JPS6017394B2 - Oxygen indicator ink composition - Google Patents

Description

[Detailed description of the invention] The present invention relates to oxygen indicator ink compositions.

Oxygen absorbers are effective in maintaining the quality of various foods, preventing mold, and preventing pests, so several types are already on the market. However, with conventional oxygen scavengers, it is often difficult to distinguish between those that have oxygen absorption capacity and those that have lost oxygen absorption capacity, leading to quality accidents due to unknowing use of substances that have already lost oxygen absorption capacity. There is a danger. Therefore, a method of visually determining the oxygen absorbing ability of an oxygen scavenger is desired. In response to these demands, various oxygen indicators made into tablets have been proposed (Samurai Sekisho 53
Publication No. 1120493, etc.). However, in the case of tablets, holes must be made in the bag in which they are packaged and they must be sealed together with an oxygen absorber, which poses problems with filling capacity, and the indicators used are expensive. be. Furthermore, an oxygen indicator that combines methylene blue with a strong reducing agent such as hydrosulfite or ascorbic acid has been developed (Akihiro Hakamaseki Publication No. 48294). This indicator has the advantage that it can be used by impregnating filter paper or gauze, etc., or by printing it with a water-soluble resin binder, but when combined with methylene blue and a strong reducing agent such as hydrosulfite, Although the reduction potential of hydrosulfite is extremely low and the reducing ability is strong, the reducing agent is consumed quickly in an atmosphere where oxygen exists, and the indicator ability is lost in a short period of time during storage. If such a reducing sulfur compound is used, it produces a bad odor peculiar to sulfur, which is not preferable in terms of use. Furthermore, since a water-repellent resin binder is used during printing, the indicator film formed has poor water resistance and cannot withstand long-term storage.Also, since water is used as a solvent, drying during the printing process is slow and work efficiency is extremely low. There are drawbacks such as. The present invention has been made in view of the above points, and an object of the present invention is to provide an oxygen indicator ink composition that can be used for a long period of time.

As a result of various studies, the present inventors have found that thiazine dyes exhibit markedly different coloration in the presence of oxygen and in deoxidized conditions (oxygen concentration 0.1% or less) in the coexistence of reducing sugars and alkaline substances. In addition, this coexisting system retains its indicator ability for a long time even when left in the presence of oxygen, unlike when hydrosulfite or ascorbic acid is used, and furthermore, this coexisting system can be dissolved or dispersed in the resin solution. It was discovered that it was possible to make ink using this technology.

Based on this knowledge, we have already developed an oxygen indicator ink composition characterized by a single composition, namely, a thiazine dye, a reducing sugar, and an alkaline substance dissolved or dispersed in a resin solution. (Patent application filed on the same day). The one-component oxygen indicator ink composition obtained in this way has excellent storage stability, and although it depends on the composition ratio, it can be stored at room temperature for about one month while retaining its indicator ability, and after storage, it can be stored on a support. By printing or coating the composition, it is possible to obtain an oxygen indicator with less color loss than when using the composition immediately after production. However, according to the present inventors, one of the reducing sugar and the alkaline substance for the thiazine dye is separately present in the resin solution to obtain a two-part separated oxygen indicator composition, and the two-part oxygen indicator composition is prepared before use. It was discovered that mixing these ingredients had excellent long-term storage stability, and the product was released.

That is, it was discovered that by creating a two-liquid separation type product, for example, even if the product is mixed after being stored at room temperature for about one year, it will have the same effect as a product that is mixed immediately after production. Therefore, the present invention provides an A method in which a thiazine dye and a reducing bran are dissolved or dispersed in a resin solution.
A two-liquid separable oxygen indicator ink composition is characterized in that it consists of a combination of a liquid and a liquid B in which an alkaline substance is dissolved or dispersed in a resin solution. The present invention will be explained in detail below.

First, in the present invention, the thiazine dye has a basic structure, such as methylene blue, methylene green, new methylene flu, brilliant alizarin blue 3R, rouss violet, and toluidine blue.

Next, reducing sugars include monosaccharides such as ○-maltose, D-glucose, D-fructose, D-esasulose, and D-arabinose; reducing oligosaccharides made of glycosidic bonds of a certain number of monosaccharide molecules such as maltose and lactose; is used.

Next, the alkaline substance may be any substance that has a pH of 8 or higher when it comes into contact with water, such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, calcium hydroxide, calcium carbonate, and sodium bicarbonate. , hydroxides, carboxylates, and various salts such as potassium hydrogen carbonate, calcium hydrogen carbonate, magnesium hydroxide, sodium acetate, potassium acetate, potassium sodium tartrate, and potassium 2-ethylhexanoate. The resin solution for dissolving or dispersing the dye and reducing sugar in the A solution and the alkaline substance in the B solution includes cellulose derivatives such as ethyl cellulose, ethyl hydroxyethyl cellulose, and cellulose acetyl propionate, butyral resin, polyester resin, One or more types of acrylic resin, polyether resin, polyamide resin, petroleum resin, various hard resins, etc.
Preferably aromatic compounds such as toluene and xylene, ester compounds such as ethyl acetate and butyl acetate, methyl ethyl ketone,
Ketones such as methyl isobutyl ketone, methanol, ethanol, isof.

Those dissolved in organic solvents such as alcohols such as lopyl alcohol, or glycols such as ethylene glycol monoethers or ethylene glycol are used. It is preferable that 5 to 20 parts of the resin be dissolved in 100 parts of the solvent (on a weight basis. Hereinafter, parts and % are on a weight basis in this specification). Liquid A constituting the ink composition of the present invention contains 0.1 to 5% of the dye to the resin solution 10. It can be obtained by dissolving or dispersing 1.0 to 5 reducing sugars.

Liquid B is obtained by dissolving or dispersing 10 to 5 parts of an alkaline substance in 10 parts of the resin solution. The method for dissolving or dispersing it is to mix all the ingredients and twill it using a general means such as a sand mill, ball mill/roll mill, attritor, etc. However, in order to maintain its performance as an indicator for a long time, it should be kept in a sealed state. It is desirable to make it into ink. Incidentally, it is effective to add about 5% of glycerin to the ink composition of the present invention, based on the total amount, in order to hasten the discoloration of the indicator. In addition, various additives and auxiliaries such as nonionic surfactants may be added to the ink composition of the present invention.

Any of these can be added to the A liquid and/or the B liquid in advance. In addition, in the present invention, for 1 part of thiazine dye, 1 to 10 parts of reducing sugar and 1 part of alkaline substance are added.
It is preferable to mix the A liquid and the 8 liquid while appropriately adjusting the amount to be in the range of 10 to 10 yen.

Furthermore, by separately adding a dye that is not reduced within the composition system to the ink composition of the present invention, the respective colors in the presence and absence of oxygen can be adjusted to easily distinguishable colors. I can do it.

This dye can be added to the A liquid and/or the B liquid or separately from the A liquid and the B liquid. Such dyes preferably have a complementary color to the thiazine dye and have a redox potential lower than that of the thiazine dye, such as Safranin T, Phenosafranin, etc. It can be added in an amount of about 0.1 to 5% based on the total amount. Furthermore, for the above purpose, monoazo and condensed azo pigments such as permanent carmine FBB may be added to Chromophthal Magenta G, Chromophthal Red G, and Permanent Carmine HF. In this way, the ink composition obtained by mixing liquid A and liquid B can be applied to paper, plastic film, metal foil, etc. by printing methods such as gravure printing, offset printing, letterpress printing, and screen printing, or coating methods. An oxygen indicator film can be formed by applying it to the surface of any base material and then drying it.

It is desirable that the coating film be coated for about 1 to 10 days per day (when dry). Furthermore, the ink composition of the present invention can be printed on air-permeable packaging materials for packaging oxygen absorbers, and can also be printed on packaging materials for packaging foods and the like. As is clear from the above description, the ink composition of the present invention has excellent printability, and the film formed after printing can be used as an oxygen indicator for a long period of time, making it possible to determine the oxygen absorbing ability of the oxygen scavenger. , it is possible to determine the deoxidization state of the part in which the deoxidizer is sealed. In particular, since the present invention is of a two-liquid separation type, it has excellent long-term storage stability. Hereinafter, the present invention will be explained in more detail with reference to Examples.
Example 0.15 parts of methylene blue, 3 parts of glucose, 0.15 parts of Safranin T (a red dye that can withstand reduction), 12 parts of ethyl cellulose, 4 parts of toluene and 44.7 parts of inpropyl alcohol were mixed and processed in a sand mill. The mixture was kneaded for 1 hour to prepare liquid A.

Next, 4 pieces of magnesium hydroxide, 1 piece of ethyl cellulose
2 parts, 24 parts of toluene, and 24 parts of inpropyl alcohol were mixed and ground in a sand mill for 1 hour to prepare liquid B. Immediately before printing, the A liquid and the B liquid obtained in this way were mixed 1:1 and used on a gravure plate with a plate depth of 80〃 on high-quality paper with a neutral surface (60 mm/〆 )
printed on. In the presence of air, this printed material had a blue-purple color mixed with blue methylene blue and red dye, but it was made by laminating vinylidene chloride coated OPP and polyethylene together with an oxygen scavenger (Ageless F manufactured by Mitsubishi Gas Chemical Co., Ltd.). When the sample was sealed in a sealed packaging material, the methylene blue color became pale and gradually turned red after about 1 hour. At this time, the oxygen concentration inside the packaging material was 0.1%. In addition, after leaving the A and B solutions for three months in the summer without mixing them, printing according to the method used in the book produced a bluish-purple print with the same hue as the previous print, and when sealed together with Ageless F, the same color as the previous print was obtained. The color changed from blue-purple to red in about the same amount of time. When I made a pinhole in the 3 bottles that had turned red after sealing them myself and the ones that had turned red after 3 months and let air in, the color returned to its original blue-purple color in about 5 hours.

Further, similar results were obtained in the same manner as in the above example, except that methylene blue, new methylene blue, toluidine blue, rouss violet, and brilliant resin blue were used instead of methylene blue.

Claims (1)

[Claims] 1. It is characterized by being composed of a combination of a solution A in which a thiazine dye and a reducing sugar are dissolved or dispersed in a resin solution, and a solution B in which an alkaline substance is dissolved or dispersed in a resin solution. A two-part separable oxygen indicator ink composition. 2. The composition according to item 1 above, wherein liquid A and/or liquid B contains glycerin.