JPS61230720A - Hygroscopic coating agent and dehumidifying method using same - Google Patents

Abstract

PURPOSE:To reduce packing cost by facilitating the integration of a container requiring dehumidification with an adsorbent by enabling the direct coating of the container, by adding a hygroscopic adsorbent to a hot melt compound under mixing. CONSTITUTION:For example, a styrene/ethylene/1-butene block copolymer, an ethylene/vinyl acetate copolymer and a hydrogenated 9C petroleum resin are mixed under heating and, after synthetic zeolite was added to the resulting mixture under mixing, polyethylene wax and liquid paraffin are further added thereto to obtain a hygroscopic coating agent. This coating agent is applied to a sheet material to constitute a hygroscopic sheet which is, in turn, cut into an arbitrary size and the cut sheets are charged in a container to be dehumidified or the container is constituted of the sheet to perform the dehumidification of the container.

Description

[Detailed description of the invention]

B) Industrial Application Field The present invention mainly relates to a hygroscopic coating agent used for dehumidifying a container, and a method of dehumidifying the inside of a container using the same. More specifically, it is a heat-melting hygroscopic coating agent that was created based on a concept completely different from that of conventional solid desiccants and has expanded uses, and the hygroscopic coating agent is used as a sealing material in containers. A method for dehumidifying the inside of a container by using it as a coating material inside the container, or using it as a coating material at the same time as sealing, and a method for dehumidifying the inside of the container by using a hygroscopic sheet in which the hygroscopic coating agent is coated on a sheet material. This relates to how to achieve this goal. Prior Art Conventionally, as means for dehumidifying the inside of a container, blocking outside air and introducing a solid desiccant agent have been known. In other words, containers for things that do not like moisture are: ■ Containers made of materials with low moisture permeability such as metal, plastic, and glass are sealed with a thin membrane, and after this membrane is broken, they are sealed with flexible plastic ink. Seal it with a lid, or put rubber on the inside of the lid.
Either seal the container with a core such as plastic or cork, or seal it by applying a liquid sealant that hardens under certain conditions to the lid, or simply use a box made of plastic film or paper to seal the container. It was constructed as a bag, or as a box or bag with a laminated structure coated or laminated with paper, metal foil, or plastic film to prevent outside air from permeating. Furthermore, among the contents stored in these containers, if the contents are to be consumed over a long period of time or require a high degree of dehumidification, the containers should be filled with water-absorbing materials such as silica gel or calcium chloride. A solid desiccant containing the same amount was added. C) Problems to be solved by the invention Among the above containers, containers ① to ② have good airtightness and can be sealed repeatedly with an airtight lid, but each time the container is opened, outside air intrudes. A desiccant is required for contents that are consumed over a long period of time, or for items that require a high degree of dehumidification. As is well known, if a desiccant is left in the air, it will gradually absorb moisture from the air and lose its function as a desiccant. There is a risk that the product may break out, and it is difficult to handle. Furthermore, since the desiccant is generally in the form of granules or powder, it is inconvenient that the desiccant must be divided into bags that are easily permeable to moisture so as not to mix with the contents of the container. In addition, when packaging only with a bag or box made of paper or plastic film, as in (■), the packaging material itself is slightly permeable, so there is a risk that outside air may enter over a long period of time, making it impossible to maintain airtightness. is incomplete. Furthermore, if a high degree of dehumidification is required, use these ■
It is placed in a container with a desiccant and double wrapped, but the packaging cost is high. In addition, bags or boxes made of paper, metal foil, or plastic film coated or laminated, as in (2), are much more airtight than (2). However, it is not possible to dehumidify the contents themselves, and strict drying is required before packaging, and if there are contents that cannot be heated, drying takes a long time. In short, the conventional technology has the following problems. (a) Making the container itself airtight leads to a complicated structure of the container, which poses a problem in terms of packaging cost. To) In addition, even if the container itself has an airtight structure, it is necessary to dehumidify the container itself before use, and if it is opened and closed repeatedly, the intrusion of outside air is unavoidable. This results in the need for additional dehumidification means. (C) Desiccants are useful for preventive hygiene and quality control, but are troublesome. D) Means for solving the problems The present invention was created with the aim of solving the problems of the prior art as described above, and it provides a hygroscopic coating agent based on a completely new idea, and a hygroscopic coating agent based on a completely new idea. Provide a dehumidification method to use. The configuration will be described below. (2) Hygroscopic Coating Agent The hygroscopic coating agent of the present invention is composed of a hot-melt compound mixed with an adsorbent having hygroscopic properties. As is well known, hot melt formulations cure instantly after being heated and applied. On the other hand, adsorbents that are generally hygroscopic can easily release moisture by heating and regain their hygroscopicity even if they once absorb moisture from the air. When these two factors are combined, the formulation not only cures quickly, but also has the great advantage that it can be applied with minimal moisture when heated. Therefore, the hygroscopic coating agent of the present invention has a combined effect of (1) a coating effect that melts or solidifies depending on temperature conditions, and (2) an adsorption effect that itself has adsorption properties, as well as a synergistic effect that it is applied in a state with the lowest moisture content. It will also have a The hot melt formulation used in the present invention is made of polyamide
polyester, thermoplastic urethane or ionomer,
Olefin polymers such as propylene, polyethylene, ethylene/vinyl acetate copolymer, ethylene/acrylic acid copolymer, ethylene/acrylic acid ester copolymer, or butyl rubber, polyisobutylene, styrene, etc.
Thermoplastic rubber such as isoprene block copolymer, styrene, butadiene block copolymer, styrene/ethylene-1-butene block copolymer, ethylene/propylene rubber, etc. alone or in a mixture of several of these, as required. Rosin, rosin derivative, terpene resin, terpene phenol resin, C5 petroleum resin, C9 petroleum resin, C5/C9
Tackifiers such as petroleum resins, paraffinic/naphthenic mineral oils, ester plasticizers, paraffin waxes 1, microcrystalline waxes, low molecular weight polyethylene waxes, and other modifiers and antioxidants added. Become. In order to impart hygroscopic properties to hot melt formulations with such compositions, calcium chloride silica gel, activated Shiratama, activated alumina, calcium oxide, inorganic adsorbents such as natural and synthetic zeolites, acrylic acid polymers, acid-modified isobutylene-based A large amount of a water-soluble polymer such as a polymer, ethylene oxide, or polyethylene glycol, or a partially crosslinked product thereof is added as a moisture adsorbent. This hygroscopic coating agent can be prepared by adding or mixing the above-mentioned adsorbent alone or in combination with the above-mentioned adsorbent while melt-mixing the above-mentioned base polymer alone or in combination with a modifier as necessary, or by mixing the above-mentioned adsorbent alone or in combination with a modifier. After mixing, the adsorbent is added and mixed. When using the hygroscopic coating agent of the present invention for various purposes,
It is desirable to have the following compositions. For example, when used as a sealant for containers, thermoplastic polyurethane, butyl rubber, polyisobutylene, styrene-isoprene block copolymer, styrene-butadiene block copolymer, etc. 5 to 30% by weight of thermoplastic rubber such as polymer, styrene/ethylene/1-butene block copolymer, ethylene/propylene rubber, 5 to 30% of tackifier, 5 to 30% of plasticizer, and wax. 1
-15%, 20 to 60% of the above adsorbent, ethylene/vinyl acetate copolymer, polyethylene, polypropylene,
It is preferable to mix olefin polymers such as ethylene/acrylic acid ester copolymer, ethylene/acrylic acid copolymer, ionomer resin, etc. in a composition of 5 to 20%. The purpose of adding wax or olefin-based polymers to this composition is to prevent the surface of the compound from becoming sticky (when a polymer with high rubber elasticity is plasticized). In addition, using liquid paraffin as a plasticizer is also effective in preventing blocking of the compound from internal harmful substances.Also, as another example, coating a sheet material with the hot melt compound, When used as a hygroscopic sheet material or a hygroscopic packaging material, rubber elasticity is not required, but blocking resistance is rather important, and 5 to 30% by weight of the above olefin polymer is added to the above-mentioned heat treatment. 0-15% plastic rubber, 5-30% tackifier, 0-15% plasticizer, 5-30% wax, 20-20% adsorbent
A composition of 60% is preferred. The purpose of using thermoplastic rubber in this composition is to prevent the brittleness of the formulation and provide flexibility. In addition, if the adsorbent is added in a small amount, the moisture absorption performance of the compound will be poor, and if it is too large, the melt viscosity of the compound will be extremely high, causing problems such as not being able to apply it uniformly or thinly. wake up Furthermore, if a polymer that easily melts in water, such as an acrylic acid-based polymer adsorbent, is added in a larger amount than a predetermined amount, the compound will also easily melt in water, and the moisture absorption of the contents containing a large amount of water will be reduced. If this is done, the mixture will be plasticized by moisture, causing problems such as a significantly increased surface tackiness and a significant decrease in the strength of the mixture, such as adhesion to the contents. Furthermore, if a polymer that easily melts in water, such as an acrylic acid-based polymer adsorbent, is added in a larger amount than a predetermined amount, the compound will also melt easily in water, and the moisture absorption of the contents containing a large amount of water will be reduced. If this is done, problems such as plasticization of the compound due to moisture, resulting in significantly increased surface tackiness, and significant decrease in strength of the compound, such as adhesion to the contents, occur. Therefore, the amount of adsorbent depends on the content and application.
It is desirable to appropriately determine the value between 0% and 0%. Furthermore, in order to know the moisture absorption state of the formulation, 1 to 10% of cobalt chloride may be added to the formulation, or a cobalt chloride solution may be applied to the application surface of the formulation. As is well known, cobalt chloride is dark red while it has water of crystallization, but turns blue when it loses water of crystallization. Since this change occurs reversibly depending on the ambient humidity, it has often been used as a humidity indicator. Taking advantage of this fact, it is intended to be used as an indicator of the humidity of the formulation. If cobalt chloride is added to the mixture, the color changes to bright blue when moisture absorption is low, or pink color when moisture absorption is present. Furthermore, when the hot melt composition is applied to the food field, certain polyamide resins, certain petroleum resins, mineral oils, etc., which have a strong odor, are not preferred. ■) Method for dehumidifying inside a container using the hygroscopic coating agent of the present invention (first) The first dehumidifying method of the present invention uses a hygroscopic coating agent prepared by adding and mixing a hygroscopic adsorbent to a hot melt compound. By using it as a sealing material for a container, as a coating material, or as a coating material at the same time as a sealing material, it maintains the airtightness of the container and simultaneously absorbs moisture inside the container. As mentioned above, the hygroscopic coating agent of the present invention cures immediately after being heated and applied, so it can be applied at high speed. Therefore, it is possible to automatically apply it to the container at high speed immediately before the contents are put into the container. To carry out such automatic coating, a melt coating device consisting of a melting section and a discharge mechanism may be used. For details, install a solenoid valve etc. on the discharge part,
In addition to automatically opening and closing the discharge port using electrical signals, the melt coating device can coat various shapes by changing the shape of the discharge port. Furthermore, in terms of dehumidification, since moisture adsorption occurs from the surface of the hygroscopic coating agent, the larger the surface area of the hygroscopic coating agent applied to the sealed container, the more moisture will be absorbed. Therefore, when melting and applying a hygroscopic coating agent to the surface of a sealed container, it is cooled immediately after being applied to the flat surface, and is then pressed using a mold with irregularities treated with a release agent to prevent the hygroscopic coating agent from adhering to the surface. By doing so, it is possible to obtain a coating surface with a large surface area. For one-sided surfaces, a comb tooth-like protrusion is attached to the discharge port,
By rubbing with the protrusions at the same time as discharging, it is possible to obtain a coated surface with unevenness at the curved portion. Furthermore, by selecting a raw material with rubber elasticity for the base polymer of the hot melt compound constituting the hygroscopic coating agent, the hygroscopic coating agent itself can be made highly elastic. If these hot-melt compounds are rolled up and coated into the core shape of a lid that maintains the airtightness of the container, it can also serve as a substitute for conventional molded products such as rubber, plastinink, and cork. . ■) Method for dehumidifying inside a container using the hygroscopic coating agent of the present invention (second) The second dehumidifying method of the present invention uses a hygroscopic coating agent prepared by adding and mixing a hygroscopic adsorbent to a hot melt compound. A moisture absorbing sheet is formed by coating a sheet material in advance, and the moisture inside the container is absorbed by exposing this moisture absorbing sheet to the air inside the container. Desiccant is generally in the form of granules or powder, and when used, there is a risk of mixing with the contents, so it must be divided into bags that allow moisture to permeate easily, but this dehumidification method In this method, a hygroscopic coating agent prepared by adding and mixing a hygroscopic adsorbent to a hot-melt compound is applied in advance to metal foil, paper, plastic film, etc. to form a hygroscopic sheet, and this sheet is rolled up and used as desired at any time. The aim is to make it easy to use by cutting it to size. This moisture-absorbing sheet is similar to a conventional desiccant in that it gradually absorbs moisture from the air and loses its effectiveness if left open, so it must be stored in an airtight container. However, since this moisture-absorbing sheet is in sheet form, it can be rolled up, and if it is rolled up and stored, it will come into contact with air much less than granular or powdered desiccant. Similarly, if it loses its effectiveness, it can be regenerated by heating it at a predetermined temperature for a predetermined period of time. In this dehumidification method, the moisture absorbing sheet is generally exposed to the inside of the container by cutting the sheet into a desired size and placing it into the container, but the sheet itself may constitute the container. In this case, since the hygroscopic coating agent coated on the hygroscopic sheet has not only hygroscopicity but also heat-sensitive adhesive properties, this property can be used to coat the hygroscopic coating agent several seconds later, before it solidifies. If the sheets are laminated together, the overlapping part becomes the adhesive part, making it possible to form bags or boxes at high speed at the same time as coating. Furthermore, by heat-sealing the adsorption sheet that has been coated and solidified by cooling, it becomes possible to form bags or boxes at high speed without the need for special adhesives. In the above case, if the contents are placed in such a container while or immediately after bag making or box making, the hygroscopic coating agent is depleted by heating and the container can be sealed when the moisture content is at its lowest. E) Examples Next, specific examples of the present invention will be explained for each invention. (First Example) Hereinafter, the first to fifth examples relate to a hygroscopic coating agent.

[Note 1] The first embodiment will be explained using both the text and Table 1, and the second to fifth embodiments will be explained mainly using Table 1 instead.

[Note 2] The names of manufacturers of raw materials used in the following examples are as follows. Kraton G-1657 Shell Chemical Ultrasen 011-720 Toyo Soda Alcon P-85 Uyo Chemical Alcon P-115〃 Diana Process Oil NS-100 Idemitsu Kosan Hicol To-350 Kinyen Yuka AC Polyethylene AC-400 Allied Chemical Zeolum A-4 Toyo Soda Sumikagel 5P-520 Sumitomo Chemical Sumikagel NP-1020'' Kl Gel 201K Claresoprene Chemical According to the present invention, a hygroscopic coating agent used as a container sealant was prepared as follows. Total capacity 300+1 Heated a heated Nigu with a sigma blade to 160°C, and added Kraton G-1657 (styrene/ethylene/1-butene block copolymer, styrene/ethylene/l-butene ratio = 14/86) to it at 20.
8 g, 12.8 g of Ultracene UE-720 (ethylene vinyl acetate copolymer, vinyl acetate content 28%, melt index 150), and 32 g of Alcon P-115 (water-added C9 petroleum resin, softening point 115°C). Add l
Mix for ~20 minutes. To this, 72 g of Zeolum A-4 (synthetic zeolite) was added little by little and mixed for 20 minutes. After confirming that the Kraton G1657 pellet was completely melted, 4.8 g of AC-400 (polyethylene wax, vinyl acetate content 14%) was added little by little and mixed. After mixing for 5 minutes after addition, add 17.6 g of -350 (liquid paraffin) little by little to Hycoal, and after addition, add 17.6 g of -350 (liquid paraffin).
Mix for 5 minutes and remove from the kneader. The respective weight percentages are as follows. Kraton G-165713% Ultracene [IE-7208% Alcon P-11520% AC Polyethylene 8C-40 3
% Hycoll -35011% Zeorum A-445% Total 100% When the tensile properties were measured according to JISK-6301, the tensile strength was 6.2 kg/cd elongation rate 100% permanent set 15%, and as mentioned above, it is flexible. A compound with high properties and low permanent deformation was obtained. The composition name, Kraton G-1657, is an A-B-A type block copolymer, where A is polystyrene, B is polyolefin, and the other B is butadiene or isoprene, which is a styrene-butadiene block copolymer.
It is also used because it has better compatibility with olefin polymers than styrene isoprene block copolymers. As is well known, this type of polymer has a micro-separated structure in which styrene moieties are solidified in a rubber matrix, and these moieties act as physical crosslinks. Therefore, it exhibits physical properties similar to vulcanized rubber at room temperature,
It is known that physical crosslinks become fluid when heated and flow when stress is applied. Therefore, it is effective in imparting rubber elasticity to the hygroscopic coating agent of the present invention. Ultracene UE-720 is an ethylene-vinyl acetate copolymer with excellent fluidity, and is made by plasticizing Kraton G-1657, the main polymer of the formulation. It suppresses the tackiness caused by oxidation, and at the same time supports the cohesive force of the main polymer. Furthermore, Clayton G-16
If only 57 is present, the adhesion to metal will be poor. Alcon P-115 is a tackifier that serves to plasticize Kraton G-1657 and Ultracene UE-720 and increase the adhesion of the formulation. High call-
350 is a high boiling liquid paraffin that provides flexibility without making the formulation significantly sticky and serves to reduce the melt viscosity of the formulation. AC polyethylene AC-4
00 is waxy low weight polyethylene. In this case, it primarily serves to prevent the blocking properties of the blend and at the same time to reduce the melt viscosity of the blend. Furthermore, Zeolum A-4 used in this example is a synthetic zeolite, and is an inorganic adsorbent having an extremely large surface area and having countless pores on its particle surface. The effects of the hygroscopic coating agent having rubber elasticity thus formulated are shown in Table 1 and FIGS. 1 and 2. The average coating amount of the hygroscopic coating agent on high-quality paper was 320 g/r+
1, cut it into a rectangle of 60 x 2 QQ cranes, put it in an iron can with an inner diameter x height of 1 82 x 63 tm, and seal it together with a No. 9 cotton cloth with an average moisture content of 23.5% / 60 x 250 cranes. The weight of each was measured and calculated as follows. Amount of moisture absorbed = 10g of hygroscopic coating agent (g/10g of hygroscopic coating agent): Weight per 10g of hygroscopic coating agent before moisture absorption Ho': Weight of No. 9 cotton cloth before moisture absorption Wt': After 10 hours of No. 9 cotton cloth From the weight table 1 and Figures 1 and 2, it can be seen that the hygroscopic coating agent is 7.
After 2 hours, about 1 g of moisture per 10 g was absorbed from the cotton fabric, and it was found that the No. 9 cotton fabric finally absorbed about 50% of the moisture from the hygroscopic coating agent. (Second Example) As described above, when the hygroscopic coating agent of the present invention is used as a coating material, blocking resistance is more important than rubber elasticity. Therefore, the composition of this example was to reduce -350 to the thermoplastic rubber Kraton G-1657 and the plasticizer Hycol, and at the same time reduce the amount of -350 to the olefinic polymer Ultracene UE-720 and the wax AC-40.
The amount of 0 is increasing. Table 1 and FIGS. 1 and 2 show that the hygroscopic coating material of this example has almost the same hygroscopicity as that of the first example. (Third Example) This is an example in which the same formulation as in the second example was used, and an acrylic polymer was used as the adsorbent. (Fourth Example) This is an example in which the same formulation as in the second example was used, and an acrylic polymer different from that in the third example was used as the adsorbent. (Fifth Example) This is an example in which the same formulation as in the second example was used, and an isobutylene-based polymer was used as the adsorbent. It can be seen from Table 1 and FIGS. 1 and 2 that the polymeric adsorbents used in Examples 3 to 5 have significantly better adsorption performance than the inorganic adsorbent Zeolum A-4. (Table 1) (Sixth Example) The following sixth to ninth examples relate to a method of dehumidifying a container using the hygroscopic coating agent of the present invention. FIG. 3 is a diagram showing an example in which the hygroscopic coating agent of the present invention is used as a coating material for a container. By applying the heated and melted hygroscopic coating agent 1 to the inner circumferential wall of the container, the coating is cooled immediately after application and the coating is completed. In this case, since the hygroscopic coating agent is active only on its surface, its hygroscopicity is proportional to the applied surface area. The unevenness 1a is provided. FIGS. 4 and 5 show an example of a coating apparatus used in the above process. This coating device includes a heated hose 10 that guides the molten hygroscopic coating agent, an automatic opening/closing pulp 11 that controls the discharge of the guided hygroscopic coating agent, a discharge guide 12 that has a plurality of discharge holes 13 on its surface, and a discharge guide 12 that has a plurality of discharge holes 13 opened on its surface. A comb-like protrusion 14 is provided at the tip of the guide and forms unevenness on the coated hygroscopic coating agent.
It becomes more. As shown in FIG. 5, this coating device positions the surface of a discharge guide 12 facing the inner circumferential wall of the container, and discharges the molten hygroscopic coating agent from the discharge hole 13, thereby discharging the hygroscopic coating agent from the discharge guide. 12 surface and the inner circumferential wall surface of the container, and by rotating the container K, the comb tooth-like protrusions 14
The accumulated hygroscopic coating agent 1 is rubbed while forming irregularities on the surface to evenly level it on the inner peripheral wall surface, thereby achieving a coating effect. (Seventh Example) FIG. 6 is a diagram showing an example in which the hygroscopic coating agent of the present invention is used as a sealing material as well as a coating material for containers. A heated and melted hygroscopic coating agent 1 is applied to the back surface of the lid KC of the container, with the peripheral edge 2 raised up in the shape of a core. This hygroscopic coating agent cools and solidifies immediately after application, but by selecting a raw material with rubber elasticity for the base polymer of the hot melt compound that makes up the hygroscopic coating agent, it becomes highly elastic and has a moisture absorption function. In addition, it is possible to obtain a sealing function that is comparable to molded products of rubber, plastic, cork, etc. that have been conventionally used as cores. In this embodiment, wrinkle-like irregularities 1a are provided on the surface of the applied hygroscopic coating agent in order to expand the surface area. An example of a molding apparatus used in the above steps is shown in FIGS. 7 and 8. This molding device has a basic configuration in which a flat circular press die 6 with uneven grooves 23 on the lower surface is moved up and down by an air cylinder 5, and a cooling pipe 22 is passed through the press die to promote cooling of the hygroscopic coating agent. In addition, a release agent is applied to the surface of the uneven grooves 23 to prevent the hygroscopic coating agent from adhering thereto, and a nozzle 24 is provided for blowing dry air to prevent moisture in the air from condensing on the uneven grooves by cooling. This nozzle is provided at the tip of the air cylinder 25 so that it can be retracted as the pressing die descends. This molding device positions a press die 6 above the hygroscopic coating agent 1 which is piled up in a molten state on the back surface of the lid KC, cools the press die, and at the same time blows dry air onto the uneven surface 23 to cool the press die. By lowering the hygroscopic coating agent and pressing it against the hygroscopic coating agent, the hygroscopic coating agent is pushed out between the outer circumferential side of the pressing mold and the inner circumferential side of the lid KC to form the periphery of the core, and at the same time, the uneven surface 23
This serves to form fold-like unevenness 1a on the surface of the hygroscopic coating agent. (Eighth Example) FIGS. 9 to 10 are diagrams showing an example in which a moisture-absorbing sheet S, which is a sheet material coated with the hygroscopic coating agent of the present invention, is placed in a sealed container. Figure 9 shows an example in which a moisture-absorbing sheet S is cut to fit the inner dimensions of a container and placed along the inside surface of the container, and Figure 10 shows an example in which the contents G are wrapped with the moisture-absorbing sheet S and placed inside the container. An example is given for each. (Ninth Embodiment) FIG. 11 is a diagram showing an example in which a container ' is formed by a moisture-absorbing sheet S itself, which is a sheet material coated with the hygroscopic coating agent of the present invention. In this embodiment, two suction sheets S are prepared, and the coating surface is turned inside and the circumferential side 30 is heat-sealed to obtain a bag-like container. It goes without saying that the container thus obtained can be easily sealed again by heat sealing after being opened. In addition, since it has the function of allowing the opening to be easily sealed repeatedly without the need for a separate sealing material, for example, if this container is used as a retail bag for coffee beans, it can be used to store coffee beans at different retail points. Even when the beans are ground and put back into the container, heat sealing allows the beans to be easily returned to their initial state without requiring a sealing material like in the past. f) Effects of the invention This invention is constructed as described above and has the following unique effects. (a1) The hygroscopic coating agent of the present invention is composed of a hot-melt composition and an adsorbent having hygroscopic properties, so
It has the ability to melt or solidify depending on temperature conditions, and unlike conventional solid desiccants, it can be applied directly to containers that require dehumidification, making it easy to integrate containers and adsorbents. (Similar to BL, the hygroscopic coating agent of the present invention has the effect of drying up when heated, so it can be applied in a state with the lowest moisture content, and there is no need to pre-heat and dry the container etc. to which it is applied. Achieving a synergistic effect. (C1) If the hygroscopic coating agent of the present invention is used as a coating material for containers, the effect of (a) above eliminates the need to add a desiccant, reducing the cost required for adding a desiccant,
and desiccant swallowing accidents are eliminated. ld) Similarly, it acts as a reinforcing material for the container at the same time as dehumidifying it, giving a degree of freedom in selecting the container material. (Similar to EL, by imparting elasticity to the hygroscopic coating agent, it also acts as a cushioning material inside the container, eliminating the need to separately add desiccant and cushioning materials as in the past, reducing packaging costs. (f) Similarly, since unevenness can be easily formed on the surface of the hygroscopic coating agent before solidification, the moisture absorption area can be adjusted freely, and the unevenness also makes the hardened hygroscopic coating agent flexible. (a) If the hygroscopic coating agent of the present invention is used as a container sealing material, it has the effect of simultaneously achieving sealing and dehumidification of the container. The cost required for sealing can be reduced. (h1) If a sheet material is coated with the hygroscopic coating agent of the present invention and used as an adsorption sheet, the sheet can be rolled up to minimize the contact area with the outside air. Since the desiccant can be stored in a reduced amount, the user can easily store it and cut it out and use it as needed, which is a management method that cannot be achieved with conventional desiccants. (1) How to use it in the above cases. In addition to simply putting items into a container, by wrapping the item itself and storing it in the container,
It can also dehumidify while acting as a buffer sheet, reducing packaging costs. (J) Furthermore, if the container is constructed from the moisture-absorbing sheet itself, a container with a very wide moisture-absorbing area can be easily realized, and packaging costs can be reduced. (b) In the above case, due to the properties of the hygroscopic coating agent of the present invention, the containers can be easily bonded and sealed by heat sealing without using separate adhesives and sealing materials.

[Brief explanation of the drawing]

Fig. 1 is a graph showing the moisture absorption effect in the first to sixth embodiments of the present invention, Fig. 2 is a graph showing the moisture release effect in the first to sixth embodiments of the above, and Fig. 3 is a graph showing the moisture release effect in the sixth embodiment of the same. FIG. 4 is a side view of the coating device used in the sixth embodiment of the same, FIG. 5 is a plan view of the coating device used in the sixth embodiment of the above, and FIG. is a cutaway end view of the lid of the container in the seventh embodiment, FIGS. 7 to 8 are front views of the application device in use in the seventh embodiment, and FIG. 9 is the eighth embodiment. FIG. 1O is a sectional view of the container in the eighth embodiment, and FIG. 11 is a plan view of the container in the ninth embodiment. In the figure, reference numeral (1) is a hygroscopic coating agent, (S) is a hygroscopic sheet, and (K) is a container. Hoof 1 Figure #P Meiji Nissin [Nissan F/I] - → Between 8I4P [Nichijimon]

Claims (1)

[Scope of Claims] 1. A hygroscopic coating agent characterized in that a hygroscopic adsorbent is added and mixed into a hot melt formulation. 2. The hygroscopic coating agent according to claim 1, wherein the hot melt formulation is a thermoplastic polymer to which a tackifier, a modifier, and an antioxidant are added as necessary. 3. By using a hygroscopic coating agent prepared by adding and mixing a hygroscopic adsorbent to a hot melt compound as a container sealing material, as a coating material, or at the same time as a sealing material,
A dehumidification method characterized by maintaining the airtightness of the container and at the same time absorbing moisture inside the container. 4. The dehumidification method according to claim 3, wherein the back surface of the lid of the container is coated with the hot melt compound in a core-like manner. 5. The dehumidification method according to claim 3 or 4, wherein irregularities are formed on the surface of the hygroscopic coating agent during coating. 6 A hygroscopic sheet is formed by coating a sheet material in advance with a hygroscopic coating agent prepared by adding and mixing a hygroscopic adsorbent to a hot melt compound, and by exposing this hygroscopic sheet to the air inside the container. A dehumidification method characterized by absorbing moisture. 7. The dehumidification method according to claim 6, wherein the moisture absorption sheet is cut into a desired size and placed in the container to absorb moisture in the container. 8. The dehumidification method according to claim 6, wherein the moisture absorption inside the container is carried out by constructing the container with the moisture absorbing sheet itself. 9. The dehumidification method according to claim 6, 7, or 8, wherein the sheet material is a metal foil. 10. The dehumidification method according to claim 6, 7, or 8, wherein the sheet material is paper. 11. The dehumidification method according to claim 6, 7, or 8, wherein the sheet material is a plastic film.