JPS60243173A - Ink composition for marking sterilization with ethylene oxide - Google Patents

Abstract

PURPOSE:The titled composition that is composed of a pigment with a specific chemical structure, a resin such as polyacrylic acid and a polar solvent, thus being used in printing ink with color change retardation in case of moisture absence. CONSTITUTION:The objective composition is obtained by using a pigment of the formula (A is ethylene residue, O-phenylene residue; R1, R2 are H, lower alkyl, hydroxy-lower alkyl), when needed, a small amount of usual pigment for color adjusting, one or more binder resins, selected from polyacrylic acid, polymethacrylic acid and copolymer therefrom, a polar solvent such as ethanol, when needed an organic acid such as oxalic acid, a surfactant, preservative and anticorrosive.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink composition for ethylene oxide sterilization marking. This ink composition is used as a printing ink or by marking butylene oxide. When sterilization is performed using these sterilization methods, in order to identify whether sterilization has been completed or not, the object to be sterilized is marked with ink that changes color when sterilization conditions are reached, and the color change of the mark indicates that the object has been sterilized. I've confirmed it.

A dye represented by the general formula AN=N-B as an ink composition for sterilization labeling using ethylene oxide [A is a pyridine ring containing a nitrogen atom to which no alkyl group is added,
Heterocyclic compound residues selected from the group of quinoline, isoquinoline, triazole, tetra-zole, indazole and thiadiazole rings - the residues may or may not have non-dissociable substituents; [Patent No. 1, 151.1'76), the effect has been recognized.

This prior art ink composition has a sterile optimum relative humidity (3
0 to 80%), the ethylene oxide concentration, sterilization temperature,
The color changes depending on the three factors of sterilization time, and can be used to indicate that it has been accurately sterilized, but the color changes in the same way under low humidity conditions. However, under low humidity conditions, bacteria become resistant to ethylene oxide and the degree of sterilization is no longer accurately indicated. For example, in sterilization treatment under 0% relative humidity, it may happen that the ink composition is not actually sterilized even though the pigment in the ink composition has changed color. In addition to the above three factors, the ink composition of the present application changes color due to the addition of a humidity factor. Therefore, optimal relative humidity conditions (30-80%
) shows similar discoloration as the prior art, but at a relative humidity of 3
Below 0%, the discoloration gradually becomes slower, consistent with the bacteria's resistance to ethylene oxide under low humidity, and the ethylene oxide concentration 9 required for ethylene oxide sterilization.
It became possible to detect the product of all four factors: time, temperature, and humidity, and it became possible to better match the state of bacterial death. The dye used in the present invention is represented by the following general formula.

[In the formula, A represents an ethylene residue or an 0-phenylene residue, and these are further substituents.Since there are a wide variety of dyes included in the above general formula, the color development before and after treatment with ethylene oxide gas , you can freely select a pigment that changes color and is suitable for the intensity of sterilization conditions.

In addition to the above-mentioned pigments, some ordinary pigments may be added to adjust the color. Examples of the binder resin I used in the present invention include polyacrylic acid, polymethacrylic acid, and acrylic acid-methacrylic acid copolymer.

System solution M, ethylene glycol molyalkyl ether solvent of ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, and as an auxiliary solvent, a ketone solvent or an ester solvent may be added to the above alcohol-based or cellosolve-based solvent. I can do it. In the present invention, in addition to polyacrylic acid, polymethacrylic acid, or acrylic acid-methacrylic acid copolymer, rosin and rosin ester are used as additive resins.

Using resins commonly used as binder resins for oil-based inks, such as rosin-modified maleic acid resin, alkylphenomal resin, rosin-modified phenolic resin, ruic acid resin, cellulose-based hydroxypropyl cellulose, hydroxyethyl cellulose, and ethyl cellulose, the ink coating film is Although the addition of other resins can increase the hardness of the ink film, eliminate stickiness of the ink coating, and improve printability, the addition of other resins tends to reduce the effect on humidity.

In the present invention, an organic acid can be added to promote discoloration of the dye.

Sulfonic acids such as bonic acid, butanesulfonic acid, butanedisulfonic acid, and benzenesulfonic acid.

Benzoic acid, hydrofluoric acid. Examples include aromatic acids such as phenol, salicylic acid, and sulfosalicylic acid. In particular, when polybasic acids of the acid salt type, such as sodium sulfosalicylate and zinc salicylate, in which one or more of the acid groups of the polybasic acid is in the form of a free acid and the other one or more are in the form of a salt, are used as printing inks. It can be used effectively because it does not sublimate from the inside of the printed surface and the storage stability of printed matter is good. Also surfactants, preservatives,
Some additives commonly used in ink compositions, such as rustproofing agents or fragrances, can be used.

To produce the ink of the present invention, the pigment of general formula (1) is added in an amount of 0.05 to 3.0% by weight, preferably 0.05 to 3.0% by weight (hereinafter, % by weight is simply referred to as %), based on 100 parts by weight of the ink composition. 1~
2% polyacrylic acid, polymethacrylic acid, or acrylic acid-methacrylic acid copolymer, based on 100 parts of the ink composition, 0.5% to 50%, preferably 2% to 30%,
30-98% polar solvent based on 100 parts of the ink composition
, preferably 50 to 95%, optionally adding resin θ to 5
0%, organic acid 0-10.0%, and other additives in appropriate amounts.

In producing ink, the polar solvent may be kept at room temperature or heated to 70 to 80°C, other components may be added while stirring, and stirring may be stopped after uniform and complete dissolution.

Next, Examples are shown in Table 1 to further clarify the present invention. All examples were prepared according to the methods described above. Also polyacrylic acid, polymethacrylic acid or acrylic acid--
In order to compare the effects of the methacrylic acid copolymer and other binder resins, comparative inks were prepared in the same manner as in the examples and are shown at the bottom of Table 1.

Qualitative filter paper was immersed or silk-printed in the ink of each example, colored and dried, and used as a test piece. At 50°C, in a closed container in the presence of water vapor (65% R11) and in the absence, the ethylene oxide concentration was 500. The specimen was left for 1 and 2 hours under ■/l (Guiside LS, manufactured by Daido Oxygen Co., Ltd.), and the discoloration of the test piece was measured using a color difference direct-connection digital colorimeter, model ND-504AA, manufactured by Nihon Heavy Industries. . The results and the ratio of discoloration at 65% RH and 0% ti11 are shown in Table 2. From this value, it is recognized that the ink composition of the present invention exhibits a slow discoloration rate in the absence of water vapor. It was separately confirmed by biological testing that the above conditions of exposure to ethylene oxide at 65% humidity for 2 hours were sufficient to complete sterilization in normal objects to be sterilized.

Claims (1)

[Scope of Claims] A dye represented by the general formula [wherein A represents an ethylene residue or an 0-phenylene residue, which is further a hydroxy lower alkyl group as a substituent. ] An ink composition for ethylene oxide sterilization markings comprising at least one resin selected from the group consisting of polyacrylic acid, polymethacrylic acid, and acrylic acid-methacrylic acid copolymers, and a polar solvent.