JP4333966B1 - Bath salt and bath water - Google Patents

Abstract

Kind Code: A1 To provide a bathing agent for removing human body dirt during bathing, etc. SOLUTION: A plaque adsorption for preparing a bath for adsorbing plaque containing 35-100 mg / l of chitosan having an average molecular weight of 20000-700000. Bath salt,
The bath agent for adsorbing plaque contains (1) 1 to 10% by weight of chitosan having an average molecular weight of 20,000 to 700,000, and (2) at least one selected from the group consisting of lactic acid, acetic acid and L-ascorbic acid. -8% by weight, (3) an aqueous solution having a pH of 3.5-6.9,
No bathing agent for plaque adsorption [selection figure]

Description

  The present invention relates to a novel bath agent, bath water, and a stain adsorption method.

  Conventionally, various types of bathing agents for home use have been provided depending on their effects and efficacy. For example, a bathing agent that relaxes by coloring and coloring, a bathing agent that improves blood circulation by adding inorganic salts, carbon dioxide, etc., a bathing agent that has a skin care effect by adding moisturizing agent, etc. Bathing agents for improving diseases such as dermatitis are also provided (for example, Patent Document 1 and Patent Document 2).

  On the other hand, skin care products containing chitosan are known. For example, in Patent Document 3, as a composition containing chitosan, chitosan was solubilized with an aqueous lactic acid solution, and then the chitosan solution whose pH was finally adjusted to a neutral level with a sodium hydroxide solution was blended with the chitosan solution. Shampoos and the like are disclosed. Patent Documents 4 to 6 disclose bath agents characterized by blending chitosan. Patent Document 7 discloses that a water-soluble chitosan salt soluble in water having a pH of 6 to 8 obtained by neutralizing an acidic aqueous solution of chitosan (acetic acid, lactic acid, etc.) with a carbonate is used in cosmetics. ing. Patent Document 8 describes a yeast or cell growth and growth inhibitor containing chitosan and ascorbic acid as active ingredients.

However, conventional skin care products containing chitosan cannot be said to have a sufficient effect from the viewpoint of plaque adsorption effect.
JP 2006-213676 JP 2001-354547 JP 2005-509059 gazette JP-A-64-16714 Japanese Patent Laid-Open No. 11-279050 JP 2000-169327 A JP-A 64-62302 JP-A-2-35065

  As a new effect of the bath agent, if bath water that automatically cleans the body at the time of bathing can be provided, in addition to washing before bathing, the body can be further cleaned, which is very convenient. However, there is currently no provision for bathing agents to have the effect of automatically washing the body. Also, the dirt clogged in the pores is difficult to remove even if you rub it with soap. Is also possible. The main object of the present invention is to provide a bath agent or the like for removing human body stains during bathing.

As a result of intensive studies in view of the problems of the prior art, the present inventor has found that the above object can be achieved by using a specific bath containing chitosan, and further studies are completed to complete the present invention. It came to do. That is, this invention relates to the bath agent, bath water, and plaque adsorption | suction method of the following items 1-6.
Item 1. A plaque adsorption bath agent for preparing a plaque adsorption bath containing 35 to 100 mg / l of chitosan having an average molecular weight of 20,000 to 700,000,
The bath agent for adsorbing plaque contains (1) 1 to 10% by weight of chitosan having an average molecular weight of 20,000 to 700,000, and (2) at least one selected from the group consisting of lactic acid, acetic acid and L-ascorbic acid. -8% by weight, (3) an aqueous solution having a pH of 3.5-6.9,
A bathing agent for adsorbing plaque.
Item 2. Item 2. The plaque adsorption bath agent according to Item 1, wherein the plaque adsorption bath agent contains 2 to 8% by weight of chitosan having an average molecular weight of 20,000 to 700,000.
Item 3. Item 3. The plaque adsorption bath agent according to Item 1 or 2, wherein the plaque adsorption bath agent contains 1 to 8% by weight of L-ascorbic acid.
Item 4. A bath water for adsorbing plaque which is an aqueous chitosan solution containing 35 to 100 mg / l of chitosan having an average molecular weight of 20,000 to 700,000.
Item 5. The bath water for plaque adsorption according to claim 4, which is obtained by diluting the plaque adsorption bath agent according to any one of Items 1 to 3 with water or warm water.
Item 6. A plaque adsorption method for adsorbing plaque onto the chitosan by bathing in a bath for washing plaque adsorption, which is an aqueous chitosan solution containing 35 to 100 mg / l of chitosan having an average molecular weight of 20,000 to 700,000.

Bathing agent The bathing agent for adsorbing plaque according to the present invention is a bathing agent for preparing bath water containing 35 to 100 mg / l of chitosan having an average molecular weight of 20,000 to 700,000. (1) Average molecular weight in the total amount of bathing agent 1 to 10% by weight of chitosan of 20000 to 700000, (2) 1 to 8% by weight of at least one selected from the group consisting of lactic acid, acetic acid and L-ascorbic acid, and having a pH of 3.5 to 6.9 It is an aqueous solution.

  By bathing in the specific bath water described below obtained by using the above-mentioned specific bath agent of the present invention, chitosan is adsorbed to the plaque adhering to the human skin, and from the human body to the plaque, especially into the skin pores. The human body can be thoroughly washed to remove clogged dirt. Moreover, since the chitosan adsorbed with the dirt floats on the surface of the water (hot water), the cleaning effect of the human body and the removal of dirt (dirt) during bathing can be easily visually confirmed.

  The bath agent of the present invention must contain chitosan having an average molecular weight of 20,000 to 700,000, and chitosan is uniformly dissolved in water. Known or commercially available chitosan can be used. Chitosan is obtained by deacetylating chitin, which is abundant in exoskeletons such as crusts. The degree of deacetylation is not limited, but is generally 60% or more.

  The average molecular weight of chitosan is usually about 20,000 to 700,000, preferably about 30,000 to 100,000, and more preferably about 40,000 to 80,000. If it is less than 20000, the effect of adsorbing the plaque will be diminished or will not be exhibited. Moreover, when it exceeds 700,000, manufacture of high concentration chitosan aqueous solution will become difficult.

  The average molecular weight of chitosan in the present invention is measured by gel permeation chromatography. Specifically, for example, Waters 2695 HPLC is used as an apparatus, column: Shodex OHpax SB-804 HQ (8 mmφ × 300 mm), exclusion limit molecular weight: 1000000, measurement temperature: 40 ° C., sample injection: autosampler 20 μl, mobile phase : 0.1 M acetic acid + 0.1 M sodium acetate aqueous solution 1.0 ml / min, detector: Waters 2410 differential refractometer, data processing: Waters Millenium32, standard substance: pullulan and D (+)-glucose Is.

  The content of chitosan in the bath agent is usually about 1 to 10% by weight, preferably about 2 to 8% by weight, particularly preferably about 2 to 6% by weight.

  If the content of chitosan in the bathing agent is less than 1% by weight, it is necessary to use a large amount of bathing agent in order to obtain a bath containing a specific concentration of chitosan, and the amount of chitosan in the bathing agent is 10% by weight. If it exceeds about%, chitosan becomes a gel, and even if this bath agent is added to water to obtain bath water, the plaque adsorption effect by the bath water is diminished or no longer exhibited.

  It is essential that the bath agent of the present invention contains at least one acid selected from the group consisting of lactic acid, acetic acid and L-ascorbic acid. Thereby, chitosan having an average molecular weight of 20,000 to 700,000 can be uniformly dissolved in water.

  The solubility of chitosan in water varies depending on the type and amount of acid used, but the pH is adjusted to 2.0 to 6. depending on at least one acid selected from the group consisting of lactic acid, acetic acid and L-ascorbic acid. By setting the number to about 9, the chitosan can be easily and uniformly dissolved in water.

  The content of at least one acid selected from the group consisting of lactic acid, acetic acid and L-ascorbic acid is not particularly limited as long as the homogeneous aqueous solution of chitosan is obtained, and is usually about 1 to 8% by weight, preferably It is about 2 to 5% by weight.

  Chitosan having a large molecular weight with an average molecular weight of 20000 or more is hardly soluble in water. Therefore, even if an acid is used, if the amount of chitosan in the aqueous solution exceeds 10% by weight, chitosan does not dissolve in water but aggregates (suspends). Even when the amount is 10% by weight or less, it takes a long time to uniformly dissolve high-concentration chitosan in water, but it may not dissolve. From the viewpoint of quickly producing a high concentration chitosan aqueous solution, L-ascorbic acid is preferred.

  The bathing agent of the present invention may further contain a pH adjuster as necessary. A pH adjuster is not limited, A well-known or commercially available thing can be used. Examples of the pH adjuster include sodium carbonate, sodium lactate, sodium hydrogen carbonate and the like. Among these, sodium carbonate is particularly preferable. Since the generation of gas can be prevented by selecting sodium carbonate, damage to the container due to the generation of gas can be prevented when the bathing agent is sealed in the container.

  The pH of the bathing agent of the present invention is usually about 3.5 to 6.9, preferably about 5.6 to 6.2. Chitosan has a property of dissolving in an acidic solution but gelling when it becomes alkaline. Therefore, it is necessary to make the pH of the bathing agent always acidic.

  When using a pH adjuster, the pH adjuster may be added to a mixed solution of chitosan, the acid and water.

  The content of the pH adjusting agent is not particularly limited as long as it varies depending on the target pH, the type and amount of acid used, and the pH of the bath agent is adjusted to be in the above range. Since the pH adjusting agent can open the pores of the human body and make chitosan easily adsorb the plaque, it can be expected to more effectively remove the plaque from the human body.

  Moreover, when generally selling as a bath agent, it is desirable that pH is a weak acid for safety. The content of the pH adjusting agent varies greatly depending on the type of acid used. For example, when L-ascorbic acid having a low acidity is used, the pH adjusting agent does not need to be used or may be used in a very small amount.

  The bath agent of the present invention mainly uses water as a solvent, but may further contain an organic solvent or the like. As an organic solvent, ethanol etc. are mentioned, for example. Thereby, the antiseptic and antifungal effects can be exhibited, and the solubility of the preservative can be improved.

  The bath agent of the present invention may contain known additives such as preservatives, fragrances, and coloring agents. Examples of the preservative include methyl paraben and phenoxyethanol.

Manufacturing method of bath agent The manufacturing method of the bath agent for plaque adsorption of this invention is at least 1 sort (s) selected from the group which consists of (1) chitosan with an average molecular weight 20000-700000, (2) lactic acid, an acetic acid, and L-ascorbic acid. And (3) a step of mixing water.

  (1) Chitosan having an average molecular weight of 20,000 to 700,000, (2) at least one selected from the group consisting of lactic acid, acetic acid and L-ascorbic acid, and (3) the mixing order of water is the total amount of bathing agent for plaque adsorption. On the other hand, the aqueous solution in which 1 to 10% by weight of chitosan is dissolved is not particularly limited.

  For example, at least one acid selected from the group consisting of lactic acid, acetic acid and L-ascorbic acid is mixed with water to prepare an aqueous solution having a pH of 2.0 to 6.9, and this aqueous solution and an average molecular weight of 20,000 to 700,000 are prepared. A homogeneous aqueous solution can be obtained by mixing with chitosan.

  The amount of at least one acid selected from the group consisting of chitosan, lactic acid, acetic acid and L-ascorbic acid is the same as described above.

  Moreover, what is necessary is just to use the said chitosan as chitosan. The shape of chitosan before being mixed with water is not limited, and may be any of agglomerates, granules, powders, and the like. Moreover, in order to make it uniform chitosan aqueous solution, you may stir as needed, for example, what is necessary is just to stir at room temperature for about 20 minutes-120 minutes.

  The pH of an aqueous solution containing at least one selected from the group consisting of lactic acid, acetic acid, and L-ascorbic acid (hereinafter, also simply referred to as “lactic acid-containing aqueous solution”) is usually about pH 2.0 to 6.9, preferably Is about pH 3.0-4.0.

  The solubility of chitosan in water varies depending on the type and amount of acid used, but the pH is adjusted to 2.0 to 6. depending on at least one acid selected from the group consisting of lactic acid, acetic acid and L-ascorbic acid. By setting it to about 9, a high concentration chitosan aqueous solution can be obtained.

  From the viewpoint of quickly producing a high concentration chitosan aqueous solution, L-ascorbic acid is preferred.

  If necessary, the pH of the bathing agent can be adjusted to 3.5 to 6.9 by adding a pH adjuster to the chitosan-dissolved aqueous solution prepared in the above step.

  As the pH adjuster, those mentioned above can be used. The addition amount of the pH adjusting agent is not particularly limited as long as the pH can be adjusted to 3.5 to 6.9, and is appropriately determined according to the type of the pH adjusting agent.

  When using a pH adjuster, the pH adjuster may be added to a mixed solution of chitosan, the acid and water.

  The content of the pH adjusting agent is not particularly limited as long as it varies depending on the target pH, the type and amount of acid used, and the pH of the bath agent is adjusted to be in the above range. The content of the pH adjusting agent varies greatly depending on the type of acid used. For example, when L-ascorbic acid is used, the pH adjusting agent does not need to be used or may be a very small amount.

  The bathing agent of the present invention mainly uses water as a solvent, but in addition, an organic solvent or the like may be added. As the organic solvent, those described above can be used. The bath agent of the present invention may contain known additives such as preservatives, fragrances, and coloring agents. The above-mentioned preservatives can be used.

Plaque attraction bath hot water for plaque adsorption bath water present invention, a chitosan having an average molecular weight from 20,000 to 700,000 in bathwater is chitosan aqueous solution containing 35 to 100 mg / l.

  In the bath water for adsorption of the present invention, chitosan having an average molecular weight of 20000 to 700000 is uniformly dissolved in the bath water, and the amount of chitosan in the bath water is 35 to 100 mg / l, preferably 37 to By being in the range of 93 mg / l, particularly preferably 40 to 90 mg / l, the plaque adsorption effect by chitosan is remarkably improved.

  There is an optimum concentration range for the aggregating ability of chitosan, and aggregation does not occur even if the addition amount is less than that range. In the bath water of the present invention, the plaque adsorption effect by chitosan is remarkably improved only when the amount of chitosan in the bath water is within the optimum concentration range of the chitosan aggregation ability. At a low concentration of chitosan concentration of 30 mg / l or less, chitosan has no aggregating ability. Moreover, chitosan does not have an aggregating ability even at a high concentration of 110 mg / l or more. This is because in the presence of excess polymer, the total adsorption sites on the surface of the suspended particles are occupied by the adsorption of individual molecules, resulting in less cross-linking.

  Chitosan may be the above-mentioned chitosan. It is preferable that the pH of the bath is around neutral (pH 6.8 to 7.2).

  The optimum temperature of the bath water for adsorption of the present invention is usually about 38 to 43 ° C, preferably about 40 to 42 ° C.

  A solid chitosan having an average molecular weight of 20000 or more is very difficult to dissolve in water. For example, if 20 g of the chitosan is added to 140 to 180 liters of water and stirred, the chitosan does not become a uniform aqueous solution. Even if you take a bath, the effect of adsorbing plaque will not be achieved. For example, chitosan is dissolved with an acid in advance before making bath water to make a uniform aqueous solution, and by adding this aqueous solution to water, bath water in which chitosan is uniformly dissolved in bath water can be obtained.

  The bath water for adsorption of the present invention can also be obtained by diluting the bathing agent of the present invention with 140 to 180 liters of water. As a result, an aqueous solution of chitosan is obtained in which the amount of chitosan is in the range of 35 to 100 mg / l and the pH of the bath water for adsorbing plaque is set to around neutral (pH 6.8 to 7.2). Can do. Since the bath agent of the present invention is a uniform aqueous solution containing a very high concentration of chitosan, it is possible to obtain bath water for adsorbing plaque only by using a small amount of the bath agent.

  If the hot water at the time of bathing is in an acidic state (less than pH 4.0), the pores are difficult to open even when heated by hot water, and the effects of the present invention may not be sufficiently exhibited.

  The plaque adsorption bath of the present invention may contain an acid. Examples of the acid contained in the plaque adsorption bath water of the present invention include lactic acid, acetic acid and L-ascorbic acid. These acids may be contained alone or in combination of two or more.

  When an acid is contained in the bath for adsorbing plaque of the present invention, for example, the amount in the case of lactic acid is usually about 0.010 to 0.100 ml / l, preferably about 0.066 to 0.085 ml / l.

  By bathing in the bath for adsorbing plaque according to the present invention, the chitosan dissolved in water is adsorbed to the plaque adhering to the human skin, and removes plaque from the human body, particularly the clogged pores in the skin. Therefore, the human body can be washed sufficiently. Moreover, since the chitosan adsorbed with the dirt floats on the surface of the water (hot water), the cleaning effect of the human body and the removal of dirt (dirt) during bathing can be easily visually confirmed.

  The plaque adsorption bath water of the present invention may further contain a pH adjusting agent. A pH adjuster is not limited, A well-known or commercially available thing can be used. Examples of the pH adjuster include sodium carbonate, sodium lactate, sodium hydrogen carbonate and the like. Among these, sodium carbonate is particularly preferable.

  The amount of the pH adjusting agent used in the bath for adsorbing plaque according to the present invention varies depending on the target pH, the type and amount of acid used, and may be adjusted so that the pH of the bath is within the above range. There is no particular limitation. Since the pH adjusting agent can open the pores of the human body and make chitosan easily adsorb the plaque, it can be expected to more effectively remove the plaque from the human body.

  In addition, the bath water for adsorbing plaque according to the present invention may contain known additives used for bathing agents such as organic solvents, preservatives, fragrances, and coloring agents. As an organic solvent, ethanol etc. are mentioned, for example. Examples of the preservative include methyl paraben and phenoxyethanol.

  In addition, the plaque adsorption method of the present invention is characterized by bathing the chitosan aqueous solution containing 35 to 100 mg / l of chitosan having an average molecular weight of 20,000 to 700,000. By this method, the dirt adhering to the human body can be easily removed. The dirt clogged in the pores is difficult to remove even if it is rubbed with soap or the like, but it is possible to easily remove the clogged clogged pores from the human skin surface by bathing in the bath for adsorbing the plaque of the present invention. it can. This makes it possible to eliminate body odors, aging odors and the like caused by dirt, and it is possible to remove dirt simply by taking a bath. Furthermore, since the removed plaque floats on the surface of the hot water, the removal of the stain can be easily recognized.

  The mechanism for exerting the plaque adsorption effect of the present invention is presumed as follows. Chitosan is charged positively (+) in an aqueous solution, and human plaque (mainly protein) is charged negatively (-). The dirt clogged in the pores is hard to fall off even when rubbed, but when the present invention is used particularly as a bath agent, the human body is heated during bathing, so the pores of the human body are in an open state. Since the dirt (-) is attracted to and absorbed by chitosan (+), the dirt clogged in the pores is easily adsorbed and removed from the skin surface of the human body. It is considered that chitosan adsorbing this plaque precipitates in the hot water and floats on the surface of the hot water. And there is an optimum concentration range for the coagulation ability of chitosan, and the amount of chitosan in the bath water is 35-100 mg / l, preferably 37-93 mg / l, particularly preferably 40-90 mg / l. , The dirt adsorption effect is remarkably improved.

  By using the bath agent of the present invention, it is possible to easily remove the dirt adhering to the human body. The dirt clogged in the pores is hard to be removed by rubbing with soap or the like. However, by bathing in the bath water of the present invention, the clogged clogged pores can be easily removed from the skin surface of the human body. This makes it possible to eliminate body odors, aging odors and the like caused by dirt, and it is possible to remove dirt simply by taking a bath. Furthermore, since the removed plaque floats on the surface of the hot water, the removal of the stain can be easily recognized.

  EXAMPLES Hereinafter, although an Example, a comparative example, and a test example are given and this invention is demonstrated further in detail, this invention is not limited to these.

Example 1
20 g of chitosan (average molecular weight 40000) is added to 0.5 liter of a 2.4% by weight aqueous solution of lactic acid (pH 3.0) and stirred at room temperature for 80 minutes to dissolve chitosan in the aqueous lactic acid solution to adjust the pH. 20 ml of 5% sodium carbonate solution was added as an agent to make a 4% by weight chitosan solution. The pH of this chitosan solution was 5.8. The aqueous solution thus obtained was used as the bath agent of Example 1.

The average molecular weight of chitosan was measured by gel permeation chromatography. In this measurement, sample preparation: About 20 mg of sample (chitosan) was completely dissolved in about 5 ml of mobile phase and subjected to analysis. The measurement conditions were as follows.
Instrument: Waters 2695 HPLC
Column: Shodex OHpax SB-804 HQ (8mmφ × 300mm)
Exclusion limit molecular weight: 1,000,000
Measurement temperature: 40 ℃
Sample injection: 20μl autosampler
Mobile phase: 0.1 M acetic acid + 0.1 M sodium acetate aqueous solution 1.0 ml / min
Detector: Waters 2410 Differential refractometer Data processing: Waters Millenium32
Standard substances: pullulan and D (+)-glucose.

Test example 1
The bath agent obtained in Example 1 was put into a bath containing 140 liters of hot water, and the chitosan concentrations were 20, 30, 35, 37, 40, 45, 65, 85, 90, 93, 95, respectively. It adjusted to 100,110 and 120 mg / l, and the bath water (42 degreeC) was obtained. About each bath water, it was investigated whether a white floating substance floated on the bath water surface 15 minutes after bathing. Moreover, a white floating substance was extract | collected and the ninhydrin reaction test was done on condition of the following. The results are shown in Table 1.

(Ninhydrin reaction test)
In this investigation, the white floating substance floating on the hot water surface was scooped up with a fine metal mesh and dried on a filter paper. 10 mg of this dried suspension was placed in a 10 ml beaker and 5 ml of 1% ninhydrin solution was added and heated for about 3 minutes. As a result, since it reacted with the ninhydrin solution, the solution turned from colorless and transparent to purple. As a result, it was confirmed that the suspended matter was protein, that is, dirt adhered to the human body.

Example 2
20 g of chitosan (average molecular weight of about 40,000) is added to 0.5 liter of an L-ascorbic acid 4 wt% aqueous solution (pH 3.0) and stirred at room temperature for 80 minutes to convert the chitosan into an L-ascorbic acid aqueous solution. After dissolution, 9 ml of 5% sodium carbonate solution was added as a pH adjuster to make a 4 wt% chitosan solution. The pH of this chitosan solution was 5.8. The aqueous solution thus obtained was used as the bath agent of Example 2.

  The average molecular weight of chitosan was measured by gel permeation chromatography. In this measurement, sample preparation: About 20 mg of sample (chitosan) was completely dissolved in about 5 ml of mobile phase and subjected to analysis. The measurement conditions for the average molecular weight of chitosan are the same as in Example 1.

Test example 2
The obtained bathing agent was put into a bathtub containing 140 liters of hot water, and the chitosan concentrations were 20, 30, 35, 37, 40, 45, 65, 85, 90, 93, respectively, as in Test Example 1. The concentration was adjusted to 95, 100, 110 and 120 mg / l to obtain bath water (42 ° C.). About each bath water, it was investigated whether a white floating substance floated on the bath water surface 15 minutes after bathing. Further, a white floating substance was collected and a ninhydrin reaction test was performed under the same conditions as in Test Example 1. The results are shown in Table 1.

Comparative Example 1
Without using the bathing agents of Examples 1 and 2, bathing was carried out in hot water (42 ° C.) for 15 minutes, but no suspended matter floated on the surface of the bathing water.

実施例３
キトサン（平均分子量８００００程度）１０ｇ及びＬ−アスコルビン酸７．０gを水に加え、室温にて２０分間攪拌することにより、２００ｍｌのキトサン水溶液とした。なお、キトサンの平均分子量の測定条件は実施例１と同様である。

Example 3
10 g of chitosan (average molecular weight of about 80000) and 7.0 g of L-ascorbic acid were added to water and stirred at room temperature for 20 minutes to give a 200 ml chitosan aqueous solution. The measurement conditions for the average molecular weight of chitosan are the same as in Example 1.

  Subsequently, 1 ml of 3% by weight sodium carbonate aqueous solution was added to 200 ml of this chitosan-dissolved L-ascorbic acid aqueous solution to adjust the pH to 5.8.

Test example 3
200 ml of the obtained bathing agent was put into a bath containing 200 liters of hot water (42 ° C.) and bathed in the bath. After 15 minutes of bathing, a white floating substance floated on the hot water surface. Further, a white floating substance was collected and a ninhydrin reaction test was performed under the same conditions as in Test Example 1. Since the suspended matter reacted with the ninhydrin solution, it was confirmed that it was protein, that is, dirt adhered to the human body. Moreover, the pH could be adjusted to 5.8 by adding only 1 ml of a 3% by weight sodium carbonate aqueous solution, and the pH adjustment was very easy.

Claims (5)

( 1) containing 1 to 10% by weight of chitosan having an average molecular weight of 20,000 to 700,000, (2) containing 1 to 8% by weight of at least one selected from the group consisting of lactic acid, acetic acid and L-ascorbic acid; 3) pH is obtained by diluting with warm water and aqueous der Ru plaque adsorption bath agent of 3.5 to 6.9, is a chitosan having an average molecular weight from 20,000 to 700,000 chitosan aqueous solution containing 40~90mg / l dross Bath water for adsorption . The plaque adsorption bath agent contains chitosan having an average molecular weight of from 20,000 to 700,000 2-8 wt%, bathwater for plaque adsorption of claim 1. The said bath agent for adsorption of plaque is bath water for adsorption of plaque according to claim 1 or 2 containing 1 to 8% by weight of L-ascorbic acid. (1) containing 1 to 10% by weight of chitosan having an average molecular weight of 20,000 to 700,000, (2) containing 1 to 8% by weight of at least one selected from the group consisting of lactic acid, acetic acid and L-ascorbic acid, 3) A plaque adsorption bathing agent, which is an aqueous solution having a pH of 3.5 to 6.9, is diluted with warm water to prepare a chitosan aqueous solution containing 40 to 90 mg / l of chitosan having an average molecular weight of 20,000 to 700,000. A method for preparing a bath for adsorbing plaque, characterized by A plaque adsorption method for adsorbing plaque onto the chitosan by bathing in the plaque adsorption bath water according to claim 1.