JP3035706B1 - Dehumidifying or drying agent - Google Patents

Abstract

An object of the present invention is to provide a dehumidifying or desiccant which causes a uniform color change from the middle stage to the end stage during moisture absorption. SOLUTION: Powder and / or granular material of deliquescent inorganic salt (A) is 50 to 95% by mass, and gelling agent (B) is 5 to 5%.
0 mass% and 0.0 with respect to the total mass of (A) and (B).
0.0001 to 5% by mass average particle size 0.001 to 100μ
m, the colorant powder (C) having a moisture absorption of less than 10% does not cause discoloration, and the color and / or color tone changes when the moisture absorption reaches 10 to 300%. desiccant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a dehumidifying or drying agent. More specifically, the present invention relates to a dehumidifying or drying agent using deliquescent inorganic salts.

[0002]

2. Description of the Related Art Conventionally, various dehumidifying or drying agents have been widely used for home and business use. As such a dehumidifying or drying agent, a deliquescent inorganic material such as calcium chloride or magnesium sulfate is used. Salts are known.
These deliquescent inorganic salts are usually used in plastic containers or moisture-permeable film containers, but those using moisture-permeable film containers are used for drawers and Japanese (yo) closets. When a large amount of water is absorbed, the deliquescent inorganic salts become liquid.If the semipermeable membrane film is damaged, a pinhole is opened, or pressure is applied, the deliquescent inorganic salts are high. There is a problem that the concentrated aqueous solution spills or oozes out and contaminates the surroundings. In order to solve this problem, in the case of using a moisture-permeable film-shaped container, a powder of a deliquescent inorganic salt and a powder of a water-soluble polymer capable of thickening and gelling a deliquescent high-concentration aqueous salt solution are added together. It is common that it is. However, usually, mixtures of deliquescent inorganic salts, water-soluble polymers, and water-absorbing resins are mostly white, and their color and state do not change much, so it is extremely difficult to confirm the hygroscopic effect or to estimate replacement. There was a problem. As a method for solving such a problem, a method of concurrently adding a coloring agent that develops a color when the deliquescent inorganic salt deliquesces and becomes hydrated (Japanese Utility Model Laid-Open No. 1-150532, Japanese Patent Laid-Open No. 5-212237, JP-A-3-90624), a method of adding anhydrous cobalt chloride (JP-A-6-90664).
165907) and the like have been proposed.

[0003]

However, in the above method, a powder of a commercially available food coloring agent or the like is used as a coloring agent. It is 100 μm or more, and the viscosity of the content is increased due to the combined use of a thickener and a gelling agent, so that the colorant cannot be uniformly colored as a whole, and the discoloration becomes extremely non-uniform (adhered). There was a point. In addition, since water-soluble dyes and dyes generally have good solubility in water, coloring occurs immediately when the deliquescent inorganic salts absorb moisture, so they are not suitable as indicators such as indicators for replacement, and the coloring is rapid. There is a problem that the color development starts due to slight moisture absorption at the time of stock and the commercial value is lost. With regard to the above method, the discoloration of the anhydrous cobalt chloride anhydrous salt from blue to a pale pink of the hydrated salt at the time of moisture absorption occurs.However, the same problem occurs when the discoloration is too fast because the anhydrous salt immediately changes to the hydrated salt due to moisture absorption. there were.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above situation, and as a result, have found that a dehumidifying or drying agent comprising a deliquescent inorganic salt, a gelling agent and a coloring agent having a specific particle size range is:
It has been found that even a high concentration aqueous solution of deliquescent salts quickly absorbs and turns into a gel, and a uniform color change occurs from the middle stage to the end stage when moisture is absorbed, so it is extremely easy to check the moisture absorption effect and to estimate the dehumidification or replacement of the drying agent. Reached the present invention.

That is, according to the present invention, at least one of the following (A) to (A) is contained in a bag-like container made of a moisture-permeable film.
By enclosing (C) and (D) if necessary,
The present invention relates to a dehumidifying or drying agent characterized in that discoloration does not occur when the water absorption relative to (A) is less than 10%, and the color and / or color tone changes when the moisture absorption reaches 10 to 300% by mass. . (A): powder and / or granular material of deliquescent inorganic salts;
50 to 95% by mass of the total mass of (A) and (B) (B): gelling agent; 5 to 5 of the total mass of (A) and (B)
0% by mass (C): colorant powder having an average particle size of 0.001 to 100 μm; 0.00000 based on the total mass of (A) and (B)
1 to 5% by mass (D): pH adjuster

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, (A) includes powders and / or granules of calcium chloride, magnesium chloride, magnesium sulfate, calcium sulfate and the like. These may be anhydrous salts or salts having water of crystallization. Further, some of these can be used in combination. Of these, calcium chloride and magnesium sulfate are preferably used in terms of both moisture absorption performance and cost. The particle size of the above (A) depends on the compounding method and the like, but is preferably 1 to 10000 μm, more preferably 2 μm.
It is a particulate matter having a size of 00 to 5000 μm.

The (B) used in the present invention may be an anionic or cationic polymer as long as it can gel and thicken an aqueous solution of a high concentration of deliquescent inorganic salts. The aqueous solution is rapidly gelled, and the gel has a strong nonionic property in all of the initial to final stages of moisture absorption and / or
Alternatively, an amphoteric water-soluble polymer (E1 and F1) or a crosslinked product thereof (E2 and F2) is preferable, and a crosslinked product (E2 and F2) is preferred in that the gelation rate and the uniformity of the gelation are high.
The crosslinked product (F2) of an amphoteric polymer is particularly preferred in that it can rapidly and largely absorb an aqueous solution of a nearly deliquescent inorganic salt in the early stage of moisture absorption. Examples of the water-soluble polymer (E1) mainly composed of nonionic structural units include polysaccharides represented by, for example, pregelatinized starch, dextrin, alkylcellulose, hydroxyalkylcellulose; polyvinyl alcohol, polyethylene oxide, vinyl acetate and (meth) Saponified alkyl acrylate copolymer, (co) polymerization of nonionic water-soluble ethylenically unsaturated monomer (i) and optionally anionic water-soluble ethylenically unsaturated monomer (h) Weight average molecular weight of 3,000 to 10,000,000
00 synthetic polymer; and the like. Here, “alkyl (meth) acrylate” means alkyl acrylate and alkyl methacrylate, and will be similarly described below. Examples of the crosslinked polymer (E2) include, in addition to a crosslinked product of polyvinyl alcohol, a crosslinked product of polyethylene oxide, and a crosslinked product of a water-soluble polysaccharide, a nonionic water-soluble ethylenically unsaturated monomer (i). And, if necessary, (co) polymerizing and crosslinking the anionic water-soluble ethylenically unsaturated monomer (h), and the like.

Examples of the nonionic water-soluble ethylenically unsaturated monomer (i) used for producing the water-soluble polymer (E1) or its crosslinked product (E2), which is a nonionic constitutional unit, include: The following are mentioned. (1) acrylamides; (meth) acrylamide, N
-Alkyl-substituted (meth) acrylamides [N-methylacrylamide, N, N-dimethylacrylamide, etc.]
(2) vinylamides; N-vinylacetamide, etc .; (3) (meth) acrylates; hydroxyalkyl mono (meth) acrylate having an alkyl group having 2 to 3 carbon atoms, etc. (4) polyalkylene glycol mono ( (Meth) acrylates; polyethylene glycol (Mw: 100 to 40)
00) mono (meth) acrylate, polypropylene glycol (Mw: 100 to 4000) mono (meth) acrylate, methoxypolyethylene glycol (Mw: 10)
0-4000) mono (meth) acrylate and the like; these may be any nonionic water-soluble ethylenically unsaturated monomer. These monomers (i) may be used alone or, if necessary, in combination of two or more. Preferred among these nonionic water-soluble ethylenically unsaturated monomers (i) are (meth) acrylamides which are inexpensive and have good polymerizability. Examples of the anionic water-soluble ethylenically unsaturated monomer (h) used as necessary include (meth) acrylic acid (alkali metal salt), maleic acid (alkali metal salt), fumaric acid (alkali metal salt), Itaconic acid (alkali metal salt),
Acrylamide-2-methylpropanesulfonic acid (alkali metal salt), sulfoalkyl (meth) acrylate,
Styrenesulfonic acid (alkali metal salt) and the like. Here, (meth) acrylic acid (alkali metal salt) means (meth) acrylic acid and / or an alkali metal salt of (meth) acrylic acid, and will be similarly described below. The degree of neutralization of the anionic water-soluble ethylenically unsaturated monomer (h) unit is preferably from 60 to 100 mol%, more preferably from 70 to 100 mol%. Neutralization degree is 60 mol%
With the above, the anion is sufficiently dissociated, and the absorption amount and the absorption rate increase. The neutralization of (h) is performed by adding an alkali metal salt (such as a hydroxide of an alkali metal such as sodium hydroxide, potassium hydroxide, or lithium hydroxide). Preferred examples of the anionic water-soluble ethylenically unsaturated monomer (h) include alkali metal salts of (meth) acrylic acid and partially neutralized salts thereof, which are inexpensive and have good polymerizability. Can be.

The mass ratio of (i) to (h) in the water-soluble ethylenically unsaturated monomer for obtaining the nonionic water-soluble polymer (E1) or its crosslinked product (E2) is usually (i) /
(H) = 80-100 / 20-0, preferably (i) / (h) = 90-100 / 10-0, more preferably (i) / (h) = 95-99 / 1-5 It is.
It is preferable that the ratio of (h) is 20% by mass or less, since the anionicity of the produced polymer does not become strong and the absorption amount of a high concentration aqueous solution of the deliquescent inorganic salt does not decrease.

In the present invention, the amphoteric water-soluble polymer (F1) used as (B) or a crosslinked product thereof (F2)
A copolymer of a cationic water-soluble ethylene monomer (g), the anionic ethylene monomer (h), and, if necessary, the nonionic water-soluble ethylene monomer (i) ( F1) and crosslinked at any stage (F2)
Can be mentioned. Examples of the cationic ethylenic monomer (g) include dialkylamino (meth) acrylates and quaternary salts thereof (a reaction product with an alkyl halide or dialkyl sulfate) [for example, (meth) acryloyloxyethyltriammonium chloride or bromide, (Meth) acryloyloxyethyltrimethylammonium sulfate, (meth) acryloyloxypropyltrimethylammonium chloride or bromide,
(Meth) acryloyloxypropyltrimethylammonium sulfate etc.]; dialkylaminohydroxyalkyl (meth) acrylate and its quaternary salt (reacted with alkyl halide or dialkyl sulfate) [eg (meth) acryloyloxyhydroxyethyltrimethylammonium chloride or bromide , (Meth) acryloyloxyhydroxyethyltrimethylammonium sulfate, (meth) acryloyloxyhydroxypropyl propyltrimethylammonium chloride or bromide]; dialkylaminoalkyl (meth) acrylamide and its quaternary salt [reacted product with alkyl halide or dialkyl sulfate ]; Dialkylaminohydroxyalkyl (meth) acrylamide and quaternary salts thereof (alkyl halide or dihalide) A reaction product of alkyl sulfate), N- alkyl vinyl pyridinium halides [such as N- methyl-2-vinyl pyridinium chloride or bromide]; and trimethyl allyl allyl ammonium halides can be mentioned. These cationic vinyl monomers may be used alone or in combination of two or more. Among these cationic ethylenic monomers, 4
The quaternary salt dissociates and swells quickly in an aqueous solution of a high concentration of deliquescent inorganic salts, and is preferably used when the counter ion of the quaternary salt is a halogen compound. It is more preferable because the gel strength is increased when the gel is formed. Dialkylamino (meth) acrylate and its quaternary salt are particularly preferable because raw materials are easily available and inexpensive.

In the present invention, a cationic ethylenic monomer (g) and an anionic ethylenic monomer (h) for preparing an amphoteric water-soluble polymer (F1) and a crosslinked product thereof (F2) are prepared. ), And the ratio of the nonionic ethylenic monomer (i) to be added, if necessary, are (g) 10 to 9
0 mass% / (h) 1-10 mass% / (i) 0-80 mass% is preferable. When the ratio of (g) is 10 to 90%,
It is preferable because the initial swelling property of a high concentration deliquescent inorganic salt aqueous solution is improved. (H) ratio of 1 to 10% by mass
In this case, Ca ions and Mg ions, which are the main components of the deliquescent inorganic salts, do not cause excessive crosslinking, do not decrease the absorption amount and swelling degree, and cause appropriate crosslinking to increase the gel strength. In the early stage of moisture absorption, since the aqueous solution of the deliquescent inorganic salt is almost a saturated aqueous solution, it is preferable that the ratio of the cationic ethylenic monomer is high, but the concentration of the deliquescent inorganic salt in the aqueous solution at the end of moisture absorption is preferable. Is reduced, and the higher the proportion of the nonionic ethylenic monomer, the higher the gel strength. Therefore, from the viewpoint that a good gel can be prepared from the initial stage to the end stage, (g) 30 to 60% by mass / (H) 1 to 5% by mass / (i) 30 to 70% by mass.

In the present invention, the crosslinked product (E2) of a water-soluble polymer mainly composed of nonionic constituent units or the crosslinked product (F2) of a water-soluble amphoteric polymer (F2) is prepared by adding a crosslinking agent (j) at an optional stage. It is prepared by crosslinking and / or heating the water-soluble polymer to 130 ° C. or more to thermally crosslink. The method of adding the cross-linking agent (j) is to add two double bonds in the molecule.
At least one polymerizable cross-linking agent (j1) is added during the polymerization and copolymerized with the water-soluble ethylene monomer (g-i), or
Alternatively, a reactive crosslinking agent (j2) having two or more functional groups that react with the functional group of the used water-soluble ethylenically unsaturated monomer is added during and / or after polymerization to effect crosslinking. Further, a crosslinking agent (j3) having at least one functional group that reacts with the functional group of the water-soluble ethylenically unsaturated monomer and at least one polymerizable double bond may be added at the time of polymerization. . The amount of the cross-linking agent (j) to be added depends on the required amount of dehumidifying or drying agent absorption and water retention and the type of cross-linking agent used, but is preferably 0.000.
It is from 0.01 to 10% by mass, more preferably from 0.001 to 5% by mass. If the addition amount is less than 0.00001% by mass,
When the gel elasticity is low, on the other hand, when it exceeds 10% by mass, the crosslink density becomes too high, and the swelling amount and water retention amount may decrease.

When the crosslinking agent (j) is used, the polymerizable crosslinking agent (j1) includes a water-soluble ethylenically unsaturated monomer (g) having two or more double bonds in the molecule. ~ I)
There is no particular limitation as long as it is a crosslinking agent copolymerizable with N, N'-methylenebisacrylamide, ethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Pentaerythritol di (meth) acrylate, pentaerythritol tri (meth)
Acrylate, pentaerythritol tetra (meth) acrylate, glycerin diallyl ether, glycerin triallyl ether, trimethylolpropane triallyl ether, trimethylolpropane triallyl ether, pentaerythritol diallyl ether, pentaerythritol triallyl ether, pentaerythritol tetraallyl ether Examples can be given.
These (j1) may be used in combination of two or more.

The reactive crosslinking agent (j2) used in the present invention
Although it depends on the functional group composition of the polymer to be crosslinked, for example, a polyvalent glycidyl compound represented by ethylene glycol diglycidyl ether, a polyvalent isocyanate compound represented by MDI, an ethylene diamine, and the like Examples thereof include polyhydric amine compounds and polyhydric alcohol compounds represented by glycerin. Examples of the crosslinking agent (j3) having at least one functional group that reacts with the functional group of the water-soluble ethylenically unsaturated monomer and at least one polymerizable double bond include, for example, N 2
-Methylol (meth) acrylamide, glycidyl (meth) acrylate, ethylene glycol monoglycidyl monoacrylate and the like. When these reactive cross-linking agents (f2 and f3) are used, at any stage after the addition of the cross-linking agent, it is usually 100 ° C. or higher, preferably 12 ° C. or more.
Generally, the crosslinking reaction is advanced by heating to 0 ° C. or higher. Further, these reactive crosslinking agents may be used in combination of two or more kinds in a predetermined amount range, and furthermore, the polymerizable crosslinking agent (j1).

A method for obtaining a crosslinked product (E2) of a water-soluble polymer mainly composed of nonionic constitutional units or a crosslinked product of an amphoteric water-soluble polymer (F2) by thermal crosslinking without using a crosslinking agent is optional. In the step, the water-soluble polymer (E1) or (F1) is preferably used at 130 ° C. or higher, more preferably 1 ° C.
By heating to 50 ° C. or higher, intramolecular and / or intermolecular crosslinking occurs, and a crosslinked product is obtained. Heating temperature is 13
If the temperature exceeds 0 ° C., it is preferable because crosslinking occurs uniformly. The heating time when performing thermal crosslinking varies depending on the functional group of the polymer to be thermally crosslinked, the degree of crosslinking, the heating temperature, and the like, but is usually 10 minutes to 50 hours, preferably 1 to 10 hours. If the heating time is less than 10 minutes, the crosslinking may be insufficient. On the other hand, if the heating time exceeds 50 hours, excessive crosslinking may proceed or the coloring of the crosslinked product may become intense. The heating step in the thermal crosslinking is carried out by a method of simultaneously performing drying and thermal crosslinking at a temperature at which thermal crosslinking occurs at the time of drying, which will be described later after polymerization, or a method of forming the powdered water-soluble polymer (E1) or (F
Heating after powdering is preferred, but heating after powdering is preferred because the crosslinking density near the surface of the resin increases and a high concentration aqueous solution of deliquescent inorganic salts can be quickly absorbed.

In the present invention, the method of (co) polymerizing the water-soluble ethylenically unsaturated monomer (g to i) may be a conventional method, for example, a method of polymerizing using a radical polymerization initiator, radiation, A method of irradiating ultraviolet rays, electron beams, or the like can be given. In the method using a radical polymerization initiator, the initiator may be an azo compound [4,4′-azobis (4
-Cyanovaleric acid), 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide, 2,2'-azobis (2-amidinopropane) hydrochloride, etc.], inorganic peroxide [Hydrogen peroxide, potassium persulfate, ammonium persulfate, sodium persulfate, etc.], organic peroxides [di-t-butyl peroxide, cumene hydroperoxide, etc.], redox initiators [sulfites or heavy metals of alkali metal salts] Sulfite, ammonium sulfite, ammonium bisulfite, L
-A combination of a reducing agent such as ascorbic acid and a peroxide such as a persulfate of an alkali metal salt, ammonium persulfate and aqueous hydrogen peroxide], and a combination of two or more of these.

The method of polymerization using this initiator is not particularly limited. For example, the polymerization temperature varies depending on the type of the initiator used, but is preferably from -10 ° C to 100 ° C, and more preferably to increase the molecular weight. −10 ° C. to 80 ° C. The amount of the initiator is not particularly limited, but is preferably 0.000000 to 3.0%, more preferably 0.00%, based on the total mass of the ethylenically unsaturated monomer.
0001 to 0.5%. The solvent at the time of polymerization is usually carried out by aqueous solution polymerization using water having a small chain transfer, but an aqueous solution of an ethylenically unsaturated monomer is optionally used in the presence of a dispersing agent in a hydrophobic solvent (for example, hexane, toluene, So-called reversed-phase suspension polymerization in which the polymer is dispersed and suspended in xylene or the like can also be suitably used. The polymerization concentration, which is the concentration of the ethylenically unsaturated monomer during the polymerization, is preferably from 10 to 60% by mass, and more preferably from 20 to 50% by mass. When the polymerization concentration is 10 to 60%, the molecular weight is easily increased and the efficiency is high, and the polymerization temperature and the like are easily controlled.

In the present invention, when an aqueous gel of a polymer is obtained by aqueous solution polymerization or reverse phase suspension polymerization, it is dried if necessary. The drying method may be a usual method. For example, in the case of aqueous solution polymerization, after the polymer gel is subdivided, air-permeable drying (such as band drying), through-air drying (such as circulation drying), and contact drying (such as drum dryer drying) are performed. In the case of reversed-phase suspension polymerization, a method of performing solid-liquid separation, followed by drying under reduced pressure or through-flow drying can be exemplified.

The dried product of the crosslinked polymer thus obtained is pulverized and pulverized if necessary. The pulverizing method may be an ordinary method, for example, an impact pulverizer (a pin mill, a cutter mill, a skirel mill, an ACM pulperizer, a centrifugal pulverizer, etc.) or an air pulverizer (a jet pulverizer, etc.). The resin powdered in this way is re-heated as necessary to perform thermal crosslinking and the like. The heating method may be an ordinary method.For example, the resin powder is thinly placed on a tray and heated using a circulating dryer or a tunnel dryer, or the resin is dried using a device such as a paddle dryer, a universal mixer, or a kneader. A method such as heating while expanding sales can be exemplified.

The particle size of (B) used in the present invention is as follows:
The average particle size is preferably 50 to 3000 μm, more preferably 500 to 3000 μm, although it varies depending on the purpose and method used.
2000 μm. In the particle size distribution, preferably, the particle size is 50 to 3000 μm at 90% by mass or more. When the average particle size is 3000 μm or less, the swelling speed of (B) is increased, and the time until gelation of the dehumidifying agent or the drying agent is increased, and when the average particle size is 50 μm or more, the water-soluble polymer (E1, Since the particle size of the deliquescent inorganic salt used by F1) and the crosslinked polymer (E2, F2) is close to that of the deliquescent inorganic salt, it is preferable because the resin and the deliquescent inorganic salt hardly separate during transportation or at a store. The particle size distribution is 50 to 300.
When 0 μm is 90% by mass or more, the swelling speed of (B) is increased and the time until gelation of the dehumidifying or drying agent is increased, and the water-soluble polymer (E1, F1) and the crosslinked polymer (E2, F2) Is used because it is close to the particle size of the deliquescent inorganic salts used, and it is difficult to separate the resin and the deliquescent inorganic salts at the time of transportation or at a store, which is preferable.

In the present invention, the dehumidifying or drying agent is prepared by blending (A) the powder and / or granular material with (B). In the present invention, the blending mass% of (A) and (B) is
(A) is usually 50 to 50% of the total mass of (A) and (B).
95 mass%, preferably 50 to 90 mass%, (B) is usually 50 to 5 mass%, preferably 50 to 10 mass%. If the compounding ratio of (A) exceeds 95% by mass, it becomes difficult to prevent the deliquescent inorganic salts from absorbing moisture and becoming liquefied, and if the ratio of (B) exceeds 50% by mass, the dehumidifying / drying effect is obtained. Is weak and inefficient.

The dehumidifying or drying agent of the present invention has a deliquescent inorganic salt having a moisture absorption of 10 to 300 in addition to (A) and (B).
%, The colorant powder (C) whose color and / or color tone changes for the first time is added. As (C) used in the present invention, 1 is usually selected from pigments, dyes and pigments.
Microencapsulated species or two or more species and / or acid-base indicators can be used. Pigments, dyes or pigments to be microencapsulated are usually dyes (direct dyes,
Acid dyes, basic dyes, disperse dyes, reactive dyes, Izoc dyes, etc.), pigments (food coloring pigments, etc.), anhydrous cobalt chloride, etc. may be used. These pigments and dyes are made of water-soluble polymers such as cyclodextrin and soluble starch. By covering and microencapsulating, discoloration due to a pigment or dye can be delayed, and discoloration can be caused when the moisture absorption rate of (A) becomes 10 to 300%.

When an acid-base indicator is used as the colorant powder, the pH of the acid-base indicator is changed at the stage when the moisture absorption rate of (A) becomes 10 to 300% to induce the acid-base indicator into a pH discoloration region. To discolor. PH of acid-base indicator
Examples of a method for inducing the H color change range include a method of changing the pH of an acid-base indicator to be used by utilizing the pH of a mixture of (A) and (B) at the time of moisture absorption, and (A)
And a method in which a pH adjuster (D) is added to (B) and (B) to change the pH of the system at the time of moisture absorption to change the color. Examples of the acid-base indicator used as (C) may be a known acid-base indicator, and may be, for example, those described in an appendix of the Encyclopedia of Chemistry (Kyoritsu Shuppan Co., Ltd.). The discoloration range where discoloration is possible without making the pH of the medium extremely acidic or alkaline is pH 3
And -10, and particularly preferred are bromophenol blue, tetrabromophenol blue, bromochlorophenol blue, amphomagenta, bromocresol green, lacmoid, cochineal, hematoxylin, bromocresol purple,
Discoloration range represented by dibromophenol, tetrabromophenolsulfonephthalein, bromothymol blue, quinoline blue, ethylbis (2,4-dinitrophenyl) acetic acid is at pH 3 to 10, and gives a refreshing image as a dehumidifier. It can change color to blue / green system.

In the present invention, (D), which is added as necessary to induce the pH of the acid-base indicator into the discoloration range, is used for the type (discoloration range) of the acid-base indicator used (A).
It varies depending on the pH of the mixture of (B) and (B) itself when it contains water, but by adding a pH adjuster, it changes the pH of the system at the time of moisture absorption, and induces the discoloration range of the acid-base indicator to change the color or change the color tone. (D) may be appropriately selected so that the above occurs. (D) may be a liquid pH adjuster, but powder type (D) is more preferred from the viewpoint of preventing seepage of contents from the moisture permeable membrane described later and causing a gradual change in pH. Polycarboxylic acid (or its alkali metal salt) represented by poly (meth) acrylic acid and its alkali metal salt has a very low dissolution rate in an aqueous solution of deliquescent inorganic salts, so the pH in the system gradually changes. It is more preferable because discoloration can be delayed. The amount of addition when (D) is used is not particularly limited as long as it can be adjusted to the desired pH. However, in order not to reduce the hygroscopicity of the deliquescent inorganic salts and the gelling power of the gelling agent, (D) A) and (B)
Is preferably 0.001 to 30% by mass based on the total mass.

The colorant in the present invention has an average particle size of usually 0.001 to 100 μm, preferably 0.001 to 50 μm.
A micronized powder is used. When the average particle size of (C) exceeds 100 μm, it depends on the solubility of the coloring agent used, but the coloring agent is not dissolved well and the coloring often becomes non-uniform (formation of spots). Absent.
In order to obtain (C) having such a small average particle diameter, a method of flu-cutting a commercially available acid-base indicator powder having a particle size of 100 μm or more and / or an Air-type pulverizer (for example, a jet mill) or a high-speed impact type Examples of the method include pulverizing the acid-base indicator using a pulverizer (for example, a palmerizer) so that the average particle size of the acid-base indicator becomes a predetermined particle size, or thereafter performing a fluid cut. When using a pigment or dye microencapsulated as a colorant, first make the average particle diameter of the pigment or dye to be used a similar predetermined particle diameter, and then microencapsulate using cyclodextrin or the like. ,
Further, if necessary, the particle size may be adjusted to a predetermined particle size by performing pulverization or the like.

The amount of (C) used in the present invention varies depending on the type of colorant used, the desired color strength, and the like, but is usually based on the total mass of (A) and (B). hand,
0.000001 to 10% by mass, preferably 0.000
01 to 1% by mass, more preferably 0.00001 to 0.1% by mass.
1% by mass. The amount of (C) added is 0.000001
If the amount is less than mass%, the amount of the colorant added is too small and the color may not be changed well, which is not preferable.
If the amount exceeds 0% by mass, the amount of the coloring agent is too large, and the dehumidifying or drying agent may be stained by the coloring agent before moisture absorption, and the change in color or color tone may be difficult to recognize even if moisture is absorbed. Absent.

The addition of (C) may be carried out at an optional stage. For example, (C) is added to (A), blended with (B) after blending, and (B) is added to (C) in an optional production step. Examples of the method include blending with (A) after blending, and simultaneously adding (C) and blending when blending (A) and (B). In addition, there is a method in which (C) is dissolved and diluted in a solvent (for example, a hydrophilic organic solvent such as ethanol or methanol, or water) and then added to (A) and / or (B). (A) is often white, and the colorant often becomes strong when diluted with a solvent or the like, so that the entire system is stained with the colorant, which is not preferable. On the other hand, when the colorant is added in the form of a powder, the color of the colorant is almost invisible due to the irregular reflection phenomenon because (C) of the present invention uses particles having a small particle size. Is more preferred.

In the dehumidifying or drying agent of the present invention, (A)
When blending (B) and (B), other additives may be added as necessary. As the other additives, for example, silica gel, zeolite, perlite, bentonite, vermiculite, activated carbon and the like can be exemplified, provided that they do not interfere with the function of the dehumidifying or drying agent,
There is no particular limitation. The amount of use is not particularly limited as long as it does not interfere with the function, but is preferably 10% by mass or less based on the total mass of (A) and (B). Two or more of these additives may be added in combination.

The dehumidifying or drying agent of the present invention is used to prepare a bag-like container by using a film, such as a moisture-permeable film, that allows gas such as moisture to pass through but does not allow powder or liquid to pass on both sides or one side. The dehumidifying or desiccant composition is prepared by enclosing the dehumidifying or desiccant composition in a bag-like container. As the moisture permeable film, a known film may be used. For example, a thermoplastic resin represented by polyethylene, polypropylene, polyvinyl chloride, polyester, polyamide polyurethane or the like is blended with a fine inorganic filler of about 0.1 to 20 μm and stretched. A perforated sheet or the like can be suitably used. If a hydrophilic urethane is used as the moisture-permeable film, the film itself has moisture permeability,
Depending on the desired moisture permeability, it may not always be necessary to add an inorganic filler or the like to make small holes in the moisture permeable film. In addition, a film obtained by laminating a nonwoven fabric and a moisture-permeable film for enhancing the strength of the moisture-permeable film can also be suitably used.

However, the moisture-permeable film to which the above-mentioned inorganic filler is added usually has poor transparency, and it is difficult to confirm the state of the inside of the dehumidifying or drying agent. Alternatively, one side is preferably a moisture-absorbing layer using a moisture-permeable film, and the other side is preferably an ordinary film having high transparency so that the state inside the desiccant can be observed, and the other side is preferably used. When these moisture-permeable materials are used, the exterior such as a moisture-permeable film container is further covered with a moisture-impermeable material, and when used as a dehumidifying or drying agent, the moisture-impermeable exterior material is broken. Starting the use of the dehumidifying or drying agent at an appropriate timing by a method such as removal or the like is more suitable for actual use.

[0031]

The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited to these examples. Amount of gelling agent used in the present invention and comparative dehumidifying or drying agent for calcium chloride aqueous solution (concentration: 30%, 45%), moisture absorption rate for calcium chloride in moisture absorption test of dehumidifying or drying agent, degree of discoloration of contents The uniformity of discoloration, the gelation state of the contents, the pH of the contents after moisture absorption, and the leaching property from the moisture-permeable membrane after moisture absorption were tested by the following methods. Hereinafter, unless otherwise specified,% indicates mass%.

[Swelling Amount of Gelling Agent in Calcium Chloride Aqueous Solution (Concentration: 30%, 45%)] 300 g and 450 g of commercially available anhydrous calcium chloride (special reagent grade) are separately put into a 1 liter beaker, and are expanded and dissolved. To prepare 30% and 45% aqueous calcium chloride solutions. 2.0 g of the gelling agent is placed in a 250-mesh nylon screen and immersed in 30% and 45% calcium chloride aqueous solution for 5 hours. Then, the nylon screen is pulled up, drained for 30 minutes, and swelled by the following formula. The amount was measured. Swelling amount (g / g) = (mass of nylon screen after immersion−mass of nylon screen) / 2

[Moisture Absorption Test] 16 cm × 11 cm moisture permeable film [Poram, manufactured by Tokso Corporation, pore size:
5 μm, 50 μm thick polyethylene film) and a non-woven fabric (PP / PE gescore) laminated film and a moisture-impermeable film (30 μm thick transparent PP)
/ PE laminated film) and three sides (1c each)
m) was heat-sealed to prepare a bag having a moisture-permeable film layer on one side. In this bag, a desiccant composition (granular calcium chloride dihydrate (manufactured by Tokso Co., Ltd.) 40 g / gelling agent 10 g / additive) is put, and the upper part of the bag is heat-sealed to prepare a dehumidifying or drying agent. did. This dehumidifying or drying agent is placed in a thermo-hygrostat at 30 ° C. and 90% humidity, and after 2 hours,
Calcium chloride moisture absorption after 0 hour, 24 hours, and 96 hours, degree of discoloration and uniformity of discoloration of contents over time, gelation state of contents over time, pH of contents after 72 hours 72 hours later, seepage from the moisture permeable membrane was observed. Moisture absorption (%) with respect to calcium chloride over time; Moisture absorption (%) = (weight of dehumidifier after moisture absorption (g)-weight of dehumidifier before moisture absorption (g)) / weight of calcium chloride dihydrate used (G) × 100 [Color of content and uniformity of color] The color and uniformity of color of the content are observed through a transparent film surface at each elapsed time, and the uniformity of color is determined according to the following criteria. evaluated. ：: The whole is uniformly colored. Δ: Partially colored. X: Coloring is bad and appearance is very poor. [Geling state of content over time] The gelation state of the content over time was observed and evaluated according to the following criteria. A: The contents are completely gelled and the gel strength is strong. ：: The contents are almost completely gelled. Δ: The content is thickened, but the content has fluidity. ×: Some or all of the contents are liquid. [PH of content after moisture absorption (after 96 hours)] The bag after the moisture absorption test was broken, the content was taken out, and the pH of the content was checked using a pH meter. [Leachability from moisture-permeable membrane after moisture-absorption test] The bag subjected to the moisture-absorption test was further stored for one month, and it was observed whether or not the contents had permeated from the moisture-permeable film.

Example 1 A commercially available crosslinked oxidized starch powder having an average particle diameter of 1000 μm (starch itself has a pH of 6.1) was gelled with a gelling agent (1).
Used as Table 1 shows the absorption of the gelling agent (1) with respect to the aqueous calcium chloride solution (concentration: 30%, 45%). 10 g of this gelling agent (1) and an average particle size of 2000
40 g of granular calcium chloride dihydrate having an average particle size of 1 μm
Bromocresol green pulverized to 0 μm (pH of acid-base indicator itself: 1.6, pH discoloration area: (yellow) 3.8)
To 5.4 (blue)) was uniformly powder-blended to prepare a dehumidifying or drying agent composition of the present invention. A dehumidifying or drying agent was prepared by the method described in the above test method, and a moisture absorption test was performed. Table 2 shows the results.

Example 2 10 g of this gelling agent (1), 40 g of granular calcium chloride dihydrate having an average particle size of 2000 μm, and an unneutralized bromothymol blue (acid-base indicator itself) pulverized to an average particle size of 10 μm PH: 1.8, pH discoloration area: (yellow) 6.
0 to 7.6 (blue)) 0.001 g and commercially available sodium polyacrylate (polymer pH: 9.6) 5 as a pH adjuster
g was uniformly powder-blended to prepare a dehumidifying or drying agent composition of the present invention. A dehumidifying or drying agent was prepared by the method described in the above test method, and a moisture absorption test was performed. Table 2 shows the results.
Shown in

Example 3 In a 5 liter beaker, 14.4 g of acrylic acid (0.1 g of acrylic acid) was added.
2 mol) to a 16.5% aqueous sodium hydroxide solution 16.5.
1391.6 g of a 50% aqueous acrylamide solution (9.
8 mol), 0.5 g of pentaerythritol triallyl ether, and 1390 g of water, and cooled to 5 ° C. This solution was put into an adiabatic polymerization tank, and the dissolved oxygen content of the solution was adjusted to 0.1 ppm through nitrogen. Then, 0.0005 g of 35% hydrogen peroxide solution and 0.00025 g of L-ascorbic acid were added.
And 0.125 g of 4,4'-azobis (4-cyanovaleric acid) was added. After about 30 minutes, the polymerization started, and after about 5 hours, the maximum temperature reached about 75 ° C., and the polymerization was completed, and a hydrogel polymer was obtained. After the gel was subdivided with a meat chopper, the band was dried at 120 ° C. using a band dryer (air-permeable dryer, manufactured by Inoue Metal Co., Ltd.).
For 1 hour and pulverized to obtain a white gelling agent (2) having an average particle size of 600 μm. Table 1 shows the absorption amounts of the 30% and 45% aqueous calcium chloride solutions of the gelling agent (2). Commercially available food pigment blue No. 1 was pulverized to an average particle size of 3 μm using a jet pulverizer. Cyclodextrin 500
g and 500 g of water, and kneaded in a biaxial kneader. Then, 50 g of finely ground blue No. 1 was added and kneaded. After freeze-drying the kneaded product, the average particle size is 20 μm using a jet mill.
m to give a fine powder of a microencapsulated pigment. 10 g of the gelling agent (2) and 0.002 g of the microencapsulated pigment having an average particle diameter of 20 μm are uniformly powder-blended, and then 40 g of granular calcium chloride is added and uniformly mixed, and the dehumidification or drying of the present invention is performed. An agent composition was prepared and subjected to a moisture absorption test. Table 2 shows the results.

Example 4 In a 3-liter beaker, 350 g of acryloyloxyethyltrimethylammonium chloride, 21 g of acrylic acid and 658 g of a 50% aqueous solution of acrylamide, 3.5 g of sodium hydroxide and 967.5 of ion-exchanged water were placed.
g was added, mixed uniformly, and cooled to 0 ° C. This solution was placed in an adiabatic polymerization tank, and the dissolved oxygen content of the solution was adjusted to 0.1 ppm through nitrogen.
005 g, L-ascorbic acid 0.00025 g, ferric sulfate 0.00003 g, and 4,4′-azobis (4
-Cyanovaleric acid) was added. After about 5 minutes, the polymerization started, and after about 5 hours, the maximum temperature reached about 85 ° C., and the polymerization was completed, and a hydrogel polymer was obtained. After this gel was subdivided with a meat chopper, it was dried at 120 ° C. for 1 hour using a band dryer (air-permeable dryer, manufactured by Inoue Metal Co., Ltd.) and pulverized to an average particle diameter of 1000 μm. Place the ground polymer on an aluminum tray at a thickness of about 5 mm
By heating for about 5 hours in a normal air dryer at 0 ° C., a thermally gelled white gelling agent (3) (polymer pH 5.5) was obtained. Table 1 shows the absorption of 30% and 45% calcium chloride aqueous solution of the gelling agent (3). 10 g of this gelling agent (3), 40 g of granular calcium chloride dihydrate having an average particle diameter of 2000 μm, and unneutralized bromochlorophenol blue finely pulverized to an average particle diameter of 10 μm (pH of acid-base indicator itself: 1. 6, pH discoloration area: (yellow) 3.2
To 4.8 (blue)) was uniformly powder-blended to prepare a dehumidifying or drying agent composition of the present invention. A dehumidifying or drying agent was prepared by the method described in the above test method, and a moisture absorption test was performed. Table 2 shows the results.

Example 5 In a 3-liter beaker, 420 g of methacryloyloxyethyltrimethylammonium chloride, 21 g of acrylic acid and 518 g of a 50% aqueous solution of acrylamide were added.
0.3 g of N, N-methylenebisacrylamide, 3.5 g of sodium hydroxide and 1035 g of ion-exchanged water were added, mixed uniformly, and cooled to 0 ° C. This solution was placed in an adiabatic polymerization tank, and the dissolved oxygen content of the solution was reduced to 0.1 through nitrogen.
ppm and 0.0005% of 35% aqueous hydrogen peroxide.
g, 0.00025 g of L-ascorbic acid, 0.00003 g of ferric sulfate, and 0.125 g of 4,4'-azobis (4-cyanovaleric acid). About 5
After about 5 minutes, polymerization starts, and after about 5 hours the maximum temperature reached about 78 ° C
And the polymerization was completed, and a hydrogel polymer was obtained. After subdividing this gel with a meat chopper,
It was dried at 120 ° C. for 1 hour using a band drier (air permeable drier, manufactured by Inoue Metal Co., Ltd.), pulverized to an average particle size of 100
It was pulverized to 0 μm to obtain (4) (polymer pH 5.1). Table 1 shows the absorption amounts of 30% and 45% aqueous calcium chloride solutions of the gelling agent (4). 10 g of this gelling agent (4), 40 g of granular calcium chloride dihydrate having an average particle size of 2000 μm, and unneutralized bromophenol blue finely pulverized to an average particle size of 10 μm (pH of the acid-base indicator itself: 1.6) , PH discoloration range: (yellow) 3.0 to 4.
6 (blue)) was uniformly powder-blended to prepare a dehumidifying or drying agent composition of the present invention. A dehumidifying or drying agent was prepared by the method described in the above test method, and a moisture absorption test was performed. Table 2 shows the results.

Comparative Example 1 10 g of the gelling agent (1), 40 g of granular calcium chloride dihydrate and 0.001 g of Food Color Blue No. 1 (average particle size: 150 μm) used in Example 1 were uniformly powdered. Blend to make a comparative dehumidifier or desiccant composition. A dehumidifying or drying agent was prepared by the method described in the above test method, and a moisture absorption test was performed. Table 2 shows the results.

Comparative Example 2 Commercially available polyacrylamide powder (average particle size 500 μm,
Polymer pH: 7.1) Cobalt chloride (special grade reagent, anhydrous salt: blue, hydrated salt: light pink) while stirring 100 g 1
5 g of a 0% aqueous solution was gradually added, and the surface of the polymer was coated with an aqueous solution of cobalt chloride. 110 ° C
For 1 hour with a circulating drier to produce a gelling agent (5) colored blue with cobalt chloride. Table 1 shows the absorption amounts of the 30% and 45% aqueous calcium chloride solutions of the gelling agent (5). 10 g of the gelling agent (5) and 40 g of granular calcium chloride dihydrate were uniformly powder-blended to prepare a comparative dehumidifying or drying agent composition. A dehumidifying or drying agent was prepared by the method described in the above test method, and a moisture absorption test was performed.
Table 2 shows the results.

Comparative Example 3 The average particle size used as a colorant in Example 4 was 10 μm.
Of commercially available neutralized bromochlorophenol blue (pH of acid-base indicator itself: 7.1, pH discoloration range:
(Yellow) 3.2 to 4.8 (blue), average particle size: 180 μm)
A comparative dehumidifying or desiccant composition was prepared in the same manner as in Example 4, except for using. A dehumidifying or drying agent was prepared by the method described in the above test method, and a moisture absorption test was performed. Table 2 shows the results.

Comparative Example 4 Polyacrylic acid N as a pH adjuster used in Example 2
A comparative dehumidifying or drying agent composition was prepared in the same manner as in Example 2 except that a was not added. A dehumidifying or drying agent was prepared by the method described in the above test method, and a moisture absorption test was performed. Table 2 shows the results.

[0043]

[Table 1]

[0044]

[Table 2]

From Tables 1 and 2, the following is clear. Unlike the dehumidifying or drying agents of Comparative Examples 1 to 4, the dehumidifying or drying agents of Examples 1 to 5 do not discolor at all when the moisture absorption of calcium chloride is less than 10%, and the moisture absorption is 10 to 30.
The color of the dehumidifying or drying agent is completely changed in the range of 0% (from the middle stage to the end stage of moisture absorption). Example 1
The dehumidifying or drying agents of Nos. To 5 are very uniform in coloring as compared with the dehumidifying or drying agents of Comparative Examples 1 and 3. The crosslinked product of the amphoteric polymer used as a gelling agent has a higher absorption of a saturated concentration (45%) of an aqueous solution of calcium chloride than the nonionic polymer used as a gelling agent. The contents can be completely gelled.

[0046]

The dehumidifying or drying agent of the present invention has the following effects. The dehumidifying or drying agent of the present invention does not discolor in the early stage of absorbing moisture,
Discoloration occurs from the middle stage to the end stage of moisture absorption, and since the discoloration is homogeneous, it is very easy to externally determine whether or not the dehumidifying or desiccant is absorbing moisture, and it is extremely easy to judge the replacement of the dehumidifying or desiccant. . In addition, since discoloration does not occur in the initial period of moisture absorption, there is no possibility that discoloration will start at the time of stock at a store or a warehouse. Furthermore, when an amphoteric polymer is used as the gelling agent, a high-concentration aqueous solution of a polyvalent metal salt, in which deliquescent inorganic salts such as calcium chloride and magnesium sulfate have absorbed moisture, is rapidly and abundantly from the initial period to the final period of moisture absorption. Absorbs and retains water to form a gel-like solid. Therefore, even if a pinhole or the like is opened in the dehumidifying or desiccant container that has absorbed moisture, the deliquescent salt solution does not spill or permeate, and does not contaminate the outside. Because of the above effects, the dehumidifying or desiccant of the present invention is a closet, a closet, a general household such as a kitchen, in a dining room,
It is useful as a dehumidifying or drying agent for business use such as in a warehouse.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-11-319468 (JP, A) JP-A-3-30814 (JP, A) JP-A-5-212237 (JP, A) JP-A-62-162 160357 (JP, A) JP-A-58-216936 (JP, A) JP-A-6-165907 (JP, A) JP-A-62-294422 (JP, A) JP-A-3-90624 (JP, U) JP-B-47-41231 (JP, B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 53/26-53/28

Claims (4)

(57) [Claims] 1. The following (A) to (C) and, if necessary, (D) are sealed in a bag-shaped container at least one of which is made of a moisture-permeable film, so that the moisture absorption of (A) is 10%. %, Discoloration does not occur and the moisture absorption is 10 to 3%.
A dehumidifying or drying agent characterized in that the color and / or color tone changes at the stage of reaching 00% by mass. (A): powder and / or granular material of deliquescent inorganic salts;
50 to 95% by mass of the total mass of (A) and (B) (B): gelling agent; 5 to 5 of the total mass of (A) and (B)
0% by mass (C): colorant powder having an average particle size of 0.001 to 100 μm; 0.00000 based on the total mass of (A) and (B)
1 to 5% by mass (D): pH adjuster 2. The method according to claim 1, wherein the colorant (C) is one obtained by microencapsulating one or more kinds selected from pigments, dyes and pigments and / or an acid-base indicator. Dehumidifier or desiccant. 3. The dehumidifier according to claim 1, wherein the gelling agent (B) is a water-soluble polymer (E1) mainly composed of a nonionic constituent unit and / or a crosslinked product thereof (E2). Or a desiccant. 4. The gelling agent (B) is a cationic water-soluble ethylenically unsaturated monomer (g) in an amount of 10 to 90% by mass and an anionic water-soluble ethylenically unsaturated monomer (h) 1 to 10% by mass. An amphoteric water-soluble polymer (F1) comprising a polymer of 10% by mass and, if necessary, a nonionic water-soluble ethylenically unsaturated monomer (i) of 0 to 80% by mass and / or a crosslinked product thereof (F2)
The dehumidifying or drying agent according to claim 1 or 2, wherein