JP2872245B2 - Oxygen indicator - Google Patents

Description

The present invention relates to an oxygen indicator. More specifically, it comprises a specific dye, an alkaline substance, a reducing agent capable of reducing the dye, and water and / or alcohols,
The present invention relates to an oxygen indicator capable of visually observing the presence or absence of oxygen in an atmosphere by a color change of a dye.

2. Description of the Related Art In recent years, various oxygen absorbers have been developed and used for oxygen-free management for food storage, metal rust-proof storage, clothing insect-proof storage, and the like. In these controls, an oxygen indicator is used in combination so that the presence or absence of oxygen can be easily confirmed. For such an oxygen indicator, see Fisheries Bacteriology, p85-86, 4th edition (Showa 21). Year), "Ge
neeskunde66, 1. ", 1423-1427 (1922), Japanese Patent Publication No. 55-4772
Various researches and developments have been attempted as described in the literatures and patents such as Japanese Patent Publication No. 56-24906, Japanese Patent Application Laid-Open Nos. 54-48294 and 56-8547.

In most cases, the known oxygen indicators shown in these documents are composed of a redox dye, a reducing agent and water, and from the results of examination of many combinations of these, as a redox dye, a thiazine-based A methylene blue dye as a dye is selected as a preferable reducing agent from a reducing saccharide under alkaline conditions. However, the following disadvantages are observed in the oxygen indicator by the combination thereof.

(A) Methylene blue dyes belong to basic dyes, which are cationic in an aqueous solution, and easily form a complex with an anionic drug to aggregate. In general, it is somewhat unstable and difficult to manage under alkaline conditions.

(Ii) Since the methylene blue dye has a cationic group, equipment contamination and human body contamination are extremely large, and workability in industrial production is extremely poor.

(C) The oxygen indicator composed of a methylene blue dye has a slow discoloration speed. In particular, when refrigerated or frozen storage is performed, as in the case of storing food, the speed change speed is significantly reduced.

(D) When the methylene blue dye is mixed with an alkaline reducing agent, the dye becomes extremely sensitive to light and discoloration is remarkable.

Problems to be Solved by the Invention There is a demand for the development of a stable oxygen indicator which contains a discolorable dye which is easy to produce a discolorable dye and has good compatibility with other chemicals, has a fast discoloration speed, and is easy to handle.

Means for Solving the Problems The present inventors have made intensive efforts to solve the above-described problems, and as a result, (A) shown by the following formula (2), (3), (4) or (5) A reducing agent capable of reducing the indophenol dye of (B) an alkaline substance (C) or (A); and (D) an oxygen indicator comprising water or / and alcohols.

(In the formulas (2), (3), (4) and (5), X represents a hydrogen atom or a halogen atom, Z is a hydrogen atom or an alkali metal, R ₁ is hydrogen, halogen, C _1-4 alkyl,
Allyl, optionally substituted aryl, optionally substituted alkoxy, cycloalkane or sulfo,
R ₂ represents C _1-4 alkyl, benzyl, optionally substituted aryl or alkoxyalkyl.
M represents 1 or 2. However, when m is 2, R ₁ may be the same group or different groups. In addition, the present invention relates to an oxygen indicator using the indophenol-based dye represented by Formula (3) or Formula (5) as (A).

 The oxygen indicator of the present invention will be specifically described.

The indophenol dye used in the present invention can be easily produced according to a known method. For example,
"Review Synthetic Dyes", (Hiraku Kuchiguchi, Sankyo Publishing) p362-36
It can be easily produced according to the method described in 3 or by dropping a commercially available Gipps reagent into an aqueous solution of the corresponding phenol or alcohol under alkaline conditions.

Indophenol-based dyes have an -OH group and become alkaline salts of phenols such as -ONa and -OK under alkalinity due to having -OH groups, and are water-soluble and have good compatibility with chemicals other than cationic chemicals. It is characterized by low pollution.

The alkaline substance used in the oxygen indicator of the present invention is an aqueous substance having a pH of 8 or more in a water solvent system, and is usually an alkali metal or alkaline earth metal hydroxide or a weak acid salt. Specific examples are NaOH, KOH, LiOH, Mg
_{(OH) 2, Ca (OH} ) 2, Na 2 CO 3, K 2 CO 3, Li 2 CO 3, MgCO 3, CaCO
₃ , NaHCO ₃ , Na ₃ PO ₄ , Na ₂ HPO ₄ , HPO ₄ , KHCO ₃ , CH ₃ COONa,
HCOONa, borax and the like may be mentioned, and these may be used in combination of two or more kinds, or may be a buffer solution containing a combination of these. Among them, Na ₂ CO ₃ , K ₂ CO ₃ , NaHCO
₃ , KHCO ₃ and CaCO ₃ are more preferred examples.

Next, as a reducing agent for reducing the indophenol-based dye, a reducing agent that exhibits a sufficient reducing power even when used in combination with the above-mentioned alkaline substance, and specific examples thereof include reducing saccharides, ascorbic acid or a salt thereof, and isoascorbic acid. Or a salt thereof, butylhydroxyanisole, pyruvic acid or a salt thereof, phosphite, hypophosphite, sulfite, thiourea dioxide, Rongalites, dithionite, borohydride, thioglycolic acid And the like. Among these reducing agents, it is preferable to use reducing saccharides from the viewpoints of decoloring speed, stability, hygiene safety and the like, and examples thereof include glucose, fructose and maltose.

In the oxygen indicator of the present invention, water and alcohols are used as essential components. Among them, water is not only normal water but also water of crystallization in a compound having crystallization water (eg, sodium tertiary phosphate). And water in a water-absorbing agent or moisture absorbing agent such as calcium chloride, water in a water retaining agent or humectant such as ε-caprolactam, or water in a water-absorbing resin. Also, as the alcohols, those having a low volatility and being in a liquid or solid state are preferable, and specific examples thereof include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and glycerin. can give. Among these, polyethylene glycol having a molecular weight of 200 to 20,000 is more preferable because it has no volatility, has no adverse effect on the pigment, and has a large water retention capacity.

The oxygen indicator of the present invention comprises 0.5 to 100 parts by weight (more preferably 1 to 50 parts by weight) of an alkaline substance and 0.5 to 50 parts by weight of a reducing agent (more preferably 1 to 20 parts by weight) based on 1 part by weight of an indophenol dye. ). Water is added in an amount equal to or more by weight than the indophenol-based dye, depending on the use form of the oxygen indicator of the present invention. The oxygen indicator of the present invention is prepared by mixing these chemicals with other chemicals as necessary and then pulverizing and mixing them with a sand mill, ball mill, roll mill, attritor or the like as necessary. When actually used, they are used in a liquid state, and are subjected to processing such as gelation, impregnation or printing on a sheet, and molding into a tablet.

The usual composition when used in a liquid form is as follows: Is put in a container, and the upper part is opened or plugged with an oxygen-permeable material, or packed in an oxygen-permeable resin bag to be used as an oxygen indicator.

The composition described above can be used as a sheet which is easy to handle by penetrating into a carrier described later. As the carrier at this time, a porous cellulose material such as paper, gauze, absorbent cotton, or the like, a nonwoven fabric, a porous synthetic resin such as poly-2-hydroxyethyl methacrylate, or the like is convenient. Further, for the purpose of firmly adhering the composition as described above to the carrier, it is preferable to add a water-soluble polymer compound used in preparing an aqueous ink described below in an amount of 0.5 to 10% (by weight) as a solid content. Further, the composition (1) as described above can be used by gelling it with a gelling agent such as agar, gelatin, dextrin, glycomannan, sodium polyacrylate and the like. The amount of the gelling agent used at this time varies depending on the type and the degree of gelation of the gelling agent, but generally 0.1 to 3% by weight based on the composition may be added.

The oxygen indicator of the present invention can be used as a water-based or oil-based ink by coating or printing on a sheet-like material such as cellulose or plastic.

In the case of an aqueous ink: For example, a sheet as described above is prepared by preparing the composition (1) as described above and adding 1 to 20 (% by weight) of a water-soluble polymer compound as a solid content to the composition. The inside of the coating is printed on the object. In this case, as the water-soluble polymer compound, sodium alginate, gum arabic, gum tragacanth, carboxymethylcellulose, hydroxyethylcellulose, methylcellulose,
Polyvinyl alcohol, dextrin, casein, SBR
Latex, polyvinyl acetate, vinyl copolymer, polyvinyl acrylamide, polyvinyl urethane and the like are suitable.

In the case of oil-based ink: A mixture is prepared using the following solvent and resin at a composition ratio as shown in the composition (II) described below, and the mixture is made into fine particles or dissolved by a sand mill, a ball mill, a roll mill, an attritor, or the like. To form an oil-based ink, which is coated or printed on a sheet-like material as described above.

Examples of the solvent include alcohols such as methanol, ethanol, and isopropyl alcohol; esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone; glycols such as ethylene glycol; and cellosolves such as ethylene glycol monoether. And aromatics such as toluene and xylene. As the resin, ethyl cellulose, ethyl hydroxyethyl cellulose, celluloses such as cellulose acetyl propionate, vinyl acetate resin butyral resin,
Polyester resin, acrylic resin, polyether resin,
A polyamide resin, a petroleum resin or the like is used. Examples of the inorganic substance include water-insoluble hydroxides of alkaline earth metals, such as calcium hydroxide, barium hydroxide, and magnesium hydroxide.

Further, the usual composition when the oxygen indicator of the present invention is used as a tablet is as follows.

The tablet is manufactured by a known method, but a release agent or the like can be added to the tablet as long as the function of the indicator is not hindered.

The oxygen indicator of the present invention comprises an indophenol dye, an alkaline substance, a reducing agent capable of reducing the indophenol dye and water and / or alcohols as essential components. Dyes (particularly anionic dyes) or pigments for adjusting the hue that do not change color in the state may be added, or a surfactant, a light resistance improver, a preservative, or the like. When a sheet is used as the carrier, the composition may be impregnated with the above-mentioned composition and then subjected to a heat treatment, if desired, to be partially dried.

The oxygen indicator of the present invention has the following features. (1) The dye used is water-soluble under alkaline conditions, and has good compatibility with anionic and nonionic concomitant drugs.

(2) Since the contamination of the dye used in various devices such as rubber, glass and metal is small, the productivity is good not only when manufacturing the dye itself but also the oxygen indicator of the present invention.

(3) It is a high-sensitivity oxygen indicator with a fast discoloration speed.

(4) High resistance to light.

And so on.

Examples The present invention will be described more specifically by way of examples.

Reference Example 1 Was weighed and dissolved by adding 25 ml of warm water.

To this, 60 g of 15% paste of Fine Gum DP-70 (CMC paste material, manufactured by Daiichi Kogyo Seiyaku) was added and mixed well.

7.5 g of polyethylene glycol 300 (molecular weight 300)
Was added and mixed, and finally 5 g of glucose was added and mixed well.

(2) Toyo Paper No. 2 was printed with the color paste of (1) in a floral pattern using a 250 mesh screen. The resultant was treated at 60 ° C. for 15 minutes and partially dried to obtain a blue floral print (oxygen indicator).

(3) The printed material obtained in (2) was sealed in an oxygen-impermeable film together with Modulan W-500 (manufactured by Nippon Kayaku Co., Ltd., a water-dependent oxygen absorber) and a 5 cm square absorbent paper. 12
When observed after an hour, it turned red.

Reference Examples 2 to 12 and Examples 1 to 5 The same as Reference Example 1 except that the dye shown in the column of “Dye” in Table 1 was used instead of 2,6-dichloroindophenol sodium salt in Reference Example 1. Thus, an oxygen indicator of the present invention using paper as a carrier was obtained. For these indicators, the hue in the presence of oxygen and the hue in the presence of deoxygenation were observed, and the results are also shown in Table 1.

Reference Example 13 Was weighed, and 76 ml of warm water was added to dissolve it. Fructose 2g, polyethylene glycol 400 (molecular weight 400) 10
g was added and dissolved. 2% of sodium alginate
10 g of the liquid was added and stirred to obtain a uniform solution.

(2) Toyo paper No.2 is padded on the solution obtained in (1) and picked up using a double mangle at a pressure of 2.5 kg / cm ^2.
5% was squeezed and partially dried at 60 ° C. for 15 minutes to obtain a blue oxygen indicator of the present invention using paper as a carrier.

(3) Put the blue oxygen indicator obtained in (2) together with a commercially available self-reactive oxygen absorber (Ageless S-50, manufactured by Mitsubishi Gas Chemical) into a bag made of oxygen-impermeable film and seal it. did.

Observation after 12 hours revealed that the blue color had disappeared and became white.

Reference Examples 14 to 26 and Example 6 The same procedure as in Reference Example 13 was carried out except that the dye shown in the column of "Dye" in Table 2 was used instead of 2,6-dichloroindophenol sodium salt in Reference Example 13. Thus, an oxygen indicator of the present invention using paper as a carrier was obtained. For these indicators, the hue in the presence of oxygen and the hue under deoxygenation were observed, and the results are shown in Table 2.

Reference Example 27 and Comparative Example The oxygen indicator and the comparative indicator of the present invention were prepared according to the composition shown in Table 3 according to Reference Example 13, and their performances were compared.

As is clear from the table, it was found that the oxygen indicator of the present invention had a more sensitive reaction to oxygen than the oxygen indicator according to the comparative example. In addition, even if using a Minolta color difference meter for both oxygen indicators after 24 hours, L,
The a and b values were measured. The results are as follows. (4th
table) As is clear from the table, the oxygen indicator of Reference Example 27 using 2,6-dichloroindophenol sodium salt has a clearer blue decoloration and a pure red color (Red No. 106) than the oxygen indicator of Comparative Example using methylene blue. Color).

On the other hand, the oxygen indicator of the comparative example was not pure red but purple.

Also, when squeezed with a mangle after padding, the mangle was scarcely contaminated in Reference Example 27, whereas extremely large contamination was left in the comparative example.
The pollution to the was also large.

Further, as a result of leaving the papers obtained in Reference Example 27 and Comparative Example in the air under the rays of the north window, the following results were obtained. (Table 5) From these results, the comparative product is extremely sensitive to light, and has a disadvantage that it is extremely difficult to handle in practice.
The indicator of Reference Example 27 is stable.

Reference Example 28 (1) 0.5 ml of a 1% aqueous solution of 2,6-dichloroindophenol sodium salt and 1 g of polyethylene glycol 400 were weighed into a mortar and mixed and dissolved. 5g of calcium carbonate,
2 g of sodium bicarbonate, 5 g of Avicel 101 (manufactured by Asahi Kasei Corporation, crystalline cellulose) and 1 g of fructose were weighed and uniformly mixed.

This was pressed at 200 kg / cm ² with a tablet press (manufactured by JASCO Corporation) to obtain a blue tablet type oxygen indicator of the present invention.

(2) The indicator obtained in (1) was put in a bag made of an oxygen-impermeable film together with a commercially available self-reactive oxygen absorber and sealed. When observed after 6 hours, the blue color had changed to white.

Reference Examples 29 to 38 In Reference Example 28, the dyes shown in the column of "Dye" in Table 6 were used in place of 2,6-dichloroindophenol sodium salt, and 20 mg of Red No. 106 was newly added. As above, a tablet type oxygen indicator of the present invention was obtained. The hue in the presence of oxygen and the hue under deoxygenation were observed for these indicators. The results are shown in Table 6.

Effect of the Invention Good compatibility with other drugs, low contamination to equipment and human body, easy to produce, high light resistance and high sensitivity oxygen indicator with fast discoloration speed can be obtained. Was.

Claims (1)

(57) [Claims] 1. A method comprising: (A) an indophenol dye represented by the following formula (1), (B) an alkaline substance, (C) a reducing agent capable of reducing (A), (D) water and / or alcohols. Oxygen indicator (In the formula (1), X represents a hydrogen atom or a halogen atom;
Q represents the following formula (3) or (5). (In formulas (3) and (5), Z represents a hydrogen atom or an alkali metal, R ₁ represents hydrogen, halogen, C _1-4 alkyl,
Allyl, optionally substituted aryl, optionally substituted alkoxy, cycloalkane or sulfo is represented by R ₂
Represents a C _1-4 alkyl, benzyl, an optionally substituted aryl or alkoxyalkyl, respectively. M represents 1 or 2. However, when m is 2, R ₁ may be the same group or different groups. ))