JP4059326B2

JP4059326B2 - Inorganic antibacterial agent

Info

Publication number: JP4059326B2
Application number: JP21262697A
Authority: JP
Inventors: 宏今井
Original assignee: Sumika Enviro Science Co Ltd
Current assignee: Sumika Enviro Science Co Ltd
Priority date: 1997-07-22
Filing date: 1997-07-22
Publication date: 2008-03-12
Anticipated expiration: 2017-07-22
Also published as: JPH1135412A

Description

【０００１】
【発明に属する技術分野】
本発明は、抗菌作用がある金属塩の銀塩および／または亜鉛塩と、モリブデンオキソ化合物のアルカリ塩との複塩の１種又は２種を有効成分とする無機系抗菌剤に関するものであり、更に詳しくは、耐変色性に優れた無機系抗菌剤に関するものである。
【０００２】
【従来の技術】
従来より、銀、銅、亜鉛等の無機金属塩類及び有機金属塩類が抗菌・殺菌性に優れている事は古くから知られており、銀、銅、亜鉛等の抗菌性金属のうち特に銀イオンを含む無機金属塩類は、安全性が比較的高く顕著な抗菌力を示すことから無機系抗菌剤として注目を集めている。このような無機系抗菌剤のうち、難溶性の塩例えば、ケイ酸塩を有効成分とする銀化合物（特開平２−２１５７０４）、ホウ酸塩を有効成分とする銀化合物（特開平４−１３４００６）、リン酸カルシウムに銀イオンを添加した抗菌剤（特開平５−１４８１１６）、その他リン酸アルミニウム系、リン酸ジルコニウム系抗菌剤等が知られている。しかし、銀イオンは、光、熱、共存物質等の影響を受けやすく、そのまま無機系抗菌剤として使用するには難点の多い素材である反面、無機系抗菌剤は、広範囲の微生物に対して顕著な抗菌性を有し、且つ耐性菌の問題もなく、安全性についても問題のない優れた特長を持った抗菌剤であることから、上述のような問題を解決し、幅広い用途に応用できるようにすることが望まれていた。そこで近年、このような銀イオンの欠点を克服するために銀イオンを様々な無機化合物に担持、反応させることが検討され、欠点の克服とともに耐熱性、適度な銀の溶出等新たな特性が付与されることから、様々な分野で利用されている。
【０００３】
【発明が解決しようとする課題】
銀系の無機系抗菌剤、例えば先に述べた難溶性塩は、抗菌・殺菌性に優れている反面、紫外線照射や加熱時に変色を有してしまう欠点を持っているため、白色である銀系抗菌剤が、塗料、プラスチックやセメント系二次製品等の抗菌対象物に配合した際、耐熱・耐候性試験に於いて、練り込み時の発泡、抗菌対象物の劣化、着色、変色を生じ長期間における使用が困難な場合があり、抗菌性を備えながら工業的に大きな制約を受けていた。
【０００４】
【課題を解決するための手段】
そこで、本発明者は上記欠点を有しない、抗菌・殺菌性に優れた無機系抗菌剤の開発を鋭意検討した結果、抗菌作用がある金属塩の銀塩および／または亜鉛塩と、モリブデンオキソ化合物のアルカリ塩とを反応させて得られる、複塩の１種又は２種を有効成分とする無機系抗菌剤が、従来の無機系抗菌剤に比べ抗菌・殺菌効果の発現性およびその効果の持続性に優れ、かつ耐変色性に優れていることを見いだし、本発明を完成した。すなわち本発明は、抗菌作用がある金属塩の銀塩および／または亜鉛塩と、モリブデンオキソ化合物のアルカリ塩とを反応させて得られる複塩の１種又は２種を有効成分とする無機系抗菌剤である。
【０００５】
【発明の実施の形態】
本発明の無機系抗菌剤は、抗菌作用がある金属塩の銀塩および／または亜鉛塩と、モリブデンオキソ化合物のアルカリ塩とを反応させて調製させる。金属塩としては、銀と亜鉛の化合物が用いられ、銀化合物では硝酸銀、酢酸銀、硫酸銀など、亜鉛化合物では硝酸亜鉛、酢酸亜鉛、硫酸亜鉛などを用いることができる。またモリブデンオキソ化合物アリカリ塩としてはモリブデン酸ナトリウム、モリブデン酸カリウム、モリブデン酸リチウム、モリブデン酸アンモニウム、ポリモリブデン酸ナトリウム、イソポリモリブデン酸ナトリウムなどを用いることができる。反応方法は、銀塩又は亜鉛塩水溶液にモリブデンオキソ化合物のアルカリ塩水溶液を添加する、あるいはこの逆の方法でもよい。本発明においては、得ようとする銀塩および／または亜鉛塩と、モリブデンオキソ化合物の複塩の粒子径は、反応条件により変えることができる。粒子径の小さいものを得るにはモリブデンオキソ化合物のアルカリ塩の水溶液、銀塩および／または亜鉛塩の金属塩水溶液の濃度を低く、また攪拌速度を速くすれば良く、自由に粒子径をコントロールすることができる。好ましい粒子径は抗菌対象物の物性面への影響、あるいは抗菌性などから１０μｍ以下がよい。このようにして得られた好ましい粒子径を有する銀塩および／または亜鉛塩と、モリブデンオキソ化合物の複塩は反応液スラリーから水をろ別し、乾燥することにより粉末状で得られる。本発明で得られた・・・・・限定されるものではない。
【０００６】
本発明の無機系抗菌剤は、抗菌作用がある金属塩の銀塩および／または亜鉛塩と、モリブデンオキソ化合物の復塩を有効成分とする無機系抗菌剤であり、優れた抗菌性を有し、耐変色性に優れている。本発明の無機系抗菌剤の優れた抗菌性を初めとする特性発揮の作用機構の詳細は不明であるが、おそらく抗菌性金属の銀および／または亜鉛とモリブデンオキソ化合物の複塩化により抗菌性金属の銀および／または亜鉛の適度の溶出性と抗菌性金属の銀および／または亜鉛の化学的安定比が達成されたため、抗菌効力の発現、効力の長期持続性、耐変色性に優れていると考えられる。
【０００７】
【実施例】
本発明について更に詳細に実施例で説明するが、本発明は本実施例に限定されるものではない。
【０００８】
（実施例１）（酸化モリブデン銀複塩の調製方法）
モリブデン酸ナトリウム二水和物（関東化学（株））６．５ｇを１００ｍｌのイオン交換水に溶解し、これに硝酸銀（関東化学（株））９．１ｇを１００ｍｌのイオン交換水に溶解した溶液を３０分で滴下し沈殿を生成させた。更に、１時間攪拌を続け沈殿を熟成させた後、得られた沈殿物をろ過、イオン交換水で洗浄し、１００℃で十分に乾燥して黄白色の本発明の無機系抗菌剤粉末を約１０ｇ得た。このときの平均粒子径は、５．０μｍであった。また、銀含有量は、粉体中に約５９％であった。
【０００９】
（実施例２）（酸化モリブデン亜鉛複塩の調製方法）
モリブデン酸ナトリウム二水和物（関東化学（株））１０．８５ｇを１００ｍｌのイオン交換水に溶解し、これに硝酸亜鉛六水和物（関東化学（株））１３．３８ｇを１００ｍｌのイオン交換水に溶解した溶液を３０分で滴下し沈殿を生成させた。更に、１時間攪拌を続け沈殿を熟成させた後、得られた沈殿物をろ過、イオン交換水で洗浄し、１００℃で十分に乾燥して白色の本発明の無機系抗菌剤粉末を約１０ｇ得た。このときの平均粒子径は、８．０μｍであった。また、亜鉛含有量は、粉体中に約２９％であった。
【００１０】
（実施例３）
実施例１で得られた酸化モリブデン銀複塩５０部と実施例２で得られた酸化モリブデン亜鉛複塩５０部を混合し本発明の無機系抗菌剤粉末１００部を得た。
【００１１】
（比較例１）（ケイ酸銀の調製方法）
メタケイ酸ナトリウム９水和物（和光純薬工業（株））９．９４ｇを１００ｍｌのイオン交換水に溶解し、これに硝酸銀（関東化学（株））１１．９ｇを１００ｍｌのイオン交換水に溶解した溶液を３０分で滴下し沈殿を生成させた。以下、実施例１同様で、１００℃で十分に乾燥後黄褐色の沈殿を約１０ｇ得た。このときの平均粒子径は、８．８μｍであった。銀含有量は、粉体中に約７０％であった。
【００１２】
（比較例２）（リン酸カルシウム系銀抗菌剤の調製方法）
イオン交換水１００ｍｌに水酸化カルシウム３ｇ懸濁させ、これに８ｇ／１００ｍｌのリン酸水溶液を徐々に滴下し、懸濁液中のｐＨが６になった時点でリン酸水溶液の滴下を終了した。３０分熟成後、イオン交換水１０ｍｌに硝酸銀、硝酸アルミニウムを各０．３ｇを溶解し、懸濁液中に滴下した。３時間熟成後沈殿物を洗浄ろ過乾燥し、白色の粉末を得た。このときの平均粒子径は、３．５μｍであった。銀含有量約１．１％であった。
次に、評価方法について説明する。
【００１３】
［無機系抗菌剤添加セメント目地の調製方法］
市販のセメント目地材１００ｇ、水道水３４ｇに対し、実施例１、実施例２、実施例３及び比較例１の各抗菌剤を０．００４％、比較例２の抗菌剤を０．２％添加し十分に混合後、温度４０℃、湿度９５％以上で約３日間固化養生を行い、直径３０ｍｍ、厚さ５ｍｍのサンプルを得た。
このサンプルを高温乾燥、温水浸漬中での変色試験、抗菌力試験に供試した。
【００１４】
［サンプル調製時、高温乾燥時及び、温水浸漬時での変色試験］
無機抗菌剤混入のセメント目地サンプルのサンプル調製時での変色、高温乾燥操作では４０℃、１週間での変色、温水浸漬操作では４０℃温水浸漬、１週間での変色をブランクのサンプル（無機抗菌剤無添加）との比較で表１に示す。
【００１５】
【表１】

【００１６】
［セメント目地材の抗菌力試験］
上記温水浸漬操作無し、有りサンプルを乳鉢で粉砕後、温度２５℃、湿度９５％以上のデシケーター内にとり、炭酸ガスを注入し１週間放置して脱アルカリを行った。得られたサンプルを２００ｍｌ三角フラスコに０．７５ｇとり、リン酸緩衝溶液（２０ｍＭｐＨ７）中に、１．０×１０⁵〜５．０×１０⁶（個／ｍｌ）に調整した供試菌懸濁液を５０ｍｌ入れ、恒温振とう機（３０℃、１２０ｒｐｍ）で接触させ、２４時間後の生菌数をハート・インヒュージョン培地を用い、寒天平板法で測定した。
表２に大腸菌（Ｅ．ｃｏｌｉ）、黄色ブドウ状球菌（Ｓ．ａｕｒｅｕｓ）での試験結果を示した。
【００１７】
【表２】

【００１８】
【発明の効果】
以上説明したように、本発明の抗菌作用がある金属塩の銀塩および／または亜鉛塩と、モリブデンオキソ化合物のアルカリ塩とを反応させて得られる複塩の１種又は２種を有効成分とする無機系抗菌剤は、極めて優れた抗菌・殺菌性を有するのみでなく、耐変色性の両者を兼ね備えている。[0001]
[Technical field belonging to the invention]
The present invention relates to an inorganic antibacterial agent containing as an active ingredient one or two double salts of a silver salt and / or zinc salt of a metal salt having an antibacterial action and an alkali salt of a molybdenum oxo compound, More specifically, the present invention relates to an inorganic antibacterial agent having excellent discoloration resistance.
[0002]
[Prior art]
Conventionally, it has been known for a long time that inorganic metal salts such as silver, copper and zinc and organic metal salts are excellent in antibacterial and bactericidal properties. Among antibacterial metals such as silver, copper and zinc, silver ions are particularly preferred. Inorganic metal salts containing are attracting attention as inorganic antibacterial agents because they are relatively safe and exhibit remarkable antibacterial activity. Among such inorganic antibacterial agents, sparingly soluble salts such as silver compounds containing silicate as an active ingredient (JP-A-2-215704), silver compounds containing borate as an active ingredient (JP-A-4-134006) ), An antibacterial agent obtained by adding silver ions to calcium phosphate (Japanese Patent Laid-Open No. 5-148116), and other aluminum phosphate-based and zirconium phosphate-based antibacterial agents. However, silver ions are easily affected by light, heat, coexisting substances, etc., and although they are a material that is difficult to use directly as inorganic antibacterial agents, inorganic antibacterial agents are prominent against a wide range of microorganisms. It is an antibacterial agent with excellent antibacterial properties, no problem of resistant bacteria, and no safety problems, so it can solve the above problems and can be applied to a wide range of applications It was hoped that. Therefore, in recent years, in order to overcome such disadvantages of silver ions, it has been studied to support and react silver ions with various inorganic compounds, and new properties such as heat resistance and appropriate silver elution are given along with overcoming the disadvantages. Therefore, it is used in various fields.
[0003]
[Problems to be solved by the invention]
Silver-based inorganic antibacterial agents, such as the sparingly soluble salts described above, are excellent in antibacterial and bactericidal properties, but have the disadvantage of having discoloration when irradiated with ultraviolet light or heated, so silver that is white When antibacterial agents are incorporated into antibacterial objects such as paints, plastics, and cement-based secondary products, foaming during kneading, deterioration of antibacterial objects, coloring, and discoloration occur in heat and weather resistance tests There are cases where it is difficult to use for a long period of time, and there are significant industrial restrictions while providing antibacterial properties.
[0004]
[Means for Solving the Problems]
Accordingly, as a result of intensive studies on the development of an inorganic antibacterial agent having excellent antibacterial and bactericidal properties, the present inventor has made a silver salt and / or zinc salt of an antibacterial action, and a molybdenum oxo compound. An inorganic antibacterial agent, which is obtained by reacting with an alkali salt of 1 and 2 types of double salt as an active ingredient, exhibits an antibacterial and bactericidal effect and sustains its effect compared to conventional inorganic antibacterial agents As a result, the present invention was completed. That is, the present invention relates to an inorganic antibacterial comprising as an active ingredient one or two of double salts obtained by reacting a silver salt and / or zinc salt of a metal salt having antibacterial activity and an alkali salt of a molybdenum oxo compound. It is an agent.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The inorganic antibacterial agent of the present invention is prepared by reacting a silver salt and / or zinc salt of a metal salt having an antibacterial action with an alkali salt of a molybdenum oxo compound. As the metal salt, a compound of silver and zinc is used. Silver nitrate, silver acetate, silver sulfate and the like can be used for the silver compound, and zinc nitrate, zinc acetate, zinc sulfate and the like can be used for the zinc compound. As the molybdenum-oxo compound an alkali salt can be used sodium molybdate, potassium molybdate, lithium molybdate, ammonium molybdate, sodium poly molybdate, and iso-poly molybdate sodium. The reaction may be performed by adding an aqueous alkaline salt solution of a molybdenum oxo compound to an aqueous silver salt or zinc salt solution, or vice versa. In the present invention, the particle diameter of the silver salt and / or zinc salt to be obtained and the double salt of the molybdenum oxo compound can be changed depending on the reaction conditions. In order to obtain a small particle size, the concentration of the aqueous solution of the alkali salt of molybdenum oxo compound, the silver salt and / or the metal salt solution of zinc salt can be lowered and the stirring speed can be increased, and the particle size can be controlled freely. be able to. A preferable particle diameter is preferably 10 μm or less in view of the influence on the physical properties of the antibacterial object or antibacterial properties. Thus obtained silver salt and / or zinc salt having a preferred particle size and a double salt of molybdenum oxo compound are obtained in powder form by filtering water from the reaction solution slurry and drying. Obtained by the present invention--not limited.
[0006]
The inorganic antibacterial agent of the present invention is an inorganic antibacterial agent comprising a silver salt and / or zinc salt of a metal salt having antibacterial action and a salt of molybdenum oxo compound as active ingredients, and has excellent antibacterial properties. Excellent resistance to discoloration. The details of the mechanism of action of the inorganic antibacterial agent of the present invention, such as excellent antibacterial properties, are unknown, but the antibacterial metal is probably due to the double chlorination of silver and / or zinc and molybdenum oxo compounds of the antibacterial metal. As a result of the moderate elution of silver and / or zinc and the chemical stability ratio of antibacterial metal silver and / or zinc, it has excellent antibacterial efficacy, long-lasting efficacy, and excellent resistance to discoloration. Conceivable.
[0007]
【Example】
The present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples.
[0008]
(Example 1) (Method for preparing molybdenum oxide silver double salt)
A solution in which 6.5 g of sodium molybdate dihydrate (Kanto Chemical Co., Ltd.) is dissolved in 100 ml of ion exchange water, and 9.1 g of silver nitrate (Kanto Chemical Co., Ltd.) is dissolved in 100 ml of ion exchange water. Was added dropwise in 30 minutes to form a precipitate. Furthermore, after stirring for 1 hour and aging the precipitate, the obtained precipitate was filtered, washed with ion-exchanged water, sufficiently dried at 100 ° C., and the yellowish white inorganic antibacterial agent powder of the present invention was reduced to about 10 g was obtained. The average particle size at this time was 5.0 μm. The silver content was about 59% in the powder.
[0009]
(Example 2) (Method for preparing molybdenum zinc oxide double salt)
10.85 g of sodium molybdate dihydrate (Kanto Chemical Co., Ltd.) was dissolved in 100 ml of ion exchange water, and 13.38 g of zinc nitrate hexahydrate (Kanto Chemical Co., Ltd.) was dissolved in 100 ml of ion exchange. A solution dissolved in water was added dropwise in 30 minutes to form a precipitate. Further, after stirring for 1 hour and aging the precipitate, the obtained precipitate is filtered, washed with ion-exchanged water, sufficiently dried at 100 ° C., and about 10 g of the white inorganic antibacterial agent powder of the present invention is obtained. Obtained. The average particle size at this time was 8.0 μm. The zinc content was about 29% in the powder.
[0010]
(Example 3)
50 parts of the molybdenum oxide silver double salt obtained in Example 1 and 50 parts of the molybdenum zinc oxide double salt obtained in Example 2 were mixed to obtain 100 parts of the inorganic antibacterial powder of the present invention.
[0011]
(Comparative Example 1) (Method for preparing silver silicate)
Dissolve 9.94 g of sodium metasilicate nonahydrate (Wako Pure Chemical Industries, Ltd.) in 100 ml of ion exchange water, and dissolve 11.9 g of silver nitrate (Kanto Chemical Co., Ltd.) in 100 ml of ion exchange water. The resulting solution was added dropwise in 30 minutes to form a precipitate. Thereafter, in the same manner as in Example 1, after drying sufficiently at 100 ° C., about 10 g of a tan precipitate was obtained. The average particle size at this time was 8.8 μm. The silver content was about 70% in the powder.
[0012]
(Comparative Example 2) (Preparation Method of Calcium Phosphate Silver Antibacterial Agent)
3 g of calcium hydroxide was suspended in 100 ml of ion-exchanged water, and 8 g / 100 ml of an aqueous phosphoric acid solution was gradually added dropwise thereto. When the pH in the suspension reached 6, the addition of the aqueous phosphoric acid solution was terminated. After aging for 30 minutes, 0.3 g of silver nitrate and aluminum nitrate were dissolved in 10 ml of ion-exchanged water and dropped into the suspension. After aging for 3 hours, the precipitate was washed, filtered and dried to obtain a white powder. The average particle size at this time was 3.5 μm. The silver content was about 1.1%.
Next, the evaluation method will be described.
[0013]
[Preparation method of cement joint with inorganic antibacterial agent]
0.004% of each antibacterial agent of Example 1, Example 2, Example 3 and Comparative Example 1 and 0.2% of the antibacterial agent of Comparative Example 2 are added to 100 g of commercially available cement joint material and 34 g of tap water. After sufficiently mixing, solidification curing was performed at a temperature of 40 ° C. and a humidity of 95% or more for about 3 days to obtain a sample having a diameter of 30 mm and a thickness of 5 mm.
This sample was subjected to high temperature drying, discoloration test in hot water immersion, and antibacterial activity test.
[0014]
[Discoloration test during sample preparation, high-temperature drying, and immersion in warm water]
Discoloration at the time of sample preparation of cement joint sample mixed with inorganic antibacterial agent, discoloration at 40 ° C for 1 week for high temperature drying operation, 40 ° C warm water immersion for warm water immersion operation, discoloration for 1 week for blank sample (inorganic antibacterial Table 1 shows the comparison with (no additive added).
[0015]
[Table 1]

[0016]
[Antimicrobial test of cement joint material]
The sample with or without the warm water immersion operation was pulverized in a mortar, then placed in a desiccator at a temperature of 25 ° C. and a humidity of 95% or more, carbon dioxide was injected, and the mixture was left for 1 week for dealkalization. 0.75 g of the obtained sample was placed in a 200 ml Erlenmeyer flask and adjusted to 1.0 × 10 ^{5 to} 5.0 × 10 ⁶ (pieces / ml) in a phosphate buffer solution (20 mM pH 7). 50 ml of the turbid liquid was added and contacted with a constant temperature shaker (30 ° C., 120 rpm), and the viable cell count after 24 hours was measured by an agar plate method using a heart infusion medium.
Table 2 shows the test results in E. coli and S. aureus .
[0017]
[Table 2]

[0018]
【The invention's effect】
As described above, one or two of the double salts obtained by reacting the silver salt and / or zinc salt of a metal salt having antibacterial activity of the present invention with an alkali salt of a molybdenum oxo compound is used as an active ingredient. The inorganic antibacterial agent has not only excellent antibacterial and bactericidal properties but also has both discoloration resistance.

Claims

Inorganic antibacterial agent containing as active ingredient one or two of double salts obtained by reacting silver salt and / or zinc salt of metal salt having antibacterial activity and alkali salt of molybdenum oxo compound