JPS62286519A - Sheet-shaped humidity conditioning material - Google Patents

Abstract

PURPOSE:To prevent loss in molding and enhance production efficiency and strength of sheet by laminating a humidity conditioning composite comprising saponified vinyl acetate - unsaturated carboxylic acid copolymer, deliquescent substance, and paper or non-woven cloth into a sheet. CONSTITUTION:Copolymer comprising 50-99.8mol% of vinyl acetate such as saponified monomethyl maleate vinyl acetate copolymer or the like and 50-0.2mol% of unsaturated carboxylic acid and containing more than 70mol% of saponified vinyl acetate component is mixed and kneaded in water solution of deliquescent substance such as calcium chloride or the like, and the solution is cast and dried on a non-woven cloth to prepare a sheet-shaped humidity conditioning material. When this sheet-shaped humidity conditioning material is used as dehumidifying agent, the same is put on a place to be sufficiently dried and dehumidified, and when used as humidity conditioning agent, water, corresponding to the humidity to be controlled and equivalent to equilibrium moisture content of the sheet-shaped humidifying conditioning agent at the relative humidity of atmosphere to be controlled, is impregnated in the humidity conditioning agent beforehand.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Industrial Application Field 1 The present invention is used as a dehumidifier (desiccant) to absorb moisture in the environment, and as a dehumidifier (desiccant) to maintain appropriate humidity. The present invention relates to a sheet-like humidity control material that is useful for so-called humidity control applications (hereinafter, in this application, such usage may be collectively referred to as humidity control).

[Prior art 1] Conventionally, materials used for the above-mentioned dehumidification or general humidity adjustment purposes include deliquescent salts such as calcium chloride and magnesium chloride, silica gel, and water-absorbing resins. For example, desiccant As for special public service 1986-285
No. 31, JP-A-59-225737, and JP-A-60
JP-A-48142, and JP-A-57-27176 and JP-A-58-65, which are used for humidity adjustment.
There have been many reports such as No. 075 and No. 59-9051. Among the above, JP-A-59-225737 and JP-A-60-48142 are related to applications filed by the present applicant, and they function very usefully as desiccant agents. In particular, according to recent studies, a composition consisting of deliquescent salts, which are the main components of the desiccant, a saponified copolymer having a specific composition, and a short fibrous material has not only a drying function but also a drying function.
It was found that it also has extremely excellent moisture absorption and dehumidification functions, and it was found that a wider range of applications can be expected.

[Problems to be Solved by the Invention] However, as the present inventors continued their research, they found that
Although it is advantageous for the composition described in Publication No. 2 to be molded into a sheet form from the viewpoint of handling, it has been found that the following problems arise during molding. That is, (1) the composition tends to adhere to the metal surface of a forming machine such as a roll when forming into a sheet, and sheet breakage occurs due to this property;
In order to avoid problems such as cracks, the molding speed must be reduced, resulting in poor production efficiency. Furthermore, even if such careful molding conditions are adopted, there is a large amount of loss, which is disadvantageous from an economical point of view.

■ Once it is formed into a sheet, it is difficult to roll it up neatly, and the finish of the final product is poor! ), which has a drawback that reduces product value.

■ Sheet strength is not sufficient.

■ Roughness and fluffing of the sheet surface was observed, and the feel was not good.

etc.

[Means for Solving the Problems] The present inventors conducted research on a sheet-like humidity control material that maintains the excellent humidity control ability as described above and does not have the above drawbacks. As a result, (A) a copolymer in which 70 mol% or more of the vinyl acetate component of a copolymer consisting of vinegar fl & vinyl 50 to 99.8 mol% and unsaturated carboxylic acid 50 to 0.2 mol% has been saponified. A sheet material formed by laminating a humidity control composition (X) consisting of a saponified substance and (B) a deliquescent substance and paper or a nonwoven fabric (Y) meets the above objectives, and as a result of adopting a laminated structure, Since sufficient voids can be secured on the surface of the dampening agent compared to conventional methods, an additional effect that was not expected at all, such as further improvement in moisture formation and drainage efficiency, has been observed. The present invention was completed based on the novel fact that when a composition (X') containing an IIL fibrous substance is used, a sheet-like humidity control agent with even better humidity control function and strength is obtained.

Composition (X) or (X゛) in the present invention is the following (
It consists of A), (, B), and (C), and (A)
and (B) act synergistically, and the excellent humidity control performance of the present invention is exhibited for the first time, and a product lacking even this component cannot be used for practical use on the side sole.

As component (A), vinyl acetate is 50 to 99.8 mol%.
It is necessary that unsaturated carboxylic acid is copolymerized at a ratio of 50 to 0.2 mol %, and that 70 mol % or more of the vinyl acetate component is saponified. Outside this range, there is a problem in that the humidity control ability decreases. Among these conditions, vinyl acetate 80 to 99.8 is more preferable.
A saponified copolymer having an unsaturated dicarboxylic acid of 20 to 0.2 mol % and a degree of saponification of 70 mol % or more has even better performance.

Examples of unsaturated carboxylic acids include monocarboxylic acids such as (meth)acrylic acid and crotonic acid, preferably (anhydrous) maleic acid, fumaric acid, itafonic acid, glutaconic acid, allylmalonic acid, and their methyl, ethyl, and propyl esters. Examples include monoesters and diesters.

Furthermore, if the amount is small, there is no problem in copolymerizing the copolymerizable monomer.

Such a saponified copolymer is obtained by subjecting vinyl acetate and an unsaturated carboxylic acid to ordinary solution polymerization to form a copolymer in the above-mentioned ratio, and then treating the resulting copolymer with an alkali catalyst such as caustic soda or sodium methylate It is manufactured by saponifying to a predetermined ratio using Such a saponified copolymer is further imparted with even better properties by heat treatment. Generally, heat treatment is performed at a temperature of 110 to 200'C for 1 to 360 minutes in air or inert gas atmosphere.

The obtained resin is a powder, but those with an appropriate particle size are selected and ground to an appropriate particle size for practical use.

Deliquescent salts as component (B) include not only calcium chloride alone, but also various salts containing crystal water such as its dihydrate, tetrahydrate, and hexahydrate salts, magnesium chloride, lithium chloride, etc. Among them, chloride Calcium is more practical in terms of both performance and cost.

The short fibrous materials of component (C) include rayon staple cut products, natural fiber cut products such as wool and cotton, nylon,
polyester, polyvinyl chloride, polyvinylidene chloride,
Any material can be used, such as synthetic fiber cut products such as polyolefin and vinylon, pulp powder, glass A fiber, ceramic fiber, 100m fiber cut products, metal fiber cut products such as iron and copper, and animal hair cut products. . The short fibers have a diameter of 0.1
~0.002 mm and a length of about 15-0.05 mm are preferably used.

The weight ratio of component (A)/component (B) is 9/1 to 1/9,
Preferably, they are mixed at a ratio of 7/3 to 1/9. If the ratio of both components is more than 9/1, the deliquescent liquid may temporarily separate, and if it is less than 1/9, the humidity control ability tends to be insufficient at low temperatures and high humidity. Therefore, an appropriate ratio should be selected from the above range.6 Also, the mixing ratio of component (C) is [(A>+(B)]/(C
) is 19/1 to 1/19 in weight ratio, preferably 19/1
~9/11 is advantageous. Anything outside this range is undesirable because it results in a decrease in humidity control ability.

There are various methods for mixing component (A), (BafL and (C)) together, and impregnating the powder of component (A) and component (C) with an aqueous solution of component (B). Mix with

In the present invention, the humidity control composition (X) obtained as described above
Or, laminating (X゛) and paper or nonwoven fabric (Y) is a vf feature. In order to obtain such a laminated composition, the composition (X) or (X゛) is formed into a sheet shape in advance and then laminated using any means such as a water-resistant adhesive, so-called dry lamination. However, an extrusion lamination method is used in which a flat gooey material is extruded into a sheet and paper or nonwoven fabric is pressed while the sheet is in a molten state.

To explain specifically, when trying to obtain the simplest two-layer sheet, paper or nonwoven fabric (Y) (hereinafter referred to as the base material) is moved by a roll or belt, etc., and the above-mentioned After uniformly extruding or casting a melt of composition (X) or (X゛) (a composition obtained by melting the composition by heating or a highly concentrated aqueous solution by adding an appropriate amount of water) , often dried at 80-160°C. In this case, it is preferable to mix binder such as polyvinyl alcohol or starch into the melt of composition (X) or (X゛) as necessary to further strengthen the adhesion to the substrate.
When the composition (X) or (X゛) is interposed between the base materials to form a three-layer composition, the above-mentioned two-layer structure is left behind, and then another base material is attached. Nails are fine, but
The following method is adopted in terms of production efficiency. That is, as shown in FIG. 1, using a pair of laminating rolls, one of the substrates is moved by roll 1 and the other by roll 1', while the same composition (X) or The melt (X゛) is extruded or cast between the upper base materials. This three-layer structure best incorporates the features of the present invention in terms of product ease of handling and good appearance. Of course, it goes without saying that the structure is not limited to only three layers, and any structure basically having such a structure is within the scope of the present invention.

In the above laminated structure, the base material and the composition (X) or (X
The thickness of each layer in (2) can be arbitrarily adopted, but the thickness of the base material is usually 0,
05-0.2+I1m, more preferably 0.1-0.
I Snu++, composition (X) or (X゛) is 0.5-
It is often set to 15 mm and 0.8-10 mm.

In the present invention, in addition to the basic laminated structure as described above, building materials such as plywood, veneer, slate, mortar, plasterboard, metal plates, metal foil, glass, cardboard, plastic films, sheets, etc. Any of the above materials may be laminated with plate-like or sheet-like materials (which may be micro- or macro-porous). That is, in the sheet-like humidity control material of the present invention, paper or nonwoven fabric (Y) is laminated on at least one side of the humidity control composition (X) or (X゛), so the above-mentioned plate is placed on either side of the paper or nonwoven fabric (Y). Even if shaped or sheet-like materials are laminated, the moisture absorption and drainage functions will not deteriorate due to the sufficient voids of (Y). Taking advantage of such characteristics, the sheet-like humidity control material of the present invention can be used in the form of being attached to walls, ceilings, floors, etc. made of concrete, pond materials, etc. by an appropriate method.

As described above, the sheet-like humidity control material of the present invention thus obtained has both the conventional functions of a dehumidifier and a humidity regulator, and therefore can be used for any purpose.

First, when using it as a dehumidifier, thoroughly dry the obtained sheet-like humidity control material (usually by exposing it to direct sunlight or
It is sufficient to dry it at 30°C for about 4 to 1 hour) and then install it in the environment where you want to dehumidify. Since the humidity control material has high moisture absorption power and capacity, it can be used for a considerable period of time, and even after use, if it is subjected to the drying treatment described above, it can be used again. The humidity control material of the present invention is excellent even after such repeated use.

Next, when using the humidity control material as a humidity control agent, it is important to impregnate the humidity control material with water in advance according to the desired humidity. That is, the sheet-like humidity control material is impregnated in advance with an amount of water corresponding to the equilibrium water content of the sheet-like humidity control material at the relative humidity of the atmosphere to be humidity-controlled. Secondly, the amount corresponding to the equilibrium moisture content of the sheet-like moisture control material is not necessarily limited to a certain amount, but the amount corresponding to the equilibrium moisture content ±
A variation of about 5% is within an acceptable range. For example, the relative humidity of the atmosphere to be controlled is 50%.
For example, if you want to maintain relative humidity at 50
The (sheet) is impregnated with water in an amount corresponding to the equilibrium moisture content of the sheet-like humidity control material in %. This water-impregnated humidity control material is applied to the target atmosphere, and the target atmosphere is usually set to the target humidity, that is, 50% relative humidity. This has the advantage that the humidity of the atmosphere will not change at all from the beginning of the application of the humidity control material. Of course, it is not always necessary to adjust the humidity of the target atmosphere to the target value from the beginning; the moisture content in the humidity control agent can be controlled to the humidity of the atmosphere at the initial stage of application by appropriately varying the moisture content in the humidity control material. The humidity control function may be exerted from the time when the relative humidity of the atmosphere almost matches the equilibrium moisture content in the relative humidity of the atmosphere. For example, when raising a dry atmosphere to a target humidity and then maintaining that value, methods such as adding the amount of water necessary to humidify the atmosphere to a humidity control material are adopted. .

Even if the amount of water impregnated into the humidity control material in the present invention corresponds to the equilibrium moisture content, there is a natural limit to its value, and in order to exhibit the humidity control ability, composition (X) Or, it is necessary to impregnate 0.5 times or more the amount of deliquescent salt (B) in (X゛), and if the amount is less than this amount, good moisture absorption/drainage function cannot be exhibited. Furthermore, the sheet itself cannot hold water approximately three times the weight of the composition (X) or (X'), so it cannot be used. Under these circumstances, the humidity control function of the humidity control material of the present invention is best exhibited when the relative humidity is maintained at a desired value between 30 and 95%, particularly preferably between 40 and 85%. This is the case. The impregnation method is not particularly limited, and may be a repeated process of directly contacting liquid water and easily removing the water, but in normal cases, the pre-dried composition sheet-shaped humidity control material is heated to a target relative humidity. It is sufficient to leave it in a set atmosphere, and when the weight of the humidity control material stops increasing, it can be determined that water corresponding to the equilibrium moisture content has been impregnated.

The sheet-like humidity control material thus obtained can be used in any place where humidity control is required, for example, in household storerooms, closets, chests of drawers, etc., and in packages for precision equipment, electronic parts, etc. However, places where the characteristics of the humidity control material of the present invention can be maximized are places with higher airtightness, such as display cases in museums, department stores, etc., storage cases for musical instruments, etc., containers used during food transportation, etc. Examples include storage warehouses, etc., and a unique way of using it is as a building material for walls, floors, ceilings, etc. of buildings, and it can be used to prevent condensation. Furthermore, by using it in conjunction with an air conditioner, it can be used economically in constant temperature rooms, clean rooms, etc. The humidity control material to be used varies depending on the environment of the place where the humidity is to be controlled.
Usually, about 50 to 500 g of composition (X) is used per 11, ie, in terms of solid content, and if necessary, it may be impregnated with the necessary amount of water as described above.

[Function 1] As described above, the sheet-shaped humidity control material of the present invention has excellent dehumidification and humidity control abilities, and in particular, has a quick humidity control action that is extremely adaptable to humidity changes over a wide range. It is very useful in showing the

[Example 1] Hereinafter, the sheet-like humidity control material of the present invention will be described in more detail with reference to Examples. In the examples, "parts" or "%" are based on weight unless otherwise specified.

Examples The following (A) saponified copolymer, (B) deliquescent salts, (C
) A short fibrous substance was prepared.

(A-1) Saponified monomethyl mayaate-vinyl acetate copolymer powder (295μ or less) with Illll vinyl 96.1 mol%, monomethyl maleate II 3.9 mol%, saponification degree of vinyl acetate component 98.1 mol% (A-2) [
1 vinyl content i9o mol%, monomethyl maleate ttx
saponified monomethyl maleate-vinyl acetate copolymer powder with a degree of saponification of vinyl acetate of 96 mol% (
(350 μ or less) (B) Calcium chloride dihydrate powder (C) Stable cut rayon product (diameter 0.1-0.05 m+o, length 1-1.5 mm
) A sheet-like humidity control material was obtained using these materials by the following process.

[Example 1 of composition (X) - Using (A-1) or A-2) and (B) 64.5 parts of (B) in 100 parts of a 10% aqueous solution of polyvinyl alcohol
(A-1) or (A-2) in a solution containing 16 parts of (A-1) or (A-2)
The mixture was thoroughly kneaded, and the solution was cast onto a nonwoven fabric (thickness: 2.7 mm) moving at a speed of 180 ca+/min to a solid content of 0.1 g/cI112. After that, the composition (X) was dried on the nonwoven fabric by drying 90'CX for 60 minutes.
A laminated two-layer sheet humidity control material (thickness approx. 311 mm)
II11) was obtained. This humidity control material will be referred to as "sheet 1".

On the other hand, a nonwoven fabric (
2 sheets), and nonwoven fabric/composition (×)/nonwoven fabric (=0
,1a+a+/1,8 mm/0,1 mm)
A sheet-like humidity control material with a two-layer structure having the composition was obtained. This base material will be referred to as "sheet 2".

(Example 1 of composition (X゛) ・<A-1) or using (A-2) and (B) and (C) In the example using composition (X), (B) 431fl
! 10% solution of polyvinyl alcohol dissolved in total 14
3 parts, 10 parts of (A-1> or (A-2), and 37 parts of (C)) were mixed in the same manner to prepare a sheet of two-layer or three-layer groove 1 (thickness is the same as before). The wet materials were obtained.The two-layered Sheet F was called "Sheet 3", and the three-layered sheet was called "Sheet 4".
”.

In the manufacturing process of the above-mentioned laminated sheets, there were no manufacturing problems such as adhesion of humidity control composition (X) or (X゛) to the rolls or adhesion of sheets to each other after winding up after lamination. The sheet was manufactured very efficiently, and the sheet was very easy to handle.

In addition, "Sheet 1" and "Sheet 2" are "Sheet 3" in terms of strength.
Although it was inferior to "Sheet 4", it had sufficient strength for practical use, and the performance of the pond was comparable to that of Izuki.

“Sheet 1” to “Sheet 4 and 4” obtained as above
The following experiment was conducted using

(Dehumidification ability) After leaving the obtained sheet in a large oven for about 5 hours to dry it thoroughly, it was left in an atmosphere of 20'CX 90% RH for 30 hours, and the moisture absorption rate (water Increase t(
g)/C) (g)X100 (%)) was measured. Thereafter, the sheet was dried again in the same manner and subjected to dehumidification. The bilayer was repeated 15 times.

Record the results in the table.

(Humidity control ability) The pre-dried sheet was left in a 20'CX60%RH1:humidity conditioned atmosphere for 24 hours to impregnate the sheet with water in an amount corresponding to the equilibrium moisture content.

The air volume ratio (
Paste so that the end 1) is 3.3 and 0.8, and change the temperature inside the box from 20°C → 35°C → 25°C → 35°C → 2
The temperature was changed to 5"C every 2 hours. The relative humidity range (book 2) at this time was investigated.

Similar experiments were conducted with the initially set relative humidity and the equilibrium moisture content of the sheet at 30% and 80%.

The results are summarized in a table.

(Thursday 1) Air volume ratio 2 Ratio of the absolute value of the surface area (m2) of the sheet used to the absolute value of the volume of the box (Ill) (Thursday 2) Relative humidity range: Relative humidity when the humidity is changed over time The relative humidity was measured for 10 hours, and the deviation (highest value and lowest value) of the actual measured value from the initially set relative humidity was expressed as a percentage.Furthermore, the following experiment was conducted using the above-mentioned Sheet 4.

3, 3 m (vertical) x 3, 3 m (horizontal) x 3.06
Plywood (121nI11 thickness) / Styrofoam (50mm) / Polyethylene sheet (100μ) /
A humidity control material laminated in the order of sheet 4 (2 mm) was installed.

Note that the sheet 4 used was one whose moisture content was adjusted to 60%.

The area of the humidity control material is 22.1 m2, and the air volume ratio is 1.1.

Under these conditions, the outside temperature of the building is 20℃ x 24 hours → 1
The change in relative humidity inside the building was measured by repeating the change 0'CX for 24 hours 10 times.

As a result, the relative humidity change was 65%±3%RH, which was very excellent.

[Effect 1] As described above, the sheet-like humidity control material of the present invention maintains excellent dehumidification and humidity control functions while eliminating the drawbacks of conventional manufacturing, and is very useful industrially.

[Brief explanation of drawings]

Figure 1 shows the sheet-like humidity control material of the present invention, in which the base material (Y)
(Secondary or non-woven fabric)/humidity conditioner composition (x)/base material (Y)
This figure shows the equipment used when adopting the laminated structure of 1゜1゛, 212゛ is the base material (Y), 3 is (
14 wetting agent composition (X) in molten form, 4 the composition (X)
and 5 indicate the sheet-like humidity control material in a laminated state. (Leaving space below) Figure 1 Procedural amendment September 1, 1988 1. Indication of the case Patent application No. 128911 of 1988 2. Name of the invention Sheet-like damp material 3. Person making the amendment Relationship to the case Patent Applicant address: 9-6 Nozaki-cho, Kita-ku, Osaka (zip code 530)
4. Detailed explanation of the invention subject to amendment

Claims (1)

[Claims] 1. (A) 70 mol% or more of the vinyl acetate component of a copolymer consisting of 50 to 99.8 mol% vinyl acetate and 50 to 0.2 mol% of an unsaturated carboxylic acid is saponified. A sheet-like humidity control material formed by laminating a humidity control composition (X) comprising a saponified copolymer consisting of a saponified copolymer and (B) a deliquescent substance, and a paper or nonwoven fabric (Y). 2. The sheet-like humidity control material according to claim 1, wherein the humidity control material is impregnated with water in advance. 3. The sheet-like humidity control material according to claim 1, which is formed by further laminating a plate-like or sheet-like material on the laminate of the humidity control composition (X) and paper or nonwoven fabric (Y). 4. (A) A copolymer ken made by saponifying 70 mol% or more of the vinyl acetate component of a copolymer consisting of 50-99.8 mol% vinyl acetate and 50-0.2 mol% unsaturated carboxylic acid. A sheet-like humidity control material formed by laminating a humidity control composition (X') comprising a compound (B) a deliquescent substance and (C) a short fibrous substance and paper or nonwoven fabric (Y). 5. The sheet-like humidity control material according to claim 4, wherein the humidity control material is impregnated with water in advance. 6. A sheet-like humidity control material according to claim 4, which is formed by further laminating a plate-like or sheet-like material on the laminate of the humidity control composition (X') and paper or nonwoven fabric (Y).