JP2017013873A - Method for keeping relative humidity constant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that electric power is needed and costs are required since a humidifier with a humidity sensor or a humidity controller is needed for controlling relative humidity in a space before and a commodity for keeping objective relative humidity does not exist before although a desiccant using silica gel exists as an inexpensive humidity control method without using electric power but is a commodity focusing only lowering humidity.SOLUTION: Humidity in an air tight container is kept to be objective relative humidity by filling a humidity controlling agent having prescribed concentration in a watertight container penetrating steam and being placed in the air tight container.SELECTED DRAWING: Figure 1

Description

The present invention relates to a technique for controlling relative humidity.

  There is a known method of keeping a relative humidity constant by placing an alcohol solution or salt solution of a predetermined concentration in an open container such as a cup in an airtight space (Non-patent Document 1). In the system container, it is difficult to carry the solution without spilling, and since the discharge and inhalation of water vapor are limited to the upper surface, the contact area with air is limited, and the efficiency of humidity control is low.

  When storing fresh vegetables for a long time, it is desirable to always maintain high humidity in order to maintain the freshness. On the other hand, when the humidity reaches 100%, condensation occurs and causes fresh vegetables to rot. Therefore, in order to maintain fresh vegetables for a long period of time, a technique for maintaining humidity at a level that does not cause condensation while maintaining high humidity is required. For this reason, until now, the humidity has been controlled to some extent by using a device such as making a small hole in a vegetable-wrapping film or using a film made of a material having high water vapor permeability (Patent Document 1). However, since these methods are not active humidity control methods, there is a drawback that they are greatly influenced by the relative humidity of the external environment. Especially when the relative humidity of the outside environment is saturated, it is impossible to suppress condensation.

  When storing and transporting a large amount of fresh vegetables, the relative humidity can be controlled using a humidity control device. For this purpose, it is necessary to purchase an expensive humidity control device and to supply power for operation. It is necessary to supply. For this reason, humidity control cannot be performed in air transportation or truck transportation without power supply.

  In addition, there is no method for moving and transporting without using electric power while keeping the relative humidity constant without condensing, not limited to the use of fresh vegetables.

Patent publication 10-509679

Forney CF and Brandl DG (1922) “Control of Humidity in Small Controlled-Environment Chamber Using Glycerol-Water Solutions”, Technology and Product Reports Jan./Mar. 2 (1)

  In order to control the relative humidity in a certain space until now, a humidifier equipped with a humidity sensor or a humidity control device is required, which requires electric power and costs. There is a desiccant using silica gel as a humidity control method that does not use electric power and is low in cost, but this is a product that focuses only on reducing the humidity, and the product that maintains the target relative humidity is this. Did not exist until.

  Although there is known a method of keeping the inside of the sealed space at a constant relative humidity by placing an alcohol solution or salt solution of a predetermined concentration in an open system container, it is spilled as it is, so it is difficult to transfer and transport. . In order to carry it, it is necessary to enclose the aqueous solution in a container by some method. However, when the above aqueous solution is sealed in a completely airtight container, water vapor cannot enter and exit, so humidity control is impossible.

  Further, when the open system container is filled with the above aqueous solution, the contact area with air is only the upper part, and the efficiency of humidity control is low. In order to increase the surface area of the open-type container, there is only a method of increasing the horizontal plane area or increasing the number of stages, and space for use in other applications is limited.

  By enclosing a predetermined concentration of an alcohol aqueous solution or a salt aqueous solution in a water vapor permeable container having a water vapor permeable membrane, the water vapor can be exchanged with the outside through the membrane, and the humidity can be controlled. Here, the water vapor permeable film is a film that transmits water vapor of 0.2 g / m 2 · day or more. When the external relative humidity is high, water vapor is taken in from the outside through the membrane. Conversely, when the external humidity is low, the internal water is released as water vapor to control the humidity. By closing the membrane in a bag shape so that there is no gap, it is possible to obtain a humidity control system that is easy to carry without leaking the aqueous solution to the outside.

  By using a bag-type water vapor permeable container, the humidity control direction is not limited to the top surface, but the entire bag. Therefore, the surface area per unit container is larger than that of the open container, and the humidity control efficiency is increased. The more the material that allows water vapor to pass through, the higher the humidity control ability, and it is also possible to increase the humidity control ability by increasing the surface area by providing a structure like a fold. Examples of the membrane include silicone rubber, polystyrene film, polyethylene film, and the like, which are materials having high water vapor permeability.

  In addition, a water vapor permeable container can be obtained by adhering a waterproof and moisture permeable material such as a hydrophobic filter having a fine pore with high water vapor permeability to the container, although liquid does not pass therethrough.

Further, by making the water vapor permeable container a hard transparent plastic container, the amount of liquid inside can be confirmed, and thus the concentration of the humidity control agent can be visually confirmed. If the concentration of the humidity control agent is known, it is possible to know the relative humidity in the airtight container and to know the replacement timing of the water vapor permeable container. In that case, the airtight container is preferably made of a transparent material.

  As the humidity control agent, an alcohol aqueous solution and various salt aqueous solutions are conceivable. In any case, the relative humidity can be controlled by changing the concentration. For example, when an aqueous glycerol solution is used as an alcohol aqueous solution, 100% relative humidity is 0% pure water, about 95% relative humidity is 20%, about 90% relative humidity is 30%, and about 50% relative humidity is 50% glycerol aqueous solution. 80% and 80% glycerol aqueous solution can control relative humidity to about 50%.

  An object of the present invention is to provide a method in which a humidity control agent is filled in a water vapor permeable container to keep the external relative humidity constant and easy to carry. Although the humidity control agent is a known material, it is inconvenient for transportation as it is.

  In order to control the relative humidity, it is possible to use a humidity control device equipped with a humidity sensor, but the cost of the device itself is high, and there are many situations where it cannot be used because it requires power supply. In the present invention, the humidity control is performed by using an aqueous solution such as glycerol and a moisturizing container. As a specific method of use, when transporting fresh vegetables in a container without power supply, the freshness of fresh vegetables is maintained in a state in which the freshness of fresh vegetables is maintained by installing the moisturizing container of the present invention in the container. Possible use.

  In addition, in order to prevent dew condensation on smaller fresh vegetables, methods of wrapping fresh vegetables with a perforated film or a film with high water vapor permeability are known. There was a problem that it was easily affected by. In the present invention, by installing the moisturizing container in a sealed space, the relative humidity in the space can be maintained high, and condensation or drying can be prevented even if the external environment changes.

  In addition, this invention is not restricted to fresh vegetables and its transport, It can be used for every scene which performs humidity control in a certain space. Specifically, when using a device that is sensitive to condensation in a space where high humidity is required, when using the camera in a high humidity environment, the lens should not be fogged by condensation, and the inside of a sealed container such as a tapper should be condensed. If you want to keep it in high humidity, it can be used in many situations, such as storing wine, storing bamboo crafts and woodwork products, storing strings of stringed instruments, and maintaining the humidity environment of ruins such as murals.

a: Airtight container, b: Water vapor permeable container, c: Humidity control agent

The present invention is composed of a water vapor permeable container, a humidity control agent, and an airtight container. The humidity control agent is filled in the water vapor permeable container and installed in the airtight container so that the airtight container has a target relative humidity. To control.

  About 1 mL of 30% (v / v) glycerol is filled in a 0.5 mm thick silicone bag, and is placed in a hermetically sealed bag (0.1 mm thick polyethylene / nylon silica-coated film) with a humidity logger. After filling with air, the four sides were heat-sealed and sealed, placed in a constant condition of 30% external environmental humidity and 20 ° C., and measured for 7 days relative humidity.

  As a result, the relative humidity after 7 days was 89.4%, and the desired humidity environment could be obtained without condensation.

  INDUSTRIAL APPLICABILITY The present invention can be used not only for storing vegetables that require high humidity, but also for protecting devices that are sensitive to condensation that operate in a space where high humidity is required. For example, cells are cultured in a high-humidity environment in a CO2 incubator, but if you put a microscope in the incubator and try to observe the cells, condensation will occur immediately and it will not work, or the lens will become cloudy and invisible . In such a case, in the present humidity control system, by installing a container that transmits water vapor filled with a humidity control agent in the incubator, it is possible to prevent the breakdown of the apparatus due to condensation or the clouding of the lens. In this case, the incubator becomes an airtight container.

  In addition, if you want to keep the inside of a sealed container such as tapper at high humidity without condensing, there are many situations such as storing wine, storing bamboo crafts and woodwork products, storing strings of stringed instruments, maintaining the humidity environment of ruins such as murals, etc. May be available in

Claims (7)

A method of keeping the relative humidity in a sealed space constant by enclosing a humidity control agent in a container that allows water vapor to pass through and placing it in a sealed space (airtight container). The method according to claim 1, wherein the humidity control agent is pure water, an alcohol aqueous solution or a salt aqueous solution. The method according to claim 1, wherein the aqueous alcohol solution according to claim 2 is pure water, an aqueous glycerol solution, or glycerol having a concentration of 0 to 100% (v / v). The container according to claim 1, wherein the water vapor-permeable container is water-tight, and a silicone rubber bag or a waterproof and moisture-permeable material is used for a part of the container. Claims in which a part or the whole of a water vapor-permeable container is transparent and the inside can be visually recognized, and the change in the concentration of the humidity control agent can be confirmed by checking the internal volume with a scale, and the replacement time can be known. The container according to 1. An airtight container having a water vapor permeability of 0.2 g / m ^ 2 · 24 hr or less in a container for creating a sealed space according to claim 1. 2. A kit for achieving the method according to claim 1, comprising a container that transmits water vapor, a humidity control agent, and an airtight container.

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