JP2021066750A - Antibacterial substance and liquid antibacterial agent, and method for manufacturing liquid antibacterial agent - Google Patents

Abstract

To provide an antibacterial substance and a liquid antibacterial agent having higher stability than prior antibacterial agents and which can be applied to a variety of antibacterial objects that are liquids.SOLUTION: An antibacterial substance comprises a water-soluble polysaccharide having an average molecular weight of 1,200,000 or greater, to which deposited silver particles having a diameter of 1 nm or greater are caused to adhere in a dispersed state. The antibacterial substance is admixed in a state of dissolved in an aqueous solvent, yielding a liquid antibacterial agent. The silver has a concentration of 80 ppm or greater.SELECTED DRAWING: Figure 1

Description

The present invention relates to an antibacterial substance, a liquid antibacterial agent, and a method for producing a liquid antibacterial agent.

Conventionally, various antibacterial substances have been proposed in order to prevent microorganisms from multiplying and being contaminated.

For example, a paraoxybenzoic acid ester (so-called paraben) is added to prevent the growth of microorganisms in cosmetics.

In foods, benzoic acid and sodium benzoate are added as preservatives to suppress the growth of microorganisms and improve the preservability of foods.

However, these antibacterial substances such as cosmetics and foods (hereinafter, also simply referred to as “objects”) are those that come into contact with the skin of the human body or are orally ingested, and paraoxybenzoic acid esters and benzoic acid as much as possible. , There is a desire to suppress the growth of microorganisms without using sodium benzoate or the like.

Therefore, the present inventor has conducted diligent research in the past, and mixed a silver solution containing a polypeptide carrying fine silver particles and a radish fermented liquid obtained by fermenting and squeezing radish in a predetermined immersion liquid. We are proposing an antibacterial agent.

According to the antibacterial agent obtained by mixing the silver solution and the fermented radish solution, it is possible to effectively perform antibacterial and sterilization against mold and yeast which are relatively difficult to sterilize and non-heated antibacterial.

Japanese Unexamined Patent Publication No. 2010-05913

However, the antibacterial agent obtained by mixing the above-mentioned conventional silver solution and fermented radish solution has a problem that silver particles easily fall off from a polypeptide that functions as a carrier of silver particles, and precipitation or aggregation may occur. It was.

The present invention has been made in view of such circumstances, and is more stable than an antibacterial agent obtained by mixing the above-mentioned conventional silver solution and radish fermented liquid, and is a variety of liquids. Provide antibacterial substances and liquid antibacterial agents that can be used for antibacterial objects.

Further, in the present invention, a liquid antibacterial agent having higher stability than the antibacterial agent obtained by mixing the above-mentioned conventional silver solution and radish fermented liquid and which can be used for antibacterial objects which are various liquids is produced. Methods and methods for suppressing microbial growth are also provided.

In order to solve the above-mentioned conventional problems, the antibacterial substance according to the present invention is composed of (1) a water-soluble polysaccharide having an average molecular weight of 1.2 million or more to which silver precipitated particles having a diameter of 1 nm or more are adhered in a dispersed state. And said.

Further, the antibacterial substance according to the present invention is also characterized in that (2) the water-soluble polysaccharide is a complex of hyaluronic acid and xanthan gum.

Further, in the liquid antibacterial agent according to the present invention, (3) the above-mentioned antibacterial substance is contained in a state of being dissolved in an aqueous solvent.

Further, the liquid antibacterial agent according to the present invention is also characterized in that (4) the concentration of the silver is 80 ppm or more.

Further, in the method for producing a liquid antibacterial agent according to the present invention, (5) a water-soluble polysaccharide having an average molecular weight of 1.2 million or more, a diammine silver ion, and an organic acid or sugar having a reducing ability of the diammine silver ion are water-based. A reaction step of reacting in a solvent to obtain a reaction solution containing a water-soluble polysaccharide having an average molecular weight of 1.2 million or more, to which precipitated silver particles having a diameter of 1 nm or more are adhered in a dispersed state, and a reaction solution contained in the reaction solution. It was decided to have a liquid antibacterial agent preparation step of removing ammonium salts, nitrates and silver salts and purifying them into liquid antibacterial agents.

Further, the method for producing a liquid antibacterial agent according to the present invention is also characterized in that (6) the reaction step is carried out under alkaline conditions.

Further, in the method for suppressing microbial growth according to the present invention, (7) an antibacterial substance composed of a water-soluble polysaccharide having an average molecular weight of 1.2 million or more, in which silver precipitated particles having a diameter of 1 nm or more are adhered to an object in a dispersed state. Was decided to be added.

According to the antibacterial substance according to the present invention, it is composed of a water-soluble polysaccharide having an average molecular weight of 1.2 million or more, to which precipitated silver particles having a diameter of 1 nm or more are adhered in a dispersed state. It is possible to provide an antibacterial substance which is highly stable as compared with an antibacterial agent obtained by mixing with and can be used for an antibacterial object which is various liquids.

Further, according to the liquid antibacterial agent according to the present invention, since the above-mentioned antibacterial substance is contained in a state of being dissolved in an aqueous solvent, it can be used as an antibacterial agent obtained by mixing a conventional silver solution and a radish fermented liquid. It is possible to provide a liquid antibacterial agent which is more stable than the other and can be used for antibacterial objects which are various liquids.

Further, in the liquid antibacterial agent according to the present invention, if the silver concentration is 80 ppm or more, it can be easily adjusted to a desired practical use concentration by diluting.

Further, in the method for producing a liquid antibacterial agent according to the present invention, a water-soluble polysaccharide having an average molecular weight of 1.2 million or more, diammine silver ion, and an organic acid or sugar having a reducing ability of the diammine silver ion are mixed in an aqueous solvent. A reaction step of reacting to obtain a reaction solution containing a water-soluble polysaccharide having an average molecular weight of 1.2 million or more, to which precipitated silver particles having a diameter of 1 nm or more are adhered in a dispersed state, and an ammonium salt contained in the reaction solution Since it has a liquid antibacterial agent preparation step of removing nitrates and silver salts to purify it into a liquid antibacterial agent, it is more stable than a conventional antibacterial agent obtained by mixing a silver solution and a radish fermented liquid. It is possible to provide a method for producing a liquid antibacterial agent which is high in quality and can be used for antibacterial objects which are various liquids.

Further, by performing the reaction step under alkaline conditions, it is possible to suppress the amount of silver particles that are not supported and precipitate, and moreover, the product stability of the liquid antibacterial agent, that is, after the liquid antibacterial agent is prepared. The formation of precipitates over time can also be suppressed.

Further, according to the method for suppressing microbial growth according to the present invention, an antibacterial substance composed of a water-soluble polysaccharide having an average molecular weight of 1.2 million or more, in which precipitated silver particles having a diameter of 1 nm or more are adhered to the object in a dispersed state. Since it is added, it is possible to suppress the growth of various microorganisms.

It is explanatory drawing which showed the electron microscope image of the antibacterial substance which concerns on this embodiment.

The present invention provides an antibacterial substance composed of a water-soluble polysaccharide having an average molecular weight of 1.2 million or more, to which silver precipitated particles having a diameter of 1 nm or more are adhered in a dispersed state.

In particular, since the diameter of the precipitated silver particles is 1 nm or more, more preferably 1 nm or more and 100 nm or less, it is possible to exert an extremely excellent antibacterial effect and bactericidal effect against mold and yeast. If the particle size of the precipitated silver is less than 1 nm, secondary agglutination occurs, which is not preferable, and if it exceeds 100 nm, precipitation or antibacterial activity is lowered, which is not preferable.

Further, since a water-soluble polysaccharide is used as a carrier to which silver particles are attached, an extremely stable antibacterial substance can be obtained.

Here, the water-soluble polysaccharide is not particularly limited as long as it is a polysaccharide soluble in an aqueous solvent (for example, water, a water-miscible organic solvent, or water to which a water-soluble substance is added). Examples of such polysaccharides include hyaluronic acid, chondroitin sulfate, fucoidan, sacran, and xanthan gum, and hyaluronic acid, sacran, and xanthan gum can be particularly preferably used.

Further, it is desirable that these water-soluble polysaccharides have an average molecular weight of 1.2 million or more. When the average molecular weight is less than 1.2 million, the stability is lowered, and the silver particles are easily dropped from the water-soluble polysaccharide or aggregated. By setting the average molecular weight to 1.2 million or more, more preferably 1.8 million or more, it is possible to obtain an antibacterial substance that does not easily aggregate while suppressing the loss of silver from the water-soluble polysaccharide.

Further, the water-soluble polysaccharide may be a complex of two or more kinds of water-soluble polysaccharides. In this case, an extremely stable antibacterial substance can be obtained by particularly preferably forming a complex of hyaluronic acid and xanthan gum, or a complex of hyaluronic acid and xanthan gum in addition to a further water-soluble polysaccharide. ..

When the water-soluble polysaccharide is a complex using hyaluronic acid and xanthan gum, the composition weight ratio of xanthan gum in the complex is 0.5 to 1.5 when the composition weight ratio of hyaluronic acid is "1". Is desirable.

When the composition weight ratio of xanthan gum is less than 0.5 with respect to hyaluronic acid "1", it becomes difficult to obtain the effect of improving stability by xanthan gum. Further, if the constituent weight ratio of xanthan gum exceeds 1.5 with respect to hyaluronic acid "1", the carrying function of the metal particles originally possessed by hyaluronic acid is canceled by the excessive amount of xanthan gum, which is not preferable because the stability is lowered. ..

Even when other water-soluble polysaccharides are added, when a complex is formed using hyaluronic acid and xanthan gum as water-soluble polysaccharides, the constituent weight ratio of hyaluronic acid is set to "1". By setting the constituent weight ratio of xanthan gum at that time to 0.5 to 1.5, that is, the weight ratio of hyaluronic acid and xanthan gum to be approximately 1: 1 ± 0.5, the shedding and precipitation of silver particles are effectively suppressed and the stability is high. It can be an antibacterial substance.

Further, the antibacterial substance according to the present embodiment can be used as an extremely stable liquid antibacterial agent by being present in an aqueous solvent.

In particular, this liquid antibacterial agent can be used as a liquid antibacterial agent that exerts an antibacterial effect in a state of being appropriately added to a predetermined object and diluted by setting the silver concentration to 80 ppm or more.

In addition, the antibacterial substance according to the present embodiment can exhibit excellent antibacterial effect and bactericidal effect by allowing the silver concentration to be about 0.1 to 8 ppm in the object. Yes, for example, if the concentration of the liquid antibacterial agent is 80 ppm, it can be diluted in the range of 10-fold to 800-fold dilution and used.

The present application also provides a method for producing a liquid antibacterial agent containing the above-mentioned antibacterial substance.

Specifically, a water-soluble polysaccharide having an average molecular weight of 1.2 million or more, diammine silver ion, and an organic acid or sugar having a reducing ability of the diammine silver ion are reacted in an aqueous solvent to have a diameter of 1 nm or more. A reaction step of obtaining a reaction solution containing a water-soluble polysaccharide having an average molecular weight of 1.2 million or more to which silver precipitated particles are adhered in a dispersed state, and purification by removing ammonium salts, nitrates and silver salts contained in the reaction solution. Provided is a method for producing a liquid antibacterial agent, which comprises a step of preparing a liquid antibacterial agent as a liquid antibacterial agent.

Diammine silver ion is a substance represented by the chemical formula [Ag (NH ₃ ) ₂ ] ⁺ , and can be obtained, for example, according to the following reaction formula.
_{^{2Ag + + 2OH - → Ag 2}} O + H 2 O
_{Ag 2 O + 4NH 3 + H} 2 O → 2 [Ag (NH 3) 2] + + 2OH -

The organic acid having a reducing ability of diammine silver ion is not particularly limited, but one that does not change the color tone when the organic acid is oxidized is more preferable. As the organic acid, for example, ascorbic acid or citric acid can be used.

Further, the sugar having a reducing ability of diammine silver ion is not particularly limited, and for example, glucose, xylose or the like can be used.

Each component is composed of 94.05 ± 5 parts by weight (that is, 89.05 to 99.05 parts by weight) of an aqueous solvent and 0.95 ± 0.5 parts by weight (that is, 0.45 to 1.45 parts by weight) of a water-soluble polysaccharide having an average molecular weight of 1.2 million or more. , 2.6 ± 2.5 parts by weight (ie, 0.1 to 5.1 parts by weight) of organic acid or sugar capable of reducing diammine silver ions, and 0.035 ± 0.0315 parts by weight (ie, 0.0035 to 0.0665 parts by weight) of diammine silver ions. It is preferable to use it in a mixed ratio.

Further, in carrying out the reaction step, sugars such as glycerin, pullulan and glucose may be added in addition to the water-soluble polysaccharide, diammine silver ion and the organic acid.

By adding glycerin to the reaction solution at a concentration of 0.5 to 5% by weight, the solubility of hyaluronic acid can be improved and the amount of silver carried can be increased.

Further, the stability of silver can be increased by adding glucose or pullulan to the reaction solution at a concentration of 0.5 to 5% by weight, more preferably 0.5 to 3% by weight.

Further, this reaction step may be carried out under alkaline conditions or per-alkaline conditions. For example, it will be described later [2. Preparation of liquid antibacterial agent] The silver particles that are not supported and precipitate under alkaline conditions within the pH range of about ± 0.5 with respect to the pH of the reaction solution in the blending ratio described in Preparation Example 2. The amount can be suppressed, and the product stability of the liquid antibacterial agent, that is, the formation of precipitation over time after the liquid antibacterial agent is used can also be suppressed. To give an example, the pH at the time of reaction can be, for example, about 9 to 12, more preferably about 10 to 12.

In the antibacterial agent preparation step, ammonium salts, nitrates, and silver are prepared from a reaction solution containing water-soluble polysaccharides having an average molecular weight of 1.2 million or more, which is obtained by adhering precipitated silver particles having a diameter of 1 nm or more in a dispersed state. This is a step for removing salts such as salts, unreacted quaternary silver ions, organic acids and the like to obtain a liquid antibacterial agent.

In this step, a known method such as removal by utilizing a difference in molecular weight can be adopted, and more specifically, dialysis may be adopted.

Further, in the present antibacterial agent preparation step, the content concentration of the antibacterial substance according to the present embodiment is adjusted by appropriately adding an aqueous solvent or the like to the solution obtained in the purification step to dilute the solution to the present embodiment. Such a liquid antibacterial agent may be prepared.

As described above, according to the method for producing a liquid antibacterial agent according to the present embodiment, the antibacterial agent obtained by mixing the conventional silver solution and the radish fermented liquid through the above-mentioned reaction step and the antibacterial agent preparation step. It is possible to produce a liquid antibacterial agent which is more stable than the agent and can be used for antibacterial objects which are various liquids.

Hereinafter, the antibacterial substance, the liquid antibacterial agent, the method for producing the liquid antibacterial agent, and the method for suppressing the growth of microorganisms according to the present embodiment will be described more specifically with reference to the experimental results and the like. In the following description, sodium hyaluronate having an average molecular weight of 1.2 million and xanthan gum having a molecular weight of 1.8 to 2.2 million, preferably about 2 million are used as water-soluble polysaccharides having an average molecular weight of 1.2 million or more to reduce diammine silver ions. An example in which citric acid or glucose is used as a capable organic acid or sugar will be described, but the present invention is not necessarily limited to a combination thereof. However, it does not prevent the applicant from limiting to these combinations.

[1. Preparation of diammine silver ion solution]
First, the diammine silver ion solution was prepared as follows. That is, 1 ml of 1.0 mol / L sodium hydroxide aqueous solution was added to 10 ml of 0.1 mol / L silver nitrate aqueous solution, and the mixture was sufficiently stirred. Then, 2.5% aqueous ammonia was added to the turbid mixture until the mixture became transparent (about 4 ml) to prepare a diammine silver ion solution having a silver concentration of about 7,000 ppm. (Dianmin silver ion solution A)

Separately, add 33.47 g of 1.0 mol / L sodium hydroxide aqueous solution to 334.69 g of 0.1 mol / L silver nitrate aqueous solution weighed in a 500 ml beaker and stir well. 2.5% aqueous ammonia of g was added until the mixture became clear to prepare a diammine silver ion solution having a silver concentration of about 7000 ppm. (Dianmin silver ion solution B)

[2. Preparation of liquid antibacterial agent]
Weigh 0.95 parts by weight of sodium hyaluronate having an average molecular weight of 1.2 million in a beaker, add 94.05 parts by weight of water to dissolve it, add 0.1 parts by weight of citric acid to this aqueous sodium hyaluronate solution, and at 30 ° C. Sufficient stirring was performed. Next, 5 parts by weight of diammine silver ion solution A was further added, and the reaction step was carried out by stirring at 30 ° C. for 22 hours to obtain a reaction solution. In the following, this reaction solution will be referred to as HA-Ag (cit).

In addition, 36 g of sodium hyaluronate and 36 g of xanthan gum were added to a 20 kg capacity stainless steel tank containing 3.5 kg of water, and another 10 kg of water was added while stirring at a rotation speed of 300 rpm with a propeller stirrer. It was dissolved at 40 ° C. Next, diammine silver ion solution B was added to the mixed aqueous solution of sodium hyaluronate and xanthan gum (hereinafter referred to as HAXA aqueous solution) in an amount such that the final concentration of silver was 250 ppm in the reaction solution while continuing stirring. , 5 to 30 minutes later, add 15 g of 2.5% aqueous ammonia to make it alkaline (hyaluronic acid), and 5 to 30 minutes later, add a glucose solution in which 225 g of glucose is dissolved in 892.5 g of water in advance. The mixture was added and stirred for 5 to 15 minutes, the stirring was stopped, and the reaction was allowed to stand for 1.5 to 3 hours or more to obtain a reaction solution. The pH of the reaction solution at this time was 10.5. In the following, this reaction solution will be referred to as HAXA-Ag (gul / am).

In addition, a reaction solution prepared by the same preparation procedure as HAXA-Ag (gul / am) without adding 2.5% aqueous ammonia was also obtained. The pH of the reaction solution at this time was 9.5. Hereinafter, this reaction solution is referred to as HAXA-Ag (gul).

Next, each reaction solution obtained through these reaction steps is dispensed by a predetermined amount and contained in a dialysis tube, and the dialysis tube is placed in a container having a capacity of about 10 times the volume of the mixed solution under running water. The dialysis was performed overnight, and then the dialysis tube was taken out to obtain a liquid antibacterial agent. The silver concentration in the obtained liquid antibacterial agent HA-Ag (cit) was 140 ± 20 ppm. The silver concentration in the liquid antibacterial agent HAXA-Ag (gul / am) was 200 ± 20 ppm, and the silver concentration in the liquid antibacterial agent HAXA-Ag (gul) was 160 ± 20 ppm.

[3. Purification degree confirmation test]
Next, it was confirmed whether or not each of the obtained liquid antibacterial agents contained an ammonium salt, a nitrate, or a silver salt.

First, each of the obtained liquid antibacterial agents was heated by adding an excessive amount of an aqueous sodium hydroxide solution, and the presence or absence of an odor and the pH of the generated gas were confirmed to determine the presence of the ammonium salt. Verified. If the liquid antibacterial agent contains an ammonium salt, an ammonia odor is felt, and the generated gas is brought into contact with pH test paper to become alkaline.

As a result, no ammonia odor was felt from any of the liquid antibacterial agents, and no change was observed in the color tone of the pH test paper. From this result, it was confirmed that each liquid antibacterial agent did not contain an ammonium salt (below the detection limit).

Next, a diphenylamine test solution was added to each of the obtained liquid antibacterial agents and reacted, and the change in color tone of the reaction solution was confirmed. If the liquid antibacterial agent contains nitrates, the reaction will turn blue.

As a result, it was confirmed that the color tone of the reaction solution did not change with any of the liquid antibacterial agents, and that each liquid antibacterial agent did not contain nitrate (below the detection limit).

Next, dilute hydrochloric acid was added to each of the obtained liquid antibacterial agents and reacted, and the presence or absence of precipitation was confirmed. If the liquid antibacterial agent contains silver salts, a white precipitate will occur.

As a result, it was confirmed that no white precipitate was formed in any of the liquid antibacterial agents, and that each liquid antibacterial agent did not contain a silver salt (below the detection limit).

As described above, it was confirmed that the liquid antibacterial agent according to the present embodiment does not contain ammonium salt, nitrate, and silver salt.

[4. Confirmation test with an electron microscope]
Next, the antibacterial substance contained in the liquid antibacterial agent was observed with an electron microscope. An electron microscope image of the liquid antibacterial agent HA-Ag (cit) is shown in FIG.

As can be seen from FIG. 1, the antibacterial substance in the liquid antibacterial agent HA-Ag (cit) has silver particles precipitated in a matrix of water-soluble polysaccharides having a diameter of 1 nm or more and approximately 1 nm to 100 nm in a dispersed state. It was observed that it was (supported). Although not shown, both the liquid antibacterial agent HAXA-Ag (gul / am) and the liquid antibacterial agent HAXA-Ag (gul) have a diameter of 1 nm or more and approximately 1 nm to 100 nm in the matrix of water-soluble polysaccharides. It was observed that the silver particles precipitated to some extent were attached (supported) in a dispersed state.

[5. Antibacterial confirmation test]
Next, a confirmation test of antibacterial properties was conducted on the liquid antibacterial agent according to the present embodiment. Specifically, 2% (w / w) of each of the liquid antibacterial agent HA-Ag (cit), the liquid antibacterial agent HAXA-Ag (gul / am), and the liquid antibacterial agent HAXA-Ag (gul) according to the present embodiment. ), Dispense 20 ml each into multiple containers, Esherichia coli (3.1 × 10 ⁸ cfu / ml), Staphylococcus aureus (2.1 × 10 ⁸ cfu / ml), green Pseudomonas aeruginosa (2.5 × 10 ⁸ cfu / ml), Bacillus subtilis (4.0 × 10 ⁷ cfu / ml), Candida albicans (8.6 × 10 ⁸ cfu / ml), Black mold (Bacillus subtilis; 4.0 × 10 7 cfu / ml) Aspergillus niger; 2.6 × 10 ⁸ cfu / ml) was added in an amount of 0.2 ml each, and the course was observed for 4 weeks. The results obtained with the liquid antibacterial agent HA-Ag (cit) are shown in Table 1.

In Table 1, parentheses indicate the process when the liquid antibacterial agent according to the present embodiment is not added. As can be seen from Table 1, when the liquid antibacterial agent according to the present embodiment was not added, the growth of microorganisms was confirmed in all of the 6 types of test bacteria.

On the other hand, when the liquid antibacterial agent according to the present embodiment was added, the effect of suppressing the growth of microorganisms was observed in all of the six test bacteria. In particular, for Escherichia coli, Pseudomonas aeruginosa, and Candida, no viable bacteria were observed one day after inoculation, and an extremely strong growth inhibitory effect was observed. As for Staphylococcus aureus, no viable bacteria were observed after 3 days.

For B. subtilis, but did not reach to also completely killed after 4 weeks, and the number of bacteria was reduced from 10 ⁷ to 10 ² orders to microorganisms that form spores, spore-forming bacteria It was suggested that it is also effective against.

Further, same applies to the black mold, but did not reach to 4 weeks elapsed after completely killed, the number of bacteria is reduced from 10 ⁸ to 10 ¹ order, it indicates that it is also effective against fungi Was done.

Although specific data are omitted, the liquid antibacterial agent HAXA-Ag (gul / am) and the liquid antibacterial agent HAXA-Ag (gul) are almost the same as the liquid antibacterial agent HA-Ag (cit). An antibacterial tendency was observed.

From these facts, it was shown that the antibacterial substance and the liquid antibacterial agent according to the present embodiment are effective against an extremely wide range of bacterial species.

[6. Stability test (1)]
Next, the stability of the antibacterial substance and the liquid antibacterial agent according to the present embodiment in the presence of various surfactants was examined.

Specifically, a 12% aqueous solution of potassium cocoyl glutamate, which is an anionic surfactant, a 24% aqueous solution of cetyltrimethylammonium chloride, which is a cationic surfactant, and 30 of lauramidopropyl betaine, which is an amphoteric surfactant. It was confirmed whether or not aggregation or precipitation occurs by adding the liquid antibacterial agent according to the present embodiment to the% aqueous solution and the 1% aqueous solution of polyoxyethyl octylamine which is a nonionic surfactant. In this test, a 1.5% aqueous solution of chitosan stearamide hydroxypropyltrimonium chloride, which is a cationized chitosan, was also tested.

In addition, as a comparison target, a test was conducted by similarly adding an antibacterial agent obtained by mixing a silver solution, which is a conventional antibacterial agent, and a fermented radish solution.

As a result, the liquid antibacterial agents (HA-Ag (cit), HAXA-Ag (gul / am), HAXA-Ag (gul)) according to the present embodiment are all resistant to the aqueous solution of the cationic surfactant. Although aggregation and precipitation were observed, no aggregation or precipitation was observed in each of the other aqueous solutions of anionic surfactant, amphoteric surfactant, nonionic surfactant, and cationized chitosan.

On the other hand, the antibacterial agents obtained by mixing a conventional silver solution and a radish fermented solution are a 24% aqueous solution of cetyltrimethylammonium chloride, which is a cationic surfactant, and chitosan stealamide hydroxypropyltrimonium chloride, which is a cationized chitosan. Aggregation and precipitation were observed in the 1.5% aqueous solution of.

From these results, the antibacterial substance and the liquid antibacterial agent according to the present embodiment are more stable than the antibacterial agent obtained by mixing a conventional silver solution and a radish fermented liquid, and are various liquids. It has been shown that it can be used for antibacterial objects.

[7. Stability test (2)]
The stability of antibacterial substances and liquid antibacterial agents according to this embodiment was investigated in the presence of various sucrose fatty acid esters having different HLB values.

Specifically, 1% (w / w) of sucrose fatty acid ester is added to a predetermined amount of water, and if it is soluble, it is sufficiently dissolved, and then the liquid antibacterial agent according to the present embodiment is sufficiently dissolved. Add 2% (w / w) of (HA-Ag (cit), HAXA-Ag (gul / am), HAXA-Ag (gul)), shake well and leave for 3 days to allow precipitation and aggregation. I confirmed the existence. As the sucrose fatty acid ester, those having HLB values of 19, 15, 13, 11, 9.5, 8, 6, 2, 1 were used.

For comparison, a test was conducted by similarly adding an antibacterial agent obtained by mixing a silver solution, which is a conventional antibacterial agent, and a fermented radish solution.

As a result, no precipitation or aggregation was observed in the liquid antibacterial agent according to the present embodiment in the presence of any HLB value of sucrose fatty acid ester.

On the other hand, in the antibacterial agent obtained by mixing the conventional silver solution and the fermented radish solution, aggregation and precipitation were observed in the samples having HLB values of 19, 15, 13 and 11.

From these results, the antibacterial substance and the liquid antibacterial agent according to the present embodiment are more stable than the antibacterial agent obtained by mixing a conventional silver solution and a radish fermented liquid, and can be used in various liquids. It has been shown to be usable for certain antibacterial objects.

[8. Stability test (3)]
Next, the presence or absence of precipitation and aggregation when the liquid antibacterial agent according to the present embodiment was added to the body soap was examined.

Specifically, 0.5% (w) of the liquid antibacterial agents (HA-Ag (cit), HAXA-Ag (gul / am), HAXA-Ag (gul)) according to this embodiment is added to about 200 g of body soap. / w) It was added and allowed to stand, and it was observed whether precipitation or aggregation occurred.

As a result, no precipitation or aggregation was observed, and it was shown that the antibacterial substance and the liquid antibacterial agent according to the present embodiment have extremely high stability.

[9. Stability test (4)]
Next, the change over time in the stability of the liquid antibacterial agent according to the present embodiment was examined.

Specifically, the liquid antibacterial agent HA-Ag (cit), the liquid antibacterial agent HAXA-Ag (gul / am), and the liquid antibacterial agent HAXA-Ag (gul) are placed in a transparent plastic container having a capacity of 50 ml and a sharp shape. 45 ml each was dispensed, placed in an incubator set at 65 ° C., and subjected to an accelerated test for 8 weeks (about 2 months).

For comparison, a test was conducted by similarly adding an antibacterial agent obtained by mixing a silver solution, which is a conventional antibacterial agent, and a fermented radish solution. The results are shown in Table 2.

As can be seen from Table 2, all of the liquid antibacterial agents according to the present embodiment were confirmed to have good stability as compared with the antibacterial agents obtained by mixing a conventional silver solution and a fermented radish solution.

It was also confirmed that the liquid antibacterial agent HAXA-Ag (gul / am) and the liquid antibacterial agent HAXA-Ag (gul) have higher stability than HA-Ag (cit). In particular, the liquid antibacterial agent HAXA-Ag (gul / am) did not show precipitation of silver particles even after 6 weeks, suggesting that it has extremely high product stability.

As described above, the antibacterial substance according to the present embodiment is composed of a water-soluble polysaccharide having an average molecular weight of 1.8 million or more, to which precipitated silver particles having a diameter of 1 nm or more are adhered in a dispersed state. It is possible to provide an antibacterial substance having high stability as compared with an antibacterial agent obtained by mixing a silver solution of radish and a fermented radish solution, and which can be used for antibacterial objects which are various liquids.

Further, according to the method for producing a liquid antibacterial agent according to the present embodiment, a water-soluble polysaccharide having an average molecular weight of 1.8 million or more, diammine silver ion, and an organic acid or sugar having a reducing ability of the diammine silver ion are water-based. A reaction step of reacting in a solvent to obtain a reaction solution containing a water-soluble polysaccharide having an average molecular weight of 1.8 million or more, to which precipitated silver particles having a diameter of 1 nm or more are adhered in a dispersed state, and a reaction solution contained in the reaction solution. Since it has a liquid antibacterial agent preparation step of removing ammonium salts, nitrates, and silver salts to purify it into a liquid antibacterial agent, it is compared with the conventional antibacterial agent obtained by mixing a silver solution and a radish fermented liquid. It is possible to provide a method for producing a liquid antibacterial agent which is highly stable and can be used for antibacterial objects which are various liquids.

Finally, the description of each embodiment described above is an example of the present invention, and the present invention is not limited to the above-described embodiment. Therefore, it goes without saying that various changes can be made according to the design and the like as long as the technical idea of the present invention is not deviated from the above-described embodiments.

Claims (7)

An antibacterial substance composed of water-soluble polysaccharides having an average molecular weight of 1.2 million or more, to which precipitated silver particles having a diameter of 1 nm or more are adhered in a dispersed state. The antibacterial substance according to claim 1, wherein the water-soluble polysaccharide is a complex of hyaluronic acid and xanthan gum. A liquid antibacterial agent containing the antibacterial substance according to claim 1 or 2 in a state of being dissolved in an aqueous solvent. The liquid antibacterial agent according to claim 3, wherein the silver concentration is 80 ppm or more. A water-soluble polysaccharide having an average molecular weight of 1.2 million or more, diammine silver ion, and an organic acid or sugar having a reducing ability of the diammine silver ion are reacted in an aqueous solvent to obtain silver precipitated particles having a diameter of 1 nm or more. A reaction step of obtaining a reaction solution containing a water-soluble polysaccharide having an average molecular weight of 1.2 million or more attached in a dispersed state, and
A method for producing a liquid antibacterial agent, which comprises a step of preparing a liquid antibacterial agent by removing ammonium salts, nitrates and silver salts contained in the reaction solution and purifying the liquid antibacterial agent. The method for producing a liquid antibacterial agent according to claim 5, wherein the reaction step is carried out under alkaline conditions. A method for suppressing microbial growth by adding an antibacterial substance consisting of a water-soluble polysaccharide having an average molecular weight of 1.2 million or more, in which precipitated silver particles having a diameter of 1 nm or more are attached to an object in a dispersed state.

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