JPH03193707A - New antibacterial silicate - Google Patents

Abstract

PURPOSE:To obtain the subject antibacterial silicate excellent in water resistance, heat resistance, chemical resistance and storage properties and capable of forming a film excellent in the duration of the above-mentioned antibacterial effect by substituting ion-exchangeable metals contained in a layer silicate with a specified metal-coordinated compound. CONSTITUTION:An antibacterial silicate obtained by substituting a part or all of ion-exchangeable metals (e.g. Li, K, Na, Ca or Mg) contained in a layer silicate such as smectites, vermiculite or a synthetic mica having cation exchange capacity with a coordinated compound between one or more metals selected from Ag, Cu and Zn and an organic ligand having one or more electron donative groups in the molecule. As the organic coordination ligand, ethylenediamine, dimethylglyoxime, phenanthroline, dipyridyl, triethylenediamine, 8-quinolinol, acrylflavin and thiazolylbenzimidazole are exemplified.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an antibacterial agent which has excellent water resistance, heat resistance, chemical resistance, and storage properties that do not reduce its effectiveness even after long-term storage, and which has an excellent long-lasting antibacterial effect. The present invention relates to an inorganic antibacterial substance, and more specifically to a novel antibacterial silicate having film-forming ability.

The silicate of the present invention can be used not only for materials without heat resistance, but also for materials without heat resistance.
Heat-resistant antibacterial coating materials, paints, adhesives, insulation materials,
It can be effectively used as fibers, paper products, caulking materials, etc.

[Prior art and problems to be solved by the invention] Various compounds are known as antibacterial substances, but most of them are specific compounds, many of which have poor heat resistance, and cannot be used in the temperature range of around 150℃. Most of them are expired. Heat-resistant antibacterial substances include various compounds of elements such as tin, lead, arsenic, mercury, and chromium, which have been known for a long time.
Many of them are extremely toxic, and there are only two practical uses for them. Low-toxicity, heat-resistant antibacterial substances include compounds of silver, zinc, and copper, but they are usually used in solutions such as silver nitrate aqueous solutions, and are difficult to handle. For the purpose of improving heat resistance, suppressing the elution of antibacterial substances, and sustaining the antibacterial effect, there is a known method of using compounds such as silver, copper, and zinc by adsorbing them on activated carbon or activated alumina. However, it cannot be said that this is sufficient in terms of suppressing the elution value of metal ions.For example, regarding the regulation when using silver as an antibacterial agent component, the US Public Health Service recommends that silver be less than 50 ppb, and that the West German "C" i 0Qppb or less, 200 in Switzerland
PPb or less.

As mentioned above, when using antibacterial components and metals, prevent metal elution into the liquid as much as possible, maintain the concentration below regulations, and maintain antibacterial effects for a long period of time. It is important to use a metal retaining agent that has a high resistance to metal retention. Aluminosilicates such as clay minerals were proposed in JP-A No. 111-181002, JP-A No. 62-7022.
No. 1) 3. However, zeolite-based antibacterial agents have poor chemical resistance, especially acid resistance, and when they come into contact with acidic substances (L/<, dilute sulfuric acid/2), they dissolve and decompose, causing damage. However, there is a drawback in terms of durability of antibacterial power.

- The antibacterial effect of clay mineral-based antibacterial agents is not sufficiently long-lasting because the metals they contain tend to precipitate as particles during storage and are easily eluted into solutions. In addition, aluminosilicates do not have sufficient affinity with organic resins, which poses a problem when used in the kneading method.

1. The object of the present invention is to overcome the drawbacks of conventional aluminosilicates as described above, and to provide a novel antibacterial silicate that has a film-forming ability with excellent resistance to acids and other chemicals. purpose.

[Means for Solving the Problem 4] The present inventors have completed the present invention as a result of intensive research to solve the above-mentioned problem.

That is, in order to achieve the above object, the present invention replaces at least a part of the ion-exchangeable needle metal ions contained in the layered silicate with at least one metal selected from silver, copper, and zinc. It is an antibacterial silicate consisting of a substituted I-coordination compound of an ion and an organic ligand.

Layered silicic acid used as antibacterial metal retaining material in the present invention
Examples of 8 include smectite, vermiculite, synthetic mica, fluorine-substituted -tr-b silicates, and R compounds thereof. Between the layers of these silicates are sodium, potassium,
Since exchangeable cations such as calcium and 7gnesium are present, various organic or inorganic ions and polar molecules can be introduced between the layers.

These 21 layered silicates usually have a Y average particle size of 0.5 h-1
It is used in powder form of 5μ6m.

The organic ligand used in the present invention has at least one electron-donating group (unpaired electron) in the molecule, and has silver, copper,
and can form coordination compounds with zinc ions. In general, ligands having electron-donating groups such as N, P, S, and 0 are mentioned, and preferred specific examples and 1
Examples of 7 include ethyl/diamine, phenane-1-loline, dipyridyl, triethyl-diamine, dimethylglyoxime, and 8-quinolinol.

When producing coordination compounds of silver, copper and/or zinc metal ions and organic ligands having antibacterial properties, it is convenient to use these metal compounds. These metal compounds include chlorides, sulfates, nitrates, nitrites,
Examples include organic acid salts and mixtures thereof, and preferred examples include silver nitrate, copper sulfur, zinc chloride, and the like.

The antibacterial silicate of the present invention is a coordination compound of silver, copper, zinc ions, and organic coordination f, which converts exchangeable ions such as soot, lithium, potassium, and calci-cum in single-layer silicates into a coordination compound of silver, copper, and zinc ions and organic coordination f. It is produced by an ion exchange reaction by δ-migration. The ion exchange reaction can be carried out in an aqueous or organic solvent system by a batch method or a column method at room temperature or under heating. As the organic solvent, ketones, amides, esters, alcohols, etc. are preferable, and methyl isobutyl coke, dimethylformamide, butyl acetate, isopropyl alcohol, etc. are particularly preferable. Layered silicon preferably adjusted to a concentration between 1-10 w/w%
v in the suspended liquid (, r, l to the ion exchange capacity specific to each layered silicate), one or more selected from the group of -1- metal salts.
Add 0.5-3 times the coordination compound to L, and stir at room temperature for about 2 to 72 hours (1) at room temperature (or at 40-90°C).
The metal concentration is 0.5 to 100,000 ppm, preferably 1
．． The resulting product is washed as it is or washed several times with ion-exchanged water to obtain a pendicon-like product. Layered silicates containing metal coordination compounds do not have the disadvantages of 1) decomposition and death when contacted with acidic substances such as dilute sulfuric acid, unlike oroaluminosilicates containing similar metals; , compared to layered silicates containing only such metal ions, precipitation of metal particles during storage,
There is no leakage of metal ions into the aqueous solution, and the metal ion coordination compound is stably maintained, resulting in an antibacterial silicate with excellent antibacterial effect C.

The layered silicate obtained by such a synthetic operation and containing metal coordination compounds such as silver, copper, and zinc can be easily dissolved in water or an organic solvent. 'Tama, suji 1/-gorting,
It is possible to form a film on the solid surface 1- using a usual film forming method such as coater-coating, tipping, brushing, rolling, etc. That is, after drying a water-free one-layer organic solvent suspension of a layered silicate onto a solid surface, the temperature is 200-700°C, preferably 250"600
Embroidery is done at an opening of ℃. By using such a film type method, antibacterial silicate can be formed as a film on various materials such as metal, plastic deck, and ceramic.

In addition, the wood or organic solvent-based suspension of the layered silicate can be used by adding and kneading it to other paints, rubbers, plastics, paper, textiles, etc. After drying, it can be used in a solid state such as a powder or a sticky substance in combination with an antibacterial composition.

The novel antibacterial silicate of the present invention is effective against various types of
It has a broad antibacterial spectrum, especially against Staphylococcus aureus, both Durham positive and negative strains, polymorphic bacilli, and Staphylococcus aureus.
ureus), Bacillus b.
us auhti! is), E. coli (E.
seherichia coli), Candida (Ca.
nclida), Aspergillus flavus (Asup
ergilus fla-was), Aspergillus
It showed excellent resistance to Hi Nus niger (Av = pc "Hi Nus niger)" etc. The antibacterial effect was determined by using seeds as a seed and agar culture according to the mold resistance test method, JIS Z 2911.
1! When the antibacterial properties were evaluated by the inhibition zone formation method after conventional culturing, most of the samples showed effective antibacterial properties. This new antibacterial silicate has excellent heat resistance, which is an inherent characteristic of layered silicates, because silver, copper, and zinc are uniformly distributed between the layers of layered silicate, and can withstand temperatures from 60 to -600℃. Shows stable antibacterial properties even after treatment in temperature range1
)is. In addition, since it is a bulky coordination compound that exists between the layers, it is possible to prevent the antibacterial effect from being reduced due to the precipitation of metal particles during storage, and by inserting the antibacterial metal ion and the organic coordination compound together, Water resistance and durability of antibacterial effect are significantly improved. Clay exhibits higher chemical resistance than zeolite and retains its properties. Furthermore, since it has a film-forming ability by itself and does not require the use of other organic or inorganic binders, it has excellent antibacterial effects and excellent durability.

Furthermore, since it has excellent heat resistance and antibacterial properties, it can be used in combination with various organic or inorganic binders in various temperature ranges. That is, polyvinyl chloride, polyethylene,
It can be heated and mixed with various plastics such as polypropylene, acrylic ester, polycarbonate, and ABS resin, and the antibacterial properties are not impaired even when used in combination with such heating and mixing operations. Natural rubber, NBR, SBR, EP
The antibacterial property is not impaired even when used in combination with various rubbers such as DM, urethane rubber, silicone rubber, and fluorine rubber in a heating kneading operation, and it is compatible with baking-type paints such as epoxy/melanin, epoxy/phenol, and acrylic/phenol. It is characterized by its antibacterial properties not being lost even when used in combination with heating operations, and furthermore, its antibacterial properties are not impaired even when it is used in combination with various inorganic binders such as water glass and mortar in heating and kneading operations. .

Because it has excellent antibacterial properties as described above, the novel antibacterial silicate with film-forming ability according to the present invention can be used not only by itself, but also in combination with various organic or inorganic materials, and can be used in a wide range of industrial fields. It can be used in

The present invention will be explained in more detail below with reference to Examples.

Example 1) To 2000 ml of an aqueous suspension containing 30 g of Kunivia F (manufactured by Kunimine Kogyo ■, sodium montmorillonite), 600 ml of a 0,IN-silver nitrate/1.10-orthophenanthroline complex solution prepared by a conventional method was added. The reaction was carried out by heating at ℃ for 48 hours.

The reaction solution turned pink, and after the reaction was completed, the slurry was washed with water and filtered until the pH reached 7. The obtained slurry is 12
It was dried at 0° C. for 40 minutes to obtain orange-pink montmorillonite/silver phenanthrophosphate.

Example 2) Aqueous suspension 2 containing 30 g of sodium montmorillonite
000ml of 0,IN-silver nitrate/adjusted by a conventional method.
Add 600ml of dipyridyl complex solution and heat at 90℃ for 48 hours.
Allowed time to react. After the reaction was completed, the slurry was washed with water and filtered until the pH reached 7.

The resulting slurry was dried at 120° C. for 40 minutes to obtain pink montmorillonite/silver dipyridylide powder.

Example 3) Aqueous suspension 2 containing 30 g of sodium montmorillonite
000ml of 0.5N copper sulfate/
Ethylenediamine complex 10,100O was added and the reaction was stirred at 80°C for 48 hours. After the reaction was completed, the slurry was thoroughly washed with water and filtered until the pH reached 7. The obtained slurry was dried with a spray dryer, and montmorillonite/
Ethylene diamine copper powder was obtained.

Example 4) Aqueous suspension 2 containing 30 g of sodium montmorillonite
000 ml was added with 500 ml of 0,5N-zinc chloride/benzotriazole complex aqueous solution prepared by a conventional method and reacted at 110°C for 48 hours. After completion of the 0 reaction, the pH
The slurry was washed with water and filtered until it reached 7. The obtained slurry was dried with a spray dryer to obtain benzotriazolized zinc-containing montmorillonite.

Example 5) 500ml of a 0,IN-silver nitrate/1,10-orthophenanthroline complex solution prepared in a conventional manner was added to 2000ml of an aqueous suspension containing 5g of sodium montmorillonite and 5g of sodium savonite, and the mixture was heated to 48ml at 80°C. After the reaction was completed for 0 hours, the slurry was washed with water and filtered until the pH reached 7.

The obtained slurry was dried with a spray dryer to obtain orthophenanthrophosphide-containing montmorillonite/sabonite.

Comparative Example 1) Instead of the 0,1N-silver nitrate/1,10 orthophoric nanthroline complex used in Example 1, 0.1N-silver nitrate 60
0 ml was added thereto, and the mixture was heated and reacted at 80° C. for 48 hours to obtain a montmorillonite/silver slurry. The slurry was washed with water until the pH reached 7, filtered, and then dried at 120° C. for 40 minutes to obtain gray montmorillonite/silver powder.

Comparative Example 2) Instead of the 0.5 N-copper sulfate/ethylenediamine complex used in Example 3, 1000 rnl of 0.5 N-copper sulfate was used.
was added, and the mixture was stirred and reacted at 80°C for 48 hours.

After the reaction was completed, the slurry was thoroughly washed with water and filtered until the pH reached 7. The obtained slurry was dried with a spray dryer to obtain copper-containing montmorillonite powder.

Comparative Example 3) Instead of the 0,5N-zinc chloride/benzotriazol complex used in Example 4, 0.5N-zinc chloride aqueous solution 50
0ml was added to 2000ml of an aqueous suspension containing 30g of sodium montmorillonite, and the mixture was reacted at 110°C for 48 hours. After the reaction was completed, the slurry was washed with water and filtered until the pH reached 7.

The obtained slurry was dried with a spray dryer to obtain zinc-containing montmorillonite powder.

Comparative Example 4) Instead of the 0,IN-silver nitrate/1,10 orthophenanthroline complex used in Example 1, only an equivalent amount of 1.10 orthophenanthroline was added, and the mixture was heated at 80°C for 48 hours, mixed and stirred. 1. A montmorillonite slurry containing lθ orthophenanthroline was obtained. Slurry at 120℃
Dry for 40 minutes, 1. A montmorillonite powder containing IO-orthophenanthroline was obtained.

Comparative Example 5) Instead of the 0,5N-copper sulfate/ethylenecyamine complex used in Example 3, only a considerable amount of ethylenediamine was added, heated at 80°C for 48 hours, and mixed and stirred to obtain an ethylenediamine-containing montmorillonite slurry. Ta. The slurry was dried with a spray dryer to obtain ethylenediamine-containing montmorillonite powder.

Comparative Example 6) Instead of the 0,5N-zinc chloride/benzotriazole complex used in Example 4, only a considerable amount of benzotriazole was added, heated at 100°C for 48 hours, mixed and stirred, and a benzotriazole-containing montmorillonite slurry was prepared. I got it. The slurry was dried with a spray dryer to obtain benzotriazole-containing montmorillonite powder.

Antibacterial Test Example 1) Novel antibacterial silicates of Examples 1 to 5 and Comparative Examples 1 to 6
Antibacterial tests of the composition against bacteria and fungi were conducted as follows.

The compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were formed into a disk shape with a diameter of 20 mm and a thickness of 2 mm using a pressurized vacuum press, and the disks were embedded and cultured in each antibacterial test medium. As a medium, Mueller Hinton medium is used for bacteria;
For fungi, Sabouraud agar medium was used. Bodhisattvas were dispersed in a clean bench using platinum wire. Culture is carried out at 37°C for 18 hours for bacteria and 3 hours for fungi.
Each was cultured at 0°C for 7 days, and the presence or absence of inhibition zone formation was confirmed, and the results are shown in Table 1. Further, each composition was washed with running city water for 48 hours, dried at 120° C. for 30 minutes, and then subjected to a similar antibacterial test, and the results are shown in Table 1.

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Table 1 Inhibition zone formation ability Staphylococcus aureus Initial period After flushing 3-4 2- 3 3 to 4 2 to 3 5 to 6 3 to 4 4 to 5 2 to 3 3 to 4 1 to 2 3 to 4 0 to 1 3 to 4 3 to 4 3 to 3 3 to 3 3 to 3 (mm) (Eacherichia coli) Initial period After flushing 4S-53-4 4-5 2-3 6-7 4-5 4-52--3 4-5 2-3 3-4 0-1 2-3 Inhibition Cand 1da albicans Cand 1da albicans After initial ■ 3 ~ 4 1 ~ 2 3 ~ 4 2 ~ 3 4 ~ 5 3 ~ 4 4 ~ 5 3 ~ 4 3 ~ 4 2 ~3 2~3 No inhibition 2~3 At 2 1~2 No inhibition Example 6) 50 g of orthophenanthrophosphide-containing montmorillonite synthesized in Example 1 was added to a moisture-curing silicone rubber compound (Shin-Etsu Chemical Co., Ltd.). 5E1400 manufactured by ■) IK g, and after hardening at 20℃ for 48 hours, the diameter was 20m.
Make a disk-shaped test piece of m.

The test was conducted under the same conditions as in Antibacterial Test Example 1 (initial period and 48 hours of immersion in running water at 20°C), and the results are shown in Table 2. Further, as Comparative Example 7, 50 g of the composition synthesized in Comparative Example 1 was kneaded with I kg of the silicone rubber compound, and after curing, the antibacterial properties were evaluated on identical test pieces having a diameter of 20 mm.

Table 2 Antibacterial inhibition zone of silicone rubber composition (mm) Staphylococcus (Eacheri)
chia (Candida aureus)
col i) albican
s) Initial period after running water Initial stage after running water After initial running water Examples 62-31-2 3-4 2-3 2-3 1-
2 Comparative Example 72-3 Inhibition Zones 3-4 Inhibition Zones 2-
3 No inhibition zone Example 7) 10 g of montmorillonite/ethylene diamine copper powder synthesized in Example 3 was added to acrylic urethane paint soo.
g (Contains 100g of acrylic urethane polymer solid content)
Disperse and knead it uniformly and spread it on an aluminum plate to a thickness of 40I.
Spray coated on Lm. The coating was heated to 4 at 120°C.
Let cure for 0 minutes.

The test was conducted under the same conditions as in Antibacterial Test Example 1 (initial stage and 48 hours of immersion in running water at 20°C), and the results are shown in Table 3. In addition, as Comparative Example 8, 10 g of the composition synthesized in Comparative Example 2 was
Uniformly dispersed in 500 g of the above acrylic urethane paint,
Antibacterial properties were evaluated under similar conditions and are also listed.

Claims (1)

[Claims] 1. At least a part of the ion-exchangeable metal contained in the layered silicate is combined with an organic ligand with at least one metal ion selected from silver, copper, and zinc. An antibacterial silicate obtained by substituting with a coordination compound. 2. The antibacterial silicate according to claim 1, wherein the layered silicate is at least one selected from smectite, vermiculite, synthetic mica, fluorine-substituted silicates, and mixtures thereof having cation exchange ability. . 3. The antibacterial silicate according to claim 1 or 2, wherein the ion-exchangeable metal is at least one metal selected from lithium, potassium, sodium, calcium, and magnesium. 4. The antibacterial silicate according to claim 1, wherein the organic ligand is a ligand having at least one electron donating group in the molecule. 5. The antibacterial silicate according to claim 1, wherein the organic ligand is at least one selected from ethylenediamine, dimethylglyoxime, phenanthroline, dipyridyl, triethylenediamine, 8-quinolinol, and mixtures thereof.