JP7514464B2 - Antibacterial solids - Google Patents

Description

The present invention relates to an antibacterial solid material. More specifically, it relates to an antibacterial solid material that contains a large amount of an antibacterial agent.

In recent years, solids such as tablets and briquettes that continuously release antibacterial and deodorizing agents have been used as relatively easy-to-use sanitary measures for the prevention of bacteria and odors in wastewater from household drains, flush toilets, plaster traps, restaurant grease traps, etc. These tablets contain a relatively small amount of antibacterial agent, up to a few percent by mass, bound with a water-soluble polymer binder (for example, Patent Documents 1, 2, and 3).

Japanese Patent Application Laid-Open No. 58-25398 Japanese Patent Application Laid-Open No. 2-145700 JP 2014-139164 A

However, in recent years, there has been a demand to extend the use period of these tablets, and therefore a method of increasing the content of the antibacterial agent has been adopted. However, this method has the problem that the high content of the antibacterial agent causes the tablet to disintegrate quickly in water, resulting in more elution of the antibacterial agent, and thus making it difficult to extend the duration of the antibacterial effect.
There is a demand for an antibacterial solid material that can suppress premature disintegration of the tablet even when it contains a large amount of antibacterial agent, reduce the elution of the antibacterial agent, and control the elution amount of the antibacterial agent for a long period of time, thereby maintaining the antibacterial effect for a long period of time.

The present invention aims to provide an antibacterial solid material that contains a large amount of antibacterial agent components, is resistant to disintegration in wastewater, and can dissolve the antibacterial agent for a long period of time, thereby maintaining antibacterial properties for a long period of time.

In view of the above problems, the inventors conducted extensive research and surprisingly discovered that by adding a specific lipophilic surfactant to solidify the antibacterial component, the solid is less likely to disintegrate in wastewater and can maintain its dissolution rate for a long period of time, resulting in the completion of the present invention.

That is, the invention described in claim 1 is as follows:
An antibacterial solid material comprising an antibacterial component and a binder for solidifying the antibacterial component, the antibacterial solid material being used by being precipitated in wastewater,
The content of the antibacterial agent component is 29% by mass or more and 50% by mass or less with respect to the total mass of the antibacterial solid material,
The content of the binder is 43% by mass or more and 60% by mass or less based on the total mass of the antibacterial solid material,
It also contains antibacterial inorganic fillers,
the antibacterial component is a cationic antibacterial agent selected from pyridinium compounds, phosphonium compounds (tributyl-4-vinylbenzylphosphonium chloride, trihexyl-4-vinylbenzylphosphonium chloride, trioctyl-4-vinylbenzylphosphonium chloride, etc.), biguanide compounds (chlorhexidine, chlorhexidine gluconate, etc.), quaternary ammonium salt compounds (benzethonium chloride, benzalkonium chloride, dialkyldimethylammonium chloride, monoalkyltrimethylammonium chloride, alkyldiaminoethylglycine, dialkyldiaminoethylglycine, etc.), polylysine compounds, aminoglycoside antibiotics (streptomycin, kanamycin, amikacin, bekamycin, dibekacin, fradiomycin, paromomycin, ribostamycin, sisomicin, tobramycin, etc.), aminocyclitol antibiotics, and peptide antibiotics (polymyxin, colistin, tyrocidine, gramicidin, etc.);
The binder is an antibacterial solid material characterized in that it is a lipophilic surfactant having an HLB of 1 to 8 and a melting point of 40° C. or higher.

The content of the antibacterial agent component is 38% by mass or more based on the total mass of the antibacterial solid material.

The invention described in claim 3 is the antibacterial solid described in claim 1 or 2, characterized in that the lipophilic surfactant is a fatty acid ester of an alcohol.

The invention described in claim 5 is a method for using the antibacterial solid material described in any one of claims 1 to 3 , characterized in that the antibacterial solid material is precipitated in wastewater and then used.

The present invention provides an antibacterial solid that contains a large amount of antibacterial agent components, is resistant to disintegration in wastewater, and can dissolve the antibacterial agent for a long period of time, thereby maintaining antibacterial properties for a long period of time.

The following describes in detail the embodiments of the present invention. Note that the present invention is not limited to the following embodiments. Various modifications can be made to the following embodiments within the same or equivalent scope as the present invention.

In the present invention, the antibacterial solid is usually used as a tablet, and there is no limitation on the shape or size, and examples include ball-shaped, rectangular, conical, and trapezoidal shapes, and it is preferable that the shape is determined according to the application. Here, the tablet refers to a tablet or briquette. A tablet or briquette is a solidified powder or granule, and is called a tablet or briquette depending on the method of solidification. The antibacterial solid in the present invention is preferably a tablet-like tablet, which can be easily produced by melting a mixture with a high melting point, pouring it into a mold, and cooling it to solidify.

(Components of antibacterial solids)
The components constituting the antibacterial solid material of the present invention will be described below.
(1) Antibacterial component The antibacterial component used in the present invention is not limited as long as it is a compound generally recognized to have antibacterial effect. For example, cationic antibacterial agents such as benzalkonium chloride and benzethonium chloride, sulfites such as sodium hydrogen sulfite, benzoic acid, benzoic acid esters such as methyl benzoate, biguanides, and amidoglycidyl compounds are mentioned as ambidextrous surface active agents, antibiotics such as penicillin and erythromycin, chlorhexidine gluconate, sorbic acid, chitosan, hinokitiol, and metal antibacterial agents such as silver ions and copper ions. These may be mixed as they are, or may be microencapsulated with phospholipids or hydrophilic polymers or supported on inorganic carriers such as organic polymers, hydroxyapatite, and silica gel to ensure stability.
Among these, cationic antibacterial agents are preferred in terms of their antibacterial effectiveness.

Examples of cationic antibacterial agents include pyridinium compounds, phosphonium compounds (tributyl-4-vinylbenzylphosphonium chloride, trihexyl-4-vinylbenzylphosphonium chloride, trioctyl-4-vinylbenzylphosphonium chloride, etc.), biguanide compounds (chlorhexidine, chlorhexidine gluconate, etc.), quaternary ammonium salt compounds (benzethonium chloride, benzalkonium chloride, dialkyldimethylammonium chloride, monoalkyltrimethylammonium chloride, alkyldiaminoethylglycine, dialkyldiaminoethylglycine, etc.), polylysine compounds, aminoglycoside antibiotics (streptomycin, kanamycin, amikacin, bekamycin, dibekacin, fradiomycin, paromomycin, ribostamycin, sisomicin, tobramycin, etc.), aminocyclitol antibiotics, and peptide antibiotics (polymyxin, colistin, tyrocidine, gramicidin, etc.). Of these, quaternary ammonium salt compounds are particularly preferred in terms of antibacterial efficacy, water solubility, stability, etc.

The content of the antibacterial component is 15% by mass or more and 50% by mass or less based on the total mass of the antibacterial solid. If the content of the antibacterial component is less than 15% by mass, it is difficult to achieve long-term antibacterial effects. If the content of the antibacterial component is more than 50% by mass, the antibacterial solid becomes brittle and is prone to crumbling during use.

(2) Binder The binder is a lipophilic surfactant having an HLB of 1 to 8 and a melting point of 40° C. or higher. The HLB is preferably 2 to 7. If the HLB is less than 1, the solubility in water is poor and the antibacterial properties are likely to be poor. If the HLB is more than 8, the antibacterial solid is likely to disintegrate and the antibacterial agent is likely to be unable to elute for a long period of time.
Examples of lipophilic surfactants having an HLB of 1 to 8 include, but are not limited to, the following:

(1) Fatty acid ester of alcohol 1. Fatty acid ester of alkylene (C=2 to 4) glycol or polyalkylene (C=2 to 4) glycol (n=2 to 4) Ester of fatty acid selected from oleic acid, stearic acid, palmitic acid, ketostearic acid, arachidic acid, and behenic acid, such as ethylene glycol, diethylene glycol, propylene glycol, and tetramethylene glycol, and includes monoesters and diesters.
2. Sugar fatty acid esters Esters of sugars selected from glucose, sorbitol (including sorbitan), mannitose, mannitol, sucrose, mannose, xylitol, or xylose with fatty acids selected from oleic acid, stearic acid, palmitic acid, ketostearic acid, arachidic acid, and behenic acid, including monoesters, diesters, or higher esters of both.

(2) Ethers of fatty alcohols and sugars These include ethers of a reducing sugar selected from glucose, xylose, arabinose, mannose, or sucrose and a fatty alcohol selected from stearic alcohol, palmityl alcohol, ketostearyl alcohol, arachidyl alcohol, and behenyl alcohol.

(3) Divalent Salts of Fatty Acids These include magnesium, zinc, and calcium salts of oleic acid, stearic acid, palmitic acid, ketostearic acid, arachidic acid, and behenic acid.

(4) Alkylene oxide (C=2-4) adducts of long chain alkylamines (n=1-5).
Examples of the alkylene oxides include ethylene oxide, propylene oxide and other alkylene oxide (C=2 to 4) adducts (1 to 4) of long chain alkylamines such as stearylamine, palmitylamine, ketostearylamine, arachidylamine, and behenylamine.
Among these, fatty acid esters of alcohols are preferred, and fatty acid esters of alkylene (C=2 to 4) glycols or polyalkylene (C=2 to 4) glycols (n=2 to 4) are particularly preferred.

The lipophilic surfactant in the present invention is one having a melting point of 40° C. or higher.
If the melting point is less than 40° C., it will not solidify properly when cooled in a mold and will tend to collapse during use. It is preferably 50° C. or higher, and particularly preferably 60° C. or higher.

When the antibacterial component is solidified with a lipophilic surfactant (hereinafter sometimes simply referred to as a lipophilic surfactant) having an HLB of 1 or more and 8 or less and a melting point of 40°C or higher, the resulting antibacterial solid is less likely to disintegrate and can maintain a dissolution rate of a certain amount or more for a long period of time.
In this case, the amount of the lipophilic surfactant is preferably 20% by mass or more and 60% by mass or less, more preferably 30% by mass or more and 50% by mass or less, based on the total mass.

When the amount of lipophilic surfactant is 20% by mass or more, the antibacterial solid is firmly solidified and is less likely to disintegrate in wastewater for a long period of time. When the amount is 60% by mass or less, a large amount of antibacterial component can be solidified.

The antibacterial solid of the present invention can be further blended with an antibacterial inorganic filler to further improve the antibacterial properties of the antibacterial agent. Examples of antibacterial inorganic fillers include, but are not limited to, zinc oxide, titanium oxide, silver oxide, etc. Zinc oxide is particularly preferred in terms of the balance between physical properties and cost.

Furthermore, a typical inorganic filler may be blended in. Typical inorganic fillers include iron powder, copper powder, zinc powder, barium sulfate, talc, mica, calcium carbonate, and the like.
The specific gravity of the antibacterial solids can be increased by mixing the antibacterial inorganic fillers and/or ordinary inorganic fillers, so that the antibacterial solids can be precipitated in the wastewater. If the antibacterial solids can be used after being precipitated, the bacteria in the wastewater can be killed or their proliferation can be efficiently suppressed.

Although lipophilic surfactants are poorly soluble in water, the hydrophilic groups present in the surfactants have affinity for water, and the lipophilic surfactants are gradually removed from the antibacterial solids. As a result, the antibacterial solids become smaller, and this process is repeated until the antibacterial composition disintegrates at some point.
That is, the disintegration of the antibacterial solid is influenced by the structure and amount of the lipophilic surfactant and the type and amount of the antibacterial agent, but from the above, the smaller the HLB of the lipophilic surfactant is, the longer the period until disintegration is, and is influenced by the HLB of the lipophilic surfactant. However, if it is too slow, the antibacterial agent is difficult to elute, and the antibacterial properties are reduced, so it is preferable to determine the elution of the lipophilic surfactant in consideration of the balance between the disintegration of the antibacterial solid and the antibacterial properties.

(Method of producing antibacterial solid material)
The antibacterial solid is formed by mixing the components of the antibacterial solid. The method for forming the solid is not particularly limited, but may be, for example, a method for forming one by one, such as a mold method or a compression molding method, or a large solid may be first cut into a desired shape, and the mold method is preferred because it is easy to manufacture.
In the mold method, the mixture of the components is heated above its melting point, melt-kneaded, and poured into a mold. It is then cooled and removed to obtain a tablet of the same shape as the mold.

Compression molding methods include tableting and briquetting.
In the tabletting method, a tablet press consisting of a compression device combined with a mortar and a pestle is basically used. When pressure is applied between the upper and lower pestle in the mortar through the compression device, a tablet of the shape formed by the mortar and pestle is formed. As such a tablet press, a commonly known single-shot tablet press that presses tablets one by one, or a rotary tablet press with high production efficiency that has multiple dies along a rotating disk can be used.

Briquetting basically involves the use of a briquetting machine, which consists of two rollers with engraved patterns and a compression device. When pressure is applied between the two rollers through the compression device, briquettes are formed that are shaped by the patterns engraved on the rollers. Any burrs around the briquettes can be removed, for example, by passing them over a vibrating screen.

In addition to the antibacterial component and binder, the antibacterial solid may contain inorganic fillers and other commonly used components such as excipients, lubricants, binders, pH adjusters, chelating agents, defoamers, pigments, and fragrances.

As mentioned above, the shape of the tablet is not particularly limited, and examples thereof include a cylindrical shape, an elliptical cylindrical shape, a disk shape, a doughnut shape, a spherical shape, a trapezoid shape, a cone shape, etc. In the case of a cylindrical or trapezoidal tablet, the diameter is usually 10 to 100 mm, preferably 30 to 70 mm, and the height or thickness is usually 5 to 100 mm, preferably 10 to 50 mm. In addition, briquettes having a major axis of 5 to 100 mm can be used.

The antibacterial solid obtained as described above is preferably and efficiently used by settling it in wastewater. If the antibacterial solid is used as it is or stored in a net or a plastic container with holes in it and placed in a desired location such as a drain or various traps, it will gradually dissolve from the surface without being damaged and the antibacterial component will elute, thereby exerting antibacterial and deodorizing effects not only on the surface in contact with the solid but also on the surrounding area.
The antibacterial solid material of the present invention is an antibacterial solid material containing a large amount of an antibacterial agent component, and the solid material is unlikely to disintegrate in wastewater, and the antibacterial agent is eluted for a long period of time, thereby maintaining antibacterial properties for a long period of time.

The present invention will now be described with reference to examples, but the present invention is not limited to the following examples.

Example 1
43 g of diethylene glycol distearate (reagent) and 28 g of zinc oxide (reagent) were placed in a 200 ml container equipped with a stirring rod and heated to 74°C . After stirring for 10 minutes at this temperature, 29 g of "CATION M2-100R " ( cationic antibacterial agent, manufactured by NOF Corporation) was added and stirred for an additional 30 minutes. At this stage, the mixture was in a molten state.
This molten mixture was poured into a mold of 5 cm x 5 cm x 4 cm and cooled to room temperature below 20° C. The solidified mixture was removed from the mold to obtain an antibacterial tablet.

The compounds shown in Table 1 were similarly blended below, and antibacterial tablets of Examples 2 to 7 and Comparative Examples 1 to 5 were prepared in the same manner as in Example 1. The size of each tablet was adjusted by cutting the height so that the mass was 12 g. Using these, the appearance of the tablet (after 2 weeks), the number of days (days) until the amount of eluted antibacterial agent reached 15 ppm or less, the amount of eluted tablet (%), and the general bacterial count on the 30th day were evaluated. The results are shown in Table 2.

(Evaluation method)
1. Appearance of Solid Product An antibacterial tablet (12 g) was immersed in 1000 ml of water, and the shape and appearance after 2 weeks was observed with the naked eye.
○: Tablet shape is maintained 2. Number of days until antibacterial agent elution amount is 15 ppm or less Antibacterial tablet (12g) was immersed in 1000ml of water, and the concentration of the elution amount (ppm) of the cationic component of the antibacterial agent was measured using cationic test paper. The water was replaced completely every day, and the number of days until the elution amount of the cationic component was 15 ppm or less was measured by repeating the measurement. It was considered that the antibacterial property can be fully exerted if it is 15 ppm or more. 3. Elution amount of antibacterial tablet Antibacterial tablet (12g) was immersed in 200ml of water, covered with a lid, and left while suppressing water evaporation, and the concentration (A%) of the aqueous solution after 7 days and 14 days was measured, and the elution amount (%) of the antibacterial tablet was calculated from the value according to the following formula.
200 x (A/100)/12
4. General Bacteria Count Test Method In measuring the amount of antibacterial agent eluted, 1000 ml of water was replaced on the 30th day, and then 10 ml of putrefactive liquid with a general bacteria count of ¹⁰⁶ or more was added. After leaving it for one day, 1 ml of the liquid was taken and added to an agar medium in a Petri dish, and the number of bacteria was measured after culturing for 48 hours in a flanker at 37.5°C.

(result)
From Table 2, it can be seen that the tablet containing a lipophilic surfactant with an HLB of 1 to 8 and a melting point of 40°C or higher gradually dissolved, so that the release of the antibacterial agent continued for a long period of 40 days or more. It can be seen that this is an excellent antibacterial solid material that has never been seen before. It was confirmed that the present invention is effective.

The present invention has been described above based on an embodiment, but the present invention is not limited to the above embodiment. Various modifications can be made to the above embodiment within the same and equivalent scope of the present invention.

Claims (4)

An antibacterial solid material comprising an antibacterial component and a binder for solidifying the antibacterial component, the antibacterial solid material being used by being precipitated in wastewater,
The content of the antibacterial agent component is 29% by mass or more and 50% by mass or less with respect to the total mass of the antibacterial solid material,
The content of the binder is 43% by mass or more and 60% by mass or less based on the total mass of the antibacterial solid material,
It also contains antibacterial inorganic fillers,
the antibacterial component is a cationic antibacterial agent selected from pyridinium compounds, phosphonium compounds (tributyl-4-vinylbenzylphosphonium chloride, trihexyl-4-vinylbenzylphosphonium chloride, trioctyl-4-vinylbenzylphosphonium chloride, etc.), biguanide compounds (chlorhexidine, chlorhexidine gluconate, etc.), quaternary ammonium salt compounds (benzethonium chloride, benzalkonium chloride, dialkyldimethylammonium chloride, monoalkyltrimethylammonium chloride, alkyldiaminoethylglycine, dialkyldiaminoethylglycine, etc.), polylysine compounds, aminoglycoside antibiotics (streptomycin, kanamycin, amikacin, bekamycin, dibekacin, fradiomycin, paromomycin, ribostamycin, sisomicin, tobramycin, etc.), aminocyclitol antibiotics, and peptide antibiotics (polymyxin, colistin, tyrocidine, gramicidin, etc.);
The antibacterial solid material is characterized in that the binder is a lipophilic surfactant having an HLB of 1 to 8 and a melting point of 40° C. or higher. The antibacterial solid according to claim 1, characterized in that the content of the antibacterial component is 38% by mass or more relative to the total mass of the antibacterial solid. An antibacterial solid material according to claim 1 or 2, characterized in that the lipophilic surfactant is a fatty acid ester of an alcohol. A method for using an antibacterial solid material according to any one of claims 1 to 3, characterized in that the antibacterial solid material is precipitated in wastewater and used.