JPH08248887A - Adhesive label - Google Patents

Abstract

PURPOSE: To easily remove a label from a used container when the container is cleaned, because a plastic film of the label shrinks by heat at about 70 deg.C. CONSTITUTION: This adhesive label is used for a container to transport foods and the label consists of a plastic film having >=30% shrinkage ratio at least in one direction with warm water at 70 deg.C and a water-insoluble adhesive showing 10-300g/25mm adhesion strength to a polypropylene plate. Further, a thermosensitive layer is formed on the film surface to make printing easier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive label attached to a plastic container used by food manufacturers or wholesalers to ship food to supermarkets and the like.

[0002]

2. Description of the Related Art Conventionally, food manufacturers or wholesalers have used plastic containers when shipping food to supermarkets and the like. By attaching an adhesive label that displays information such as the destination, product name, and quantity as a bar code to this container, sorting and other efficiency were increased. A thermal transfer printer is used to display the label because it is easy to print. When a thermal printer is used, it is necessary to provide a thermal layer on the uppermost layer of the label. In general, this container is standardized in material and size, making it easy to reuse. After use, it is usually returned to the food manufacturer or wholesaler for cleaning. The used label is also peeled off and used for a new destination.

[0003]

The used container is usually washed with hot water. However, in removing the used label from the empty container returned for reuse, the label may be torn, may not be peeled off cleanly, or the adhesive may remain in the container. Therefore, there is a demand for a pressure-sensitive adhesive label that retains a necessary adhesive force during use and that is easily peeled off when washed with warm water.

[0004]

The present invention relates to a pressure-sensitive adhesive label for a food transportation container, which comprises a heat-shrinkable plastic film and a pressure-sensitive adhesive layer exhibiting an adhesive property such that the film shrinks from the container due to the shrinkage of the film.

As a plastic film which is easily shrunk by heat, shrinkage is negligible at room temperature.
A film having a shrinkage ratio of 30% or more in at least one direction with 0 ° C. hot water is used. Although an arbitrary material is used, a PET film or a PVC film is suitable, and the thickness is preferably about 20 to 70 μm.

Information such as a bar code is directly printed on the surface of the film by a thermal transfer printer, a dot matrix printer or the like, if necessary. Further, in order to make it easier to transfer the ink to the film surface side, label paper such as high-quality paper, cast-coated paper, art-coated paper or the like can be attached if necessary. It is sufficient that these papers have such a softness that they easily wrinkle together with the shrinkage of the plastic film layer.

When the printing is further facilitated by using a thermal printer, a thermal layer can be provided on the surface side of the plastic film which shrinks by heat. The heat-sensitive layer comprises a heat-sensitive paper or a coating layer of a heat-sensitive agent. In the case of heat-sensitive paper, it is necessary to have the softness that easily wrinkles together with the shrinkage of the plastic film layer, so that the weight is preferably about 40 to 90 g / m ² . If it exceeds 90 g / m ² , the plastic film tends to hinder free shrinkage, and peeling becomes difficult. If it is less than 40 g / m ² , the stiffness of the paper is too weak and it is not practical because it is easily broken in the manufacturing process for sticking to a plastic film.

In the case of the heat-sensitive agent, any known material can be used as long as it does not prevent the heat shrinkage of the plastic film.

The pressure-sensitive adhesive needs to be adhesive enough to be peeled off from a container which is an adherend when the plastic film shrinks in hot water. Since the material of the plastic container as the adherend is usually polypropylene or polyethylene, an adhesive having an adhesive force to polypropylene of 10 to 300 g / 25 mm is used. Further, a non-water-soluble pressure-sensitive adhesive is desirable in order to prevent elution of the pressure-sensitive adhesive into hot water for washing when washing with warm water. The thickness of the adhesive layer is preferably about 20 to 30 μm.

The shrinkage rate of a plastic film is measured by
After immersing a 10 cm × 10 cm film in warm water at 70 ° C. for 30 seconds, the length is measured in each of the orthogonal directions, and the value of the shrinkage ratio in the more shrunken direction is taken.

The adhesive force of the pressure-sensitive adhesive is such that a pressure-sensitive adhesive tape having a width of 2.5 cm and a length of about 10 cm is reciprocally pressed on a polypropylene plate by a roller having a load of 2 kg, and one end thereof is 300 mm / min in a longitudinal direction of 180 degrees. It is defined as the average load when peeled at a speed (average value after removing 15% before and after).

[0012]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Example 1 As a heat sensitive layer, the weight is 66 g /
thermal paper m ² (Shin'ojiseishi Co., 75SEX) and pasted to the heat-shrinkable plastic film with a suitable adhesive.
As the heat-shrinkable plastic film, a 40 μm-thick PET film (Gunze, Fancy Wrap TAS, shrinkage rate at 70 ° C. 40%) was used, and an acrylic adhesive (Dainippon Ink and Chemicals Incorporated) Made by FTN, Adhesive strength to polypropylene 200g / 25m
m) was applied to a thickness of 25 μm to prepare an adhesive label sample of 2.5 cm × 10 cm. This adhesive label sample was attached to a polypropylene plate made of the same material as the container, and a reciprocating pressure was applied by a 2 kg roller to give an evaluation sample. 70 days after leaving at room temperature for 7 days
When soaked in warm water of ℃ for 30 seconds, the label shrank and easily peeled off from the polypropylene plate as the adherend.

(Example 2) As a heat-sensitive layer, the weight was 66 g /
thermal paper m ² (Shin'ojiseishi Co., 75SEX) and pasted to the heat-shrinkable plastic film with a suitable adhesive.
As the above-mentioned heat-shrinkable plastic film, a PVC film having a thickness of 40 μm (manufactured by Mitsubishi Plastics Co., Ltd., Hishirex 502, shrinkage rate at 70 ° C .: 37%) was used, and an acrylic adhesive (Dainippon Ink and Chemicals Inc.) was used as an adhesive. Manufactured by Kogyo Co., Ltd.
AER, adhesive strength to polypropylene 70 g / 25 mm) was applied to a thickness of 27 μm to prepare a 2.
A 5 cm × 10 cm adhesive label sample was prepared. This adhesive label sample was attached to a polypropylene plate made of the same material as the container, and a reciprocating pressure was applied by a 2 kg roller to give an evaluation sample. After leaving it for 7 days at room temperature and immersing it in hot water at 70 ° C. for 30 seconds, the label contracted and easily peeled off from the polypropylene plate as the adherend.

(Comparative Example 1) As a heat sensitive layer, the weight is 66 g /
thermal paper m ² (Shin'ojiseishi Co., 75SEX) and pasted to the heat-shrinkable plastic film with a suitable adhesive.
As the above-mentioned heat-shrinkable plastic film, a 50 μm-thick PVC film (manufactured by Mitsubishi Plastics Co., Ltd., Hishirex 302S, shrinkage rate at 70 ° C. 16%) was used, and an acrylic adhesive (Dainippon Ink and Chemicals) Made by Kogyo Co., A2, adhesive strength to polypropylene 400g / 25m
m) was applied to a thickness of 25 μm to prepare an adhesive label sample of 2.5 cm × 10 cm. This adhesive label sample was attached to a polypropylene plate made of the same material as the container, and a reciprocating pressure was applied by a 2 kg roller to give an evaluation sample. 70 days after leaving at room temperature for 7 days
When soaked in warm water of ° C for 30 seconds, the label did not shrink sufficiently and could not be easily peeled off from the adherend polypropylene plate.

[0016]

When the container is washed with warm water, the 70
The heat of about ℃ causes the plastic film to shrink, and the force causes the adhesive to peel off from the container, which is the adherend, and the label to be easily detached. Therefore, the process of removing the debris of the torn label and the adhesive remaining on the container surface can be greatly simplified.

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Claims (6)

[Claims] 1. A pressure-sensitive adhesive label for a food transportation container, which comprises a heat-shrinkable plastic film and a pressure-sensitive adhesive layer provided on the back surface thereof. 2. The heat-shrinkable plastic film has a shrinkage factor of 3 in at least one direction when heated to 70 ° C.
The pressure-sensitive adhesive label for a food transportation container according to claim 1, which is 0% or more. 3. The pressure-sensitive adhesive label for a food transport container according to claim 1, wherein a heat-sensitive layer is provided on the surface of the heat-shrinkable plastic film. 4. The pressure-sensitive adhesive label for a food transport container according to claim 3, wherein the heat-sensitive layer is a heat-sensitive paper. 5. The pressure-sensitive adhesive label for a food transport container according to claim 3, wherein the heat-sensitive layer is coated with a heat-sensitive agent. 6. The adhesive label for a food transport container according to claim 1, wherein the adhesive force of the adhesive layer to polypropylene is 10 to 300 g / 25 mm.