JP4722418B2 - Indicator for checking heating history - Google Patents

Description

  The present invention relates to an indicator for confirming a heating history used for confirming that it has been heated at a predetermined temperature for a predetermined time by a clear and visible color change.

  Medical products / pharmaceuticals and long-term preserved foods are sterilized and sterilized.

  In order to confirm the completion of sterilization / sterilization treatment by heating such as high-pressure steam sterilization treatment, retort sterilization treatment, and boil sterilization treatment, inexpensive chemical indicators that change color according to heating temperature and heating time are widely used.

  Patent Document 1 discloses a chemical indicator coated with a composition comprising a bismuth compound, a thiourea compound, and a synthetic rubber resin.

Japanese Patent Publication No. 04-62746

  Such a chemical indicator is simple in that the color changes when the coexisting bismuth compound and thiourea compound react under high temperature and high pressure conditions. However, when these compounds coexist, the reaction proceeds gradually even at a temperature lower than a predetermined temperature to be confirmed during storage of the indicator for a long time, causing a color change little by little. The chemical indicator has a problem that the higher the reactivity of these compounds, the lower the predetermined temperature to be confirmed, but the lower the storage stability.

  The present invention has been made to solve the above-mentioned problems, and by a visible color change, a history of a wide range of heating temperatures can be accurately and accurately confirmed, and an inexpensive and simple heating history confirmation having excellent long-term storage stability. An object is to provide an indicator.

The invention according to claim 1 of the present invention made to achieve the above object contains an inorganic metal compound or a heavy metal complex compound and a resin softened by heating in a weight ratio of 10-15: 20-100. A layer and a layer containing a sulfur-containing compound and a resin softened by heating at a weight ratio of 10 to 20:10 to 100 are held in a separated state, and by contacting the two layers while being bonded , as inorganic metal compound in the environment or the hydrated sulfur compounds react in contact with the heavy metal complex compounds of heating is confirmed heating history for indicators, characterized by changing color.

  This indicator is stable because it does not cause a reaction and does not change color unless the two layers are brought into contact.

  This reaction is irreversible. For this reason, the indicator does not return to the original color once the color has changed.

  Similarly, in the invention according to claim 2, the inorganic metal compound is at least one selected from a bismuth compound, a cobalt compound, a nickel compound, a chromium compound, an aluminum compound, and an iron compound; the heavy metal complex compound is a heavy metal-hexamethylenetetramine. At least one selected from complex compounds, heavy metal-phosphate complex compounds, and heavy metal-ammonium complex compounds; the sulfur-containing compound is a thiourea compound, thiuram compound, thiazole compound, sulfur-containing amino acid compound, sulfur-containing protein, sulfur-containing organic acid It is at least 1 sort (s) chosen from a compound, The indicator for heat history confirmation of Claim 1 characterized by the above-mentioned.

  Examples of the inorganic metal compound include bismuth compounds such as bismuth oxalate, bismuth sulfate, bismuth chloride, bismuth oxide, basic bismuth carbonate, bismuth hydroxide, bismuth nitrate nitrate, and basic bismuth acetate. Examples include nickel nitrate hexahydrate, cobalt chloride hexahydrate, anhydrous cobalt chloride, basic cobalt carbonate, cobalt carbonate, cobalt oxide, cobalt oxalate dihydrate, and cobalt sulfate heptahydrate. , Nickel nitrate hexahydrate, anhydrous nickel chloride, nickel chloride hexahydrate, basic nickel carbonate, nickel acetate tetrahydrate, nickel oxide, nickel sulfate hexahydrate, nickel sulfate heptahydrate, oxalic acid Nickel dihydrate can be mentioned, and chromium compounds include chromium nitrate nonahydrate, chromium chloride hexahydrate, acid Chromium include chromium sulfate n-hydrate, as aluminum compound, include aluminum nitrate nonahydrate, include iron nitrate nonahydrate as an iron compound. The inorganic metal compound may be any one of these or a mixture of plural kinds.

  The heavy metal complex compound may be a hydrate containing water of crystallization or a hydrated body. The heavy metal complex compound is, for example, as a heavy metal-hexamethylenetetramine complex compound, a decahydrate or a hydrate of a complex of cobalt nitrate and hexamethylenetetramine, or a decahydrate of a complex of cobalt nitrate, nickel nitrate and hexamethylenetetramine. , Nickel nitrate and hexamethylenetetramine complex decahydrate, cobalt oxide and hexamethylenetetramine complex nonahydrate, cobalt chloride and hexamethylenetetramine complex decahydrate, heavy metal -Examples of the phosphate complex compound include cobalt phosphate octahydrate and cobalt ammonium phosphate monohydrate. Examples of the heavy metal-ammonium complex compound include cobalt ammonium chloride hexahydrate, cobalt ammonium sulfate hexahydrate, Ammonium chromium sulfate dodecahydrate is mentioned. The heavy metal complex compound may be any one of these or a mixture of plural kinds.

  Examples of the sulfur-containing compound include thiourea compounds such as thiourea, 1,3-dimethyl-2-thiourea, 1,3-diethyl-2-thiourea, 1,3-ditolylthiourea, 2,2′-ditolylthiourea, 1,3-diphenyl-2-thiourea, 1-phenyl-2-thiourea, allylthiourea, 1-acetyl-2-thiourea, ethylenethiourea, trimethylthiourea, tolylthiourea, methylthiourea, ethylthiourea, 1- Phenyl-3-thiosemicarbazide, 4-phenyl-3-thiosemicarbazide, thiocarbohydrazide are exemplified, dipentamethylene thiuram tetrasulfide is exemplified as the thiuram compound, 2-aminobenzothiazole is exemplified as the thiazole compound, Sulfur-containing amino acid compounds include methionine, cysteine, thiamine Nitrate, and examples of sulfur-containing proteins, the proteins mentioned which contains sulfur-containing amino acid compound of the sulfur-containing organic acid compound, thiosalicylic acid, thioglycolic acid, saccharin. The sulfur-containing compound may be any one of these or a mixture of plural kinds. The sulfur-containing compound is more preferably a thiourea compound, a thiuram compound, or a thiazole compound.

Similarly invention according to claim 3, at least one of the two layers, a heating history confirmation indicator according to claim 1, characterized in that it contains the adhesive or bond.

  The inorganic metal compound or heavy metal complex compound-containing layer and the sulfur-containing compound-containing layer are added to these compounds, if necessary, such as resins such as pressure-sensitive adhesives / adhesives and binders, dyes / pigments, and dispersants. It is preferable that the additive and the solvent are mixed and applied by printing, coating or spraying.

  As this resin, various resins such as a binder resin, an adhesive resin, and an adhesive resin that are generally used for inks and paints are used. More specifically, vinyl resin, silicon resin, rosin resin, terpene resin, phenol resin, polyester resin, polyether resin, acrylic resin, polyurethane resin, natural rubber and synthetic rubber, petroleum resin, epoxy resin, ketone resin, malein Examples include acid resins, coumarin resins, polyvinyl alcohol, and polyvinyl butyral. Any one of them or a mixture of plural kinds may be used.

  This resin has an appropriate softening point so that the reaction does not start instantaneously when the inorganic metal compound or heavy metal complex compound-containing layer and the sulfur-containing compound-containing layer are brought into contact with each other. It is preferable. More preferably, the softening point is 60 ° C. or higher.

  Similarly, the invention according to claim 4 is characterized in that the color changes corresponding to the heating history of the heating temperature and the heating time according to the amount of the inorganic metal compound or heavy metal complex compound and the sulfur-containing compound. It is an indicator for heating history confirmation in any one of 1-3.

  The indicator for confirming the heating history of the present invention separates the inorganic metal compound or heavy metal complex compound-containing layer from the sulfur-containing compound-containing layer until it is used to confirm the heating history, so it is stored for a long time before use. Even if it does not cause discoloration, the quality does not deteriorate.

  When this indicator is heated after laminating a layer containing an inorganic metal compound or a heavy metal complex compound and a layer containing a sulfur-containing compound, a visible color change is caused by a chemical reaction between the compounds in both layers. The heating history is displayed with high sensitivity and accuracy. When any layer contains a pressure-sensitive adhesive or an adhesive, the reactivity is further increased.

  Further, the indicator does not return to the original color after the color change and the heating history is confirmed, and the indicator does not decolorize, so that the indicator can be stored for a long time as evidence through a predetermined heating history.

  Hereinafter, the heating history confirmation indicator of the present invention will be described in detail with reference to FIG. 1 showing an example of its implementation, but the scope of the present invention is not limited to the example.

  FIG. 1 is a cross-sectional view illustrating the heating history confirmation indicator during use.

  The heating history confirmation indicator 1 includes a sheet 11 made of polyethylene terephthalate (PET) and a transparent film 15 which is a label made of PET.

  An ink layer 12 printed with an ink composition containing an inorganic metal compound, a binder resin, an additive, and a solvent is formed on the surface of the sheet 11.

  On the surface of the label 15, an adhesive layer 14 applied with an adhesive composition containing a sulfur-containing compound, an adhesive, an additive, and a solvent is formed. A release paper 13 is attached to the adhesive layer 14.

  This heating history confirmation indicator 1 is used as follows.

  First, the release paper 13 attached to the adhesive layer 14 of the label 15 is peeled off. The exposed adhesive layer 14 is attached to the ink layer 12 on the sheet 11. Then, it heats to predetermined temperature.

  As a result, the resin of each layer softens, and the molecules of the inorganic metal compound contained in the ink layer 12 and the molecules of the sulfur-containing compound contained in the adhesive layer 14 come into active molecular motion and finally come into contact with each other. As a result, the indicator changes color depending on the heating temperature and the heating time.

  When a color change is visually observed through the transparent label 15, it can be confirmed that a predetermined heating history has passed.

  In addition, although the example of the indicator which attached the ink layer 12 to the sheet | seat 11 and attached the adhesive layer 14 to the label 15 was shown, it attached | subjected the adhesive layer to the sheet | seat 11, and attached | subjected the ink layer to the label 15, Also good.

  A heavy metal complex compound may be used in place of the inorganic metal compound. By appropriately adjusting the amount of inorganic metal compound or heavy metal complex compound, sulfur-containing compound, resin, additive and solvent, the heating temperature to be confirmed, the time until the color changes after being heated, and the degree of color change are adjusted. be able to. One of the sheet 11 and the label 15 is transparent, and may be made of plastic such as polypropylene (PP), paper, or metal. Instead of the sheet 11, a container, a lid, or a cylinder may be used. A sheet may be used instead of the label 15. The indicator 1 may be provided with color samples before and after the color change. Printing is performed by any method such as screen printing, offset printing, flexographic printing, and gravure printing.

  An indicator for confirming the heating history to which the present invention is applied was prototyped and its performance was evaluated.

  First, an ink composition used for forming the layers 12 and 15 on the sheet 11 or the label 15 was prepared at a composition ratio shown in Table 1.

  Next, the pressure-sensitive adhesive composition used for forming the layers 12 and 14 on the sheet 11 and the label 15 was prepared at the composition ratio shown in Table 1.

  Examples 1 to 6 show examples of prototypes of heating history confirmation indicators to which the present invention is applied using the obtained ink composition and pressure-sensitive adhesive composition, and examples of prototypes of indicators not applicable to the present invention Is shown in a comparative example.

(Examples 1-6)
As shown in Table 3, the ink composition prepared as described above was applied to one of the sheet 11 and the label 15 to form an ink layer, and the pressure-sensitive adhesive composition prepared as described above was applied to the other. An adhesive layer was formed to obtain an indicator for confirming heating history in which the layers were separated. The heating history confirmation indicator with the ink layer and the adhesive layer attached thereto was immediately immersed in a hot water bath at a predetermined temperature and heated for a predetermined time, and then the color change was visually confirmed.

  On the other hand, the same kind of heating history confirmation indicators that were unused and separated from each other were subjected to a long-term severe test in which they were stored in a constant temperature bath at 40 ° C. for one month, and the color change was visually confirmed.

  The results are shown in Table 3.

(Comparative example)
An ink composition containing an inorganic metal compound and an ink composition containing a sulfur-containing compound were mixed and applied to a PET sheet to obtain an indicator. The color change was observed in the same manner as in the example. The results are shown in Table 3.

  As is apparent from Table 3, the heating history confirmation indicators of Examples 1 to 6 change color when heated at a predetermined temperature for a predetermined period of several minutes to several days, and are visually observed to have passed a predetermined heating history. It was confirmed easily and accurately. Further, it has been found that the unused heating history confirmation indicator can be stored stably for a long period of time. On the other hand, the indicator of the comparative example was able to display the heating history, but it was found that it could not be stored for a long time without being used.

  According to the heating history confirmation indicator of the present invention, the history of the heating temperature and the heating time can be displayed simply and accurately. Therefore, this indicator is used to display the process of high-pressure steam sterilization of medical devices / pharmaceuticals, process control of boil sterilization of long-term preserved foods / retort foods, cup noodles poured with hot water, and instant foods to be heated. Can be used.

It is sectional drawing which shows the use middle of the indicator for heating history confirmation to which this invention is applied.

Explanation of symbols

  1 is an indicator for confirming heating history, 11 is a sheet, 12 is an ink layer, 13 is a release paper, 14 is an adhesive layer, and 15 is a transparent film or sheet.

Claims (4)

Inorganic metal compound or a heavy metal complex compound and a resin that is softened by heating 10 to 15: 20 to 100 and a layer in a weight ratio of the resin to be softened by a sulfur-containing compound and heated 10-20 10-100 weight ratio of in the layer containing the is held in a separated state, by contacting with paste the two layers, the hydrated sulfur reacts in contact with the inorganic metal compound in the environment of the heating or heavy metal complex compounds An indicator for confirming a heating history, wherein the compound changes color.   The inorganic metal compound is at least one selected from a bismuth compound, a cobalt compound, a nickel compound, a chromium compound, an aluminum compound, and an iron compound; the heavy metal complex compound is a heavy metal-hexamethylenetetramine complex compound, a heavy metal-phosphate complex compound And at least one selected from heavy metal-ammonium complex compounds; the sulfur-containing compound is at least one selected from thiourea compounds, thiuram compounds, thiazole compounds, sulfur-containing amino acid compounds, sulfur-containing proteins, and sulfur-containing organic acid compounds. The heating history confirmation indicator according to claim 1. At least one of the two layers, a heating history confirmation indicator according to claim 1, characterized in that it contains the adhesive or bond.   The color change corresponding to the heating history of the heating temperature and the heating time according to the amount of the inorganic metal compound or the heavy metal complex compound and the sulfur-containing compound. Indicator for checking heating history.

Images