JPS63185430A - Humidity conditioning sheet-like material - Google Patents

Abstract

PURPOSE:To enhance the dehumidifying and humidity conditioning function of the title material and to eliminate the stickiness after moisture absorption by treating the laminate of the humidity conditioning composition consisting of specified copolymeric saponified material and deliquescent substance and paper or nonwoven fabric with boric acid or borax. CONSTITUTION:The copolymeric saponified material consisting of 50-99.8mol.% vinyl acetate and 50-0.2mol.% unsaturated carboxylic acid and wherein >=70mol.% vinyl acetate component is saponified and the deliquescent substance are mixed to obtain the humidity conditioning composition. The laminate of the composition and paper or nonwoven fabric is treated with boric acid or borax to produce the sheet humidity conditioning material. In addition, the material obtained by incorporating a staple substance or perlite into the composition can be appropriately used. Calcium chloride alone, the dihydrate, magnesium chloride, lithium chloride, etc., can be exemplified as the deliquescent substance.

Description

[Detailed description of the invention]

[Industrial Application Field 1] The present invention is applicable to use as a dehumidifier (desiccant) to absorb moisture in the environment, and as a so-called humidity control agent to maintain appropriate humidity (hereinafter referred to as "desiccant" in this application). This paper relates to a sheet-like humidity control material that is useful for various uses (sometimes 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-6048142 are related to applications filed by the present applicant, and they function very usefully as desiccant agents. In particular, according to recent studies, m-degradable salts forming the main components of the desiccant and saponified copolymers having specific 11 components,
Furthermore, it has been found that the composition made of short fibers has not only a drying function but also an extremely excellent tactile absorption and dehumidification function, and it has been found that a wider range of applications can be expected. However, as the present inventors continued their research, they found that
Although the composition described in Publication No. 2 is advantageous in terms of handling because it can be molded into a sheet, it has been found that the following problems occur during molding. That is, ■ When forming into a sheet, the composition tends to adhere to the metal surfaces of the forming machine such as rolls, and in order to avoid problems such as sheet breakage and cracking that occur due to this property, forming The 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. (1) Once formed into a sheet, it is difficult to roll it up neatly (I), and the final product has a poor finish, which reduces its commercial value. ■ The strength of the sheet is not sufficient. ■ Roughness and fluffing of the sheet surface was observed, and the feel was not good. etc. [Problems to be Solved by the Present Invention] Therefore, the present inventors have conducted research on a sheet-like humidity control material that retains the above-mentioned excellent functions and does not have the above-mentioned drawbacks. (A) A saponified copolymer obtained by saponifying 70 mol% or more of the vinyl acetate component of a copolymer consisting of 50 to 99.8 mol% of vinyl acetate and 50 to 0.2 mol% of an unsaturated carboxylic acid. and (B) a sheet-like material formed by laminating a humidity control composition (X) made of a deliquescent substance and paper or a non-woven fabric (Y) meets the above objectives, and as a result of adopting a laminated structure, it is a humidity control agent. Since sufficient voids can be secured on the surface of the moisture control composition (x), an entirely unexpected additional effect of further improving moisture formation and moisture drainage efficiency has been observed. We have discovered a new fact that when using the composition (X゛) containing the above-mentioned substance, it becomes a sheet-like humidity control material with even better humidity control function and strength, and we have previously applied for a patent. It was found that humidity control materials tend to become sticky on the surface when they absorb moisture, and improvements in this problem are desired. Means for Solving the L Problem 1 However, as a result of extensive research, the present inventors found that <A) 50 to 99.8 mol% of vinyl acetate, 50 to 99.8 mol% of unsaturated carboxylic acid.
A saponified copolymer obtained by saponifying 70 mol% or more of the vinyl acetate component of the copolymer consisting of ~(), 2 mol% I), and (B) a deliquescent substance, preferably further (C) a short A sheet-like humidity control material characterized in that a structure formed by laminating a humidity control composition made of a fibrous substance or perlite and paper or nonwoven fabric is treated with boric acid or borax. He discovered that the object could be achieved, and completed the present invention. Composition (X) or (X゛) in the present invention is the following (
It is composed of A), (B), and (C), and 1), when (A) and (B) act synergistically, the excellent humidity control performance of the present invention is exhibited for the first time. Therefore, it is impossible to put it into practical use without even this component. 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, hepmaric acid, itaconic acid, glutafonic acid, allylmalonic acid, and their methyl, ethyl, and propyl esters. Examples include monoesters and diesters such as. 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 having the above-mentioned ratio, and then adding the resulting copolymer to caustic soda, Na) +7
It is produced by saponifying it to a predetermined ratio using an alkaline catalyst such as um methylate. Such a saponified copolymer can be imparted with even better performance by further heat treatment. Generally, heat treatment is carried out in air or inert gas atmosphere at a temperature of 110 to 200°C for 1 to 360 minutes. 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 stable cuff), wool, cotton, and other natural materials. fiber-cut products, synthetic materials such as nylon, polyester, polyvinyl chloride, polyvinylidene chloride, polyolefin, vinylon, etc.;
Any materials such as Asahi pulp powder, glass fibers, ceramic fibers, cut asbestos fibers, metal fibers such as iron and copper fibers, and hair-cut products can be used. The short fibers have a diameter of about 0.1 to 0.002+n+++ and a length of 15 to 0.0
A diameter of about 5 mm is preferably used. Alternatively, pearlite having a particle size of about 1,000 to 3,000 microns is practical. 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, but if the ratio is less than 1/9, the humidity control ability tends to be insufficient at low temperatures and high humidity, so depending on the purpose. An appropriate ratio should be selected from the above range. Also, the mixing ratio of component (C) is [(A)+(B)]/
(C) is 19/1 to 1/19 in weight ratio, preferably 19
/1 to 9/11 is advantageous. Any value r outside this range is undesirable because it results in a decrease in humidity control ability. Component (A), component (B), and component (C) are mixed together as powders, and an aqueous solution of component (B) is mixed with component (A) and (C) r&. It can be mixed in various ways, such as by impregnating it into powder. In the present invention, the humidity control composition (X) obtained as described above
The feature is that (X') and paper or nonwoven fabric (Y) are laminated. In order to obtain such a laminated composition, the composition (X) or (X゛) is previously formed into a sheet shape and then laminated using any means such as a water-resistant adhesive.
Although so-called dry lamination is also possible, an extrusion lamination method is used in which the sheet is extruded from a flat die and paper or nonwoven fabric is pressed while the sheet is in a molten state. Specifically, when trying to obtain the simplest two-layer sheet, paper or nonwoven fabric (Y) (hereinafter referred to as the base material) is moved on a roll or belt, and the above composition is applied onto it. After uniformly extruding or casting a melt of product (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), It is often dried at 80-160°C. in this case,
It is desirable to mix a binder such as polyvinyl alcohol or starch into the melt of composition (X) or (X゛), if 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 manufactured, and then another base material is attached. There is no difference in the count, 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 was moved to roll 1, and the same composition (X) or The molten material (X゛) is extruded or cast upward between the two store members. Such a three-layer structure best incorporates the features of the present invention in terms of ease of product 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 of
), 05-0.2+am, more preferably (1,1-
Q, 15++u+, composition (X) or (X゛) is 0.
515+am, 0.8-1 t')mm. Next, the laminated structure is treated with boric acid or borax. The treatment is carried out by immersing the structure in an aqueous or organic solvent solution of boric acid or borax, or by spraying the solution. Further, in the present invention, the composition is not necessarily limited to the above, and a portion of boric acid or borax may be mixed into the compositions (A), (B), and (C). The content of boric acid or borax is from 0.1 to the weight of the structure
Processing is carried out so that it is approximately 5%. The pH of the treatment liquid is preferably slightly alkaline at 7 or higher. After the treatment is completed, dry according to the usual method. Furthermore, although this treatment is somewhat effective for powdered dehumidifiers made of the compositions (A) and (B) or the compositions (A), (B), and (C), it cannot be applied to sheet-like dehumidifiers. It is more effective. In the present invention, in addition to the basic laminated structure as described above, building materials such as plywood, veneer, slate, mortar, gypsum board, metal plate, metal foil, plastinum, corrugated cardboard, plastin film, sheet, etc. (Any of the above may be micro- or macro-porous) plate-like or sheet-like materials may be laminated. 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 that the above-mentioned plate-like or sheet Even if the 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 do not expose it to direct sunlight).
It is sufficient to dry it at 130° C. for 4 to 1 hour) and then install it in the environment where you want to dehumidify. Since the humidity control material has a high moisture absorption power and a high moisture absorption capacity, it can be used for a considerable period of time, and if it is subjected to the drying treatment after use, 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 moisture content of the sheet-like humidity control material at the relative humidity of the atmosphere to be humidity-controlled. Here, the amount corresponding to the equilibrium moisture content of the sheet-like moisture control material is not necessarily limited to a fixed amount, and a variation of about ±5% of the corresponding equilibrium moisture content is within an allowable range. For example, the relative humidity of the atmosphere to be controlled is 50.
For example, if you want to maintain relative humidity at 5%
The moisture control material 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. The following two advantages are obtained: 1) The humidity of the atmosphere does not change at all from the initial stage of 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, but it is necessary to adjust the moisture content of the humidity control material to the target value at the initial stage of application by appropriately changing the moisture content of the humidity control material. The humidity control function may be exerted from the time when the moisture content substantially 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. . In the present invention, even if the amount of water impregnated into the humidity control material corresponds to the equilibrium moisture content, there is a natural limit to that value, and in order to exhibit the humidity control ability, composition (X) or (
It is necessary to impregnate at least 0.5 times the amount of deliquescent salt (B) in
Unable to perform moisture drainage function. Also composition (X) or (X゛)
It cannot be used because the sheet itself cannot hold water more than three times its weight. Under these circumstances, the humidity control function of the humidity control material of the present invention is best exhibited by maintaining the humidity 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 it may be impregnated at any time by directly contacting liquid water and easily draining the water, but in normal cases, the relative humidity of the pre-dried composition sheet humidity control material is The moisture control material may be left in an atmosphere set to , and when the weight of the humidity control material stops increasing, it may be determined that water equivalent to the equilibrium moisture content has been impregnated. The sheet-like humidity control material obtained in this way can be used in any place where humidity control is required, such as a home storage room, closet, or chest of drawers. It can be used for packaging of devices, electronic parts, etc. However, the best places to take advantage of the characteristics of the humidity control material of the present invention are places with a higher degree of airtightness, such as display cases in museums, department stores, etc., storage cases for musical instruments, etc., containers for food transportation, and places for storage. For example, it can be used in warehouses, etc., and as a unique usage, it can be used as a construction material for walls, floors, ceilings, etc. of buildings, and 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 amount of humidity control material used varies depending on the environment of the place to be humidity controlled, but
Usually, about 50 to 500 g of composition (X) is used per 113 g, 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 that it shows no stickiness on the surface when it absorbs moisture. [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. Example 1 The following (A) saponified copolymer, (B) deliquescent salts, (C
) A short fibrous substance was prepared. (A-1) Vinyl acetate tjt9G, 1 mol%
, monomethyl maleate-vinyl acetate copolymer saponified powder (295μ
Below) (A-2) Saponified monomethyl maleate-vinyl acetate copolymer powder (350μ or less ) (B) Powder of calcium chloride dihydrate (C) Stable cut rayon product (diameter 0.1-0.05mm - 1 length 1-1.5 mm)
Using these materials, a sheet-like humidity control material was obtained 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 cm/min to give a solid content of 0.1 g 7 cm 2 . After that, 9
The mixture was dried at 0° C. for 60 minutes to obtain a two-layer moisture control sheet material (thickness: approximately 3111 m) in which composition (X) was laminated on a nonwoven fabric. 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
,1■/1.8IIIIII10. A sheet-like humidity control material having a three-layer structure having the composition ll11) was obtained. This base material will be referred to as "sheet 2". [Example of composition (X゛)] - (A-1> uses A-2), (B) and (C) In the example using the material (X), 43 parts of (B) was dissolved. 10% solution of polyvinyl alcohol itl 43
1, 10 parts of (A-1) or (A-2), and 37 parts of (C) were mixed in the same manner, but a sheet-like humidity control material with a two-layer or three-layer structure (the thickness is the same as before) was prepared. I got it. A two-layer sheet is called "Sheet 3," a three-layer sheet is called "Sheet 4," and a three-layer sheet is 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 ponds was comparable. Next, each sheet was immersed in a 2.5% aqueous solution of borax.
It was dried at 80°C. The amount of borax deposited was () 5%. The following experiments were conducted using "Sheet 1" to "Sheet 4J" obtained as described above. After sufficiently drying, it was left in an atmosphere of 20'CX 90%RH for 30 hours, and the moisture absorption rate (increase in water amount) was
g)/C) (g)X100 (%)) was measured. Thereafter, the sheet was dried again in the same manner and subjected to dehumidification. This was repeated 15 times. Record the results in the table. (Humidity control ability) The pre-dried sheet was left in a 20°C x 60% RH1: humidity controlled atmosphere for 24 hours to impregnate the sheet with water in an amount corresponding to the equilibrium moisture content. Paste this on the wall of a sealed steel box (volume 0.012m') set at 20℃ x 60%RH so that the air volume ratio (Kyo1) is 3.3 and 0.8. , change the temperature inside the box from 20°C → 35°C → 25°C → 35°C → 25°C
and was changed every two hours. The relative humidity range (Thursday 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. (Tree 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 (m3) of the box (Book 2) Relative humidity range: Relative humidity when the humidity is changed over time The deviation of the actual measured value (highest value and lowest value) from the initial membrane constant relative humidity is 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 (12II+m thick)/Styrofoam (50II+m)/Polyethylene seam) (100μ
)/sheet 4 (2IIIm) 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. Example 2 (A-2) Saponified product of monomethyl maleate-vinyl acetate copolymer with vinegar 1' [I2 vinyl content 90 mol%, monomethyl maleate content ffi 10 mol%, degree of saponification of vinyl acetate component 96 mol% Powder (350μ) (B) Calcium chloride dihydrate powder was used, pearlite with a particle size of 2,000μ was used instead of the rayon stable cut product in (C), and (D) 0.2 part of borax was used in combination. produced a structure with a Y/X/Y configuration in the same manner as in Example 1. Further, the structure was immersed in a 2.5% borax aqueous solution and then dried to obtain a sheet-like humidity control material with a borax adhesion amount of 0.3%. The dehumidification ability is 190 for the first time and 184 for the 15th time.
There was no sticky feeling on the surface after moisture absorption. [Effects] As described above, the sheet-like humidity control material of the present invention maintains excellent dehumidification and humidity control functions, does not become sticky after absorbing moisture, and solves the drawbacks of conventional manufacturing, making it suitable for industrial use. The above is very useful.

[Brief explanation of the drawing]

Figure 1 shows the sheet-like humidity control material of the present invention, in which the base material (Y)
(=paper or nonwoven fabric)/humidity conditioner composition (X)/base material (Y)
This shows the equipment used when adopting the laminated structure, so 1゜1゛ is the roll, 2,2゛ is the base material (Y), and 3 is (
The humidity control composition (X) in a molten state, 4 indicates a discharge port for the composition (X), and 5 indicates a sheet-like humidity control material in a laminated state. Patent applicant Nippon Gosei Kagaku Kogyo Co., Ltd. No. 1
Figure, S: Sea Fn I dog J Zhou j1 ward suspension procedure amendment December 28, 1985 1, Indication of the case 1988 Patent Application No. 16780 2, Name of the invention Sheet-shaped humidity control material 3, Amendment Relationship with the case involving a person who does
5. Contents of correction

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 characterized by treating a structure 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 a nonwoven fabric (Y) with boric acid or borax. Moisture control material. 2. (A) A copolymer consisting of 50 to 99.8 mol% of vinyl acetate and 50 to 0.2 mol% of an unsaturated carboxylic acid, in which 70 mol% or more of the vinyl acetate component is saponified. A structure formed by laminating a humidity control composition (X') consisting of a compound (B) a deliquescent substance and (C) a short fibrous substance or pearlite and paper or a nonwoven fabric (Y) is treated with boric acid or borax. Characteristic sheet-shaped humidity control material.