] The spreading agent preferably adheres to the outer surface of the carrier impregnated with the aforementioned ink composition.

[0095] Examples of spreading agents include silica, calcium silicate hydrate, magnesium oxide, calcium hydroxide, and charcoal. Activated carbon is preferred. Silica is preferred.

[0096] The spreading agent is preferably spherical microparticles, more preferably spherical silica, and even more preferably spherical hydrophobic silica.

[0097] From the viewpoint of improving fluidity, the amount of spreading agent in the carbon dioxide detector is preferably 0.1 to 5% by mass, more preferably 0.2 to 2% by mass.

[0098] [Carbon dioxide detector packaging]

[0099] The carbon dioxide detector packaging of the present invention comprises the aforementioned carbon dioxide detector and packaging material containing the carbon dioxide detector.

[0100] The aforementioned carbon dioxide detector is a highly free-flowing granular substance. Depending on the intended use, it can be used directly, or preferably packaged and stored as a carbon dioxide detector packaging.

[0101] The packaging form of carbon dioxide detectors can include bags, boxes, etc., with bags being the preferred form.

[0102] As a packaging material for carbon dioxide detectors, a transparent resin film is preferably used to determine the presence or absence of carbon dioxide by visually confirming changes in color.

[0103] Preferred packaging materials include: biaxially oriented polypropylene (OPP), unstretched polypropylene (CPP), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), polyethylene terephthalate (PET), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), and stretched polyamide (ONY). One of these materials can be used, or two or more of these materials can be layered. Preferred laminated packaging materials include films made from biaxially oriented polypropylene (OPP) and low-density polyethylene (LDPE).

[0104] Furthermore, since a portion of the packaging needs to be open and exposed to the external atmosphere used for detecting carbon dioxide concentration, it is preferable to provide a vent in a part of the packaging. The vent is preferably designed to allow carbon dioxide to pass through without allowing the carbon dioxide detector of this invention to pass through, and is preferably formed of a filament or a fine porous membrane, more preferably a filament. Examples of porous membranes include nonwoven fabrics.

[0105] A portion of the aforementioned thread is located inside the packaging (the carbon dioxide detector housing), and a portion extends to the outside of the packaging. When the thread forms vents, it achieves ventilation by means of the space between the fibers constituting the thread or between the fibers and the materials used in the packaging.

[0106] The aforementioned thread-like material can be any aggregate of fibrous materials forming a thread. For packaging purposes, a thread-like material with a melting point of 80°C or higher is preferred. Sewing thread is a preferred example of such a thread-like material. Examples of materials for the thread-like material include polyethylene terephthalate, cotton, polyester, vinylon, silk, and nylon, with polyethylene terephthalate, nylon, and vinylon being preferred. The thread thickness is preferably 1 to 100 count yarn, more preferably 10 to 80 count yarn, and even more preferably 15 to 60 count yarn.

[0107] [Manufacturing method of carbon dioxide detector]

[0108] There are no limitations on the manufacturing method of the carbon dioxide detector of the present invention. Preferably, it is manufactured by impregnating a carrier with an ink composition containing a pH indicator, an alkali, a water-retaining agent, a silver-based antibacterial agent and water. More preferably, it is manufactured by impregnating a carrier with an ink composition containing a pH indicator, an alkali, a water-retaining agent, a silver-based antibacterial agent and water, and then mixing it with a spreading agent.

[0109] To ensure that the ink composition is evenly impregnated into the carrier, it is preferable to use a mixer for stirring.

[0110] In addition, to ensure that the spreading agent adheres evenly around the carrier, it is preferable to use a mixer for stirring.

[0111] As for the conditions during stirring, it is preferable to stir at a speed of 10 to 40 rpm.

[0112] [Carbon dioxide sealed into the packaging]

[0113] The carbon dioxide-sealed packaging of the present invention is characterized in that the aforementioned carbon dioxide detector or the aforementioned carbon dioxide detector packaging is disposed within an outer packaging body, and the outer packaging body is sealed with a gas containing carbon dioxide. Specifically, the carbon dioxide-sealed packaging of the present invention is characterized in that a carbon dioxide detector, or the aforementioned carbon dioxide detector packaging, is disposed within an outer packaging body, wherein the carbon dioxide detector is impregnated with an ink composition containing a pH indicator, an alkali agent, a water-retaining agent, a silver-based antibacterial agent, and water into a carrier, and the content of the silver-based antibacterial agent, calculated in silver equivalents, is 0.001 to 0.02% by mass relative to the total amount of the carbon dioxide detector, and the outer packaging body is sealed with a gas containing carbon dioxide.

[0114] The carbon dioxide-sealed packaging of the present invention contains carbon dioxide gas and the aforementioned carbon dioxide detector inside the packaging body, i.e., the outer packaging body. In addition, the outer packaging body contains medicine, food, etc. as contents.

[0115] The contents of liquid medicines, food, etc. are preferably further stored in a container, preferably placed inside the outer packaging.

[0116] The outer packaging used for the carbon dioxide-sealed packaging of the present invention is preferably made of a gas-barrier material that makes it difficult for carbon dioxide-containing gases to permeate. Specifically, examples include resin films such as ethylene-vinyl alcohol copolymer, polyethylene terephthalate, and nylon; and composite films obtained by vapor-depositing silica, alumina, etc., onto these resin films. Furthermore, to visually confirm the color change of the aforementioned carbon dioxide detector from the outside of the outer packaging, part or all of the outer packaging is transparent.

[0117] The gas containing carbon dioxide may consist solely of carbon dioxide, or it may consist of carbon dioxide and inert gases such as nitrogen. The concentration of carbon dioxide in the gas is preferably 1-50%, more preferably 1-15%, and even more preferably 3-10%.

[0118] Examples of contents that can be contained in the carbon dioxide-sealed packaging of this invention include pharmaceuticals, food, and more specifically, pharmaceuticals containing bicarbonates such as sodium bicarbonate, fruits and vegetables, raw meat, and snacks. When using an infusion containing bicarbonates as the pharmaceutical solution, the detection of carbon dioxide concentration over a short period by the aforementioned carbon dioxide detector allows for early use or movement and storage in a carbon dioxide atmosphere, thus inhibiting product deterioration; therefore, this is preferred.

[0119] [Preservation methods for infusions containing bicarbonate]

[0120] In the method for preserving bicarbonate-containing infusion solutions of the present invention, the aforementioned carbon dioxide detector or the aforementioned carbon dioxide detector packaging body and the bicarbonate-containing infusion solution are disposed within an outer packaging body, and the outer packaging body is sealed with a gas containing carbon dioxide. Specifically, in the method for preserving bicarbonate-containing infusion solutions of the present invention, the carbon dioxide detector or the aforementioned carbon dioxide detector packaging body and the bicarbonate-containing infusion solution are disposed within an outer packaging body. The carbon dioxide detector is impregnated with an ink composition containing a pH indicator, an alkali agent, a water-retaining agent, a silver-based antibacterial agent, and water into a carrier, and the content of the silver-based antibacterial agent, calculated in silver equivalents, is 0.001~0.02% by mass relative to the total amount of the carbon dioxide detector. The outer packaging body is sealed with a gas containing carbon dioxide.

[0121] Bicarbonate-containing infusions are used as extracellular fluid resuscitation solutions, with bicarbonate ions acting as alkalizing agents to regulate the extracellular fluid. However, bicarbonate-containing infusions have the property of releasing carbon dioxide, thus losing their efficacy. Therefore, they are preserved by packaging the container holding the bicarbonate-containing infusion along with carbon dioxide in a gas-barrier packaging container to prevent carbon dioxide release.

[0122] When bicarbonate-containing infusions are stored in a carbon dioxide atmosphere, the reduction in carbon dioxide concentration in the gas can be detected in a short time by using the aforementioned carbon dioxide detector. Therefore, easily deteriorating bicarbonate-containing infusions can be used up early and then stored again in a carbon dioxide atmosphere, effectively preventing the deterioration of bicarbonate-containing infusions. This is therefore preferred.

[0123] The outer packaging used in the preservation method of the present invention is preferably an outer packaging that is suitable for the aforementioned carbon dioxide sealing packaging. Specifically, it is preferably made of a gas-barrier material that makes it difficult for carbon dioxide-containing gases to pass through. Examples of such materials include ethylene-vinyl alcohol copolymers, polyethylene terephthalate, nylon, and other resin films; and composite films obtained by vapor-depositing silica, alumina, etc., onto these resin films.

[0124] The gas containing carbon dioxide is preferably composed of carbon dioxide and nitrogen. The concentration of carbon dioxide in the gas is preferably 1 to 50%, more preferably 1 to 15%, and even more preferably 3 to 10%.

[0125] The storage temperature of the preservation method of the present invention is preferably 5~40℃.

[0126] The preservation method of the present invention is more effective when moving or transporting infusions containing bicarbonate. Specifically, a preferred method for moving or transporting infusions containing bicarbonate includes placing the aforementioned carbon dioxide detector and the bicarbonate-containing infusion within an outer packaging body, which is sealed with a gas containing carbon dioxide.

[0127] When moving or transporting bicarbonate-containing infusions, damage to the outer packaging that cannot be visually determined is often caused by external stimuli or impacts. However, the aforementioned carbon dioxide detector can detect the reduction in carbon dioxide concentration in a short time. This allows bicarbonate-containing infusions with damaged outer packaging to be used up early and then stored again in a carbon dioxide atmosphere, effectively preventing the deterioration of bicarbonate-containing infusions. Therefore, this method is preferred.

[0128] Example

[0129] The present invention will now be described in more detail using examples and comparative examples, but the present invention is not limited to these examples.

[0130] [evaluate]

[0131] The carbon dioxide detectors obtained in the examples and comparative examples were evaluated as follows.

[0132] <Appearance of the antibacterial / carbon dioxide detector after storage>

[0133] (Manufacturing of carbon dioxide detector packaging)

[0134] 0.2g of the carbon dioxide detector obtained in the examples and comparative examples was placed into a bag (with a ventilation line) formed by a transparent laminated film of OPP / LLDPE of 2.5cm×3.0cm, and the opening was heat-sealed to obtain the packaging of the carbon dioxide detector.

[0135] (Experimental Methods)

[0136] [1] Evaluation of antibacterial properties

[0137] 0.2 g of the carbon dioxide detector obtained in the Examples and Comparative Examples was attached with Cladosporium species and stored at 25°C for one month. Next, the stored carbon dioxide detector was inoculated onto PDA medium. The inoculated PDA medium was incubated at 25°C for 5 days, and then the colonies were counted. The lower the colony count, the better the antibacterial activity. Based on the colony count, the following evaluation was performed, with A being considered acceptable.

[0138] The carbon dioxide detector exhibited excellent antibacterial properties, and no mold was observed after storage. Its appearance after storage was excellent, with excellent visibility of color changes accompanying variations in carbon dioxide concentration. It should be noted that colony counts were not performed in Example 1, but no mold was observed in the appearance of the stored carbon dioxide detector; therefore, it was rated A according to the following evaluation criteria.

[0139] (Evaluation Criteria)

[0140] A: Colony count less than 500

[0141] B: Colony count is above 500 but less than 1500

[0142] C: Colony count above 1500

[0143] [2] Evaluation of the appearance of carbon dioxide detectors after storage

[0144] (Manufacturing of carbon dioxide detector packaging)

[0145] 0.2g of the carbon dioxide detector obtained in the examples and comparative examples was placed into a bag (with a ventilation line) formed by a transparent OPP / LLDPE film of 2.5cm×3.0cm, and the opening was heat-sealed to obtain the carbon dioxide detector package.

[0146] (Storage and evaluation of carbon dioxide detector packaging)

[0147] The aforementioned carbon dioxide detector packaging was placed in a 250mL gas-barrier film bag, the opening was heat-sealed, and the detector was stored. The appearance of the carbon dioxide detector was observed after 2 weeks and 6 weeks. The appearance of the carbon dioxide detector after 2 weeks and 6 weeks was compared with that immediately after storage to evaluate the timing of black aggregate formation and the proportion of black aggregate after 6 weeks. The proportion of black aggregate after 6 weeks was evaluated according to the following criteria. It should be noted that in Table 1, cases where no black aggregate formed after 6 weeks are recorded as "no aggregate formation". The slower the formation of black aggregate and the lower the proportion of black aggregate, the better the appearance after storage. In addition, the appearance after storage is even better when no black aggregate forms, and the visibility of the color change accompanying the change in carbon dioxide concentration is extremely excellent.

[0148] It should be noted that no color change was observed in the carbon dioxide detector of the embodiment before storage or after 6 weeks, indicating that the use of silver-based antibacterial agents did not affect the colorimetric properties of the carbon dioxide detector. Therefore, it can be concluded that the carbon dioxide detector according to the present invention can perform accurate detection.

[0149] (Evaluation Criteria)

[0150] A: No black aggregates were observed (0%)

[0151] B: The proportion of black aggregates is greater than 0% and less than 30%.

[0152] C: The proportion of black aggregates is above 30% but less than 50%.

[0153] D: The proportion of black aggregates is more than 50% but less than 70%.

[0154] E: The proportion of black aggregates is above 70% and less than 90%.

[0155] F: The proportion of black aggregates is over 90%.

[0156] [Carbon Dioxide Detector]

[0157] Example 1

[0158] A purple ink composition was obtained by mixing 0.016 g of m-cresol purple (pH indicator), 0.25 g of trisodium phosphate dodecahydrate (alkali agent), 59.5 g of glycerol (water-retaining agent), and 0.12 g of Zeomic (antibacterial agent carrier: zeolite, silver content: 2.5% by mass, manufactured by Sinanen Zeomic Co., Ltd.) (silver-based antibacterial agent) with 83 g of distilled water. This ink composition was then impregnated with 100 g of magnesium aluminum silicate (trade name: Neucilin SG2, average particle size: approximately 200 μm) as a carrier, and 0.75 g of hydrophobic silica (spreading agent) was added and stirred to obtain a purple carbon dioxide detector. The evaluation results are shown in Table 1.

[0159] Examples 2-6 and Comparative Examples 1-5

[0160] As shown in Table 1, the type and amount of silver-based antibacterial agent were changed, and the procedure was otherwise the same as in Example 1 to obtain a purple carbon dioxide detector. The evaluation results are shown in Table 1.

[0161] Comparative Example 6

[0162] Without using silver-based antibacterial agents, the procedure was the same as in Example 1, yielding a purple carbon dioxide detector. The evaluation results are shown in Table 1.

[0163] [Table 1]

[0164]

[0165] As shown in Table 1, it can be seen that the carbon dioxide detector of the embodiment also inhibits the growth of black mold after storage, and no aggregates were observed. Therefore, the visibility of color change is excellent even after storage. Thus, it can be seen that the carbon dioxide detector of the present invention can inhibit the growth of mold and the like, and has excellent visibility of color change, enabling accurate detection of changes in carbon dioxide concentration.

Claims

1. A carbon dioxide detector, which is obtained by impregnating an ink composition into a carrier. The ink composition contains a pH indicator, an alkali agent, a water-retaining agent, a silver-based antibacterial agent, and water. The content of the silver-based antibacterial agent, calculated as silver relative to the total mass of the carbon dioxide detector, is 0.001 to 0.02 by mass.

2. The carbon dioxide detector according to claim 1, wherein, The silver-based antibacterial agent is a silver-supported antibacterial agent formed by loading silver ions onto an antibacterial agent carrier, wherein the antibacterial agent carrier is selected from at least one of the groups consisting of silicate-based carriers and phosphate-based carriers.

3. The carbon dioxide detector according to claim 1 or 2, wherein, The pH indicator is m-cresol purple.

4. The carbon dioxide detector according to any one of claims 1 to 3, wherein, The water-retaining agent is selected from at least one of the following groups: polyols, polyalkylene glycols, acrylic polymers, and cellulose.

5. The carbon dioxide detector according to any one of claims 1 to 4, wherein, The mass ratio of water to the carrier, i.e., water / carrier, is 0.7~1.

0.

6. The carbon dioxide detector according to any one of claims 1 to 5, wherein, The mass ratio of water to the water-retaining agent, i.e., water / water-retaining agent, is 1.2 to 1.

9.

7. The carbon dioxide detector according to any one of claims 1 to 6, further comprising a spreading agent.

8. The carbon dioxide detector according to claim 7, wherein, The spreading agent is silicon dioxide.

9. A carbon dioxide detector packaging body comprising a carbon dioxide detector according to any one of claims 1 to 8 and a packaging material containing the carbon dioxide detector.

10. A method for manufacturing a carbon dioxide detector, wherein, An ink composition containing a pH indicator, an alkali agent, a water-retaining agent, a silver-based antibacterial agent, and water is impregnated into a carrier, and then mixed with a spreading agent.

11. A carbon dioxide-sealed packaging, characterized in that, The carbon dioxide detector of any one of claims 1 to 8 or the carbon dioxide detector packaging of claim 9 is disposed in an outer packaging body, wherein the outer packaging body is sealed with a gas containing carbon dioxide.

12. A method for preserving an infusion containing bicarbonate, wherein, The carbon dioxide detector of any one of claims 1 to 8 or the carbon dioxide detector packaging of claim 9 is disposed in an outer packaging body along with an infusion containing bicarbonate, the outer packaging body being sealed with a gas containing carbon dioxide.

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