JP2805524B2 - Dew condensation preventing material and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a dew condensation preventing material used as a wall material or the like and a method for producing the same.

[Prior art] Conventionally, the walls of buildings and the like are subject to dew condensation due to the temperature difference between the outside air and the room, and as a result, mold is unsanitary,
And it wasn't good.

Therefore, conventionally, as a means for preventing the generation of mold, a device for preventing condensation has been devised. As a specific means, by using a membrane or sheet that is permeable to moisture but cannot pass moisture, moisture is removed to the outside of the room, or by using a water-absorbing polymer to absorb moisture. , A method of preventing dew condensation has been adopted.

For example, JP-A-62-231740 discloses a water-absorbing polymer,
A moisture-absorbing and desorbing vinyl wall covering having continuous air holes obtained by applying a mixture of a foaming agent, a polyolefin resin, and a vinyl chloride resin onto a substrate, followed by heating and foaming is disclosed. However, the wall material obtained by this method is disadvantageous in that the water-absorbing polymer cannot be absorbed or the water-absorbing performance cannot be sufficiently exhibited because the water-absorbing polymer is surrounded by the vinyl chloride resin. was there. Furthermore, since the water-absorbing polymer absorbs water only in the state of water, it is easy to condense without absorbing water completely in high humidity places due to the relationship between the water absorption rate and the aggregation rate. Because the molecules are cross-linked, once water is absorbed, it is difficult to release moisture, so water is accumulated one after another, but it is impossible to accumulate moisture indefinitely, so wallpaper swollen by absorbing water And the like have poor dimensional stability and are difficult to use over a long period of time.

As described above, although an anti-condensation material using a water-absorbing polymer has been proposed, it does not exhibit an effect of preventing dew condensation over a long period of time, and has an excellent anti-condensation effect over a long period of time. Has long been awaited.

[Problems to be Solved by the Invention] An object of the present invention is to provide a dew condensation preventing material excellent in dew condensation preventing property and shape retention, and a method for producing the same.

[Means for Solving the Problems] In the present invention, a mixture of a water-soluble polymer and a highly absorbent and desorbable material in which metal ions are contained in a colloidal state in a water-soluble polymer is attached to a substrate. It is an anti-condensation material.

More preferably, the water-soluble polymer of the present invention is a vinyl chloride resin.

It is more preferable that a moisture permeable film and / or paper is laminated on the above dew condensation preventing material.

The anti-condensation material of the present invention is obtained by mixing an aqueous emulsion of a water-soluble polymer with an aqueous solution in which a water-soluble polymer and a metal salt are dissolved in water, stirring and uniformly dispersing the mixture, and then adhering to the substrate and drying. It is manufactured by doing.

[Operation] The anti-condensation material of the present invention is basically manufactured in the following order.

Dissolve the water-soluble polymer and metal salt in water.

An aqueous emulsion of a water-soluble polymer is mixed with the aqueous solution and stirred to be uniformly dispersed.

After adhering the mixed solution to the base material, the mixed solution is dried.

The anti-condensation material of the present invention produced in this manner has a highly moisture-absorbing and desorbing material adhered to the substrate mainly due to the cohesive force of the water-soluble polymer, and usually absorbs moisture with the water-soluble polymer. Is considered to be inhibited, but the hygroscopicity is hardly reduced, and the material is excellent in shape retention.

As described above, the excellent form retention is mainly due to
This is due to the cohesive force of the water-soluble polymer. Further, it is considered that the moisture absorption performance of the material of the present invention does not decrease despite the use of the water-soluble polymer. That is, the material of the present invention comprises a highly moisture-absorbing and desorbing material and a water-soluble polymer, which is obtained by removing water from an aqueous emulsion, and has a high moisture-absorbing and desorbing property used in the present invention. Because the material is in a colloidal state,
Even if the two types of mixtures are uniformly dispersed and dried,
Since it is in a state of aggregation with micropores when viewed microscopically,
It is considered that the moisture is absorbed by the highly hygroscopic material through the micropores.

When a superabsorbent polymer and an aqueous water-soluble polymer are mixed and used as a dew condensation preventive material as in the past, in addition to absorbing water, it is not absorbed unless it is in a water state. Due to the tension, water does not easily pass through the micropores, and the moisture absorption performance is extremely low.On the other hand, the high moisture absorption / release material of the present invention absorbs moisture in the state of water vapor before becoming water, so that it has excellent moisture absorption power. To maintain.

Such a highly hygroscopic material used in the present invention is a material in which metal ions are contained in a colloidal state in a water-soluble polymer.

The water-soluble polymer in the highly moisture-absorbing and releasing material includes all water-soluble polymers such as natural polymers, semi-synthetic polymers, and synthetic polymers.

The colloid state means a state in which metal ions are dispersed in a water-soluble polymer when a highly hygroscopic material is dissolved in water. In this state, the absorption wavelength obtained from the absorbance analysis performed by dissolving the highly hygroscopic material in water and the absorption wavelength obtained from the absorbance analysis obtained when the metal salt is simply dissolved in water almost match. You can check. When the highly hygroscopic material is dissolved in water, the highly hygroscopic material swells with excessive moisture and is a viscous liquid such as a sol. Different states.

When the metal ion and the water-soluble polymer form a chelate, that is, when they are coordinated, they should exhibit an absorption wavelength different from the absorption wavelength obtained by simply dissolving the metal salt in water. However, when the highly hygroscopic material of the present invention is dissolved in water, it exhibits the same absorption wavelength as when the metal salt is simply dissolved in water. In the same state as the colloidal state of the ion, it is considered that no chelate is formed.

Since the highly moisture-absorbing and desorbing material used in the present invention is stable and does not change before and after drying even during the drying process, the absorbance analysis may be performed before drying during the manufacturing process, or the highly moisture absorbing and desorbing material may be used. May be dissolved in water again. It should be noted that the degree of dissolution of the highly hygroscopic material in water is such that absorbance analysis is possible, and differs depending on the metal salt, water-soluble polymer, and the like used.

Since the highly moisture-absorbing and desorbing material of the present invention uses a water-soluble polymer, water tends to collect on the polar portion of the water-soluble polymer. That is, hydrogen atoms having low electron density of water molecules are easily electrostatically attracted to a portion having high electron density. After the water molecules are sucked, the hydration power of the metal ions dispersed in the highly hygroscopic material is higher than the electrostatic force, so the collected water moves to the metal ions, The metal ions are also electrostatically held in the polar portion inside the water-soluble polymer.

Conversely, if the humidity of the outside air drops or dries,
The vapor pressure of the outside air decreases, and the force by the vapor pressure is stronger than the hydration power of the metal ions, so that the highly hygroscopic material of the present invention releases the absorbed moisture. In other words, the water hydrated by the metal ions moves to the polar part of the water-soluble polymer, contrary to the case of absorbing moisture, and then is released to the atmosphere.

When the moisture absorption / desorption material used in the present invention reaches a saturated state, the moisture absorption / desorption is repeated in that state.
This is because the interaction of the water molecules with the metal ions after reaching the saturated state is weak, so that the moisture is easily released.

In other words, the highly moisture-absorbing and desorbing material of the present invention absorbs excess moisture, and when the moisture absorption reaches a saturated state, the material absorbs and desorbs repeatedly to reach an equilibrium state as if breathing. As described above, in the equilibrium state, not only moisture is absorbed but also moisture is released, so that it is possible to maintain a constant humidity. The humidity maintained at a constant level depends on the type of the highly hygroscopic material, that is, the type of the water-soluble polymer that constitutes the highly hygroscopic material, the type of metal ion, the mixed amount of the metal ion, It can be adjusted by changing the impregnation amount or the like.

Hereinafter, the metal ion and the water-soluble polymer will be specifically described.

Examples of the metal ion used for the material having high moisture absorption / release properties include lithium ion, calcium ion, iron ion, aluminum ion, magnesium ion, chromium ion, cobalt ion, cadmium ion, zinc ion, and nickel ion.

Examples of metal salts that provide these metal ions include, for example,
Calcium chloride [CaCl ₂ ], iron (III) chloride hexahydrate [FeCl
₃ (6H ₂ O)], aluminum nitrate (III) hydrate [Al (NO
₃ ) ₃ (9H ₂ O)], magnesium chloride hexahydrate (MgCl ₂ (6H
₂ O)], zinc chloride [ZnCl ₂ ], chromium (III) chloride hexahydrate [CrCl ₃ (6H ₂ O)], cobalt (II) chloride hexahydrate [CoCl ₂
(6H ₂ O)], cadmium (II) nitrate tetrahydrate [Cd (NO ₃ )
₂ (4H ₂ O)] and nickel chloride (II) hexahydrate [NiCl
₂ (6H ₂ O)] and the like are preferably used. However, it is not limited to the above-mentioned metal salts, and chlorides, sulfates, acetates, nitrates, and other salts other than the above-mentioned metal salts may be used as long as they are salts composed of the above-mentioned metal ions. I can do it. Of the above metal salts, calcium chloride having deliquescence exhibits particularly excellent high moisture absorption / release properties.

It is considered that as the mixing ratio of the metal salt to the water-soluble polymer increases, higher moisture absorption / release properties are obtained.However, since the solubility of the metal salt in the polyvinyl alcohol aqueous solution decreases, metal ions can be highly dispersed. However, the metal ions come into contact with each other, and the hygroscopic effect of the metal ions is reduced, and conversely, the hygroscopicity may be deteriorated in the initial stage.

On the other hand, when the mixing ratio of the metal salt is low, the amount of metal ions itself is small, so that the moisture absorbing ability is inferior.

Therefore, the mixing ratio of an appropriate metal salt is different depending on the type of the metal salt. For example, when calcium chloride [CaCl ₂ ] is used as a metal salt and polyvinyl alcohol is used as a water-soluble polymer, when polyvinyl alcohol is dissolved in water to form a 10% aqueous solution, the mixing ratio of calcium chloride is polyvinyl alcohol. 20 mol% or more is necessary, and preferably 40 mol%
It is more preferable to mix the above. It should be noted that even if the mixing ratio of calcium chloride exceeds 100 mol%, the moisture absorption rate hardly changes. Therefore, it is not necessary to mix 100 mol% or more, and it is necessary to mix calcium chloride at 40 mol% to 100 mol%. preferable.

In addition, the metal salt may be one kind, but of course, two or more kinds may be mixed.

In the present invention, since water is used as the solvent because water-soluble polymers are used, there is an advantage that there is little danger such as toxicity and explosion in the drying process during the manufacturing process, and that it is easy to handle.

As described above, the water-soluble polymers that can be used in the present invention include natural polymers, semi-synthetic polymers, and synthetic polymers. For example, natural polymers include starch, mannan, seaweed, plant mucilage, microbial mucilage, protein and the like. Examples of semi-synthetic polymers include cellulose-based and starch-based. Synthetic polymers include polyvinyl alcohol sodium polyacrylate, polyethylene oxide, polyvinyl pyrrolidone, and the like.

Among them, polyvinyl alcohol and polyvinylpyrrolidone are compatible with metal salts and water-soluble polymers.
It is preferably used.

In the case of using polyvinyl alcohol, it is preferable to use completely saponified polyvinyl alcohol because the solubility of the metal salt is excellent when producing a highly moisture-absorbing and desorbing material. Since the hygroscopicity of the hygroscopic material is excellent, it is preferable to appropriately select the type of polyvinyl alcohol.

The following is an example of a method for producing a highly moisture-absorbing and desorbing material used in the present invention containing the above-mentioned water-soluble polymer and metal salt as components.

Select the water-soluble polymer and metal salt to be used.

Dissolve the water-soluble polymer in water to make a 10% aqueous solution.

This aqueous solution is mixed with a metal salt and stirred at room temperature for 2 to 3 hours to obtain a viscous liquid.

An aqueous emulsion of a water-soluble polymer is mixed with the highly hygroscopic material thus obtained. This water-soluble polymer is used to strengthen the adhesive force with the substrate.
When only the material with high moisture absorption and desorption was adhered to the substrate as in the past, it was based only on the adhesive force of the water-soluble polymer, so the material with high moisture absorption and desorption swelled under high humidity conditions,
Although the morphological stability was poor, the material obtained by mixing and stirring the water-soluble polymer emulsion and the aqueous solution of the highly hygroscopic material as in the present invention, and then adhering and drying the material, has a high hygroscopic property. Since the material and the base material are surrounded by the water-soluble polymer, the form of the dew condensation preventing material does not change even under high humidity.

In this case, as described above, since a large number of micropores are present on the surface of the dew condensation preventing material obtained in this way, it is estimated that moisture is absorbed through the micropores, and a high absorption rate is obtained. The moisture absorption of the wet material itself is not impeded at all. Furthermore, since the anti-condensation material of the present invention is surrounded by a water-soluble polymer which does not like moisture, moisture immediately moves to the highly moisture-absorbing and desorbing material, so that the highly moisture-absorbing and desorbing material is more efficiently absorbed. The material can absorb.

In the present invention, unless a water-soluble polymer emulsion is mixed with a viscous liquid of a highly moisture-absorbing and desorbing material and uniformly dispersed, only a dew condensation preventing material having uneven moisture absorption can be obtained. Since water is used as the solvent of the moisture absorbing and releasing material, it is essential to use an aqueous emulsion.

Such water-soluble polymers include phenolic resins, epoxy resins, acrylic resins, vinyl resins, urea and melamine resins, polyester resins, styrene resins,
Silicon resin, polyethylene resin, polyamide resin, urethane resin, or the like can be used. However, the present invention is not limited to these water-soluble polymers, and it is sufficient that these water-soluble polymers are stably present as an emulsion. Among these, it is preferable to use a vinyl resin, and among these vinyl resins, it is most preferable to use a vinyl chloride resin having a strong cohesive force.

Although the concentration of the water-based emulsion is not particularly limited, the weight ratio of the highly hygroscopic material after drying is 1%.
In this case, the concentration is preferably such that the ratio of the water-soluble polymer becomes 1 to 10. This is because if the ratio of the water-soluble polymer is less than 1, a material having no strength and no form stability is obtained despite the use of the water-soluble polymer. This is because, when the ratio of the water-soluble polymer is more than 10, uniform dispersion of the highly moisture-absorbing / desorbing material and the water-soluble polymer emulsion becomes impossible. Among these ranges, the ratio of the water-soluble polymer to the highly hygroscopic material 1 is preferably 2 to 6.

The resulting mixture of the highly moisture-absorbing and releasing material and the water-soluble polymer is attached to a base material to form the dew condensation preventing material of the present invention.

As the substrate of the present invention, a porous fiber substrate, a film-like material such as a moisture permeable membrane, or the like can be used. Among them, when a porous fiber substrate is used as the substrate, the water-soluble polymer is easily aggregated and fixed at the intersection of the fibers.

As the porous fiber substrate that can be used in the present invention, for example, a woven fabric, a knitted fabric, and a nonwoven fabric can be used. Among them, the nonwoven fabric is the most preferable in terms of handling, workability, and the like. As the fibers used for the nonwoven fabric, general synthetic fibers, for example, polyester fibers, nylon fibers, polyolefin fibers, acrylic fibers, and the like can be used, and are not particularly limited, but may be used as building materials. Therefore, it is more preferable to use flame-retardant inorganic fibers, organic modacrylic fibers, polyclar fibers, flame-retardant polyester fibers, and the like, and a flame-retardant adhesive or a flame retardant can be mixed.

In addition, such a nonwoven fabric can be produced by either a wet method or a dry method.
It may be manufactured by any method.

The porous fiber base material in the present invention can hold the highly moisture-absorbing and releasing material and the water-soluble polymer, and can increase the amount of moisture absorption and the rate of moisture absorption by increasing the contact area with air.

It is preferable that the porous fiber base material of the present invention is imparted with flame retardancy or added with an antibacterial agent.

The mixture of the highly moisture-absorbing and desorbing material of the present invention and the water-soluble polymer is impregnated into the above-mentioned porous fiber substrate, applied, sprayed, and the like, and then dried to form a part of the porous fiber substrate or Adhere to all.

This attachment state may be such that the highly moisture-absorbing and releasing material and the water-soluble polymer are attached to the intersections of individual fibers of the porous fiber base material, or to the intersections of fibers and the fiber surface.
Alternatively, the highly moisture-absorbing and desorbing material and the water-soluble polymer may be filled in only one surface portion of the porous fiber substrate, or may be partially adhered, or the porous fiber substrate It may be attached over the entire space.

In order to prevent dew condensation, which is the object of the present invention, it is necessary that the highly moisture-absorbing and desorbing material and the water-soluble polymer occupy at least 5% by weight of the dew condensation preventing material. From the viewpoint, 90% by weight or less is preferable, and 15% by weight or less.
More preferably, it is contained at 70% by weight.

As a production method, a mixed solution of a highly hygroscopic material and a water-soluble polymer is impregnated into a porous fiber base material, squeezed with a mangle or the like, and dried by a general method to uniformly form a highly hygroscopic material. And a wall material in which a water-soluble polymer is present,
This is preferable because the moisture absorption and desorption does not cause unevenness, and the appearance becomes a beautiful wall material.

The anti-condensation material thus obtained may be used as it is, but by laminating a moisture-permeable film and / or paper such as rayon paper on one of the anti-condensation materials, it becomes a more practical anti-condensation material. . In other words, the most preferable stacking order is from the inside of the room to the wall, in the order of the moisture permeable film, the dew condensation preventing material, and the paper.

As described above, the purpose of laminating the moisture permeable membrane is to make it feel smoother during actual use. It is to improve.

Although the anti-condensation material of the present invention uses a water-soluble polymer, in addition to the fact that the hygroscopic power of high moisture absorption and desorption does not decrease, it is dimensionally stable mainly due to the cohesive force of the water-soluble polymer. Properties, strength is improved, and it is firmly attached to the substrate, so even if it absorbs moisture during use and contains moisture, it loses gravity,
It does not occur that the highly hygroscopic material moves downward.

Further, the porous fiber base material can produce various patterns depending on the composition of the constituent fibers and the entangled state.

[Example] (Example 1) Calcium chloride was used as a metal salt, and polyvinyl alcohol was used as a water-soluble polymer.

First, polyvinyl alcohol having a saponification degree of 97.0 to 98.5% was dissolved in water to obtain a 10% by weight aqueous solution. Calcium chloride is added to the hydroxyl groups of this polyvinyl alcohol.
100 mol% was mixed and stirred for 3 hours to obtain a sol-like highly hygroscopic material.

An aqueous vinyl chloride resin emulsion having a concentration of 42% by weight was used as the water-soluble polymer emulsion. The dry weight of the vinyl chloride resin and the dry weight of the highly hygroscopic material were mixed so as to be equal in weight, and the mixture was stirred for 3 hours to obtain a uniformly dispersed sol.

The above sol mixture obtained by the wet method, a glass nonwoven fabric having a mass per unit area of 50 g / m ^2, dry weight of the high moisture-absorbing and desorbing material is impregnated such that the 18 g / m ^2, dew condensation preventing material was dried I got

(Example 2) Rayon fiber was applied to one side of the dew condensation preventing material obtained in Example 1.
25g / m of basis weight consisting of fiber 60% pulp fiber 40%^TwoStack of paper
And on the other side, Miku consisting of nylon taffeta and tefuran film
Rotex (Nitto Electric Industry Co., Ltd.) as a moisture permeable membrane
Laminated to form a dew condensation preventing material.

(Comparative example) Mixing only calcium chloride and polyvinyl alcohol,
Sol obtained by stirring, that is, not mixed MizuHanare soluble polymer, the dry weight of the sol-like material of high moisture sorption material only so that the 18 g / m ^2, obtained by the wet method the basis weight 50
g / m ² of glass nonwoven fabric was impregnated and dried to obtain a dew condensation preventing material.

The anti-condensation materials of Examples 1, 2 and Comparative Example were subjected to a humidity of 65%
, And the moisture absorption per 1 m ² after 1, ² , 3, 5, and 24 hours was measured.

 The results are as shown in Table 1.

As can be seen from these results, the anti-condensation material of the present invention hardly deteriorates in moisture absorption despite the use of a vinyl chloride resin as the water-soluble polymer. It can also be seen that the lamination of paper and a moisture permeable membrane on the substrate of the anti-condensation material of the present invention hardly reduces the moisture absorption performance.

Example 3 An aqueous vinyl chloride resin having a concentration of 42% by weight as a water-soluble polymer was mixed with the highly hygroscopic material obtained in the same manner as in Example 1. The mixing ratio was such that the dry weight of the vinyl chloride resin was 4 to 1 with respect to the dry weight of the highly hygroscopic material obtained as described above. This mixture was stirred for 3 hours to obtain a uniformly dispersed sol.

This mixture was obtained by a wet method. 50g / m ²
Was impregnated so that the content of the highly hygroscopic material was 18 g / m ^2, and dried to obtain a dew condensation preventing material.

Example 4 Example 3 was the same as Example 3 except that the mixing ratio was such that the dry weight of the vinyl chloride resin was 2: 1 with respect to the dry weight of the highly hygroscopic material. Similarly, a dew condensation preventing material was obtained.

65% and 80% humidity for the anti-condensation materials of Examples 1, 3 and 4.
, And the moisture absorption per 1 m ² after 1, ² , 3, 5, and 24 hours was measured.

 The results are shown in Table 2.

As can be seen from Table 2, it can be seen that the anti-condensation material of the present invention hardly affects the moisture absorption performance even when the amount of vinyl chloride changes.

Also, it can be seen that the moisture absorption changes sensitively according to the humidity.

[Effects of the Invention] Although the anti-condensation material of the present invention uses a water-soluble polymer, the hygroscopic power of high hygroscopicity hardly decreases.

In addition, the dew condensation preventing material of the present invention mainly adheres firmly to the substrate by the cohesive force of the water-soluble polymer, so that dimensional stability and strength when absorbing moisture are improved.

In addition, when using a porous fiber substrate as the substrate,
Various patterns can be produced depending on the entangled state of the constituent fibers, and the like, and the design is excellent.

Claims (4)

(57) [Claims] An anti-condensation method wherein a mixture of a water-soluble polymer and a highly absorbing and desorbing material in which metal ions are contained in a colloidal state in a water-soluble polymer is adhered to a substrate. Wood. 2. The anti-condensation material according to claim 1, wherein the water-soluble polymer is a vinyl chloride resin. 3. A dew condensation preventing material according to claim 1, wherein a moisture permeable film and / or paper is laminated on the dew condensation preventing material. 4. A method in which an aqueous emulsion of a water-soluble polymer is mixed with an aqueous solution in which a water-soluble polymer and a metal salt are dissolved in water, uniformly dispersed by stirring, and then adhered to a substrate and dried. A method for producing a dew condensation preventing material.