JP2007302816A - Sterile indicator ink composition for offset printing or letterpress printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an ink composition for thinly forming a color change layer of a sterilization indicator, for checking the completion of high-pressure steam sterilization or ethylene oxide gas sterilization by a clear color change, by offset printing or letterpress printing. <P>SOLUTION: The sterilization indicator ink composition comprises 4-40 parts wt. of an aromatic group-containing carboxylic acid, 1-10 parts wt. of a thiazole azo dye to change a color by the action of the aromatic group-containing carboxylic acid in a high-pressure steam atmosphere and/or in an ethylene oxide gas atmosphere and 50-95 parts wt. of a binder so that it is adjusted to a viscosity of 50-1,000P useful for offset printing or letterpress printing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is used to produce a sterilization indicator for confirming whether sterilization with high-pressure steam or ethylene oxide gas is possible, and relates to an ink composition suitable for offset printing and letterpress printing.

  In order to use medicines and medical instruments in aseptic conditions, it is necessary to sterilize them in advance. Such articles to be sterilized such as medical instruments are sealed in containers, bags, and sheets, respectively, in the case of pharmaceuticals under a high-pressure steam atmosphere in an autoclave, and in the case of medical instruments under an ethylene oxide gas atmosphere, respectively. Sterilization is performed. At this time, a chemical indicator that causes a chemical reaction and changes color under sterilization conditions is interposed between the objects to be sterilized, and the color change of the indicator is visually observed to confirm whether sterilization is sufficient.

  Patent Document 1 discloses a sterilization indicator composition containing sulfur, a sulfur compound, a transition metal compound, an organic acid, a metal salt thereof, and a monoazo dye. An indicator having a discoloration layer printed with this composition changes its color by reacting with sulfur or the like and a transition metal compound in a high-pressure steam atmosphere to form a metal sulfide, while it and a monoazo dye in an ethylene oxide gas atmosphere. Reacts with the organic acid to change its color while promoting its speed.

  Since this composition has a relatively low degree of discoloration in an ethylene oxide gas atmosphere, an indicator having a discoloration layer formed by printing this composition thickly on a substrate is used to change the color tone of the discoloration layer. It was necessary to make it easy to recognize. This composition is suitable mainly for screen printing and flexographic printing for printing to about 10 to 40 μm, and for gravure printing using a gravure plate having a plate depth of 10 to 40 μm, but for offset printing. In addition, it is not suitable for printing as thin as about 0.5 to 10 μm as in letterpress printing.

  Since screen printing is a printing method in which the discoloration layer printed with the ink composition can be adjusted to be thick, an indicator that makes the color change clear by making the discoloration layer as thick as possible can be produced. On the other hand, since the printing speed is slow, the yield is poor and the cost is increased, which increases the terminal price of the indicator.

  In addition, gravure printing and flexographic printing are printing methods that are suitable for manufacturing products by large-scale printing of 8000 m or more and are low in cost because printing speed is high. On the other hand, since the start-up and adjustment of the plate making and the printing press are complicated and take a lot of time, when manufacturing products such as indicators by small-scale printing of less than 8000 m, the cost is increased. . Furthermore, since it has to print on the base material which passed through many processing steps, it lacks mobility and versatility.

  On the other hand, offset printing and letterpress printing are easier to plate-making than screen printing, gravure printing, and flexographic printing, can be adjusted in a printing machine in a short time, and the printed layer thickness must be very thin. It is a printing method that can. In addition, when printing, the layer can be irradiated with ultraviolet rays to dry, or a variety of processing steps, such as semi-cutting or full-cutting, can be performed at the same time, making it highly versatile, excellent in mobility, and producing Good and economical.

  A sterilization indicator ink composition that can be printed by offset printing or letterpress printing to produce a discoloration layer for the indicator, and even when printed thinly, it is more easily recognizable in both high-pressure steam and ethylene oxide gas atmospheres Things were sought.

Japanese Patent Laid-Open No. 04-364174

  The present invention was made to solve the above-mentioned problems, and the discoloration layer of the sterilization indicator for confirming the completion of high-pressure steam sterilization or ethylene oxide gas sterilization by clear discoloration is obtained by offset printing or letterpress printing. It aims at providing the ink composition used for forming thinly.

  The sterilization indicator ink composition according to claim 1 made to achieve the above object comprises 4 to 40 parts by weight of an aromatic group-containing carboxylic acid, a high-pressure steam atmosphere and / or Alternatively, it contains 1 to 10 parts by weight of a thiazole azo dye that changes color by the action of the aromatic group-containing carboxylic acid in an ethylene oxide gas atmosphere, and 50 to 95 parts by weight of a binder, thereby being used for offset printing or letterpress printing. The viscosity is adjusted to 50 to 1000 P.

  The sterilization indicator ink composition described in claim 2 is the sterilization indicator ink composition described in claim 1, wherein the binder is vinyl resin, silicon resin, rosin resin, terpene resin, phenol resin, polyester resin, polyether resin, At least one oxidation selected from acrylic resin, polyurethane resin, natural rubber, synthetic rubber, petroleum resin, epoxy resin, ketone resin, maleic acid resin, coumarin resin, polyvinyl alcohol, polyvinyl butyral, rosin modified phenolic resin, and alkyd resin It is one of a polymerizable resin component and an ultraviolet curable resin component in which a monomer and a photopolymerization initiator are dissolved.

  The sterilization indicator ink composition described in claim 3 is the sterilization indicator ink composition described in claim 1, wherein the aromatic group-containing carboxylic acid may have a hydroxy group, an alkoxy group or an oxo group. A group containing an aromatic monocarboxylic acid, aromatic polycarboxylic acid, aromatic group-substituted saturated aliphatic carboxylic acid and at least one selected from aromatic group-substituted unsaturated aliphatic carboxylic acid It is characterized by being.

  The sterilization indicator ink composition described in claim 4 is the one described in claim 1, wherein the thiazole azo dye is C.I. I. Discharge Red 43, C.I. I. Discharge Red 58, C.I. I. Discharge Red 88, C.I. I. Discharge Blue 102, C.I. I. Discharge Red 110, C.I. I. Discharge Red 111, C.I. I. Discharge Red 117, C.I. I. Discharge Red 137, and C.I. I. It is at least any one selected from discharge red 206. C. I. Means color index.

  The sterilization indicator ink composition described in claim 5 is the one described in claim 1 and includes up to 20 parts by weight of extender pigment, compound, pigment dispersant, and / or surfactant. To do.

  The indicator according to claim 6 is characterized in that the sterilization indicator ink composition according to claim 1 is printed on a substrate by offset printing or letterpress printing to form a discoloration layer.

  A sterilization indicator according to a seventh aspect is the sterilization indicator according to the sixth aspect, wherein the thickness of the discoloration layer is 0.5 to 10 μm.

  The method for confirming sterilization according to claim 8 comprises exposing the sterilization indicator according to claim 6 together with an object to be sterilized to an atmosphere of at least one of high-pressure steam and ethylene oxide gas, thereby sterilizing the object to be sterilized. The sterilization indicator changes color upon completion of the step.

  The sterilization confirmation method described in claim 9 is the method described in claim 8, wherein the temperature of the high-pressure steam is 100 to 135 ° C, and the concentration of the ethylene oxide gas is 500 to 650 mg / L. It is characterized by being.

  The sterilization indicator ink composition of the present invention clearly changes color when exposed to either high pressure steam or ethylene oxide gas. Also, the color difference before and after the color change is large. Moreover, since this composition has a high viscosity, it is suitable for offset printing and letterpress printing.

  An indicator formed by printing this composition on a substrate by offset printing or letterpress printing to form a discolored layer can be used to confirm completion of sterilization under an atmosphere of high-pressure steam or ethylene oxide gas. Since this indicator can easily and thinly print the discoloration layer by offset printing or letterpress printing, it has high production efficiency, is inexpensive, and is economical.

  According to the sterilization confirmation method using this indicator, since the discoloration during the sterilization is clear, the completion of sterilization can be confirmed accurately visually. In addition, since it can be used for sterilization with either high-pressure steam or ethylene oxide gas, it is not necessary to use a separate indicator.

  Examples of the present invention will be described in detail below, but the scope of the present invention is not limited to these examples.

  The sterilization indicator ink composition comprises 4 to 40 parts by weight of an aromatic group-containing carboxylic acid, 1 to 10 parts by weight of a thiazole azo dye, 50 to 95 parts by weight of a binder, and optionally a solvent and an additive. Is prepared by kneading. The viscosity is adjusted to 50-1000P by the increase / decrease in the quantity of a binder, a solvent, and an additive. This composition is used for printing on a substrate by offset printing or letterpress printing to form a discolored layer.

  If the aromatic group-containing carboxylic acid in the composition is less than 4 parts by weight, the change in color tone of the discoloration layer becomes unclear, whereas if it exceeds 40 parts by weight, the fixing strength of the composition is reduced. It becomes difficult to print the composition on the substrate by offset printing or letterpress printing. It is more preferable that the aromatic group-containing carboxylic acid is 10 to 35 parts by weight.

As an aromatic group-containing carboxylic acid, an aromatic monocarboxylic acid which may have a hydroxy group, an alkoxy group or an oxo group, for example, benzenecarboxylic acid, methylbenzoic acid, dimethylbenzoic acid, 2,3-dimethylbenzoic acid, 3,5-dimethylbenzoic acid, 2,3,4-trimethylbenzoic acid, 2,3,5-trimethylbenzoic acid, 2,4,5-trimethylbenzoic acid, 2,4,6-trimethylbenzoic acid, 3, 4,5-trimethylbenzoic acid, 2-hydroxybenzoic acid, methoxybenzoic acid, hydroxy (methyl) benzoic acid, 2-hydroxy-3-methylbenzoic acid, 2-hydroxy-4-methylbenzoic acid, 2-hydroxy-5 -Methylbenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydro Cibenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 3-hydroxy-4-methoxybenzoic acid, 3,4-dimethoxybenzoic acid, 2, 3-dimethoxybenzoic acid, 2,4-dihydroxy-6-methylbenzoic acid, 3,4,5-trihydroxybenzoic acid, 4-hydroxy-3,5-dimethoxybenzoic acid, 2,4,5-trimethoxybenzoic acid ;
Aromatic polycarboxylic acid optionally having a hydroxy group, an alkoxy group or an oxo group, for example, benzene-1,2-dicarboxylic acid, benzene-1,3-dicarboxylic acid, benzene-1,4-dicarboxylic acid, benzene -1,2,3-tricarboxylic acid, benzene-1,2,4-tricarboxylic acid, benzene-1,3,5-tricarboxylic acid, benzene-1,2,3,4-tetracarboxylic acid, benzene-1, 2,3,5-tetracarboxylic acid, benzene-1,2,4,5-tetracarboxylic acid, benzenehexacarboxylic acid, biphenyl-2,2'-dicarboxylic acid, 5-methylisophthalic acid, 4,5-dimethoxy Phthalic acid, 2- (carboxymethyl) benzoic acid, 3- (carboxymethyl) benzoic acid, 4- (carboxymethyl) benzoic acid, 2- (carboxycarbonyl) ) Benzoic acid, 3- (carboxycarbonyl) benzoic acid, 4- (carboxycarbonyl) benzoic acid;
Aromatic group-substituted saturated aliphatic carboxylic acids optionally having a hydroxy group, an alkoxy group or an oxo group, such as 4-isopropylbenzoic acid, phenylacetic acid, 2-phenylpropanoic acid, 3-phenylpropanoic acid, hydroxy (phenyl ) Acetic acid, hydroxy (4-hydroxy-3-methoxyphenyl) acetic acid, (4-methoxyphenyl) acetic acid, (2,5-dihydroxyphenyl) acetic acid, (3,4-dihydroxyphenyl) acetic acid, (4-hydroxy-3) -Methoxyphenyl) acetic acid, (3-hydroxy-4-methoxyphenyl) acetic acid, (3,4-dimethoxyphenyl) acetic acid, (2,3-dimethoxyphenyl) acetic acid, hydroxydiphenylacetic acid, 2-hydroxy-2-phenylpropane Acid, 3-hydroxy-2-phenylpropanoic acid, 3- (4-hydroxyphenyl) Yl) propanoic acid;
An aromatic group-substituted unsaturated aliphatic carboxylic acid which may have a hydroxy group, an alkoxy group or an oxo group, such as 2-phenylacrylic acid, 3-phenylacrylic acid, 3- (4-hydroxyphenyl) acrylic acid, 3- (2,4-dihydroxyphenyl) acrylic acid, 3- (3,4-dihydroxyphenyl) acrylic acid, 3- (4-hydroxy-3-methoxyphenyl) acrylic acid, 3- (3-hydroxy-4- Methoxyphenyl) acrylic acid and 3- (4-hydroxy-3,5-dimethoxyphenyl) acrylic acid.

  If the thiazole azo dye in the composition is less than 1 part by weight, the color tone of the color changing layer becomes thin. On the other hand, if it exceeds 10 parts by weight, the color tone of the color changing layer before and after the color change is too dark. Changes in color tone are difficult to see. It is more preferable that the thiazole azo dye is 3 to 8 parts by weight because the change in the color tone of the discolored layer is easily visually observed.

  Thiazole azo dyes are C.I. I. Discharge Red 43, C.I. I. Discharge Red 58, C.I. I. Discharge Red 88, C.I. I. Discharge Blue 102, C.I. I. Discharge Red 110, C.I. I. Discharge Red 111, C.I. I. Discharge Red 117, C.I. I. Discharge Red 137, C.I. I. Discharge Red 206 is preferred, but C.I. I. Discharge Red 88, C.I. I. Discharge Red 111, C.I. I. Discharge Red 137, C.I. I. Discharge Red 206 is more preferable because it exhibits more excellent discoloration performance. These may be used alone or in combination.

  If the total of the aromatic group-containing carboxylic acid and the thiazole azo dye is less than 5 parts by weight, the change in color tone of the discoloration layer becomes unclear, while if it exceeds 50 parts by weight, the fixing strength of the composition is increased. Therefore, the composition cannot be printed on the substrate by offset printing or letterpress printing. When the total is 15 to 45 parts by weight, both of them are uniformly dispersed in the composition. As a result, high offset printability and letterpress printability, uniformity without color tone variation, and clear color tone change are obtained. Since the composition which has the outstanding color-change property is obtained, it is more preferable.

  The details of the reaction mechanism in which the discoloration layer printed with this sterilization indicator ink composition causes a change in color tone under a high-pressure steam atmosphere or an ethylene oxide gas atmosphere is not clear, but is presumed as follows.

  Under a high-pressure steam atmosphere, the thiazole azo dye sublimates due to the action of the aromatic group-containing carboxylic acid, causing a fading change. As a result, the discolored layer changes from red to colorless or yellow. On the other hand, under the atmosphere of ethylene oxide gas, ethylene oxide is accelerated by the action of the aromatic group-containing carboxylic acid, and the resonance structure is changed by the alkylation reaction to the thiazole group of the thiazole azo dye. The color changes from blue to blue.

  This composition is discolored under an environment of sterilization conditions in a high-pressure steam atmosphere or an ethylene oxide gas atmosphere, but the color tone does not change at all in other environments.

  Examples of the binder in the composition include an oxidation polymerizable resin component and an ultraviolet curable resin component.

  For example, vinyl resin, silicon resin, rosin resin, terpene resin, phenol resin, polyester resin, polyether resin, acrylic resin, polyurethane resin, natural rubber, synthetic rubber, petroleum resin, epoxy resin, ketone resin , Maleic acid resin, coumarin resin, polyvinyl alcohol, polyvinyl butyral, rosin modified phenolic resin, and alkyd resin. These may be used alone or in combination. Among these, rosin-modified phenol resins and alkyd resins are more preferable.

  In order to adjust the viscosity of the composition to 50 to 1000 P, together with this oxidative polymerizable resin component, a solvent such as mineral spirit, solvent naphtha, isopropyl alcohol, methyl isobutyl ketone, isoamyl acetate, butyl cellosolve and ethyl acetate is contained in the composition. Such organic solvents; drying oils such as tung oil, linseed oil, soybean oil, castor oil, drying oil, and mixtures thereof may be included. These solvents may be used alone or in combination.

  On the other hand, examples of the ultraviolet curable resin component include a resin in which a monomer curable by ultraviolet rays is dissolved.

  As the monomer, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) ) Acrylate, alkyl (meth) acrylate, glycidyl (meth) acrylate, bisphenol A type epoxy resin, phenol novolac type epoxy resin, epoxidized polybutadiene epoxy resin, rosin modified urethane (meth) acrylate, fatty acid modified alkyd resin ( And (meth) acrylate.

  In order to adjust the viscosity of the composition to 50-1000 P, with or in place of this monomer, diluted monomers that are cured with UV light, such as N, N-dimethylaminoethyl acrylate, N, N-dimethylaminopropylacrylamide , N, N-dimethylacrylamide, acryloylmorpholine, N-isopropylacrylamide, N, N-diethylacrylamide, N- (2-hydroxyethyl) acrylamide, methoxypolyethylene glycol methacrylate, methoxydiethylene glycol methacrylate, β-methacryloyloxyethyl hydrogen phthalate , Β-methacryloyloxyethyl hydrogen succinate, methoxypolyethylene glycol acrylate, lauryl acrylate, ethylene glycol Dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, may be used polypropylene glycol dimethacrylate or polyethylene glycol diacrylate. These monomers may be used alone or in combination.

  Examples of resins that dissolve these monomers include polyurethane resins, polyester resins, ketone resins, and epoxy resins.

  In the composition, a photopolymerization initiator may be contained together with the ultraviolet curable resin component. As photopolymerization initiators, carbonyl group-containing polycyclic compounds such as thioxanthone, xanthone, and halogen-substituted products thereof; aryl ketones such as benzophenone, methyl o-benzoylbenzoate and acetophenone; 4,4′-bisdiethylamino Examples include dialkylaminoaryl ketones such as benzophenone, p-dimethylaminobenzoic acid, and isoamyl-p-dimethylaminoacetophenone; acyloins such as benzoin; and alkyl ethers. These may be used alone or in combination.

  A commercially available binder may be used. For example, F-Gloss medium, Scepter medium (all manufactured by Dainippon Ink & Chemicals, Inc .; trade name); Hy Unity Soy medium, FD O New Medium KR2, FD S Medium TK, FD Form TF Medium (all Toyo Ink Manufactured by Mfg. Co., Ltd .; trade name); Nobel Maxi medium, Novel Senior Soy medium (both manufactured by Daiichi Seika Kogyo Co., Ltd .; trade name); 5 UV L Carton Medium GW, No. 5 5 UV L Carton OP Varnish, UV STP Medium W, UV 161 Medium, UV 161 OP Varnish (all manufactured by T & K TOKA; trade name); UV ACE Excel Medium (trade name, manufactured by Kuboti Ink Co., Ltd.); UV Carton Medium (manufactured by Godo Ink Co., Ltd .; trade name)

  In order to adjust the viscosity of the composition to 50 to 1000 P, the composition may contain additives such as extender pigments, compounds, pigment dispersants, and surfactants that promote emulsification. .

  Examples of the pigment dispersant include talc, magnesium carbonate, Carplex (manufactured by Shionogi Pharmaceutical Co., Ltd.) and Aerosil (manufactured by Nippon Aerosil Co., Ltd .; registered trademark).

  As surfactants, for example, anionic surfactants such as fatty acid alkali salts, alkyl sulfates, alkyl sulfonates, alkyl aryl sulfonates, sulfosuccinates; amine halides, alkylpyridinium halides, quaternary Examples include cationic surfactants such as ammonium salts; nonionic surfactants such as polyethylene glycol alkyl ethers, polyethylene glycol fatty acid esters, sorbitan fatty acid esters, and fatty acid monoglycerides; amphoteric surfactants such as amino acids.

  The viscosity of this composition is adjusted to 50 to 1000P. It is more suitable for offset printing and letterpress printing than an ink composition for screen printing having a viscosity of 50 P at most.

  For example, when this composition is applied to a printing plate and transferred to a printed material to form a discoloration layer by offset printing, if the composition has a viscosity of less than 50 P, the viscosity is too low and the composition is printed. It is not uniformly applied to the plate, and the discolored layer is blurred and printed, or the discolored layer is printed unevenly, resulting in uneven color tone or unclear color change. End up. On the other hand, when the viscosity of the composition exceeds 1000 P, the dispersibility of the aromatic group-containing carboxylic acid or thiazole azo dye in the composition is deteriorated. As a result, the composition becomes inhomogeneous and the color tone of the discoloration layer becomes uneven. As a result, the change in color tone becomes unclear, and as a result of separation of the aromatic group-containing carboxylic acid and thiazole azo dye from the binder, the discolored layer is rubbed and easily peeled off. The same applies to letterpress printing.

  The sterilization indicator of the present invention is produced by offset printing this ink composition on the surface of a substrate to form a discoloration layer.

  Examples of the substrate include sheet materials such as white polyethylene terephthalate (PET) tack paper, polypropylene synthetic paper, and fine paper. Moreover, the adhesion layer and the release paper which covers it may be attached on the back surface of the base material.

  In the sterilization confirmation method of the present invention, the sterilization indicator is interposed between objects to be sterilized, for example, exposed to high-pressure steam at 100 to 135 ° C. for 10 to 60 minutes, or ethylene oxide gas having a concentration of 500 to 600 mg / L. In addition, when exposed to a humidity of 60% ± 20% RH and a temperature of 30 to 55 ° C. for 2 hours or more, the discoloration of the discoloration layer of the sterilization indicator confirms the completion of sterilization.

  Examples of a sterilization indicator ink composition to which the present invention is applied and a sterilization indicator prototype using the same are shown in Examples 1 to 6, an ink composition to which the present invention is not applied, and an indicator prototype using the same. Examples are shown in Comparative Examples 1-4.

Example 1
4 parts by weight of Miketon Polyester Red 2BSF (manufactured by Dystar Japan Co., Ltd .: CI Discharge Red 88), 24 parts by weight of 2,3,4-trimethylbenzoic acid, 7.2 parts by weight of talc, rosin-modified phenol 80 parts by weight of resin (manufactured by Hitachi Chemical Co., Ltd.) and 40 parts by weight of ethyl acetate as a solvent were kneaded. From this kneaded product, the viscosity was adjusted to 100 P by volatilizing the solvent, and a red sterilization indicator ink composition of the oxidation polymerization type was prepared.

  The viscosity is measured with an SV type viscometer (manufactured by A & D Co., Ltd.) calibrated with a standard solution for viscosity calibration according to JIS Z88209-1992.

  The color change layer was formed by printing the ink composition on high-quality tack paper with a roll using an actual offset printing press. It was cut into a label to produce a sterilization indicator.

  An indicator was placed in the autoclave and treated under a high-pressure steam atmosphere at a temperature of 134 ° C. for 20 minutes as in the actual high-pressure steam sterilization conditions. The discolored layer of the indicator that was red before the treatment turned yellow after the treatment.

  Another indicator was placed in the ethylene oxide gas sterilizer, and the treatment was performed in an atmosphere of ethylene oxide gas having a concentration of 530 mg / L at a humidity of 70% RH and a temperature of 50 ° C. for 2 hours in the same manner as the actual ethylene oxide gas sterilization conditions. The discoloration layer of the indicator that was red before the treatment turned blue after the treatment.

(Example 2)
3 parts by weight of Miketon Polyester Red BSF (manufactured by Dystar Japan Co., Ltd .: CI Discharge Red 111), 28 parts by weight of 2-hydroxybenzoic acid, 7.2 parts by weight of talc, rosin modified phenolic resin (Hitachi Chemical) 80 parts by weight of Polymer Co., Ltd. and 40 parts by weight of ethyl acetate as a solvent were kneaded. From this kneaded product, the viscosity was adjusted to 500 P by volatilizing the solvent component to prepare a red sterilization indicator ink composition of the oxidation polymerization type.

  The color change layer was formed by printing the ink composition on high-quality tack paper with a roll using an actual offset printing press. It was cut into a label to produce a sterilization indicator.

  An indicator was placed in the autoclave and treated under a high-pressure steam atmosphere at a temperature of 134 ° C. for 20 minutes as in the actual high-pressure steam sterilization conditions. The discolored layer of the indicator that was red before the treatment turned yellow after the treatment.

  Another indicator was placed in the ethylene oxide gas sterilizer, and the treatment was performed in an atmosphere of ethylene oxide gas having a concentration of 530 mg / L at a humidity of 70% RH and a temperature of 50 ° C. for 2 hours in the same manner as the actual ethylene oxide gas sterilization conditions. The discoloration layer of the indicator that was red before the treatment turned blue after the treatment.

(Example 3)
4 parts by weight of Miketon Polyester Red 3BSF (Dystar Japan Co., Ltd .: CI Discharge Red 206), 26 parts by weight of 3,5-dihydroxybenzoic acid, 7.2 parts by weight of talc, rosin-modified phenolic resin ( 80 parts by weight of Hitachi Chemical Co., Ltd.) and 40 parts by weight of ethyl acetate as a solvent were kneaded. From this kneaded product, the viscosity was adjusted to 800 P by volatilizing the solvent, and a red sterilization indicator ink composition of the oxidation polymerization type was prepared.

  The color change layer was formed by printing the ink composition on high-quality tack paper with a roll using an actual offset printing press. It was cut into a label to produce a sterilization indicator.

  An indicator was placed in the autoclave and treated under a high-pressure steam atmosphere at a temperature of 121 ° C. for 20 minutes in the same manner as the actual high-pressure steam sterilization conditions. The discolored layer of the indicator that was red before the treatment turned yellow after the treatment.

  Another indicator was placed in the ethylene oxide gas sterilizer, and the treatment was performed in an atmosphere of ethylene oxide gas having a concentration of 530 mg / L at a humidity of 70% RH and a temperature of 50 ° C. for 2 hours in the same manner as the actual ethylene oxide gas sterilization conditions. The discoloration layer of the indicator that was red before the treatment turned blue after the treatment.

Example 4
4 parts by weight of Miketon Polyester Red 2BSF (manufactured by Dystar Japan Co., Ltd .: CI Discharge Red 88), 24 parts by weight of 2,3,4-trimethylbenzoic acid, 7.2 parts by weight of talc, F-Gloss 80 parts by weight of medium (manufactured by Dainippon Ink and Chemicals, Inc .; trade name) and 40 parts by weight of ethyl acetate as a solvent were kneaded. From this kneaded product, the viscosity was adjusted to 800 P by volatilizing the solvent, and a red sterilization indicator ink composition of the oxidation polymerization type was prepared.

  The color change layer was formed by printing the ink composition on high-quality tack paper with a roll using an actual offset printing press. It was cut into a label to produce a sterilization indicator.

  An indicator was placed in the autoclave and treated under a high-pressure steam atmosphere at a temperature of 134 ° C. for 20 minutes as in the actual high-pressure steam sterilization conditions. The discolored layer of the indicator that was red before the treatment turned yellow after the treatment.

  Another indicator was placed in the ethylene oxide gas sterilizer, and the treatment was performed in an atmosphere of ethylene oxide gas having a concentration of 530 mg / L at a humidity of 70% RH and a temperature of 50 ° C. for 2 hours in the same manner as the actual ethylene oxide gas sterilization conditions. The discoloration layer of the indicator that was red before the treatment turned blue after the treatment.

(Example 5)
4 parts by weight of Miketon Polyester Red 2BSF (Dystar Japan Co., Ltd .: CI Discharge Red 88), 24 parts by weight of 2,3,4-trimethylbenzoic acid, 7.2 parts by weight of talc, epoxy acrylate resin 40 parts by weight, 20 parts by weight of trimethylolpropane tri (meth) acrylate resin, 8 parts by weight of 4,4′-bisdiethylaminobenzophenone, 0.1 part by weight of methylhydroquinone, 5 parts by weight of polyethylene glycol alkyl ether Kneaded. N, N-dimethylacrylamide was further added to this kneaded product and kneaded to adjust the viscosity to 200 P, thereby preparing an ultraviolet curable red sterilization indicator ink composition.

  The ink composition was printed on a roll-shaped high-quality tack paper by an offset actual printing machine, and then cured with ultraviolet rays to form a discolored layer. It was cut into a label to produce a sterilization indicator.

  An indicator was placed in the autoclave and treated under a high-pressure steam atmosphere at a temperature of 134 ° C. for 20 minutes as in the actual high-pressure steam sterilization conditions. The discolored layer of the indicator that was red before the treatment turned yellow after the treatment.

  Another indicator was placed in the ethylene oxide gas sterilizer, and the treatment was performed in an atmosphere of ethylene oxide gas having a concentration of 530 mg / L at a humidity of 70% RH and a temperature of 50 ° C. for 2 hours in the same manner as the actual ethylene oxide gas sterilization conditions. The discoloration layer of the indicator that was red before the treatment turned blue after the treatment.

(Example 6)
4 parts by weight of Miketon Polyester Red 2BSF (Dystar Japan Co., Ltd .: CI Discharge Red 88), 24 parts by weight of 2,3,4-trimethylbenzoic acid, 7.2 parts by weight of talc, UV 161 medium 80 parts by weight (made by T & K TOKA Corporation; trade name) and 40 parts by weight of ethyl acetate were kneaded. To this kneaded product, N, N-dimethylacrylamide was further added and kneaded to adjust the viscosity to 300 P, thereby preparing an ultraviolet curable red sterilization indicator ink composition.

  The ink composition was printed on a roll-shaped high-quality tack paper by an offset actual printing machine, and then cured with ultraviolet rays to form a discolored layer. It was cut into a label to produce a sterilization indicator.

  An indicator was placed in the autoclave and treated under a high-pressure steam atmosphere at a temperature of 134 ° C. for 20 minutes as in the actual high-pressure steam sterilization conditions. The discolored layer of the indicator that was red before the treatment turned yellow after the treatment.

  Another indicator was placed in the ethylene oxide gas sterilizer, and the treatment was performed in an atmosphere of ethylene oxide gas having a concentration of 530 mg / L at a humidity of 70% RH and a temperature of 50 ° C. for 2 hours in the same manner as the actual ethylene oxide gas sterilization conditions. The discoloration layer of the indicator that was red before the treatment turned blue after the treatment.

(Comparative Example 1)
4 parts by weight of Miketon Polyester Red 2BSF (manufactured by Dystar Japan Co., Ltd .: CI Discharge Red 88), 24 parts by weight of 2,3,4-trimethylbenzoic acid, 7.2 parts by weight of talc, and medium (Nouvel) 100 parts by weight of Senior Soy Medium (manufactured by Dainichi Seika Kogyo Co., Ltd.) and 50 parts by weight of ethyl acetate as a solvent were mixed. From this kneaded product, the viscosity was adjusted to 20 P by volatilizing the solvent component to prepare an oxidation polymerization type red ink composition.

  The color change layer was formed by printing the ink composition on high-quality tack paper with a roll using an actual offset printing press. It was cut into a label to produce a sterilization indicator.

  An indicator was placed in the autoclave and treated under a high-pressure steam atmosphere at a temperature of 134 ° C. for 20 minutes as in the actual high-pressure steam sterilization conditions. The discolored layer of the indicator, which was a light red color before processing, turned to an obscure light brown color after processing.

  Another indicator was placed in the ethylene oxide gas sterilizer, and the treatment was performed in an atmosphere of ethylene oxide gas having a concentration of 530 mg / L at a humidity of 70% RH and a temperature of 50 ° C. for 2 hours in the same manner as the actual ethylene oxide gas sterilization conditions. The discoloration layer of the indicator that was light red before the treatment did not change color after the treatment and remained an indistinct light red color.

(Comparative Example 2)
4 parts by weight of Miketon Polyester Red 2BSF (manufactured by Dystar Japan Co., Ltd .: CI Discharge Red 88), 7.2 parts by weight of talc, 80 of media (Nouvel Senior Soy Medium, manufactured by Daiichi Seika Kogyo Co., Ltd.) 40 parts by weight of mineral spirits were kneaded as parts by weight and solvent. From this kneaded product, the viscosity was adjusted to 200 P by volatilizing the solvent, and an oxidation polymerization type red ink composition was prepared.

  The color change layer was formed by printing the ink composition on high-quality tack paper with a roll using an actual offset printing press. It was cut into a label to produce a sterilization indicator.

  An indicator was placed in the autoclave and treated under a high-pressure steam atmosphere at a temperature of 134 ° C. for 20 minutes as in the actual high-pressure steam sterilization conditions. The discoloration layer of the indicator that was red before the treatment did not change color after the treatment and remained red.

  Another indicator was placed in the ethylene oxide gas sterilizer, and the treatment was performed in an atmosphere of ethylene oxide gas having a concentration of 530 mg / L at a humidity of 70% RH and a temperature of 50 ° C. for 2 hours in the same manner as the actual ethylene oxide gas sterilization conditions. The discoloration layer of the indicator that was red before the treatment did not change color after the treatment and remained red.

(Comparative Example 3)
0.4 parts by weight of Miketon Polyester Red 2BSF (manufactured by Dystar Japan Co., Ltd .: CI Discharge Red 88), 2.4 parts by weight of 2,3,4-trimethylbenzoic acid, 0.7 parts by weight of talc 100 parts by weight of medium (manufactured by T & K TOKA; trade name) and 50 parts by weight of mineral spirit were kneaded. N, N-dimethylacrylamide was further added to the kneaded product and kneaded to adjust the viscosity to 300 P, thereby preparing a UV-curable light red ink composition.

  The ink composition was printed on a roll-shaped high-quality tack paper by an offset actual printing machine, and then cured with ultraviolet rays to form a discolored layer. It was cut into a label to produce a sterilization indicator.

  An indicator was placed in the autoclave and treated under a high-pressure steam atmosphere at a temperature of 134 ° C. for 20 minutes as in the actual high-pressure steam sterilization conditions. The discolored layer of the indicator, which was a light red color before processing, turned to an obscure light brown color after processing.

  Another indicator was placed in the ethylene oxide gas sterilizer, and the treatment was performed in an atmosphere of ethylene oxide gas having a concentration of 530 mg / L at a humidity of 70% RH and a temperature of 50 ° C. for 2 hours in the same manner as the actual ethylene oxide gas sterilization conditions. The discoloration layer of the indicator that was light red before the treatment did not change color after the treatment and remained an indistinct light red color.

(Comparative Example 4)
1.2 parts by weight of Miketon Polymer Red 2BSF (manufactured by Dystar Japan Co., Ltd .: CI Discharge Red 88), 20.8 parts by weight of malonic acid, 7.2 parts by weight of talc, medium (Nouvel Senior Soy medium) 60 parts by weight of Dainichi Seika Kogyo Co., Ltd.) and 40 parts by weight of mineral spirits were kneaded. From this kneaded product, the viscosity was adjusted to 200 P by volatilizing the solvent, and an oxidation polymerization type red ink composition was prepared.

  The color change layer was formed by printing the ink composition on high-quality tack paper with a roll using an actual offset printing press. It was cut into a label to produce a sterilization indicator.

  An indicator was placed in the autoclave and treated under a high-pressure steam atmosphere at a temperature of 134 ° C. for 20 minutes as in the actual high-pressure steam sterilization conditions. The discolored layer of the indicator that was red before the treatment turned yellow after the treatment.

  Another indicator was placed in the ethylene oxide gas sterilizer, and the treatment was performed in an atmosphere of ethylene oxide gas having a concentration of 530 mg / L at a humidity of 70% RH and a temperature of 50 ° C. for 2 hours in the same manner as the actual ethylene oxide gas sterilization conditions. The discoloration layer of the indicator that was a light red color before the treatment turned to an indistinct reddish purple color that was difficult to visually confirm the color change after the treatment.

  The above results are summarized in Table 1.

  As is clear from Table 1, it was confirmed that the indicators of Examples 1 to 6 were easily and accurately visually confirmed that they were treated under high-pressure steam or ethylene oxide gas sterilization conditions. On the other hand, it was difficult to visually confirm that the indicators of Comparative Examples 1 to 4 had undergone treatment under high-pressure steam and ethylene oxide gas sterilization conditions.

  The sterilization indicator ink composition of the present invention is useful for preparing an indicator for confirming the completion of sterilization of medical instruments, pharmaceuticals, processed foods such as retort foods, and the like.

  The sterilization indicator printed with offset printing or letterpress printing with this composition to form a discoloration layer can be used to confirm the completion of sterilization in the form of a card, sticker or label printed with numbers, letters or designs as the discoloration layer. It is used to save it as evidence. This indicator is conveniently attached in the form of a seal corresponding to the handler label.

  The sterilization confirmation method using this sterilization indicator is useful for confirming either sterilization of high-pressure steam sterilization or ethylene oxide gas sterilization.

Claims (9)

  4 to 40 parts by weight of an aromatic group-containing carboxylic acid, and 1 to 10 parts by weight of a thiazole azo dye that changes color by the action of the aromatic group-containing carboxylic acid under a high-pressure steam atmosphere and / or an ethylene oxide gas atmosphere, A sterilization indicator ink composition which is adjusted to a viscosity of 50 to 1000 P used for offset printing or letterpress printing by containing 50 to 95 parts by weight of a binder.   The binder is vinyl resin, silicon resin, rosin resin, terpene resin, phenol resin, polyester resin, polyether resin, acrylic resin, polyurethane resin, natural rubber, synthetic rubber, petroleum resin, epoxy resin, ketone resin, maleic acid resin. , A coumarin resin, polyvinyl alcohol, polyvinyl butyral, rosin-modified phenol resin, and at least one oxidative polymerizable resin component selected from an alkyd resin, and an ultraviolet curable resin component in which the monomer and the photopolymerization initiator are dissolved It is either, The sterilization indicator ink composition of Claim 1 characterized by the above-mentioned.   The aromatic group-containing carboxylic acid contains an aromatic group which may have a hydroxy group, an alkoxy group or an oxo group, and is an aromatic monocarboxylic acid, aromatic polycarboxylic acid, aromatic group The sterilization indicator ink composition according to claim 1, wherein the sterilization indicator ink composition is at least one selected from a substituted saturated aliphatic carboxylic acid and an aromatic group-substituted unsaturated aliphatic carboxylic acid.   The thiazole azo dye is C.I. I. Discharge Red 43, C.I. I. Discharge Red 58, C.I. I. Discharge Red 88, C.I. I. Discharge Blue 102, C.I. I. Discharge Red 110, C.I. I. Discharge Red 111, C.I. I. Discharge Red 117, C.I. I. Discharge Red 137, and C.I. I. The sterilization indicator ink composition according to claim 1, wherein the sterilization indicator ink composition is at least one selected from Discharge Red 206.   2. The sterilization indicator ink composition according to claim 1, further comprising 20 parts by weight of extender pigment, compound, pigment dispersant, and / or surfactant.   A sterilization indicator, wherein the sterilization indicator ink composition according to claim 1 is printed on a substrate by offset printing or letterpress printing to form a discoloration layer.   The sterilization indicator according to claim 6, wherein the discoloration layer has a thickness of 0.5 to 10 μm.   The sterilization indicator according to claim 6 is exposed to an object to be sterilized together with at least one of high-pressure steam and ethylene oxide gas, and the sterilization indicator changes color in accordance with the completion of sterilization of the object to be sterilized. The sterilization confirmation method characterized by this.   The temperature of the said high pressure steam is 100-135 degreeC, and the density | concentration of the said ethylene oxide gas is 500-650 mg / L, The sterilization confirmation method of Claim 8 characterized by the above-mentioned.