JPH0749656A - Sheet for temperature indication of refrigerated food - Google Patents

Abstract

PURPOSE:To provide the simple sheet capable of indicating the temp. showing the preservation state of refrigerated food by the discoloration of printing films under a certain specified temp. condition. CONSTITUTION:This sheet for temp. indication of the refrigerated food has a structure obtd. by superposing a polyolefin nonwoven fabric 3 impregnated with an aq. gel of agar and further a polyolefin nonwoven fabric 4 at need between a polyolefin film 2 and a polyolefin film 6 printed with white oily ink 5 contg. water-soluble dyes and adhering the periphery. The water-soluble dyes are contained in the white oily ink and to not develop colors before a refrigeration operation but the water-soluble dyes are dissolved by the water leaching out through the fine pores of the nonwoven fabrics at the time of rising of the temp. of the contents to a thawing temp. after the contents are once refrigerated. The surface 5 printed with the white oily ink is then colored and the temp. change of the contents is thus easily indicated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple sheet capable of displaying the temperature indicating the storage state of frozen foods by the discoloration of a printed film under a certain temperature condition.

[0002]

2. Description of the Related Art In general, an indication of the current temperature itself is
Various thermometers are used according to the purpose. However, there is something that can automatically and clearly display and record whether or not individual products have been kept below the specified temperature in the storage state of frozen foods, that is, at each stage of production, distribution, and consumption. , Not yet used. Therefore, at present, there is no guarantee as to the storage temperature of individual frozen foods on the market. There are only records of refrigerated warehouses or refrigerated vehicles where a certain quantity of merchandise is stored. Especially in the consumer's home, there is a case where the storage temperature is inadvertently high, or the food that has been thawed once is re-frozen, which is a very dangerous situation in terms of food hygiene.

[0003]

A temperature display mechanism for the above purposes must be simple, inexpensive, small and easy to handle, yet clearly displayable and capable of storing the results. Since the normal freezing temperature is -18 ° C, this temperature display mechanism must be capable of displaying and recording in the temperature range of 0 ° C to -18 ° C, but it is not necessary to continuously display and record this temperature range. Instead, according to the present invention, any temperature within the above temperature range can be displayed.

[0004]

The present invention relates to a polyolefin nonwoven fabric in which an agar aqueous gel is impregnated between a polyolefin film and a polyolefin film printed with a white oil-based ink containing a water-soluble dye, and further, if necessary. Before the freezing operation, the water-soluble dye is white oil-based, which is characterized by a structure in which polyolefin non-woven fabrics not impregnated with ordinary agar water-based gel are stacked and the periphery is adhered by heat, seal, etc. When it is contained in the ink and does not develop color, but once frozen, when the temperature of the contents rises to the temperature at which it is thawed, the water separated from the agar water-based gel leaching through the fine pores of the nonwoven fabric causes For the temperature display of frozen foods, in which the organic dye dissolves and the printed surface of the white oil-based ink is colored to easily indicate the temperature change of the contents. - a preparative, temperature display sheet of frozen food that greatly characterized in that the freezing operation is "triggered" automatically change in temperature - can be achieved by preparative.

The polyolefin used in the present invention
As a film, a polyethylene film having high cold resistance, as a printing ink resin, an acrylic resin, an ethylene vinyl acetate resin, and as a gelling agent, agar that separates water by freezing, gelatin, and a water-soluble dye It is desirable to use food dyes. The structure and the like of the sheet of the present invention will be described with reference to the schematic enlarged sectional view (I) and plan view (II) of FIG. A polyolefin film (6) printed with a white oil-based ink (5) having a water-soluble dye dispersed therein, and a polyolefin nonwoven fabric (3) impregnated with an agar aqueous gel between the polyolefin film (2). A normal polyolefin nonwoven fabric (4) is inserted and the periphery is heat-sealed. It is desirable to print the white oil-based ink (1) around the surface of (2) to enhance the effect of discoloration. The white oil-based ink (1) can be printed by various printing methods. The white oil is an ink containing a white pigment or a white pigment and a colored pigment, and further containing a water-soluble dye dispersed therein.

[0006] In this situation before freezing,
Although it shows a white state, once frozen and thawed, water separates from the agar, and this water passes through the polyolefin nonwoven fabric (4) and reaches the surface of the printing surface (5) to dissolve the water-soluble dye. Then, as shown in FIG. 2, the dye is colored on the white surface, which means that the process of freezing and thawing has been completed. As described above, the temperature display seal of the present invention does not develop color in the state before freezing, but the operation of freezing becomes "hinging", and it is possible to automatically respond to changes such as freezing and thawing. It is like this. The color tone showing the change can be freely selected by selecting a water-soluble dye.

According to the present invention, this temperature indicating seal can be heat sealed directly to the package, or it can be adhered using an adhesive. You can also

[0008]

The present invention will be described in detail with reference to the following examples.
It goes without saying that the present invention is not limited to these examples. Example 1 Water-soluble dye food blue on a polyethylene film 1
The white acrylic gravure ink containing the dispersed No. is printed to prepare the portions (5) and (6) in FIG. Also,
On the same polyethylene film surface (1) of Fig. 1,
As in (2), a contour is printed with white acrylic gravure ink, and a mark or the like is printed on it. Separately, a polyethylene non-woven fabric (3) impregnated with agar 10% aqueous gel is overlaid on the polyethylene non-woven fabric (4) and inserted between the above-mentioned polyethylene films, and the periphery is heat-sealed to obtain a sheet having the structure shown in FIG. -Prepare

The temperature indicating sheet as shown in FIG. 1 prepared here is such that the aqueous dye dispersed in the white oil-based gravure ink is in a non-colored state before the freezing operation at a temperature close to room temperature. The sheet as a whole shows a white color, but when this sheet is thawed by raising the temperature through a freezing operation, the water content of the agar aqueous gel separates, and this water content permeates the non-woven fabric. The water-soluble dye is dissolved, and the white printed surface is entirely colored in blue, which indicates that this product goes through the phenomenon of freezing and thawing. When the sheet for temperature indication thus obtained is heat-sealed on the surface of frozen food to freeze the food at -25 ° C., the circular portion at the center as shown in FIG. As before the freezing operation, it shows a white state and does not change, but when the temperature of the contents rises to 0 ° C, the water-soluble dye is dissolved by the water separated from the agar aqueous gel and the center circle Is colored blue. Example 2 In Example 1, food red 4 was used instead of food blue No. 1.
Exactly similar results were obtained using No. 0 or Edible Yellow No. 1.

[Brief description of drawings]

1 (I) and (II) are a schematic cross-sectional view and a plan view showing the structure of a temperature display sheet of the present invention, respectively.

FIG. 2 shows a surface state that does not discolor at room temperature and freezing, and a colored surface state when thawing, respectively. The reference numerals in the figure are 1 ... Printed surface, 2 ... Polyolefin film, 3 ... Agar aqueous gel-impregnated polyolefin non-woven fabric layer, 4 ... Polyolefin non-woven fabric layer, 5 ...
Water-soluble dye-dispersed white oil-based ink printed surface, 6 ... Polyolefin film, respectively.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shiro Kojima 2-33 Kyobashi, Chuo-ku, Tokyo Toyo Inki Manufacturing Co., Ltd. (72) Inventor Fumio Tateshima 3-13-3 Kyobashi, Chuo-ku, Tokyo Toyo Inki Manufacturing Co., Ltd. (72) Inventor Mitsuru Endo 6-5-19 Shimoodachu, Nakahara-ku, Kawasaki-shi, Kanagawa

Claims (1)

[Claims] 1. A polyolefin non-woven fabric impregnated with an agar water-based gel, and a polyolefin non-woven fabric, if necessary, are laminated between the polyolefin film and the polyolefin film printed with a white oil-based ink containing a water-soluble dye, and the periphery is covered. Before the freezing operation, which is characterized by the structure obtained by adhering, the water-soluble dye is contained in the white oil-based ink and does not develop color, but once frozen, the temperature of the contents reaches the temperature at which it is thawed. When rising, water leaching through the fine pores of the non-woven fabric dissolves the water-soluble dye to color the surface of the white oil-based ink printing frozen food that can easily indicate the temperature change of the contents. Sheet for temperature display.