JP2017118977A - Method for imparting indicator function to water-absorbing polymer, and water-absorbing polymer with indicator function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for facilitating end point timing determination, at which a residual amount of medicine contained in a water-absorbing polymer decreases to an effective amount or less.SOLUTION: In a method, an end point at which a residual amount of volatile medicine in a water-absorbing polymer swollen by including a volatile medicine-containing chemical solution decreases to an effective amount or less is displayed by whitening of the water-absorbing polymer. In the water-absorbing polymer with an indicator, the chemical solution includes a compound with a vapor pressure lower than that of water and water, the compound is an alcohol or an ether represented by formula (1) or (2) with molecular weight of 118 or more, and the amount of the compound to the total sum of the compound and water is 70 mass% or less.SELECTED DRAWING: None

Description

  The present invention relates to a method of imparting an indicator function to a water-absorbing polymer and a water-absorbing polymer with an indicator function, and particularly when the remaining amount of a volatile drug contained in the water-absorbing polymer reaches an end point of an effective amount or less. The present invention relates to a method for imparting an indicator function to a water-absorbing polymer exhibiting the function, and a water-absorbing polymer with the indicator function.

Conventionally, water-absorbing polymers have been used for the purpose of absorbing body fluids and excrement in paper diapers, sanitary napkins, cat sands, and the like. As another application, use as a drug carrier has been studied.
For example, Patent Document 1 reports a deodorant capable of remarkably enhancing the deodorizing effect by adsorbing a deodorant on a water-absorbing polymer. Patent Document 2 reports a flying insect repellent that exhibits an excellent flying insect repellent effect over a predetermined period by adding a flying insect repellent composition to a water-absorbing polymer.

Japanese Patent Laid-Open No. 62-298361 JP 2014-237622 A

  By using the water-absorbing polymer, it is possible to hold or release the drug, and the user can easily imagine the effect by reducing the water-absorbing polymer due to volatilization of water or the like. Furthermore, since the water-absorbing polymer becomes smaller, it is easy for the user to recognize that the use end point of the preparation, that is, the replacement time is approaching.

  However, the criterion for determining how small the water-absorbing polymer is is the end point at which the active ingredient in the preparation is less than the effective amount varies depending on the user, and does not lead to efficient use or replacement of the preparation.

  This invention is made | formed in view of the said situation, The objective is to make easy judgment of the time when the residual amount of the chemical | medical agent contained in a water absorbing polymer becomes an end point below an effective amount. It is another object of the present invention to provide a water-absorbing polymer that can be easily determined.

As a result of extensive research, the present inventor has found that the end point of a drug can be displayed by whitening the water-absorbing polymer by incorporating the drug and a specific compound into the water-absorbing polymer. It came to be completed.
That is, the present invention is as follows.
<1> The volatile drug is volatilized from the swollen water-absorbing polymer containing the chemical solution containing the volatile drug, and the remaining amount of the volatile drug in the contracted water-absorbing polymer is the end point of the effective amount or less. Is displayed by the whitening of the water-absorbing polymer, the method of providing an indicator function,
The chemical solution contained in the swollen water-absorbing polymer further contains a compound having a vapor pressure lower than that of water and water, and the compound is an alcohol or ether having a molecular weight of 118 or more represented by the following formula (1) or (2). And a method of imparting an indicator function to a water-absorbing polymer, wherein the amount of the compound is 70% by mass or less based on the total amount of the compound and water.

[In the formulas (1) and (2)
R ^{1 to} R ⁷ and R ^{11 to} R ²⁰ are each independently a hydrogen atom or an alkyl group. However, the case where R ¹⁹ and R ²⁰ are both hydrogen atoms is excluded. ]

<2> The compound is 3-methoxy-3-methyl-1-butanol, 2-methyl-2,4-pentanediol, 2- (2-ethoxyethoxy) ethanol, dipropylene glycol methyl ether, dipropylene glycol-n. -The method to provide an indicator function to the water absorbing polymer as described in <1> above, which is at least one compound selected from the group consisting of propyl ether, dipropylene glycol dimethyl ether, and diethyl diglycol.
<3> A water-absorbing polymer swollen with a chemical solution containing a volatile drug,
The chemical solution further contains a compound having a vapor pressure lower than that of water and water, and the compound is an alcohol or ether having a molecular weight of 118 or more represented by the following formula (1) or (2), and the amount of the compound Is 70% by mass or less based on the total amount of the compound and the water,
Further, when the volatile agent is volatilized and the water-absorbing polymer contracts, the volatilization agent is whitened to indicate that the remaining amount of the volatile agent is an effective amount or less. A water-absorbing polymer with an indicator function, wherein the content ratio of the sex medicine, the compound and the water is adjusted.

[In the formulas (1) and (2)
R ^{1 to} R ⁷ and R ^{11 to} R ²⁰ are each independently a hydrogen atom or an alkyl group. However, the case where R ¹⁹ and R ²⁰ are both hydrogen atoms is excluded. ]

  The method of imparting an indicator function to the water-absorbing polymer of the present invention is to determine the end of the period of use of the drug by whitening at the end of use of the water-absorbing polymer (when the remaining amount of the drug reaches the end point of the effective amount or less). Thus, an excellent indicator function can be imparted to the water-absorbing polymer. Therefore, at the end point of the medicine, the user can efficiently end use and replace the medicine, and a sufficient effect can always be provided to the user without waste.

FIG. 1 is a photograph showing a whitened state when a swollen water-absorbing polymer was placed in a room temperature environment in Test Example 2-1. FIG. 2 is a photograph showing a state in which the swollen water-absorbing polymer was kept white and not transparent when placed in a room temperature environment in Test Example 2-9.

Hereinafter, the present invention will be described in more detail.
The present invention is directed to a water-absorbing polymer that can be used as various products such as fragrances, deodorants, insecticides, insect repellents, insect repellents, and the like. The indicator function is imparted by whitening of the water-absorbing polymer, indicating that the volatile agent has volatilized from the water-soluble polymer and that the remaining amount of the volatile drug in the contracted water-absorbing polymer has reached the end point of the effective amount or less. The chemical liquid contained in the swollen water-absorbing polymer further contains a compound having a vapor pressure lower than that of water and water, and the amount of the compound is 70% by weight with respect to the total amount of the compound and water. The present invention provides a method for imparting an indicator function to a water-absorbing polymer, characterized in that the ratio is not more than%.
Here, the compound having a vapor pressure lower than that of water is an alcohol or ether having a molecular weight of 118 or more represented by the following formula (1) or (2).

[In the formulas (1) and (2)
R ^{1 to} R ⁷ and R ^{11 to} R ²⁰ are each independently a hydrogen atom or an alkyl group. However, the case where R ¹⁹ and R ²⁰ are both hydrogen atoms is excluded. ]

The present invention is also a water-absorbing polymer swollen with a chemical solution containing a volatile drug, wherein the chemical solution further contains a compound having a vapor pressure lower than that of water and water, and the amount of the compound is 70% by mass or less based on the total amount of the compound and the water, and further, when the volatile drug is volatilized and the water-absorbing polymer contracts, the remaining amount of the volatile drug is an effective amount or less of an end point. What is provided is a water-absorbing polymer with an indicator function, wherein the content of the volatile agent, the compound and the water is adjusted so as to indicate that the water-absorbing polymer is whitened. It is.
Here, the compound having a vapor pressure lower than that of water is an alcohol or ether having a molecular weight of 118 or more represented by the above formula (1) or (2).

<Water-absorbing polymer>
In the present invention, the swollen water-absorbing polymer containing a chemical solution refers to a material in which the water-absorbing polymer as a raw material swells by absorbing the chemical solution and is transparent. The term “transparent” means that it is transparent so long as it transmits light and the other side can be seen through the water-absorbing polymer, and may be colored with a pigment or the like.
The water-absorbing polymer is characterized by whitening when the compound represented by the above formula (1) or (2) contained in the water-absorbing polymer reaches a certain concentration or more. Whitening when the water-absorbing polymer is colored means that, for example, a red transparent water-absorbing polymer has an opaque pink color, and a blue transparent water-absorbing polymer has an opaque light blue color.

  The form of the formulation comprising the water-absorbing polymer of the present invention may consist of each of the granular water-absorbing polymers swollen by causing the raw water-absorbing polymer to absorb the chemical solution, and has a low molecular weight and is soluble in water. The polymer may be used to form a lump formed by thickening and solidifying a liquid, or a sheet. As the polymer having a small molecular weight and soluble in water, a polymer having a weight average molecular weight of 1 million or more is suitable. However, since the visibility of whitening of a water absorbing polymer is favorable, the granular thing which becomes one by one is more preferable.

  When the raw water-absorbing polymer is granular, it is prepared by using a highly water-absorbent resin that is insoluble in water and swells in water. Specifically, an acrylic acid polymer can be used, and a polymer having a weight average molecular weight of 10 million or more is preferable. If the molecular weight is lower than this, it becomes easier to dissolve in water as the molecular weight decreases, so that it becomes soluble in water and imparts thickening, so that the granular form cannot be maintained.

  Examples of the acrylic acid polymer include, for example, a starch-sodium acrylate graft polymer cross-linked product, a polyacrylic acid soda cross-linked product, a polyvinyl alcohol sodium acrylate graft polymer cross-linked product, and a long-chain alkyl acrylate cross-linked polymer. Preferably, polyacrylic acid-acrylic acid amide copolymer, polyisobutylene-maleic anhydride copolymer, polyacrylic acid copolymer and the like can be mentioned.

In addition, known polymers having water absorption can be used, such as hydrolyzate of starch-acrylonitrile graft polymer, cross-linked product of isobutylene-maleic acid copolymer and salt thereof, polyvinyl acetate-ethylene. Examples thereof include a salt of a saponified product of a saponified unsaturated carboxylic acid copolymer, a polysorbbornene, an alkylstyrene-divinylbenzene copolymer, a methacrylate-based crosslinked polymer, and a polyalkylene oxide-based polymer.
Especially, since the visibility of whitening of a water absorbing polymer is favorable, it is preferable to use a highly transparent polymer.

  Since the swollen water-absorbing polymer substantially reflects the shape of the raw water-absorbing polymer, it can be made into a desired shape at the time of production of the water-absorbing polymer as a raw material, for example, spherical, elliptical, rod-shaped, polygonal It can be made into various shapes such as a shape, a confetti shape, and a hollow shape and swelled to give a visual value.

When the water-absorbing polymer used as a raw material is a lump, it is prepared by using a highly water-absorbing polymer having a small molecular weight and soluble in water.
In the case of the massive water-absorbing polymer, it is preferable to use a highly transparent polymer because the whitening visibility of the water-absorbing polymer is good as in the case of the granular shape.

<Chemical solution>
The chemical solution contained in the water-absorbing polymer of the present invention contains a volatile drug, a compound (alcohol or ether) having a lower vapor pressure than water, and water.

(Compound)
The vapor pressure lower than that of water means that the vapor pressure at room temperature (20 ° C. or 25 ° C.) is lower than that of water, and the compound in the present invention has a molecular weight of 118 expressed by the formula (1) or (2). These compounds are compounds having a vapor pressure lower than that of water. Hereinafter, the compound may be simply referred to as “compound”.

[In the formulas (1) and (2)
R ^{1 to} R ⁷ and R ^{11 to} R ²⁰ are each independently a hydrogen atom or an alkyl group. However, the case where R ¹⁹ and R ²⁰ are both hydrogen atoms is excluded. ]

By using the said compound, water with a high vapor pressure volatilizes first from a water absorbing polymer with volatilization of a volatile chemical | medical agent. As the water-absorbing polymer shrinks with the volatilization, the concentration of the compound in the water-absorbing polymer increases. In the water-absorbing polymer, whitening occurs when the concentration of the contained compound exceeds a certain value.
Therefore, when the remaining amount of the volatile drug contained in the contracted water-absorbing polymer reaches the end point of the effective amount or less, the content ratio of the volatile drug, the compound and the water is adjusted so that the water-absorbing polymer is whitened. By doing, the water-absorbing polymer with an indicator function which displays the end point of a volatile chemical | medical agent can be obtained.

In the compound represented by formula (1) or (2), R ^{1 to} R ⁷ and R ^{11 to} R ²⁰ are each independently a hydrogen atom or an alkyl group (provided that both R ¹⁹ and R ²⁰ are hydrogen atoms. Except when).
When R ^{1 to} R ⁷ and R ^{11 to} R ²⁰ are alkyl groups, the alkyl group may have 1 or more carbon atoms, and the upper limit is the molecular weight of the compound represented by formula (1) or (2). There is no particular limitation as long as it is set to 118 or more and the vapor pressure is set lower than that of water. In addition, R ^{1 to} R ⁷ and R ^{11 to} R ²⁰ are preferably selected so that the solubility of the compound represented by the formula (1) or (2) in water is 1% by mass or more.
Satisfying the above condition ^R 1 to R ⁷ and ^R 11 ^{to R 20,} generally preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, A hydrogen atom, a methyl group, an ethyl group or an n-propyl group is particularly preferred.

The molecular weight of the compound may be 118 or more, and the upper limit molecular weight is not particularly limited as long as the vapor pressure of the compound is lower than that of water. Moreover, it is more preferable to determine the upper limit of the molecular weight so that the solubility of the compound in water is 1% by mass or more.
The compound should just satisfy the said conditions and whiten a water absorbing polymer. Moreover, this compound may be used individually or may be used in mixture of multiple.

  More specifically as compounds, 3-methoxy-3-methyl-1-butanol, 2-methyl-2,4-pentanediol, 2- (2-ethoxyethoxy) ethanol, dipropylene glycol methyl ether, dipropylene glycol More preferred is at least one compound selected from the group consisting of -n-propyl ether, dipropylene glycol dimethyl ether and diethyl diglycol.

  The content ratio of the volatile agent, the compound, and water for displaying the end point of the volatile agent by whitening the water-absorbing polymer varies depending on the type of the volatile agent and the compound to be used, and is adjusted accordingly each time.

  Here, the amount of the compound in the chemical solution contained in the swollen water-absorbing polymer is 70% by mass or less based on the total amount of the compound and water. If the amount of the compound is larger than this, the chemical solution may not be absorbed by the water-absorbing polymer. The upper limit of the amount of the compound is preferably 40% by mass or less.

The lower limit of the compound amount relative to the total amount of the compound and water is not particularly limited.
For example, in the case of 3-methoxy-3-methyl-1-butanol, the whitening of the water-absorbing polymer is easy to visually recognize, so it is preferably more than 0.1% by mass and more preferably 1% by mass or more.
Moreover, when it is 10-40 mass%, it is further dried after the end point of a volatile chemical | medical agent, and since a water absorbing polymer can maintain a shape larger than the initial state before swelling even if a water absorbing polymer becomes small, it is preferable. For example, the water-absorbing polymer may have a diameter after drying of about 5 to 10 mm with respect to an initial diameter of 3 to 4.5 mm.
Even if it is dried after the end point of the volatilizing agent, the water-absorbing polymer is maintained at a certain size or more, so even if the formulation is brought down, the water-absorbing polymer inside the formulation is the opening part of the formulation provided for volatilization. This is preferable because it is difficult to spill.
However, the preferred amount of the compound is not limited to these values because it varies depending on the type of the compound, the type of the liquid-absorbing polymer, other additives, and the like.

(Volatile chemicals)
Volatile agents include, for example, plant extracts, essential oils, fragrances, chemical substances, etc. used in various applications such as deodorants, fragrances, insecticides, insect repellents, insect repellents, pest control agents, These may be used alone or in combination.

  For example, Mosouchiku, Grapefruit, Tea, Yucca, Olive, Grape, Mullayer, Licorice, Perilla, Mustard, Ginger, Egony, Kawaragigi, Honoki, Forsythia, Momiji, Pepper, Soybean, Pimenta, Aloe, Ages, Ogon, Ogiri, Otogiri , Orange, seaweed, chamomile, raspberry, kiwi, cucumber, gardenia, clara, mulberry, burdock, sasa, pomegranate, hawthorn, salamander, dianthus, shikon, linden, peonies, shobu, birch, honeysuckle, arnica, yakuinin, horsetail, Kizota, Achillea millefolium, Sage, Senkyu, Assembly, Taiso, Clove, Chimpi, Toki, Tokisenka, Spruce, Dokudami, Carrot, Novara, Hamamelis, Tobikoshi, Biwa, Kuryou, loofah, safflower, lime, hops, pine, pine cone, horse chestnut, Sapindaceae, peach, cornflower, arnica, Otogisou, lily, mugwort, apple, lemon, rose, plant extracts such as burnet, its extract or carbonization thereof;

  Cypress oil, moon peach oil, hiba oil, spearmint oil, basil oil, rose oil, jasmine oil, eucalyptus oil, cubaba oil, peppermint oil, orange oil, lemon oil, grapefruit oil, lime oil, pettibar oil, lemongrass oil, rosemary oil Essential oils such as lavender oil, ylang ylang oil, tea tree oil, bored rose oil, marjoram oil, hop oil, perilla oil, bergamot oil, geranium oil, neem oil, chamomile oil;

  Fragrances such as carvone, linalool, α-pinene, β-pinene, limonene, geraniol, citral, citronellal and the like.

  Others such as natural pyrethrin, praretrin, imiprothrin, phthalthrin, allethrin, transfluthrin, bifenthrin, resmethrin, phenothrin, ciphenothrin, permethrin, cypermethrin, cyfluthrin, deltamethrin, fenpropatrin, empentrin, methfluthrin, profluthrin, etc. , Organophosphorus compounds such as fenitrothion and dichlorvos, carbamate compounds such as carbaryl and thiodicarb, methoxadiazone, fipronil, amidoflumet, dinotefuran, imidacloprid, metoprene, hydroprene, pyriproxyfen, chlorfenapyr, deto, P-menthane-3, 8-diol, ethyl-butylacetylaminopropionate, ha Oil, Citronella Oil, Eucalyptus Oil, galley iodonium oil, Karen grass, and the like.

  In addition to these, preservatives such as phenoxyethanol, p-hydroxybenzoate, dehydroacetic acid, propionic acid, ε-polylysine, isothiazolinone or derivatives thereof, anti-corrosion agents such as pepper extract, denatonium benzoate, 5, 5 ′ UV absorbers such as -bis (2-ethylhexyloxy) -2,2 '-[6- (4-methoxyphenyl) -1,3,5-triazine-2,4-diyl] diphenol can also be used. .

(Other ingredients)
In addition, in the chemical solution, as long as the effects of the present invention are not impaired, for example, organic solvents such as alcohols, polyhydric alcohols, ketones, esters, ethers, chelating agents such as edetic acid and edetate, etc. Etc. can be included.

  Since the liquid absorption capacity varies depending on the water-absorbing polymer, it is not always necessary to absorb the chemical liquid to the maximum liquid-absorbing capacity of the water-absorbing polymer.

<Method for producing water-absorbing polymer>
By causing the water-absorbing polymer of the present invention to swell by containing a specific compound represented by the formula (1) or (2) and water in a specific content ratio, the vapor pressure is lower than that of the volatile drug and water. Indicator function to indicate by whitening of the water-absorbing polymer that the remaining amount of the volatilizing agent of the water-absorbing polymer that has shrunk from the swollen water-absorbing polymer is the effective amount or less. Can be granted. Specifically, the water-absorbing polymer with an indicator function for displaying the end point of the volatile drug can be produced by including the following steps (a) and (b).
(A) a step of allowing a raw water-absorbing polymer to absorb a solution containing a compound having a lower vapor pressure than water and water;
(B) A step of absorbing the volatile chemical into the raw water-absorbing polymer.

The steps (a) and (b) may be performed separately in random order, or may be performed simultaneously.
In the case where the steps (a) and (b) are performed simultaneously, the raw water-absorbing polymer absorbs a chemical solution obtained by dissolving or mixing a volatile chemical in a solution containing a compound having a vapor pressure lower than that of water and water. Let
Moreover, when performing a process (a) and (b) separately, when a process (b) is performed previously, the liquid absorption of a process (a) may become difficult to be carried out. In that case, it is preferable to perform a process (b) after performing a process (a).
In addition to the above steps (a) and (b), other components may be absorbed by the water-absorbing polymer.

  In the step (a), the compound is a compound represented by the formula (1) or (2) described above, having a vapor pressure lower than that of water and having a molecular weight of 118 or more. 70 mass% or less with respect to the total amount, and when the remaining amount of the volatile agent contained in the water-absorbing polymer when the volatile agent is volatilized becomes the end point of the effective amount or less, and the water-absorbing polymer The content ratio of the volatile agent, the compound and water is adjusted so that the time when the water-absorbing polymer is whitened due to the increase in the concentration of the compound in the mixture is adjusted.

  Hereinafter, the present invention will be further described with reference to test examples, but the present invention is not limited thereto.

<Test Example 1>
A perfume (0.3 g) containing limonene, 3-methoxy-3-methyl-1-butanol (0.957 g) and ion-exchanged water (94.743 g) are mixed to form a granular polyacrylic acid as a water-absorbing polymer. Acrylic amide copolymer (3 to 4.5 mm in diameter, 4 g) was allowed to absorb liquid at room temperature to obtain a swollen water-absorbing polymer. At this time, the swollen water-absorbing polymer had a diameter of 15 to 30 mm and was colorless and transparent.
Next, the swollen water-absorbing polymer is raised in a room temperature environment, and the time when the remaining amount of limonene reaches an end point below the effective amount is judged by gas chromatography analysis, and whether or not the water-absorbing polymer is whitened before and after the end point is determined. Judgment was made visually. In addition, the gas chromatography analysis was performed using what crushed the water absorbing polymer and extracted with acetone.

The determination results are shown in Table 1. In Table 1, “swelling” of the water-absorbing polymer represents the water-absorbing polymer at the time of swelling, and “whitening” represents the water-absorbing polymer at the time when the remaining amount of limonene reached the end point of the effective amount or less.
As a result, a whitening phenomenon of the water-absorbing polymer was observed at the end point of limonene. The diameter of the water-absorbing polymer at that time was 7 to 15 mm, and further 4 to 7 mm after drying.

<Test Example 2>
A granular polyacrylic acid-acrylic acid amide copolymer (diameter 3 to 4.5 mm) is used as the water-absorbing polymer. Liquid was absorbed at a ratio to obtain a swollen water-absorbing polymer. At this time, the ratio of the compound was 1% by mass with respect to the total amount of the compound and water. Next, the swollen water-absorbing polymer was placed in a room temperature environment, and the presence or absence of whitening of the water-absorbing polymer was visually determined. The physical properties of each compound and the presence or absence of whitening are shown in Table 2.
In addition, all the compounds in Test Examples 2-1 to 2-7 have a solubility in water of 1% by mass or more.

<Test Example 3>
A granular polyacrylic acid-acrylic acid amide copolymer (diameter 3 to 4.5 mm) is used as the water absorbing polymer, and 96 aqueous 3-methoxy-3-methyl-1-butanol solution is added to 4% by mass of the water absorbing polymer. The liquid was absorbed at a ratio of mass%, and the presence or absence of whitening of the water-absorbing polymer was visually judged in the same manner as in Test Example 2. The diameter of the water-absorbing polymer after liquid absorption was 3 to 30 mm, the diameter during whitening was 3 to 15 mm, and the diameter after drying was as shown in Table 3. In Test Example 3-12, no liquid was absorbed into the water-absorbing polymer.
Table 3 shows the ratio of 3-methoxy-3-methyl-1-butanol to the total amount of 3-methoxy-3-methyl-1-butanol and water, the presence or absence of whitening, and the size of the water-absorbing polymer after drying. .

  From the above results, by using a specific compound (alcohol or ether) having a vapor pressure lower than that of water and a molecular weight of 118 or more, an end point where the residual amount of the volatile drug contained in the water-absorbing polymer is less than the effective amount This can be indicated by whitening of the water-absorbing polymer.

Claims (3)

The volatile chemical is volatilized from the swollen water-absorbing polymer containing the chemical solution containing the volatile chemical, and the residual amount of the volatile chemical in the contracted water-absorbing polymer is the end point of the effective amount or less. A method of providing an indicator function, which is displayed by whitening the functional polymer,
The chemical solution contained in the swollen water-absorbing polymer further contains a compound having a vapor pressure lower than that of water and water, and the compound is an alcohol or ether having a molecular weight of 118 or more represented by the following formula (1) or (2). And a method of imparting an indicator function to a water-absorbing polymer, wherein the amount of the compound is 70% by mass or less based on the total amount of the compound and water.
[In the formulas (1) and (2)
R ^{1 to} R ⁷ and R ^{11 to} R ²⁰ are each independently a hydrogen atom or an alkyl group. However, the case where R ¹⁹ and R ²⁰ are both hydrogen atoms is excluded. ]   The compound is 3-methoxy-3-methyl-1-butanol, 2-methyl-2,4-pentanediol, 2- (2-ethoxyethoxy) ethanol, dipropylene glycol methyl ether, dipropylene glycol n-propyl ether. The method for imparting an indicator function to the water-absorbent polymer according to claim 1, which is at least one compound selected from the group consisting of dipropylene glycol dimethyl ether and diethyl diglycol. A water-absorbing polymer swollen with a chemical solution containing a volatile drug,
The chemical solution further contains a compound having a vapor pressure lower than that of water and water, and the compound is an alcohol or ether having a molecular weight of 118 or more represented by the following formula (1) or (2), and the amount of the compound Is 70% by mass or less based on the total amount of the compound and the water,
Further, when the volatile agent is volatilized and the water-absorbing polymer contracts, the volatilization agent is whitened to indicate that the remaining amount of the volatile agent is an effective amount or less. A water-absorbing polymer with an indicator function, wherein the content ratio of the sex medicine, the compound and the water is adjusted.
[In the formulas (1) and (2)
R ^{1 to} R ⁷ and R ^{11 to} R ²⁰ are each independently a hydrogen atom or an alkyl group. However, the case where R ¹⁹ and R ²⁰ are both hydrogen atoms is excluded. ]