Background Art [2] Generally, to safekeep any goods at low temperatures, basically refrigerators or re- frigerated transport systems are used. These can store or deliver items in a large scale at low temperatures, but are unsuitable for smaller scaled purposes over relatively shorter periods and are required additional devices, such as electric power supplies, etc. With the intention of safekeeping goods on a small scale, dry ice has been typically employed. However, in case of using dry ice, the goods may be damaged or have difficulties in handling, attributable to excessive cooling. In the cases of simply using ice, the goods may be contaminated by water flowing from the melting ice, or water may leak externally.

[3] In U. S. Patent No. 4,931, 333, there is disclosed a method cf using a refrigerant in a container, in which refrigerant is placed into each capsule, thus overcoming the above problems and increasing the insulation effects. However, the above patent suffers from complicated manufacturing processes, and limited dimensions of the capsules, because a plurality of chemical compounds are used as temperature maintenance material to maintain the temperature at a specific temperature in the range (e. g., +40 ° C to-90 ° C) so as to store expensive medicines or foodstuffs, while air bubbles are prevented from occurring in the capsules.

[4] Additionally, since the product obtained by the above patent is suitable for use in storing expensive medicines at specific temperatures, it should be very carefully handled. Also, the above product is costly due to complicated manufacturing processes to remove air bubbles from the capsules, and thus, is unsuitable for use in storing general foodstuffs. Further, since the temperature maintenance material of the above patent is composed of the plurality cf melting compounds, it may contaminate the foodstuffs when the capsule is broken through carelessness and the temperature maintenance material therein flows out. When fragile goods, such as glass bottles, want to be stored, the above product has no means of acting to protect the goods from an external impact.

[5] Moreover, in cases where a conventional safekeeping product or refrigerant is used to deliver goods by express, it has no means capable of representing the description related to the handling method of goods or goods per se, and advertisement words for the goods.

Disclosure of Invention [6] Therefore, it is an object of the present invention to alleviate the problems en- countered in the related art and to provide a safekeeping product, which can be subjected to printing to display words for careful handling or advertisements of items to be safekept.

[7] Another object of the present invention is to provide an economical safekeeping product, suitable for maintain items in a constant temperature.

[8] A further object of the present invention is to provide a safekeeping product, which is harmless to humans even though the safekeeping product is in directly contact with items to be safekept, such as foodstuffs, or cells of the safekeeping product are broken.

[9] Still another object of the present invention is to provide a safekeeping product, capable of effectively protecting items to be safekept from an external impact.

[10] To achieve the above objects cf the present invention, there is provided a safekeeping product, for use in safekeeping items for a predetermined period, comprising a flexible impermeable film having a plurality of layers laminated, a cell formed with the laminated film, and temperature maintenance material contained in the cell to maintain a predetermined temperature for a predetermined period, wherein a letter, a photograph, or a diagram is printed on an inner surface of an outermost layer of the laminated film.

[11] Further, there is provided a safekeeping product, for use in safekeeping a items for a predetermined period, comprising a flexible impermeable film having a plurality cf layers laminated, a cell formed with the laminated film, and temperature maintenance material contained in the cell to maintain a predetermined temperature for a pre- determined period, wherein air is injected into the cell when the temperature maintenance material is filled into the cell and then the cell is sealed, whereby the cell contains a predetermined amount of air and is maintained in a predetermined shape, regardless cf a temperature change, and a letter, a photograph, or a diagram is printed on an inner surface of an outermost layer cf the laminated film.

[12] In such cases, the impermeable cells can be continuously disposed in a longitudinal and/or transverse direction by the bendable connecting parts, each of which has rounded corners.

[13] Also, the impermeable cells are formed by mutually compressing margins of two films through a thermal compression process or an electrical compression process.

[14] Moreover, a safekeeping product of the present invention includes a plurality of cells disposed in a longitudinal and/or transverse direction and connected to each other by a plurality of bendable connecting parts, each having rounded corners, and temperature maintenance material contained in the cell, wherein air is injected into the cell when the temperature maintenance material is filled into the cell and then the cell is sealed, whereby the cell contains predetermined amounts of air bubbles. As such, the laminated film of the cell is formed with a three-layered structure, in which an innermost layer is made of LDPF, and a middle layer is made of polyethylene, with an outermost layer made of nylon, in which an inner surface of the outermost layer is printed with various colors, thus enhancing the advertisement effects of the items to be safekept.

[15] Further, the safekeeping product of the present invention is advantageous in terms of extended temperature maintaining periods and increased impact preventing effects, by placing the safekeeping product and the items to be safekept together into a container.

Description of Drawings [16] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: [17] FIG. 1 is a schematic view illustrating a cell, in a safekeeping product according to a preferred embodiment cf the present invention; [18] FIG. 2 is a schematic view illustrating a film structure of the cell cf the safekeeping product cf FIG. 1; [19] FIG. 3 is a schematic view illustrating a plurality of cells connected by a plurality of bendable connecting parts, in the safekeeping product according to the preferred embodiment of the present invention; [20] FIG. 4 is a schematic view illustrating the connecting part of the safekeeping product bent to an excessive acute angle; [21] FIG. 5 is a schematic view illustrating a plurality of cells connected by a plurality of bendable connecting parts, in a safekeeping product according to a modification of the preferred embodiment of the present invention; [22] FIG. 6 is a schematic view illustrating the safekeeping product cf FIG. 5 which surrounds a items to be maintained at low temperatures; and [23] FIGS. 7 and 8 are schematic views illustrating the safekeeping product of FIG. 5 in practical use, together with a container, to safekeep the item at low temperatures.

Best Mode [24] Reference should now be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.

[25] FIG. 1 illustrates an impermeable cell made of a flexible material, in a safekeeping product according to a preferred embodiment of the present invention. The cell is formed by disposing two films each of which is made cf a plurality of flexible layers laminated in the appropriate chamber containing temperature maintenance material, and then bonding margins cf the laminated films by a thermal compression process.

Alternatively, two laminated films of the cell are sealed, with the exception of one side serving as an inlet of the cell, after which temperature maintenance material is filled into the cell through the inlet of the cell and then the inlet is sealed, thereby forming the cell. The cell is freely formed in a rectangular, triangular, or circular shape, according to end uses cf the safekeeping product. The bonding process of the two laminated films, including electrical compression, in addition to the thermal compression, is known to those skilled in the art.

[26] FIG. 2 illustrates a film structure of the cell, in the safekeeping product according to the preferred embodiment of the present invention, in which the film includes a three-layered structure composed of an outermost layer 4, a middle layer 5 and an innermost layer 6. As for the outermost layer 4 in contact with items to be safekept, use is taken of a flexible material having a fine surface to perform high-grade printing so as to display various colors, while being harmless to humans. Further, the outermost layer 4 should be transparent, so that the printed contents are readable externally even though a printing dye 7 is printed on an inner surface of the outermost layer 4 to preserve the printed state for long periods while not being in direct contact with the items to be safekept, such as foodstuffs. In addition, the middle layer 5 functions to bond the outermost layer 4 and the innermost layer 6 to each other, but it may be absent so long as the outermost layer 4 may be mutually bonded to the innermost layer 6. Alternatively, instead cf the middle layer 5, an adhesive may be used. The innermost layer 6 is in contact with the temperature maintenance material. As described above, the cell 1 of the safekeeping product is formed by mutually bonding the margins of the two laminated films through a thermal compression process, in which each laminated film is formed with a three-layered structure. Hence, the innermost layer 6 of the upper three-layered structure and the innermost layer 6 of the lower three-layered structure should be made of mutually bondable materials. Thus, in the preferred embodiment of the present invention, the outermost layer 4 is formed of nylon which is transparent with a fine surface, and the middle layer 5 is formed of polyethylene exhibiting adhesion upon thermal compression. Also, the innermost layer 6 is formed of LDPE which is mutually bondable.

[27] In the present invention, the laminated film of the cell of the safekeeping product is not limited to the three-layered structure and the above layer material, and may be formed with two-or four-layered structures and be made cf different materials satisfying the above requirements.

[28] As for the safekeeping product of the present invention, the letters, figures, or symbols 7 printed with various colors can be printed on the inner surface cf the outermost layer 4. That is, the printing process is performed on the inner surface of the outermost layer 4 made of nylon. Therefore, since the items to be safekept is not in direct contact with the printing dye, even though it may be foodstuffs, the safekeeping product cf the present invention is harmless to humans. Further, the outermost layer of the safekeeping product is made of a transparent material, and hence, the printed contents are exposed externally. The surface of the nylon film is very fine and has high flexibility, and may be subjected to gravure printing of various colors, instead of a silk printing process cf one or two colors. The printing process is performed on the safekeeping product, whereby advertisement effects are suitably exhibited for the items to be safekept, thus increasing industrial availability of the safekeeping product.

[29] Further, the safekeeping product of the present invention is characterized in that air 2 is injected into the cell 1 cf the safekeeping product when the cell 1 containing the temperature maintenance material is sealed. Thereby, the cell 1 can be maintained in the predetermined shape even though the temperatures are changed. In the preferred embodiment of the present invention, the temperature maintenance material is water, which is high in specific gravity and acts to maintain the temperature for relatively long periods. Also, since water is non-toxic and harmless to humans, even though when flowing out the cell, it does not impede the items to be safekept. Hence, water can be effectively used for the storage of foodstuffs or medicines. However, water consists of oxygen and hydrogen linked by a hydrogen bond and expands in volume after being frozen. If water fully fills the cell, upon freezing water for low temperature maintenance cf the items the cell is internally subjected to high pressure, due to the volume expansion of water, and thus, the sealed state of the cell becomes weak. Con- sequently, the cell may be broken even under a small external impact, or the sealed part cf the cell may be cracked by repetitive use.

[30] To solve the above problems, water may be charged only in a part cf the cell. In this case, a dead space in which anything does not exist is present in the cell. And due to the dead space the cell is not uniformly shaped and may be crumpled. This phenomenon occurs at the cell upon being frozen, as well as the cell at room temperature. The crumpled cell suffers from low cooling efficiencies, due to the reduction of the area in contact with the items to be safekept. Further, the crumpled cell of the safekeeping product is not in uniform contact with the items to be safekept, and thus, only the specific part of the cell chafes against the items and as the result this part may be broken. Also, if the items to be safekept are fragile, such as a glass bottle, it may be easily broken for the rigidly frozen cell. The cell crumpling due to the dead space in the cell will increase as the size of the cell increases.

[31] Hence, the cell 1 of the safekeeping product of the present invention contains a predetermined amount of air 2, in addition to the temperature maintenance material, to remove the dead space. That is, all spaces cf the cell are filled with the temperature maintenance material or air, whereby the cell can be maintained in a predetermined shape, regardless of the temperature change. The volume cf air reduces as the tem- peratures decreases in the range cf room temperature to freezing temperature of water, 0 ° C. When the safekeeping product is completely cooled, the temperature maintenance material therein is frozen, and thus, expands in volume. In this case, such volume expansion offsets volume contraction cf air. Thus, the cell is hardly changed in its entire volume, and can be maintained in the predetermined shape in the temperature range of between room temperature and the phase transition temperature of the temperature maintenance material.

[32] Further, the cell 1 contains the air 2, whereby it can function as a cushion. The safekeeping product of the present invention is used to safekeep not only foodstuffs but also medicines or drinking water in a fragile container, such as a glass bottle, thus requiring a function capable of absorbing an external impact. Therefore, the safekeeping product of the present invention, which is capable of maintaining the shape of the air-containing cell 1 regardless cf the temperature change, can satisfy the above requirement, even without an additional external container.

[33] The amount of air 2 included into the cell 1 can be appropriately controlled, depending on the kinds of the items to be safekept. For example, if the safekeeping product cf the present invention is used to safekeep non-fragile materials, such as meats or fish, at low temperatures, the amount of the air decreases to increase cooling efficiencies. Meanwhile, when the safekeeping product of the present invention is used to safekeep fragile glass bottles containing drinking water or injection solution, the amount of the air increases to enhance cushioning effects.

[34] In addition, the safekeeping product including the air in the cell 1 is advantageous in terms of controllable safekeeping temperatures by adjusting a ratio of the air to the temperature maintenance material. That is, when a safekeeping is performed at low temperatures near 0 ° C, the proportion of the temperature maintenance material increases. On the other hand, when relatively high temperatures (e. g. 10-15 ° C) need to be maintained, the proportion of the air 2 increases. Thereby, the safekeeping tem- peratures can be controlled even though other compounds are not additionally used.

For instance, if water and air having a ratio of 7: 3 are contained in the cell and the cell is cooled in the state of being laid, the ice is positioned at one side of the cell and the air 2 is positioned at the other side thereof, as shown in FIG. 5. When the glass bottle is safekept by use of the safekeeping product having the above cells, the cell portion having air comes into contact with the glass bottle, whereby an external impact is not directly transferred to the glass bottle. Thus, the glass bottle can be protected from an external impact. Simultaneously, the ice in the cell is in indirect contact with the glass bottle through the air in the cell, whereby the glass bottle can be safekept at a pre- determined temperature (e. g., 10 ° C) higher than 0 ° C.

[35] FIG. 3 illustrates a plurality of cells connected mutually, in the safekeeping product according to another preferred embodiment of the present invention, in which the basic structure of the safekeeping product, the shape cf each cell constituting the safekeeping product, and the cell configuration are shown. The safekeeping product has a plurality of cells 1 connected mutually by a plurality of bendable connecting parts 3 and continuously disposed in a longitudinal and/or transverse direction. Each cell 1 has the temperature maintenance material to safekeep the items at low tem- peratures. The safekeeping product can sufficiently surround the items of various shapes by the bendable connecting parts, serving to connect each cell 1. Thus, the safekeeping product of the present invention can function to safekeep the items at low temperatures for relatively short periods, for example, one or two days, even without an additional adiabatic container.

[36] As for the cells 1 constituting the safekeeping product of the present invention, each corner cf the cell 1 is treated to be round. In cases where the corner is angled, pressure cf the cell is concentrated on each corner, and hence, the sealed state of the cell becomes weak, resulting in the possibility of the temperature maintenance material leaking externally. In the present invention, the safekeeping product is applied for low temperature storage by surrounding the items to be safekept without the use of the outer adiabatic container, as shown in FIG. 6. In such cases, according to the outer appearance of the items, the connecting parts cf the safekeeping product may be ex- cessively bent at acute angels as shown in FIG. 4, and each cell 1, which is in mutual contact therewith as represented by a dotted circular line of FIG. 4, exchanges con- tinuously loads. Moreover, even when the connecting parts 3 of the safekeeping product are relatively gently bent as in FIG. 6 the safekeeping product may be externally subjected to undesired impact caused by carelessness upon handling. When the cell 1 of the safekeeping product is internally or externally stressed, such loads are concentrated on each corner of the cell 1. Thus, the angled corner of the cell 1 may result in the breakage of the cell 1, by which the temperature maintenance material in the cell 1 leaks externally. Because the safekeeping product of the present invention is intended to be used in various situation including careless or tough treatment, the cell 1 thereof may be continuously or intermittently subjected to external pressure thereupon.

Meanwhile, where the temperature maintenance material is frozen and expands in volume, the cell may be internally subjected to pressure, compared to being present at room temperature. Hence, such pressure may lead to the breakage cf the cell 1.

[37] Therefore, in the present invention, the corners of the cell, as the weakest part of the cell, are treated to be round to prevent the cell from breaking under internal or external pressure, as shown in FIG. 3. Thereby, pressure applied to the cell having the rounded corners is uniformly dispersed to the entire cell, instead of being concentrated on the corners of the cell, thus firmly maintaining the sealed state of the cell 1. In the safekeeping product of the present invention that surrounds the items, the cell 1 is prevented from breaking or being damaged under poor environmental conditions, and thus, can stably contain the temperature maintenance material.

[38] FIG. 5 illustrates a safekeeping product, according to a modification of the preferred embodiment of the present invention, in which a predetermined amount of air 2 is contained in each cell 1 as shown in FIGS. 1 to 3, and therefore, the cell 1 is hardly changed by volume by temperature changes and thus can exhibit cushioning effects. Further, each corner of the cell 1 is treated to be round so as to uniformly disperse the internal or external pressure to the entire cell. In the safekeeping product of FIG. 5, a plurality cf cells are disposed in a transverse direction, and thus, are arranged in a line. Also, each cell is shaped in a long rounded rectangle with a ratio of width to length cf two times or more. Therefore, the safekeeping product cf FIG. 5 is used to safekeep rather long items, such as pickled cabbages or radish pickles. FIG. 6 illustrates the safekeeping product of FIG. 5 that practically surrounds cabbage 9.

[39] FIGS. 7 and 8 illustrate the safekeeping product in use, together with a additional container, to safekeep a items, such as a wine bottle, at low temperatures. As shown in FIGS. 7 and 8 the safekeeping product of FIG. 5 and the wine bottle are disposed in the container having two cylinders. As for a conventional wine cooler, ice and a wine bottle are placed together into one cylinder thereof, so that wine is safekept at low tem- peratures. In such case, the wine bottle is in contact with melted water and thus in- convenient in use. However, when the safekeeping product of the present invention is used to keep the wine bottle at low temperature, since the temperature maintenance material is contained in the impermeable cell of the safekeeping product, the wine bottle can be maintained in the neat state.

Industrial Applicability [40] As described hereinbefore, the present invention provides a safekeeping product, which is advantageous in that relatively inexpensive items, such as foodstuffs, can be safekept at low temperatures at low costs. Further, the safekeeping product of the present invention is structured to sufficiently endure internal or external pressure, and thus, need not be carefully handled. As temperature maintenance material contained in each cell of the safekeeping product, a harmless material to humans (e. g. , water) is used, whereby contamination of the items to be safekept can be prevented even though the cell is broken. In addition, the inventive safekeeping product can be colorfully printed on an outer surface thereof, thereby exhibiting advertisement effects of the items.

[41] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modi- fications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims, for example, other proper materials, in addition to water, may be used as the temperature maintenance material and the size of the cell and the amount of air in the cell may be suitably controlled, depending on the kinds of the items to be safekept.