JPS5933831Y2 - Condensation prevention sheet - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a dew condensation prevention sheet.

When cargo is transported by air or sea in sealed containers, it is often exposed to sudden changes in outside temperature.

In particular, when the temperature drops from high to low, condensation naturally occurs inside the container, and there are many cases where the condensed water damages the cargo inside.

Condensation generally tends to form on the inner surface of metal containers, and when the cargo contained therein is a metal product, the condensation formed on the surface often causes rust.

Furthermore, when the cargo is food or the like, condensation can cause fatal damage to its quality.

For such cargo, condensation is out of the question, but a built-in desiccant that absorbs moisture in high humidity conditions and releases moisture in low humidity conditions maintains the container at an appropriate humidity through its breathing action. is desired.

For this reason, silica gel has traditionally been used inside containers to prevent cargo damage due to condensation.

Physical desiccants such as alumina gel and acid clay, or chemical desiccants such as phosphorus pentoxide, calcium chloride, and quicklime have been encapsulated, but recently silica gel, which has high stability, has been used in accordance with JIS Z 1401. is prescribed and commonly used.

However, simply placing a bag filled with a desiccant such as silica gel in one or several places inside the container and covering it will result in the desiccant being localized or unevenly distributed over the entire surface of the container or cargo, which is prone to condensation. In such a situation, it is difficult to exert sufficient and rapid dew condensation prevention power.

In particular, transport aircraft such as ships and aircraft are subject to significant turbulence, so bags containing desiccant are unevenly distributed.

The present invention was developed from the above viewpoint, and consists of a desiccant sheet that retains its drying function, and is used by attaching it to the inner surface of the container, or if necessary, the outer surface of the cargo. This is what I did.

This will now be explained with reference to the attached FIG.

In the figure, 1 is a sheet that serves to cover and protect a water-absorbing sheet 3, which will be described later.

Therefore, for example, a rectangle with a width of 45 cm and a length of 240 cm
m is any breathable protective sheet, preferably basis weight 15-50
g/m2 nonwoven fabric, and an adhesive layer 2 is provided on at least two opposing sides thereof.

This adhesive layer is a pressure-sensitive adhesive coating layer with a width of about 0.5 to 20 mm, which is already commercially available as double-sided tape or hot melt, and can be used as is.

On the inside of this adhesive layer 2, a water-absorbing sheet 3 is line-adhered or dot-adhered by a known adhesion method such as using an adhesive or heat sealing or hot melting.

Of course, line or point adhesion does not mean adhesion by points or lines in a geometric sense, but rather, the water absorbent sheet 3 and its protective sheet 1 should be bonded as much as possible so as not to reduce the air permeability. This means that they are adhered to each other in a narrow area, and that the partial adhesive portions 4 allow them to be adhered to such an extent that they cannot be separated and can be handled as an integrated dew condensation prevention sheet.

The water absorbing sheet 3 is composed of two breathable membranes, preferably having a basis weight of 10 to 4.
A synthetic polymeric water absorbing agent 3C is sandwiched between two sheets of absorbent paper 3a and 3b of about 5 to 40 g/m2 at 0 g/m" and 8 degrees.

The synthetic polymeric water-absorbing agent used here is an organic compound that is the same as or equivalent to starch polyacrylonitrile graft copolymer, alkali metal carboxylate salt of starch-polymethacrylonitrile graft copolymer, carboxymethyl cellulose, etc. Polymeric substances are already being used in Japan, such as Aqua Keep by Tetsuko Kagaku Kogyo Co., Ltd., Nigel by Clary Soprene Chemical Co., Ltd., Sunwet IM-300 by Sanyo Chemical Co., Ltd., and Sumitomo Chemical Co., Ltd. ), Aqualic CA (Nippon Shokubai Kagaku Kogyo Co., Ltd.), Arasoap (Arayo Kagaku Kogyo Co., Ltd.), etc., and are known as having high water absorption properties.

These water-absorbing agents easily absorb moisture if the atmosphere is humid, but they do not have deliquescent properties like conventional calcium chloride and do not leak from the water-absorbing sheet itself.

Furthermore, when the atmosphere is sufficiently dry, the moisture absorbed by the insects will not be released into the atmosphere, creating an excessively dry condition.

The water-absorbing sheet 3 used in the present invention can be easily and quickly produced based on the apparatus and method of use thereof described in Japanese Utility Model Publication No. 54-177799, which was invented by the present applicant.

This water-absorbing sheet 3 is, for example, Aqua Keep (Steel Chemistry K.
15 g/m2 (manufactured by K), its water absorption capacity is 2385 g (water) per m2.

The water-absorbing sheet itself, which has such a large water-absorbing capacity, has low mechanical strength because it is made by sandwiching a polymeric water-absorbing agent between two sheets of absorbent paper.

Therefore, a non-woven fabric with high mechanical strength is integrated as a protective sheet by point or line adhesion, and an adhesive layer is provided on both edges of the protective sheet to facilitate adhesion to the inner surface of the container. .

Since the dew condensation prevention sheet of the present invention is constructed as shown above, it can be easily cut to the required size with scissors, etc., and it can be applied to the inner surface of the container very easily. is maintained in a desirable dry state.

For example, even with rapid fluctuations in atmospheric temperature in the range of -20 to 50°C, the inside of the container is kept substantially dry and free from condensation.

For convenience, we have mentioned condensation on containers above, but the sheet of this invention can also be applied to windshields of automobiles, etc., which are a kind of closed room like the inside of a container, and where dew condensation is likely to occur due to changes in atmospheric temperature. can be pasted to prevent condensation.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of the dew condensation prevention sheet of the present invention. 1 is a breathable protective sheet, 2 is an adhesive layer, and 3 is a water-absorbing sheet)
, 3a, 3b are breathable membranes, 3C is a synthetic polymer water absorbing agent, 4
is the adhesive part.

Claims (1)

[Scope of utility model registration request] On one side of the rectangular breathable protective sheet 1, an adhesive layer 2 is provided at least on the edges of two opposing sides, and on the inside of the adhesive layer, two breathable membranes 3a, A dew condensation prevention sheet characterized in that a water-absorbing sheet 3, which is a synthetic polymer water-absorbing agent 3C sandwiched between 3B and 3B, is adhered 4 by point adhesion or line adhesion.