JP2791125B2 - Wet heat sensitive composition and indicator composition for high pressure steam sterilization containing the same - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a wet heat sensitive composition and a sterilizing indicator composition which are remarkably discolored by a wet heat sterilization treatment.
More specifically, the present invention relates to a wet heat-sensitive composition and an indicator composition for sterilization used for various wet heat-sensitive paints, inks, and other wet heat discolorable articles used for packaging medical equipment or retort foods. These various wet heat-sensitive paints or inks change color by steam sterilization at a predetermined temperature for a predetermined time.

[Prior Art] Conventionally, as a wet heat sensitive composition of this type and an indicator ink composition for sterilization, a metal compound such as a carbonate used in an ink of an autoclave tape # 1222 manufactured by Sumitomo 3M Limited, for example, a carbonate, Those containing sulfur as a main component are widely used. It is disclosed in U.S. Pat. No. 2,889,799. Particularly, as an indicator ink composition for sterilization, one disclosed in Japanese Patent Publication No. 45-4690 is known. Further, Japanese Patent Application Laid-Open No. Sho 51-3381 discloses a heat-sensitive composition utilizing discoloration at the time of formation reaction and decomposition reaction of a metal complex. Examples of the application of the wet heat sensitive composition to inks are disclosed in JP-B-55-18464 and JP-B-59-13550.

[Problems to be Solved by the Invention] However, the conventional wet heat-sensitive compositions or sterilizing indicator compositions have not always been satisfactory from the following points.

1) Color development is limited to black system.

2) When the temperature reaches a certain temperature, discoloration starts, and it is not possible to confirm whether or not the treatment with high-pressure steam has been performed for a time necessary for completing the sterilization.

3) Since the components of the composition have sublimability, storage stability is poor and discoloration is not uniform.

4) In particular, compositions containing sulfur have an odor.

In particular, those utilizing a metal complex formation reaction are liable to be discolored only by temperature conditions, and it has been difficult to confirm whether or not the treatment with high-pressure steam has been performed for the time required for sterilization. In addition, in all cases, those utilizing the discoloration during the formation reaction or decomposition reaction of the metal complex may not be sufficient in storage stability. In particular, those utilizing a decomposition reaction have not always been sufficient in storage stability, particularly stability against moisture such as humidity in the air.

An object of the present invention is to solve such problems and to obtain a wet heat sensitive composition and an indicator composition for sterilization having the following various properties.

1) It shows remarkable discoloration only when all the conditions of steam sterilization such as heat at a predetermined temperature, steam for providing a predetermined humidity, and a predetermined elapsed time are satisfied.

2) Good storage stability. Specifically, it does not react at low temperature (for example, room temperature), is insoluble in water, is not reactive with water, and has no sublimability.

3) The color change after autoclaving is uniform and clear.

4) Be odorless.

[Means for Solving the Problems] According to the present invention, there are provided a practical wet heat sensitive composition and a sterilizing indicator composition having all the above-mentioned various properties and discolored by steam sterilization. . That is, (1) a wet heat sensitive composition comprising a combination of a metal complex and an exchange ligand, wherein the metal complex is bis (dimethylglyoximato) nickel (hereinafter abbreviated as Ni (dmg) ₂ ) or bis ( 2-furyldioximato) nickel (hereinafter abbreviated as Ni (fdo) ₂ ), zirconium chloranilate or bis (nioximato) nickel (hereinafter abbreviated as Ni (nox) ₂ ), and the exchange ligand is 1 to
An aminopolycarboxylic acid containing 6 carboxylic acid groups and 1 to 4 amino groups, or citric acid or a salt thereof, or tartaric acid or a salt thereof, or a mixture thereof, (2) The wet heat sensitive composition according to (1), wherein the exchange ligand is a glycine derivative, an alanine derivative, or a salt of the glycine derivative. (3) The (1) and (2) )) A sterilizing indicator composition comprising a wet heat sensitive composition, a binder and a solvent as main components, (4) the wet heat sensitive composition of (1) and (2),
An indicator composition for sterilization, comprising a binder solvent and a discoloration rate adjusting agent as main components, (5) the discoloration rate adjusting agent is thiocyanate, cyanate, citric acid, citrate, tartaric acid or An indicator composition for sterilization according to the above (4), which is a tartrate salt.

The present invention utilizes a ligand exchange reaction under high-pressure steam conditions represented by the general formula ML _n + Y → MY + nL. Here, ML _n represents a metal complex, Y represents an exchange ligand, M represents a metal, and L represents a ligand constituting the metal complex. Further, n represents an integer, and is 2 in the case of the above metal complex. ML _n is usually a colored metal complex, while Y is usually a colorless exchange ligand. In the high-pressure steam sterilization conditions, ML _n and Y produce other metal complex MY and a ligand L reacts. This metal complex MY
When, liberated ligand L, colorless or respectively, the color different from one and ML _n.

The exchange ligand of the present invention comprises: 1) an aminopolycarboxylic acid containing 1 to 6 carboxylic acid groups and 1 to 4 amino groups,
And 2) citric acid or tartaric acid and salts thereof. Preferred salts of these acids are the sodium, potassium, calcium and ammonium salts. Specifically, for example, ethylenediaminetetraacetic acid (hereinafter referred to as ED
TA) or a salt thereof, glycol ether diamine tetraacetic acid (hereinafter abbreviated as GEDTA), trans-1,2-cyclohexanediaminetetraacetic acid (hereinafter abbreviated as CyDTA), nitrilotriacetic acid (hereinafter abbreviated as NTA), or a salt thereof , Iminodiacetic acid (hereinafter abbreviated as IDA) or a salt thereof, dihydroxyethylglycine (hereinafter abbreviated as DHEG), N-hydroxyethylethylenediaminetriacetic acid (hereinafter abbreviated as EDTA-OH), hydroxyethyliminodiacetic acid (hereinafter abbreviated as HIDA) ), Ethylenediamine dipropionic acid dihydrochloride (hereinafter
EDDP), diethylenetriaminepentaacetic acid (DTPA)
), Triethylenetetramine hexaacetic acid (hereinafter abbreviated as TTHA), 1,3-diaminopropan-2-ol-tetraacetic acid (hereinafter abbreviated as DPTA-OH) and 1,2-diaminopropanetetraacetic acid (hereinafter abbreviated as Methyl- EDTA).

A desirable example of a salt of citric acid is diammonium citrate. Desirable tartrate salts include ammonium tartrate.

The compounding ratio of the metal complex and the exchange ligand is such that the exchange ligand needs to be at least equimolar to the metal complex, preferably 2 to 20 moles, in view of the degree of discoloration and the speed change. Most preferably, it is 2 to 10 moles.

The indicator composition for sterilization of the present invention having all the above-mentioned various properties contains the heat-sensitive composition (ML _n and Y) of the present invention, a binder and a solvent as essential components.

As the binder contained in the indicator composition for sterilization of the present invention, any of resins such as cellulose resin, petroleum resin, phenol resin, maleic acid resin and vinyl resin used in general-purpose ink compositions may be used. In particular, nitrocellulose, ethylcellulose, chlorinated rubber, and chlorinated polyolefin can be suitably used. This binder is used from the viewpoints of the film forming property of the indicator ink composition for sterilization, the adhesion to the object, the heat and moisture resistance, and the solubility in a drying solvent, particularly a fast drying solvent.

As the solvent in the composition according to the present invention, any of the general-purpose solvents used for oil-based inks can be used. Useful solvents include alcohols, esters, aromatic hydrocarbons and ketones. In particular n-propyl acetate,
n-Propanol, methanol, 2-ethoxyethanol, butyl acetate, n-butanol, toluene, cyclohexanone and a mixed solvent thereof can be suitably used.

In a preferred embodiment of the indicator composition for sterilization according to the present invention, a speed changing agent is included. The rate regulator desirably includes a thiocyanate that accelerates the rate of the ligand exchange reaction or a cyanate that decreases the rate of the ligand exchange reaction. Desirable cyanates are
Includes sodium cyanate and potassium cyanate.

In particular, thiocyanate is preferred from the viewpoint of increasing the speed of the discoloration reaction, and examples thereof include ammonium thiocyanate, sodium thiocyanate, potassium thiocyanate and calcium thiocyanate. In addition, citric or tartaric acid and their salts can be used as speed regulators to accelerate the color forming ability of inks containing other aminocarboxylic acid type exchange ligands.

The indicator composition for sterilization of the present invention may further contain substances usually added to the ink composition for various purposes, such as a drying oil, a semi-dry oil, a plasticizer, a pigment, and a dispersant. The extender may include, for example, titanium oxide or other commercially available color pigments commonly used in inks. Specifically, “Resino Yellow MD-556
-AD "," Resino Blue MD-1132-AD "and" Resino Green MD-2811-AD ", all of which are commercially available from Resino Color Industries.
These pigments have a remarkable effect when a color change different from the original color change of the wet heat sensitive composition of the present invention is desired.

For example, "Resino Yellow" is Ni (dmg) ₂ and EDT
When added to the composition for a sterilization indicator containing A.2Na, the composition that was initially red turns yellow after steam sterilization. "Resino Green"
When added to the same composition instead of "Resino Yellow", the composition, which was originally brown, turns green after steam sterilization.

The indicator composition for sterilization of the present invention can be applied to various inks such as gravure ink, letterpress ink, screen ink, and stamp ink. This ink composition is applied to various substrates by a normal application operation to obtain various sterilization monitoring articles such as a tape, a label, and a card. This article can be applied for practical use by applying a sticky (contact) adhesive for adhering to an adherend.

The essential component ratio of the indicator composition for sterilization of the present invention is, from a practical point of view, in the case of a gravure ink, the moisture and heat sensitive composition of the present invention is 30 to 40% by weight, and the binder is 30% by weight.
Preferred is a range of 6060% by weight and 10-40% by weight of solvent. In the case of a screen ink, the humidity and heat sensitive composition is 7 to 33.
% By weight, 35-65.5% by weight binder and 15-35% by weight solvent. As described above, the desired discoloration rate of the composition of the present invention can be obtained by changing the mixing ratio of the metal complex and the exchange ligand.
The discoloration rate can also be arbitrarily changed by adding 0.1 to 15% by weight of the discoloration rate adjusting agent to the whole composition. In the case of extenders, they are based on metal complexes of 10-
If it is used at 100% by weight, and if it is titanium dioxide, a similar color change can also be obtained if it is used at 50-300% by weight.

Among the compositions of the present invention, those having different discoloration conditions selected and applied to the same substrate in plural types are practical as steam sterilization indicators.

[Effect] The composition of the present invention comprises a normally colored metal complex (ML _n )
And a colorless exchange ligand (Y). In these, the next reaction ML _n + Y → MY + nL proceeds only under the moist heat condition under sterile conditions to generate another metal complex (MY) and a ligand (L). This formation constant of the metal complexes of the present invention (ML _n) is because you have selected a smaller than the formation constant of the resulting metal complex (MY). The composition of the present invention is such that the metal complex (ML _n ) having a strong color before the reaction becomes another color or colorless metal complex (MY) and the ligand (L) under wet heat conditions and other Since the metal complex (ML _n ) and the exchange ligand (Y) are selected so as to satisfy various conditions, the completion of the sterilization can be clearly sensed by the remarkable change of the color.

[Examples] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

Example 1 A mixture having the following composition was uniformly dispersed in a ball mill to prepare a composition of the present invention.

This composition was applied to a latex-impregnated paper marketed as “Crepe Paper Backing S-03” by Kojin Co., Ltd. using a Meyer bar (# 20) to obtain a dried test piece. 121 ° C / 1 minute in an autoclave of this test piece, 1
Table 1 shows the rate of discoloration at 32 ° C / 3 minutes and 132 ° C / 15 minutes. Here, the rate of discoloration is Nippon Denshoku Industries SZ-Σ80 CO
Using the LOR MEASURING SYSTEM, the color difference (Δ
It was determined by measuring E).

Here, L, a, and b represent the lightness, hue, and saturation of the ink before discoloration, respectively, and L ', a', and b 'represent the lightness, hue, and saturation after discoloration in the autoclave, respectively.
The discoloration rate (%) is expressed as a percentage of ΔE of the test piece, with 0 before discoloration and 100 when ΔE when complete discoloration is completed.

Examples 2 to 47 The combinations of the metal complexes and the exchange ligands in Tables 2 to 5 were the same as those in Example 1 except that the molar ratio of the exchange ligand to the metal complex was 8 times the mole. A test piece was prepared in the same manner as in Example 1 using the same binder and solvent in the same ratio. The discoloration ratio was measured by the method described in Example 1, and the results are shown in Tables 2 to 5.

According to the wet heat test, when the metal complex was Ni (dmg) ₂ (Tables 1 and 2), the color changed from dark red to colorless, and Ni (fd
o) In the case of ₂ (Table 3), the color changes from brown to colorless; in the case of zirconium chloranilate (Table 4), the color changes from gray to purple; in the case of Ni (nox) ₂ (Table 5), the color changes to light red. To colorless.

If the discoloration rate is less than 50% at 132 ° C / 15 minutes, the reaction starts only when the three conditions for high-pressure steam sterilization are met, but the elapsed time until the discoloration is completed is too long to be practical. Is not suitable. In the case of those showing a discoloration rate of 50% or more already at 121 ° C./min, it is not possible to confirm whether or not a certain period of time necessary for high-pressure steam sterilization has elapsed because the discoloration is too fast, and the purpose of the present invention is not satisfied. Is not suitable. As shown in Tables 1 to 5, all the compositions of the present invention show sufficient performance to achieve the object of the present invention.

Example 48 A mixture having the following composition was uniformly dispersed in a ball mill to prepare an indicator composition for sterilization of the present invention.

This composition was applied to the latex-impregnated paper described in Example 1 using a Meyer bar (# 20) and dried to obtain a test piece.

The test piece prepared in this way was pink-red and completely turned white in an autoclave at 120 ° C. in saturated steam in 15 to 20 minutes. Under a condition of 135 ° C. in saturated steam in an autoclave, it became completely white in 3 to 5 minutes.

Example 49 Except for not using ammonium thiocyanate,
A test piece was produced with the same composition and the same method as in Example 48. Under a steam sterilization condition of saturated steam of 120 ° C. in an autoclave, the color changed from pink red to completely white in 20 to 30 minutes.
5 at 135 ° C in saturated steam in an autoclave
It became completely white in ~ 8 minutes. This indicates that the addition of ammonium thiocyanate increases the rate of the ligand exchange reaction.

Example 50 A test piece was produced in the same manner as in Example 49, except that 3.87 parts by weight of EDTA · 2Na (2 times mol with respect to Ni (dmg) ₂ ) was used. Under a steam sterilization condition of 135 ° C. in saturated steam in an autoclave, it completely turned white in 8 to 10 minutes.

Example 51 A mixture having the following composition was uniformly dispersed in a ball mill to prepare an indicator composition for sterilization.

This composition was applied to a Meyer bar (# 2) as described in Example 1.
Using (0), the test piece was applied to a latex-impregnated paper and dried to obtain a test piece. The specimen prepared in this way is brown,
Under a steam sterilization condition of 120 ° C. in saturated steam in an autoclave, it completely turned white in 20 minutes. In an autoclave, under a condition of 135 ° C. in saturated steam, it completely turned white in 5 minutes.

Example 52 A mixture having the following composition was uniformly dispersed in a ball mill to prepare an indicator composition for sterilization.

This composition was applied to a Meyer bar (# 2) as described in Example 1.
Using (0), the test piece was applied to a latex-impregnated paper and dried to obtain a test piece. The test specimen prepared in this way is gray,
Under a steam sterilization condition of 135 ° C. in saturated steam in an autoclave, it turned completely purple in 30 minutes.

Example 53 A mixture having the following composition was uniformly dispersed in a ball mill to prepare an indicator composition for sterilization.

This composition was applied to a Meyer bar (# 2) as described in Example 1.
Using (0), the test piece was applied to a latex-impregnated paper and dried to obtain a test piece. The test piece thus prepared was pink-red and completely white in 20 minutes under steam sterilization conditions of 135 ° C. in saturated steam in an autoclave.

Example 54 A mixture having the following composition was uniformly dispersed in a ball mill,
A composition according to the invention was prepared.

Composition Amount (parts by weight) Ni (dmg) ₂ 3.00 EDTA.2Na 30.86 Binder 50.00 Solvent 16.67 The binder has the following composition.

Composition Amount (parts by weight) Nitrocellulose 4.20 Ethyl cellulose 4.90 Triacetin 2.11 Methanol 8.76 2-Ethoxyethanol 15.07 n-Propyl acetate 14.96 The solvent consists of 10 parts by weight of n-propyl acetate and 6.67 parts by weight of n-propanol.

The composition was applied to a latex-impregnated paper marketed as “Crepe Paper Backing S-03” by Kojin Co., Ltd. using a Meyer bar (# 7), and dried to obtain test pieces.

Examples 55-56, Comparative Examples 1-7 Ni (dmg) ₂ was used as the metal complex, and EDTA · 2
Examples using various other compounds in place of Na
A test piece was prepared in the same manner as in 54.

The amounts of the binder and the solvent used were the same as in Example 54. Ni (dmg) ₂ usage and additives are 6th
It is shown in the table. The color change (ΔE) of the test pieces prepared according to Examples 54-56 and Comparative Examples 1-7 was measured in the same manner as in Example 1. That is, in an autoclave, 121 ° C, 1
Min, 132 ° C, 1 minute, 3 minutes, 5 minutes, 15 minutes and 30 minutes. Table 6 shows the results.

From Table 6, it can be seen that ammonium citrate and ammonium tartrate act as exchange ligands and exhibit properties approximately equal to EDTA · 2Na. Other cyanic and thiocyanates and ammonium acetate do not react well with metal complexes as exchange ligands in the practice of the present invention.

Examples 57-60 and Comparative Example 8 Ni (dmg) ₂ was used as the metal complex, and EDTA · 2
Example 54 using various other compounds in place of Na
A test piece was prepared in the same manner as described above. The color change (ΔE) was measured by the same method as in Comparative Example 1-7 and Example 55.
Table 7 shows the results.

From Table 7, it can be seen that tartaric acid and citric acid act as exchange ligands and have performance characteristics approximately equal to EDTA · 2Na.

Examples 61-75 and Comparative Examples 9-11 In the same manner as in Example 1, test pieces of a composition for a sterilization indicator containing various discoloration rate regulators were prepared. The color change (ΔE) was measured in the same manner as in Example 1. That is, in an autoclave, 121 ° C., 1 minute, 132
It is the difference from the initial color of the test piece that changed color under the conditions of 1, 0, 3 and 5 minutes. Table 8 shows the results when the discoloring speed regulator was used at 1% by weight, and Table 9 shows the results when the discoloring speed regulator was used at 5% by weight.

From the results of Tables 8 and 9, the discoloration rate regulators of thiocyanate, tartrate and citrate accelerate the rate of the discoloration reaction, whereas the rate modifier of cyanate is the sterilizing agent of the present invention. It can be seen that the discoloration reaction of the indicator composition is slowed down.

Example 76 The following components for a sterilization indicator were prepared by uniformly dispersing with a ball mill. : Ingredients Amount (parts by _{weight) Ni (dmg) 2 3.44 EDTA} · 2Na 26.58 TiO 2 1.72 Ca (SCN) 2 0.22 green pigment ^{Note 1)} 1.37 Binder ^{Note 2)} 50.00 Solvent ^{Note 3)} 16.67 ^{Note 1)} "Lezno Green MD-2811-AD ”(manufactured by Resino Color Industry Co., Ltd.) ^{Note 2) The} binder has the following composition.

Component amount (parts by weight) Nitrocellulose 4.20 Ethyl cellulose 4.90 Triacetin 2.11 Methanol 8.76 2-Ethoxyethanol 15.07 n-Propyl acetate 14.96 ^{Note 3)} Solvent is 10 parts by weight of n-propyl acetate and n
-Consists of 6.67 parts by weight of propanol.

In the same manner as described in Example 1, this ink composition was applied to a latex-impregnated paper and dried to prepare a test piece. The test specimen prepared in this way is brown, 132 ° C
Under the steam sterilization condition, the color was completely green in 5 minutes.

[Effects of the Invention] As described above, the wet heat-sensitive composition of the present invention and the indicator ink composition for sterilization containing the same,
Three conditions for high-pressure steam sterilization, namely, heat at a predetermined temperature,
Only when all the conditions of the water vapor for providing the predetermined humidity and the predetermined elapsed time are satisfied, uniform and remarkable discoloration was realized, and the confirmation of sterilization became extremely easy.

In addition, since a compound already forming a metal complex is used as a starting material, storage stability is good, and discoloration does not start at a low temperature and does not start due to humidity in the air. Further, as is apparent from the components of the composition of the present invention, the composition has no sublimability, is stable even after discoloration, and does not accompany odor.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ identification symbol FI G01N 31/22 122 G01N 31/22 122 (58) Fields investigated (Int.Cl. ⁶ , DB name) C09D 11/00-11 / 20 C09D 5/00-5/46 A61L 2/26 G01N 21/81 G01N 31/22 A23L 3/00

Claims (5)

(57) [Claims] 1. A wet heat sensitive composition comprising a combination of a metal complex and an exchange ligand, wherein the metal complex is bis (dimethylglyoximato) nickel, bis (2-furyldioximato) nickel, Zirconium chloranilate or bis (nioximato) nickel, wherein the exchange ligand has 1 to 6 carboxylic acid groups and 1
An aminopolycarboxylic acid or citric acid or salt thereof containing up to 4 amino groups, or tartaric acid or a salt thereof, or a mixture thereof, wherein: 2. The wet heat-sensitive composition according to claim 1, wherein the exchange ligand is a glycine derivative, an alanine derivative or a polydentate ligand of a salt of the glycine derivative. 3. The composition according to claim 1 or 2, comprising a heat and heat sensitive composition according to claim 1 as a main component, a binder and a solvent.
An indicator composition for sterilization, comprising: 4. An indicator composition for sterilization, comprising the wet heat sensitive composition according to claim 1 or 2 as a main component, a binder solvent and a discoloration rate regulator. 5. The sterilizing indicator composition according to claim 4, wherein the discoloration rate controlling agent is thiocyanate, cyanate, citric acid, citrate, tartaric acid or tartrate.