JP2874945B2 - 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.

[Related Art] Conventionally, dew condensation often occurs due to a difference in temperature between the outside air and a room, and as a result, mold may be generated, which is unsanitary and unsightly.

Therefore, conventionally, as a means for preventing the generation of mold, a device for preventing condensation has been devised. As a specific means, moisture is permeable but water cannot be removed to the outside of the room using a membrane or sheet that does not allow moisture to pass through, or water is absorbed using a superabsorbent polymer or a superabsorbent polymer. By absorbing water to prevent dew condensation.

For example, Japanese Patent Application Laid-Open No. 56-139957 discloses that a laminate of a polyvinyl alcohol-based synthetic resin film and a polyvinyl alcohol-based synthetic resin network absorbs moisture and transmits moisture, thereby preventing dew condensation. However, in such a laminate, since the portion in contact with air is a film, that is, a film, in addition to the small contact area with air, the moisture absorption rate of polyvinyl alcohol itself is small, so the moisture absorption rate is low, Dew condensation could not be completely prevented. Even if moisture is absorbed before dew condensation, since the film body and the mesh body as the reinforcing layer are made of polyvinyl alcohol, they have no strength and are difficult to use over a long period of time. Furthermore, in order to release moisture absorbed inside the house to the outside of the house, it is practically impossible to prevent condensation because the walls are not made of only the anti-condensation material. Was.

In Japanese Patent Application Laid-Open No. Sho 61-282465, a hydrophilic powder is sealed with a binder, and the hydrophilic powder is contained in a mineral fiber molded article. However, since the hydrophilic powder used here is sealed with a binder, the hydrophilic powder could not contact the outside air, it was difficult to absorb moisture, and it was impossible to prevent dew condensation.

In addition, a large number of dew condensation preventing materials using a water-absorbing polymer have been proposed, such as Japanese Patent Application Laid-Open No. Sho 62-231740. However, in each case, since a water-absorbing polymer is used, it absorbs water only in the state of water. In other words, it does not absorb water until it is in a water state, so in places with high humidity, it may not be able to completely absorb water due to the relationship between the speed of water absorption and the speed of condensation, and condensation may occur. Is crosslinked, so once it absorbs water, it is difficult for it to release moisture, so water accumulates one after another.It is impossible to accumulate moisture indefinitely, and at the same time, it swells by absorbing water. In addition, the dimensional stability of the wallpaper has deteriorated, and it has been difficult to use the wallpaper for a long period of time.

As described above, various anti-condensation materials have been proposed, but none of them actually exhibit the effect of preventing dew condensation over a long period of time. Was eagerly awaited.

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

[Means for Solving the Problems] A dew condensation preventing material in which a highly hygroscopic material in which a metal ion is contained in a polar polymer in a colloidal state is attached to a part or all of a porous fiber base material. Preferably, the polar polymer is a water-soluble polymer, and more preferably polyvinyl alcohol.

As a production method, it is preferable that the porous fiber substrate is impregnated with a highly hygroscopic material having a polar polymer in which metal ions are contained in a colloidal state, and then dried, followed by drying.

[Function] The porous fiber base material used for the dew condensation preventing material of the present invention may be made of any fiber, but the porous fiber base material has a high moisture absorption / release material in part or all. Is what it is. As the porous fiber base material, for example, a woven fabric, a knitted fabric, a nonwoven fabric, and the like can be used. Among them, the nonwoven fabric is the most preferable in terms of handling, workability, and the like. As the fiber used for the nonwoven fabric, it is preferable to use a flame-retardant inorganic fiber, a modacrylic fiber, a polyclar fiber, a flame-retardant polyester fiber, etc., since it is used as a wall material.

Also, general synthetic fibers, for example, polyester fibers,
Nylon fiber, polyolefin fiber, acrylic fiber or the like can be used, and is not particularly limited.
In this case, if a flame-retardant adhesive is used or a flame retardant is mixed, the nonwoven fabric can be made to have flame retardancy.

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 function of the porous fiber base material in the present invention is to increase the amount of moisture absorption and the rate of moisture absorption by increasing the contact area with air while retaining the highly moisture-absorbing and desorbing material. The conductive fiber substrate is not particularly limited, even though there are preferable conditions such as imparting flame retardancy and adding an antibacterial agent.

The highly hygroscopic material used in the present invention is a material in which a metal ion is contained in a polar polymer in a colloidal state.

The polar polymer in the highly moisture-absorbing and desorbing material includes not only a polymer having a polar group but also a polymer having an active portion with a high electron density due to an unsaturated bond or the like. As the polar group, a hydroxyl group (-OH),
Examples of a carbonyl group (—CO), an amino group (—NH ₂ ), an imino group (＝ NH), a cyano group (—CN), etc., which have an unsaturated bond and a high electron density include polybutadiene. Is mentioned.

The colloidal state means a state in which metal ions are dispersed in a polar polymer when a highly hygroscopic material is dissolved in a solvent. In this state, the absorption wavelength obtained from the absorbance analysis performed by dissolving the highly hygroscopic material in the solvent almost matches the absorption wavelength obtained from the absorbance analysis when the metal salt is simply dissolved in the solvent. You can check. When the highly hygroscopic material is dissolved in the solvent, 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 polar 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 a solvent. However, when the highly hygroscopic material of the present invention is dissolved in a solvent, it exhibits the same absorption wavelength as when the metal salt is simply dissolved in the solvent, so that the metal salt is simply dissolved in the solvent, that is, the metal ion Is in the same state as the colloidal state, and 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 a solvent again. The degree of dissolution of the highly hygroscopic material in the solvent is such that absorbance analysis can be performed, and differs depending on the metal salt, polar polymer, and the like used.

Since the highly moisture-absorbing and desorbing material of the present invention uses a polar polymer, it is easy for water to collect in the polar portion of the polymer, that is, a hydrogen atom having a low electron density of a water molecule is contained in a portion having a high electron density. This is because it is easily attracted electrostatically. Since the hydration power of the metal ions dispersed in the highly moisture-absorbing and desorbing material exceeds the electrostatic force, the collected water moves toward the metal ions and is firmly held by the metal ions, This metal ion is also firmly electrostatically held in the polar portion inside the polar polymer, so that it hardly sticks due to the absorbed moisture.

Conversely, if the humidity of the outside air drops or dries,
The vapor pressure of the outside air decreases, and the force due to the difference in vapor pressure is stronger than the hydration power of the metal ions, and the highly moisture-absorbing and desorbing material of the present invention tends to release moisture absorbed. That is, the water hydrated by the metal ions moves to a portion having the polarity of the polymer, contrary to the case of the moisture absorption, and is then 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 moisture has a weak interaction with the metal ions after reaching the saturated state, so that moisture is easily released.

In other words, the anti-condensation material using the high moisture absorption / release material of the present invention absorbs excess moisture, and when moisture absorption reaches a saturated state, repeats moisture absorption / desorption, resulting in an equilibrium state as if breathing. So there is no condensation. 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 moisture-absorbing and releasing material, that is, the type of the polar polymer constituting the highly absorbing and releasing material, the type of the metal ion, the mixed amount of the metal ion and the porous fiber base material. It can be adjusted by changing the amount of impregnation of the highly hygroscopic material into the material.

In addition, the highly moisture-absorbing and desorbing material of the present invention has excellent light resistance. This is a characteristic of chromophores because the polar polymer, another component of the highly hygroscopic material, is less affected by light energy because the metal colloid in the highly hygroscopic material absorbs and disperses light energy. This is because unsaturated bonds do not occur in the polar polymer.

Hereinafter, metal ions and polar polymers 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 other than the above-mentioned metal salts, and even other 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 higher moisture absorption / release properties are obtained as the mixing ratio of the metal salt to the polar polymer increases. Since the solubility of the metal salt in the solvent of the polar polymer decreases, the metal ions cannot be highly dispersed, and as a result, the contact area between the metal ions increases, and the hygroscopic action of the metal ions decreases, and conversely, However, the result may be that the hygroscopicity is deteriorated at an early 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 polar polymer, polyvinyl alcohol is dissolved in water used as a solvent, and a 10% aqueous solution is used. 20 mol% or more is required based on the hydroxyl group of the alcohol, and preferably 40 mol% or more is more preferably mixed. It should be noted that even if the mixing ratio of calcium chloride exceeds 100 mol%, the moisture absorption rate hardly changes, so 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, although the metal salt may be one kind, it is easy to adjust the hygroscopic ability of the highly hygroscopic material itself.
Two or more types may be mixed.

Examples of the polar polymer that can be used in the present invention include polyvinylamine, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylamide, polyvinyl acetate, polyethyleneimine, polyethylene glycol, polyvinylformal, polyacrylic acid, polybutadiene, polystyrene, and nylon 6.

Among them, water-soluble polyvinyl alcohol and polyvinylpyrrolidone can use water as a solvent, and since all of the above-mentioned metal salts are soluble in water, both the water-soluble polymer and the metal salt can be dissolved. Water can be used as a solvent that can be used, which is practically advantageous. Moreover,
Since there is a drying step in the production process of the present invention, when water is used as a solvent, it is particularly advantageous because danger such as toxicity and explosiveness is small and handling is easy.

In addition, since water is used not only in the manufacturing process but also as a wall material and does not generate an odor of an organic solvent during use, it is preferable to use water.

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 hygroscopic property of the hygroscopic material is excellent, it is preferable to select polyvinyl alcohol according to the purpose of use.

The solvent is selected depending on the combination of the polar polymer and the metal salt, but if water is used, the advantage in the production process is large as described above. In addition, as the solvent, in addition to water, chloroform, ethanol, carbon tetrachloride, acetone, water / ethanol, benzene, methanol, toluene, acetone / methanol, cyclohexane, and the like can be appropriately used.

An example of a method for producing a highly moisture-absorbing and desorbing material used in the present invention, which comprises the above-mentioned polar polymer and metal salt as components, is as follows.

Select the polar polymer and metal salt to be used.

A solvent that can dissolve both the selected polar polymer and metal salt is selected.

Dissolve the polar polymer in a solvent to make a 10% solution.

This solution is mixed with a metal salt and stirred at room temperature for 24 hours to obtain a viscous liquid.

The viscous high moisture absorption / desorption material thus obtained is impregnated into the above-mentioned porous fiber base material, applied, sprayed, etc.
By drying, a highly moisture-absorbing and releasing material may be attached to a part or the whole of the porous fiber base material.

In this state of attachment, the highly moisture-absorbing / desorbing material may be attached to intersections between individual fibers of the porous fiber base material, or to intersections of fibers and the fiber surface. Alternatively, the highly moisture-absorbing and desorbing material may be filled only on one surface portion of the porous fiber substrate, may be partially adhered, or may adhere over the entire pores of the porous fiber substrate. May be.

In order to prevent dew condensation and maintain a constant humidity by absorbing and releasing moisture as the object of the present invention, it is necessary that the material having high moisture absorption and desorption occupies at least 5% by weight of the dew condensation preventing material. 90% by weight or less is preferable from the viewpoint of shape retention of the preventive material, and more preferably 15% by weight to 70% by weight.

As a production method, if a method of impregnating a porous fiber base material with a highly moisture-absorbing and desorbing material and squeezing it with a mangle or the like is used, a wall material in which the highly moisture-absorbing and desorbing material is uniformly obtained is obtained. It is preferable because it does not move and becomes a beautiful wall material in appearance.

The drying step may be performed by a commonly used dryer or the like, and is not particularly limited.

The anti-condensation material obtained in this way has a high surface area and a large surface area as compared with a film or the like, because the high moisture absorption / release material is attached to a part or the whole of the porous fiber base material. In addition, the dimensional stability and strength are improved by the adhesive force of the polar polymer at the same time as the presence of the porous fiber substrate, so that the workability is greatly improved. Further, even if the material is actually used and absorbs moisture and contains moisture, it adheres firmly to the fiber, so that the material having high moisture absorption and release properties does not move downward against the gravity.

Furthermore, there is a problem in terms of aesthetics with only the material having high moisture absorption / release properties. However, if a porous fiber base material is used, various patterns can be produced depending on the blending of the constituent fibers and the entangled state.

This wall material may be used directly on the wall, but if a vinyl chloride layer is provided between the wall and the dew condensation preventing material, the vinyl chloride layer becomes a heat insulating layer that reduces the temperature difference between the outside air and the room. ,
Furthermore, if dew condensation hardly occurs, and if a vinyl chloride layer or a rayon paper layer is provided on the opposite side of the vinyl chloride layer of the dew condensation preventing material, the surface can be prevented from being stained by dust or the like as it is used over a long period of time. Can be done.

[Example] A basis weight obtained by a wet method as a porous fiber base material
A 100 g / m ² glass nonwoven fabric was used.

Calcium chloride with a degree of saponification of 9 as a highly hygroscopic material
7.0 to 98.5% of polyvinyl alcohol hydroxyl groups
What was obtained by mixing 0 mol% was used.

The glass nonwoven fabric is impregnated with a highly moisture-absorbing and desorbing material, and then dried to prevent three types of dew condensation prevention materials, including 7% by weight, 15% by weight and 30% by weight of the highly moisture-absorbing and desorbing material. Wood was obtained.

(Change in Moisture Absorption Depending on Impregnation Amount) With respect to these three types of dew condensation preventing materials, changes with time in the amount of moisture absorption under the condition of 65% humidity were examined. The results are shown in Table 1 and FIG. As can be seen from Table 1 and FIG. 1, the amount of moisture absorption can be changed by changing the amount of impregnation of the highly moisture-absorbing and desorbing material into the porous fiber base material. It can be seen that the desired dew condensation preventing material can be obtained by appropriately changing In addition, it can be seen that the humidity can be kept constant since the equilibrium moisture absorption is almost reached in about one hour.

(Change in moisture absorption due to change in humidity) These three types of dew condensation preventing materials were left in a room at a humidity of 80% for 5 hours. As a result, 15.7g /
m ^2, 15% impregnated dew condensation preventing material of 39.3g / m ^2, 30% impregnated dew condensation preventing material showed moisture absorption of 77.5 g / m ^2.

From this result and the result of (the change in the amount of moisture absorption depending on the amount of impregnation), it can be seen that even with the same dew condensation preventing material, it can respond more sensitively to humidity.

(Lightfastness test) The anti-condensation material impregnated with 30% of a highly moisture-absorbing and desorbing material was examined for lightfastness according to a fading test defined in JIS A-6921. As a result, it was determined by visual inspection that it was a fifth class in which little change was observed from before the test.

As described above, the dew condensation preventing material of the present invention has excellent light resistance.

(Comparative Example) A film-shaped material was obtained by applying the same highly moisture-absorbing and desorbing material as described above to a glass plate without impregnating the fiber, and drying.

The time-dependent change in the moisture absorption rate of a film of the moisture-absorbing / desorbing material having a moisture-absorbing / desorbing material content ratio of 15% by weight and the humidity-absorbing / desorbing material of 45% was examined.

The results are shown in Table 2 and FIG. As can be seen from Table 2 and FIG. 2, since the dew condensation preventing material of the present invention has a material having high moisture absorption and desorption on the fiber surface, the contact area of the material with high moisture absorption and desorption is large. It can be seen that both the rate of moisture absorption and the amount of moisture absorption are far superior to the high moisture absorbing / releasing material in the film state.

[Effect of the Invention] Since the highly moisture-absorbing and desorbing material is attached to part or all of the porous fiber base material of the dew condensation preventing material of the present invention, the contact area of the highly moisture-absorbing and desorbing material with air is increased. Therefore, since the amount of moisture absorption is large and the rate of moisture absorption is high, dew condensation does not occur. In addition, there is an effect that the dimensional stability, strength, shape retention of the wall material, and the design are also excellent.

Since the anti-condensation material of the present invention uses a highly moisture-absorbing and desorbing material as its component, in addition to being excellent in both moisture absorption rate and moisture absorption, it responds sensitively to changes in humidity and has a saturated state. Is reached, the moisture absorption and the moisture release are in an equilibrium state, that is, in a breathing state, so that dew condensation does not occur and the humidity can be kept constant.

In addition, since the highly moisture-absorbing and desorbing material contains metal ions, light energy is easily absorbed by the metal ions and has little effect on the polar polymer. In addition, there is no problem that the appearance is spoiled.

When the polar polymer is water-soluble, it is easy to handle and safe in the process of manufacturing a highly moisture-absorbing and releasing material,
There is no danger of producing bad odor during use.

The method for producing a dew condensation preventive material of the present invention is a rational production method that can be easily produced because it comprises a step of simply impregnating a porous fiber base material with a highly moisture-absorbing and releasing material and drying it.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the amount of moisture absorption and the change with time due to a change in the content of the highly hygroscopic material at a humidity of 65%. FIG. 2 is a graph showing a relationship between a moisture absorption rate per unit weight and a change with time in a case where a fiber is impregnated with a material having a high moisture absorption / release property and in a case of a film.

Claims (4)

(57) [Claims] An anti-condensation material characterized in that a highly moisture-absorbing and desorbing material in which a polar polymer contains metal ions in a colloidal state is attached to a part or the whole of a porous fiber base material. 2. The dew condensation preventing material according to claim 1, wherein the polar polymer is a water-soluble polymer. 3. The anti-condensation material according to claim 1, wherein the polar polymer is polyvinyl alcohol. 4. An anti-condensation material produced by impregnating a porous fiber base material with a highly hygroscopic material having a polar polymer in which metal ions are contained in a colloidal state, followed by drying. Manufacturing method.