JP4052526B2

JP4052526B2 - Antibacterial resin

Info

Publication number: JP4052526B2
Application number: JP21262797A
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: 2008-02-27
Anticipated expiration: 2017-07-22
Also published as: JPH1135414A

Description

【０００１】
【発明の属する技術分野】
本発明は、抗菌作用がある無機系抗菌剤を含有する抗菌性樹脂に関するものであり、更に詳しくは、耐変色性、耐熱性・耐候性、安全性に優れた抗菌性樹脂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、塗料やプラスチック等に配合した際、耐熱・耐候性試験に於いて、練り込み時の発泡、樹脂の劣化、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・殺菌性に優れた抗菌性樹脂の開発を鋭意検討した結果、有効成分として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種を無機系抗菌剤として含有する抗菌性樹脂が、従来の無機系抗菌剤を練り込んだ樹脂に比べ抗菌・殺菌性に優れかつ耐変色性、耐熱性・耐候性、安全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、有効成分として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種または２種以上を無機系抗菌剤として含有する抗菌性樹脂である。
【０００５】
【発明の実施の形態】
本発明の樹脂に添加される無機系抗菌剤は、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、および銀塩および／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。本発明に使用される樹脂としては、・・・・その製法や形状は特に限定されるものではない。
【０００６】
【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。
【０００７】
（調製例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。
【０００８】
（調製例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。
【０００９】
（調製例３）
調製例１で得られた酸化モリブデン銀複塩５０部と調製例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。
【００１０】
（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、調製例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。
【００１１】
（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。
【００１２】
［抗菌性樹脂の作製（ポリプロピレン：ＰＰ）］
ＰＰ（ＡＷ−６３０Ｖ：住友化学社製）を１５００部、紫外線吸収剤としてスミソーブ３００（住友化学社製）を１．５部、酸化防止剤としてスミライザーＰ−１６（住友化学社製）を０．７５部、スミライザーＢＰ−１０１（住友化学社製）を０．７５部、安定剤としてステアリン酸カルシウム（関東化学（株））を０．７５部混合し、ミキシングロール（安田精機製作所（株））でロール表面温度約１９０℃で先に混合したＰＰを５０ｇに対し調製例１、調製例２、調製例３及び比較例１の各抗菌剤をＰＰに対して０．０２％、比較例２の抗菌剤を１％添加し１５分間混練りした。次に、電熱プレス（関西ロール（株））シート成型器では、温度２３０℃で、混練りした各樹脂を約１３ｇ取り、溶融３分、加圧２分、冷却３分で成型サイズ：１２０×１２０×１ｍｍの抗菌性樹脂シートを１枚得た。
このシートを耐熱性試験、耐候性試験、抗菌力試験に供試した。
【００１３】
［抗菌性樹脂の成型時、耐熱性、耐候性試験］
実験で得られた、抗菌性樹脂の成型時の色の変化、耐熱性、耐候性を調べるために、耐熱操作では１５０℃で１０日目での色の変化を、耐候操作を調べるために、ＳＷＯＭ（８３℃ 雨あり）で１８０時間目での色の変化をブランクシート（無機抗菌剤無添加）との比較で表１に示す。
【００１４】
【表１】

【００１５】
［樹脂中での抗菌力試験］試験方法（フィルム密着法）
培養した供試菌を１／２００ＮＢ培地を加えた滅菌精製水で２．０×１０⁵〜１．０×１０⁶（個／ｍｌ）に調整する。上記で得られた耐候操作無し、有りのＰ．Ｐ．のシートを５ｃｍ平方に切り取った試料を滅菌シャーレに入れ、試料上に０．５ｍｌの菌液を接種し、被覆フィルムを被せてシャーレをシールし、３５℃で保存する。２４時間後にＳＣＤＬＰ培地９．５ｍｌで洗い出して１ｍｌ中の生菌数を寒天平板培養法で測定する。結果を表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。
試験方法は１９９５年度版銀系無機抗菌剤研究会抗菌加工製品の効力試験法１に準ずる。
【００１６】
【表２】

【００１７】
【発明の効果】
以上説明したように、有効成分として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種を含有する抗菌性樹脂は、極めて優れた抗菌・殺菌性を有するのみでなく、耐熱性・耐変色性の両者を兼ね備えている。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an antibacterial resin containing an inorganic antibacterial agent having an antibacterial action, and more particularly to an antibacterial resin excellent in discoloration resistance, heat resistance / weather resistance and safety.
[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 paints, plastics, etc., in heat and weather resistance tests, foaming during kneading, resin deterioration, coloring, and discoloration may occur, making it difficult to use for a long time. However, it was severely industrially restricted.
[0004]
[Means for Solving the Problems]
Therefore, as a result of intensive studies on the development of an antibacterial resin excellent in antibacterial and bactericidal properties, the present inventor has found that a silver salt and / or zinc salt of a metal salt having an antibacterial action as an active ingredient, molybdenum Antibacterial resin containing one or two double salts obtained as a reaction with alkali salt of oxo compound as an inorganic antibacterial agent is more antibacterial and sterilizing than conventional resins containing inorganic antibacterial agents. The present invention has been completed by finding that it has excellent color resistance, discoloration resistance, heat resistance / weather resistance, and safety. That is, the present invention provides an inorganic antibacterial agent as one or more of double salts obtained by reacting silver salts and / or zinc salts of metal salts having antibacterial activity as active ingredients with alkali salts of molybdenum oxo compounds. Antibacterial resin contained as an agent.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The inorganic antibacterial agent added to the resin 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. Further, as the molybdenum salt of the molybdenum oxo compound, sodium molybdate, potassium molybdate, lithium molybdate, ammonium molybdate, sodium polymolybdate, sodium isopolymolybdate and the like can be used. The reaction method may be adding an aqueous alkali 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. To obtain a small particle size, the concentration of the aqueous solution of the alkali salt of molybdenum oxo compound and the aqueous solution of the metal salt of silver salt and / or zinc salt can be reduced and the stirring speed can be increased, and the particle size can be freely controlled. can do. 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. The resin used in the present invention is not particularly limited in its manufacturing method and shape.
[0006]
【Example】
The present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples.
[0007]
(Preparation 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.
[0008]
(Preparation 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.
[0009]
(Preparation Example 3)
50 parts of the molybdenum oxide silver double salt obtained in Preparation Example 1 and 50 parts of the molybdenum zinc oxide double salt obtained in Preparation Example 2 were mixed to obtain 100 parts of the inorganic antibacterial powder of the present invention.
[0010]
(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 Preparation 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.
[0011]
(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.
[0012]
[Production of antibacterial resin (polypropylene: PP)]
1500 parts of PP (AW-630V: manufactured by Sumitomo Chemical Co., Ltd.), 1.5 parts of Sumisorb 300 (manufactured by Sumitomo Chemical Co., Ltd.) as an ultraviolet absorber, and 0.1 part of Sumizer P-16 (manufactured by Sumitomo Chemical Co., Ltd.) as an antioxidant. 75 parts, 0.75 parts of Sumilizer BP-101 (manufactured by Sumitomo Chemical Co., Ltd.), 0.75 parts of calcium stearate (Kanto Chemical Co., Ltd.) as a stabilizer, and mixing roll (Yasuda Seiki Seisakusho Co., Ltd.) Each antibacterial agent of Preparation Example 1, Preparation Example 2, Preparation Example 3 and Comparative Example 1 is 0.02% of PP with respect to 50 g of PP previously mixed at a roll surface temperature of about 190 ° C., and antibacterial of Comparative Example 2 1% of the agent was added and kneaded for 15 minutes. Next, in an electric heat press (Kansai Roll Co., Ltd.) sheet molding machine, about 13 g of each kneaded resin is taken at a temperature of 230 ° C., molded for 3 minutes, pressurized for 2 minutes and cooled for 3 minutes. One 120 × 1 mm antibacterial resin sheet was obtained.
This sheet was subjected to a heat resistance test, a weather resistance test, and an antibacterial activity test.
[0013]
[At the time of molding antibacterial resin, heat resistance and weather resistance test]
In order to investigate the color change, heat resistance, and weather resistance during molding of the antibacterial resin obtained in the experiment, in order to investigate the color change in the 10th day at 150 ° C. in the heat resistant operation, Table 1 shows the change in color at 180 hours after SWOM (with 83 ° C. rain) in comparison with a blank sheet (without addition of an inorganic antibacterial agent).
[0014]
[Table 1]

[0015]
[Antimicrobial test in resin] Test method (film adhesion method)
The cultured test bacteria are adjusted to 2.0 × 10 ^{5 to} 1.0 × 10 ⁶ (pieces / ml) with sterilized purified water added with 1 / 200NB medium. P. with no weathering operation and with the above obtained. P. A sample obtained by cutting a sheet of 5 cm into a square is placed in a sterile petri dish, 0.5 ml of the bacterial solution is inoculated on the sample, and the petri dish is sealed with a coating film and stored at 35 ° C. After 24 hours, the cells were washed with 9.5 ml of SCDLP medium, and the number of viable bacteria in 1 ml was measured by an agar plate culture method. The results are shown in Table 2 and the test results in E. coli and S. aureus .
The test method is the same as that of the 1995 edition Silver-Based Inorganic Antibacterial Study Group Antibacterial Processed Product Effectiveness Test Method 1.
[0016]
[Table 2]

[0017]
【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 the metal salt having antibacterial activity of the present invention with an alkali salt of a molybdenum oxo compound as an active ingredient. The contained antibacterial resin not only has extremely excellent antibacterial and bactericidal properties, but also has both heat resistance and discoloration resistance.

Claims

Antibacterial activity containing as an inorganic antibacterial agent one or two of double salts obtained by reacting silver salt and / or zinc salt of metal salt having antibacterial activity as an active ingredient with alkali salt of molybdenum oxo compound resin.