JPS6339479Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a packing material for food containers, in particular, it can be easily attached to and removed from the mounting groove, and the surface of the part that is fitted into the mounting groove is smooth, so it sticks to the packing material. To provide an easily attachable and detachable packing material for food containers in which stains from food, etc., can be easily removed, and stains such as mold, etc., are difficult to form in mounting grooves.

(Prior art) Food containers are currently made of metals such as aluminum, aluminum, duralumin, polyethylene,
Various types of plastic containers such as polypropylene, acrylic resin, ABS resin, and urea resin are commercially available, but these use packing material in the seal between the container body and the lid to prevent the contents from leaking. There are many. Rubber elastic bodies are usually used as packing materials due to their convenience, and from a hygiene perspective, silicone rubber molded products that are non-toxic to the human body or silicone rubber products such as silicone rubber sponge bodies are often used. .

(Problem to be solved by the invention) Silicone rubber molded products are not soft like sponge bodies, and their surfaces are smooth, so they are easy to attach and detach from the packing installation groove, and they are easy to get dirty when cleaning. Although it has excellent properties such as the ability to fall, the elongation is too small when used alone.
It requires advanced technology to take off the silicone rubber at high speed immediately after it has been discharged from the die, and at low speeds, the silicone rubber tends to partially harden inside the extruder, making it difficult for the finished packing to be homogeneous, making extrusion molding difficult. Since this is difficult, press molding has to be used, which results in an expensive product, and the packing effect is far inferior to that of the silicone rubber sponge body described below. On the other hand, silicone rubber sponge bodies can be extruded and are therefore inexpensive and have excellent packing effects, but they stretch too much when inserted into the mounting grooves of containers, causing them to twist or become lopsided. Moreover, since it is spongy and does not slide, it is troublesome to add mold release powder when installing it into the container mounting groove, and when removing it, it has poor tear strength. It is easily torn, torn, or twisted, and is not easy to clean after use.

The purpose of the present invention is to eliminate the disadvantages of the silicone rubber molded product and the silicone rubber sponge body, and to provide a packing material for easily attachable and detachable food containers, such as lunch boxes, that combines the advantages of both. It is in.

(Means for Solving the Problems) The easily attachable and detachable packing for food containers according to the present invention is characterized in that the silicone rubber layer conforming to the shape of the packing mounting groove and the container surface deforms freely to exhibit the packing effect. The gist of this invention is that it consists of a connected and integrated structure with a silicone rubber sponge layer extending from a groove.

The packing material of the present invention will be explained in detail below based on the drawings. Figures 1 and 2 are longitudinal cross-sectional views illustrating the packing material 1 of the present invention, and the lid body 2.
The silicone rubber layer A (see Fig. 2) conforms to the shape of the packing attachment groove 4 provided in the container surface, e.g. the collar 5.
The silicone rubber sponge layer B is connected to the silicone rubber sponge layer B extending from the mounting groove 4 to form a two-layer structure.

Regarding the shape of the packing material according to the present invention, as long as the silicone rubber layer A matches the shape of the attachment groove 4 and the silicone rubber sponge layer B is not too large and protrudes from the joint surface when it is locked with the container body 3, There are no particular restrictions and it is considered arbitrary. In general, as shown in Figure 1 a to c, the overall vertical cross section is approximately rectangular or trapezoidal, or only the sponge layer is semicircular or circular.
Various shapes can be considered depending on the shape of the mounting groove 4 of the container and the flange 5 of the container body, but in any case, a silicone rubber layer A that matches the shape of the mounting groove 4 and a silicone rubber layer A that is connected and integrated therewith are used. It is important that the silicone rubber sponge layer B is a connected and integrated structure. The silicone rubber layer A is placed in the packing attachment groove of the lid 2, and the silicone rubber sponge layer B is placed in the portion of the container body 3 that contacts the flange 5. When attaching the packing material of the present invention to the mounting groove 4, the silicone rubber layer A has a small elongation, a smooth surface, and is moderately hard, so it can be easily fitted and installed. Since it conforms to the shape of the groove 4, it has the advantage that a rib with relatively high rigidity is formed together with the side wall and bottom part of the groove 4, and this relatively rigid rib is formed by a silicone rubber sponge layer. Since B is in a freely released state, the sponge layer B can be uniformly and reliably pushed out to the flange 5 and sealed when pressed against the container body 3. Figures 2 to 4
The figure is a longitudinal sectional view showing this state, and the packing material 1 (Fig. 2) installed in the mounting groove 4 is
When pressed by the flange 5 of the container body 3, the sponge layer B begins to expand and deform in the lateral direction in order to relieve the pressing force (Fig. 3), and eventually ends its expansion deformation (Fig. Then, it is pressed and fixed by a conventionally known holder (not shown) such as a clip, a plate spring, a wire spring, etc., and is sealed. Note that if the thickness of the silicone rubber layer A is thinner than the depth of the groove 4, when the sponge layer B gradually becomes flat due to permanent strain due to repeated compression, it will be obstructed by the side walls of the groove and the packing effect will be lost. There is a risk that the thickness of the silicone rubber layer A may be insufficient.
If it is thicker than the depth of the groove 4, the sponge layer B will not be thick enough and the packing effect will be insufficient, so it is preferable that the sponge layer B substantially conforms to the shape of the groove 4.

The silicone rubber layer A used in the present invention is made by mixing organopolysiloxane raw rubber represented by the general formula RnSiO _4-o/2 with a vulcanizing agent and extruding it into a shape that matches the mounting groove 4 of the lid body. You can get it by twisting it. Of course, press molding may also be used. The silicone rubber sponge layer B is made by mixing the above-mentioned organopolysiloxane raw rubber with a conventionally known harmless foaming agent for use in food containers, etc., and extruding this into a string-like sponge body having a shape and structure as illustrated in Fig. 1. Obtained by molding. The packing material according to the present invention can also be manufactured by bonding the silicone rubber molded body obtained as described above and the silicone rubber sponge body with an adhesive, but an extrusion molding machine equipped with a crosshead etc. If used, since the silicone rubber sponge layers are connected, the silicone rubber layer can be extruded simultaneously to form an integral piece without tearing the silicone rubber layer.

(Effects) As described above, in the packing material according to the present invention, the parts that function as a packing material are made of different materials, so it is possible to make materials with properties suitable for each function. In other words, the part that fits into the packing installation groove of the lid body is made of a silicone rubber layer, so it does not stretch easily, so it is easy to put on and take off, and the surface is smooth, so dirt can be easily removed when cleaning. It is especially suitable for preventing the growth of mold, etc. that tends to occur in the packing mounting groove, and since it matches the shape of the mounting groove, it provides reinforcement equivalent to providing rigid ribs on the periphery of the lid along with the mounting groove. It is effective,
Therefore, in combination with the fact that the portion in contact with the container body is a silicone rubber sponge layer, the packing effect is excellent. Furthermore, the packing material according to the present invention can be manufactured by integral extrusion molding using an extrusion molding machine equipped with a crosshead, etc., so that effects not seen in conventional packing materials, such as being inexpensive, can be obtained.

(Example) A 4 x 4 mm square string-like silicone rubber sponge body and a 4 x 3 mm square silicone molded body (hardness 50°C) manufactured separately were made into room temperature curable silicone rubber KE42RTV.
(trade name manufactured by Shin-Etsu Chemical Co., Ltd.) and then cut into a 490 mm length, and the cut surfaces were glued with the same KE42RTV to form a ring shape.
A comparison was made of the ease and packing effect when attaching the same annular body made of ×7 mm square silicone sponge string and silicone rubber string to the mounting groove provided on the lid of the container. The body is too soft and it is difficult to attach it in the specified state, and it is difficult to attach it without adding mold release powder.Furthermore, the packing effect is insufficient due to twisting and constriction, and the water contained in the container body is difficult to attach. However, the packing material of the connected integrated structure of the present invention could be easily attached and removed without using mold release powder, and the packing effect was also excellent. In addition, the packing material of this example was attached to the mounting groove of a commercially available lunch box filled with rice, and a cold/heat test was repeated 100 times at a relative humidity of 90% → 20%, 90% → 15% cycle for 1 hour/time. I repeated the test by removing the packing material, cleaning it, and putting it back on each time, but no mold was found in the grooves.

[Brief explanation of the drawing]

Figures 1a, b, and c are longitudinal cross-sectional views showing different aspects of the packing material of the present invention, respectively.
The figure is a vertical cross-sectional view of the container body and lid in a separated state showing the attachment state of the packing material of the present invention,
The figure is a longitudinal sectional view of the container in a state in which both are joined, and FIG. 4 is a longitudinal sectional view in a state in which both are fitted by further pressing. 1...Packing material, 2...Lid, 3...Container body, 4...Mounting groove, 5...Brim part, A...
Silicone rubber layer, B...Silicone rubber sponge layer.

Claims (1)

[Scope of utility model registration request] An easily attachable and detachable packing material for food containers comprising a connected and integrated structure of a silicone rubber layer conforming to the shape of a packing attachment groove and a silicone rubber sponge layer extending from the attachment groove.