PACKAGE OF LIQUID CONTAINER

Abstract: This invention relates to a package of a liquid container which stores therein a liquid and whose walls have steam permeability. In order to prevent dewing in the package, a humidity controlling agent is stored together with the liquid container. This agent is produced by wrapping a resin agent having steam absorptivity, water absorptivity and a steam evaporation property, such as an acrylic resin consisting principally of polypotassium acrylate between water/steam permeable sheets. A resin agent which absorbs water in a quantity of 10 to 1,000 cc/g is used.

Description: Technical Field This invention relates to a package for liquid containers, e.g., blood bags, and more particularly, to a liquid container package, which can prevent moisture condensation from forming inside the package. Background Art Heretofore, for preserving blood bags it has been the practice to lay Japanese paper as a water absorption sheet beneath the blood bags to absorb the condensed water droplets. The blood bag is made of a soft plastic material permeable by water vapor. Water vapor penetrates the blood bag as condensed moisture inside a sealed container package due to, for example, a difference in temperature between the sealed container package and the environment. The amount of condensed water can be as much as 8 to 10 cm³ in the case of a single container package, in which five sets of 200 cm³ blood bags (a total blood content amounting 140 cm³) are sealed. Heretofore, Japanese paper has been used by laying it beneath the bottom of the blood bag to absorb the condensed moisture. Japanese paper, however, has a poor water absorption property and can not absorb water unless it is contacted by water, that is, it can not absorb water in the state of vapor, and it is only when this vapor condenses, that the paper is sufficiently able to absorb water. Further, the Japanese paper lacks a water-retaining capacity, i.e., it lacks an absorbent quality. Therefore, water once absorbed by the paper can readily dissipate due to a temperature rise or like cause. Therefore, an over-saturation state is produced inside the blood bag, and evaporation, dissipation, and condensation of water repeatedly take place. Further, the surface of the blood bag which is not in contact with Japanese paper has no ability whatsoever to absorb water. Therefore, affixing labels indicating the blood type and other data to the bags is difficult due to the moisture which collects on the surface of the blood bags when collecting blood. Further, a label once applied is liable to fall off. There is a further problem in that water that has not been absorbed by the Japanese paper beneath the blood bags in the package may be mistaken as leakage of the blood bag content. There is also known from document US-A-4 561 543 a liquid container package comprising a liquid container having a wall permeable to water vapour and containing a liquid, and a package for hermetically wrapping one or several such liquid containers. Disclosure of the Invention An object of the invention is to provide a liquid container package, which can maintain an adequate humidity therein and which can also prevent moisture from condensing on the inside of the bag. To attain the above object of the invention, there is provided a liquid container package, which comprises a liquid container having a wall permeable to water vapor and containing a liquid, and a package for hermetically wrapping one or more of said liquid containers, characterized in that it further comprises a humidity control member disposed between said liquid container or containers and said package and comprised of a water- and water vapor-permeable sheet and resinous material enclosed by said water- and water vapor-permeable sheet and having a water vapor absorption property, water absorption property, and a water vapor dissipation property, said resinous material comprising resin particles contained in a quantity such that the liquid container surface is not substantially wetted and that the water content is not excessively absorbed in the liquid container content. It is one feature of the invention that the humidity control member has properties which are highly absorbant of water as well as water vapor and that it also has a water vapor dissipation property, and that this humidity control member is used in lieu of Japanese paper which has a poor water absorption property and has substantially no water vapor absorption property. It is another feature of this invention that the humidity control member can be used in a versatile fashion, i.e., it can be disposed on the bottom, the side walls or the entire inner wall surfaces of a liquid container package. Brief Description of Drawings Fig. 1 is a sectional view showing a relative humidity control member accommodated in a liquid container package according to the invention; Fig. 2 is a perspective view showing an example of use of the humidity control member; Figs. 3 and 4 are perspective views, each showing a different example of use of the humidity control member; Fig. 5 is an exploded perspective view showing the liquid container package according to the invention; Fig. 6 is a perspective view showing the assembled form of the liquid container package shown in Fig. 5; and Fig. 7 is a perspective view showing a prior art liquid container package. Best Mode for Carrying Cut the Invention The invention will now be described in conjunction with the preferred embodiments thereof with reference to the drawings. Fig. 1 is a sectional view showing a humidity control member accommodated as a liquid or water absorber in a liquid container package according to the invention. Resinous material 2 having a water vapor absorption property, a water absorption property, and a water vapor dispersion perperty is provided in an embossed form between two water- and water vapor-permeable sheets 3 (such as paper sheets). Resinous material 2 has a water absorption capacity of 10 to 1,000 cm³, preferably 100 to 800 cm³, more preferably 300 to 700 cm³, per one gram. Such a water-absorptive resinous material as noted above is well-known; for example, an acrylic acid resin mainly composed of potassium polyacrylate (marketed under a trade name "Arasoap 800A" by Arakawa Kagaku Kogyo Co., Ltd.). This humidity control member has a mesh-like structure constituted by resinous material 2, water being trapped in the mesh structure. It can cope with a temperature rise or like changes to maintain a saturation state inside the package by releasing water vapor. When water vapor is increased beyond the saturation state, it positively absorbs moisture. When such humidity control member is provided in the sealed liquid container package, water generated due to various causes is absorbed and dispersed by the resin particles, so that it is possible to maintain at all time the saturation state inside the sealed liquid container package. In other words, it is possible to suppress dispersion of water by evaporation from the liquid container such as a blood bag and also suppress generation of water drops. Now, an embodiment of the invention and a comparative example will be described with reference to the drawings. Fig. 1 shows a humidity control member for a package for blood bags (liquid containers) according to the invention. Reference numeral 1 designates the humidity control member. Humidity control member 1 consists of an embossing of a pair of slightly water- and water vapor permeable paper sheets 3 with resinous material 2 being disposed between the paper sheets 3. Resinous material 2 has a water vapor absorption property, a water absorption property, and a water vapor dissipation property; for instance, it may be a highly water-absorptive acrylic acid resin (in the form of particles mainly composed of potassium polyacrylate [available under a trade name "Arasoap 800A" by Arakawa Kagaku Kogyo Co., Ltd.,] with a water absorption capacity of 950 cm³/g). Humidity control member 1 contains 20 g of the highly water-absorptive resin per 1 m². Fig. 2 shows how the humidity control member according to the invention is used in an embossed form. As is shown, molding 4 of humidity control member 1, which has substantially the same shape as package A, is prepared and disposed in package A. After humidity control molding 4 has been set in package A, blood bags (not shown) are enclosed in package A, which is then sealed with lap B. The method of disposing the humidity control member in package A as shown in Fig. 2 is by no means limitative. For example, it is possible to use humidity control molding member 5 as shown in Fig. 3, or disposed relative humidity control molding member 6 only on the bottom of package as shown in Fig. 4. The shapes of humidity control molding members 4 to 6 obtained from humidity control member 1 are by no means limitative, and member 1 may be processed to any shape and size which conforms to package A. Fig. 5 shows an example of packing blood bags (not shown) by using a package as shown in Fig. 2. As shown, this package is formed by using two humidity control members 4 as shown in Fig. 2. More particularly, humidity control members 41 and 42 are set in respective packages A₁ and A₂. Then, after setting the blood bags in packages A₁ and A₂, packages A₁ and A₂ are sealed with respective laps B₁ and B₂. Thereafter, packages A₁ and A₂ with the blood bags sealed therein are overlaid, face-to-face, with laps B₁ and B₂ and then their edges are heat-sealed together, thus completing the package as shown in Fig. 6. Packages A₁ and A₂ each have a volume of 65 mm by 105 mm by 180 mm. When each of packages A₁ and A₂ contains five sets of blood containers with 200 cm³ of collected blood (a total liquid content of 140 cm³), it suitably contains 0.05 to 5 g, preferably 0.1 to 2 g, of the highly water-absorptive resin. If the resin is excessively contained therein, the moisture in package A is excessively absorbed so that the blood bag content eventually begins to lack water content. If the resin is insufficiently contained therein, on the other hand, failure of the resin to sufficiently absorb the moisture is liable. A temperature cycle test was conducted on a liquid container package consisting of two packages A₁ and A₂ with blood bags sealed therein and sealed together, face-to-face, with laps B₁ and B₂. The test was conducted by transferring the package, every 3 hours, between a temperature controller at 60°C and a refrigerator at 6°C and repeating this cycle ten times, and subsequently checking the extent of wetting to the surface of the blood bags. A like temperature cycle test was conducted under the Same conditions on a package (refer to Fig. 7), which was formed in the same manner as the package shown in Fig. 6, except that conventional Japanese paper (or Japanese art paper) was used in lieu of humidity control member 4 according to the invention and was disposed under the bottom of the individual blood containers. With the package according to the invention, the surface of the blood bags on the upper side of humidity control member 4 was proven to be only slightly wet, and the blood bag surface on the lower side of humidity control member 4 was perfectly dry. With the contrasting package formed by using Japanese paper, the blood bag surface on the upper side of the Japanese paper was considerably wet, and the blood bag surface on the lower side of the Japanese paper was proven to be extremely wet. It was thus confirmed that the wetting of the blood bag surface can be considerably remedied in cases where humidity control member 4 is used as compared to the case where the Japanese paper was used. As has been described in the foregoing, according to the invention, it is possible to maintain the saturation state of humidity in a sealed package containing blood bags or like liquid containers. It is thus possible to prevent water vapor from condensing inside the package as well as to suppress the dispersion of water content from the liquid container. Further, since the liquid container surface is not wet, a label indicating the blood type or like data can be reliably applied to the liquid container surface. Industrial Applicability As explained above, a liquid container package according to this invention is useful for every kinds of sealed package which is required to keep the inside thereof free from the generation of moisture condensation, and in particular for a package which is adapted to keep a vapor permeable liquid container therein for a long period of time.

Claims: A liquid container package comprising a liquid container having a wall permeable to water vapor and containing a liquid , and a package (A, B) for hermetically wrapping one or more of said liquid containers, characterized in that it further comprises a humidity control member (1; 41, 42) disposed between said liquid container or containers and said package and comprising a water-and water vapor-permeable sheet (3) and a resinous material (2) enclosed by said water- and water vapor-permeable sheet and having a water vapor absorption property, a water absorption property and a water vapor dissipation property, said resinous material comprising resin particles contained in a quantity such that the liquid container surface is not substantially wetted and that the water content is not excessively absorbed in the liquid container content, The liquid container package according to claim 2, wherein the water absorption capacity of said resin particles is 10 to 1,000 cm³/g. The liquid container package according to claim 2, wherein the water absorption capacity of said resin particles is 100 to 800 cm³/g. The liquid container package according to claim 4, wherein the water absorption capacity of said resin particles is 300 to 700 cm³/g. The liquid container package according to claim 1, wherein said liquid container is a blood bag. The liquid container package according to claim 1, wherein said humidity control member (1; 41, 42) is disposed on the bottom (42) of said package. The liquid container package according to claim 1, wherein said humidity control member (1; 41, 42) is disposed on the bottom and side walls of said package. The liquid container package according to claim 1, wherein said humidity control member (1; 41, 42) is disposed on substantially the entire inner wall surfaces of said package. The liquid container package according to claim 1, wherein said resin particles are contained by 20 g per 1 m² of said humidity control member (1; 41, 42). The liquid container package according to claim 1, wherein said resinous material consist of an acrylic acid resin mainly composed of potassium polyacrylate.

Inventors: MATSUDA, YUTAKA TERUMO KABUSHIKI KAISHA, OHACHI, YOSHINORI TERUMO KABUSHIKI KAISHA, OHNAKA, YUKIHIRO TERUMO KABUSHIKI KAISHA
Applicants: TERUMO KABUSHIKI KAISHA
Application year: 1988
Main classification: B65D81
IPC codes: B65D81, A61J1, A61J3