JP2008074781A - Silver-based inorganic antimicrobial agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silver-based inorganic antimicrobial agent having excellent heat resistance, chemical resistance, slight resin discoloring property and excellent processability. <P>SOLUTION: The silver-based inorganic antimicrobial agent is a silver ion-containing zirconium phosphate represented by general formula [1] Ag<SB>a</SB>Na<SB>b</SB>H<SB>c</SB>(H<SB>3</SB>O)<SB>d</SB>Zr<SB>e</SB>Hf<SB>f</SB>(PO<SB>4</SB>)<SB>3</SB>-nH<SB>2</SB>O, wherein a, b, c, d and e are each a positive number, f is 0 or a positive number and a, b, c, d, e and f are each a number satisfying 1.75<(e+f)<2.25 and a+b+c+d+4(e+f)=9, and n is a positive number of ≤2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a silver phosphate-supported zirconium phosphate, which is a silver-based inorganic antibacterial agent that is excellent in heat resistance, chemical resistance and processability, and has little discoloration when blended with plastic.

  In recent years, zirconium phosphate-based inorganic ion exchangers have been used for various purposes by taking advantage of their characteristics. The zirconium phosphate-based inorganic ion exchanger includes an amorphous one, a crystalline one having a two-dimensional layer structure, and a crystalline one having a three-dimensional network structure. Among these, hexagonal zirconium phosphate, which has a three-dimensional network structure, is excellent in heat resistance, chemical resistance, radiation resistance and low thermal expansibility, etc., fixing radioactive waste, solid electrolyte, gas adsorption and It is applied to separation agents, catalysts, and antibacterial raw materials.

Various hexagonal zirconium phosphates are known so far. For example, A _X NH _{4 (1-X)} Zr ₂ (PO ₄ ) ₃ .nH ₂ O (for example, see Patent Document 1), AZr ₂ (PO ₄ ) ₃ .nH ₂ O (for example, see Patent Document 2) H _n R _1-n Zr ₂ (PO ₄ ) ₃ .mH ₂ O (for example, see Patent Document 3).
Also known are zirconium phosphates with different ratios of Zr and P. For example, Na _{1 + 4x} Zr _2-x (PO ₄ ) ₃ (see, for example, Non-Patent Document 1), Na _{1 + 2x} Mg _x Zr _2-x (PO ₄ ) ₃ (see, for example, Non-Patent Documents 1 and 2) ), Na _{1 + x} Zr ₂ Si _x P _3-x O ₁₂ (for example, see Non-Patent Documents 2 and 3).

  These hexagonal zirconium phosphates are synthesized by mixing the raw materials and then firing them at 1000 ° C. or higher using a firing furnace, etc., mixing the raw materials in a state containing water or water and then pressurizing There are known a hydrothermal method for synthesis by heating, a wet method for synthesis by mixing raw materials in water and then heating under normal pressure.

Among these, the firing method can synthesize zirconium phosphate having an appropriately adjusted P / Zr ratio by simply preparing raw materials and heating them at a high temperature. However, in the firing method, uniform mixing of the raw materials is not easy, and it is difficult to form zirconium phosphate having a uniform composition. Furthermore, since it must be pulverized and classified to form particles after firing, there are problems in terms of quality and productivity. Naturally, crystalline zirconium phosphate containing ammonia cannot be synthesized by the firing method. On the other hand, the wet method and the hydrothermal method can obtain homogeneous particulate zirconium phosphate, but the P / Zr ratio is 1.5 and the P / Zr ratio as shown by the following formula [4] is No crystalline zirconium phosphate other than 2 was known.
NH ₄ ZrH (PO ₄ ) ₂ [4]

  Ions such as silver, copper, zinc, tin, mercury, lead, iron, cobalt, nickel, manganese, arsenic, antimony, bismuth, barium, cadmium and chromium are metal ions that exhibit antifungal, antibacterial and antialgal properties ( Hereinafter, it is known as an antibacterial metal ion for a long time. In particular, silver ions are widely used as an aqueous silver nitrate solution having a disinfecting action and a bactericidal action. However, the above-mentioned metal ions exhibiting antifungal, antibacterial or anti-algal properties are often toxic to the human body, and there are various restrictions in usage, storage, disposal, etc., and their use is also limited. .

  In order to exert antifungal, antibacterial or algal control properties, it is sufficient to cause a small amount of antibacterial metal to act on the application target. Therefore, as an antibacterial, antibacterial or algaeic antibacterial agent, an organic supported antibacterial agent in which an antibacterial metal ion is supported on an ion exchange resin or a chelate resin, and the antibacterial metal ion in a clay mineral Inorganic antibacterial agents supported on inorganic ion exchangers or porous bodies have been proposed.

Among the various antibacterial agents described above, inorganic antibacterial agents have features that are higher in safety than organic-supported ones, have a long antibacterial effect, and are excellent in heat resistance.
As one of the inorganic antibacterial agents, antibacterial agents obtained by ion exchange of alkali metal ions such as sodium ions and silver ions in clay minerals such as montmorillonite and zeolite are known. This is because the skeletal structure of the clay mineral itself is inferior in acid resistance. For example, silver ions are easily eluted in an acidic solution and the antibacterial effect is not sustained.
In addition, silver ions are unstable with respect to heat and light exposure, and are immediately reduced to metallic silver, causing coloration, and thus there is a problem in long-term stability.

In order to improve the stability of silver ions, there are zeolites in which silver ions and ammonium ions coexist by ion exchange. However, even in this case, the prevention of coloring has not reached a practical level, and has not led to a fundamental solution.
Furthermore, as another inorganic antibacterial agent, there is an antibacterial agent in which an antibacterial metal is supported on activated carbon having adsorption properties. However, since these are physically adsorbed or adhered to the soluble antibacterial metal salt, the antibacterial metal ions are rapidly eluted when brought into contact with moisture, and the antibacterial effect is not sustained.

Recently, an antibacterial agent in which an antibacterial metal ion is supported on a special zirconium phosphate salt has been proposed. For example, the following formula [5] is known (for example, see Patent Document 4).
M ¹ M ² xHyAz (PO ₄ ) ₂ · nH ₂ O [5]
(In Formula [5], M ¹ is ^one selected from tetravalent metals, M ² is silver, copper, zinc, tin, mercury, lead, iron, cobalt, nickel, manganese, arsenic, antimony, bismuth, barium, cadmium. Or one selected from chromium, A is one selected from alkali metal ions or alkaline earth metal ions, n is a number satisfying 0 ≦ n ≦ 6, and x, y, and z are 0 <(l) × (x) <2, 0 <y <2, 0 <z <0.5, and (l) × (x) + y + z = 2, where l is a valence of M ² .
This antibacterial agent is known as a material which is chemically and physically stable and exhibits antifungal and antibacterial properties for a long period of time. However, when it is kneaded into a synthetic resin such as nylon, the entire resin may be colored, and the processability is poor due to the size of the particles, so that it may not be used as a product.

JP-A-6-48713 JP-A-5-17112 JP-A-60-239313 JP-A-3-83906 C. JAGER, 3 others, "31P and 29Si NMR Investigatios of the Structure of NASICON-Strukturtyps", Expermentelle Technik der Physik, 1988, 36, 4/5, p339-348 C. JAGER and two others, "31P MAS NMR STUDY OF THE NASICON SYSTEM Na1 + 4yZr2-y (PO4) 3", Chemical Physics Letters, 1988, 150, 6, p503-505 H.Y-P.HONG, “CRYSTAL STRUCTURE AND CYSTAL CHEMISTRY IN THE SISTEM Na1 + xZr2SixP3-xO12”, Mat. Res. Bull. , Volume 11, p173-182

  An object of the present invention is to provide a silver-based inorganic antibacterial agent that is excellent in heat resistance and chemical resistance, has little resin colorability, and is excellent in processability.

As a result of intensive studies to solve the above problems, the present inventors have achieved the above problems by the means described in (1) and (4) below. Moreover, it describes below with (2) and (3) which are preferable embodiments.
(1) A silver-based inorganic antibacterial agent represented by the following formula [1].
_{Ag a Na b H c (H} 3 O) d Zr e Hf f (PO 4) 3 · nH 2 O [1]
In the formula [1], a, b, c, d, and e are positive numbers, f is 0 or a positive number, and 1.75 <(e + f) <2.25, a + b + c + d + 4 (e + f) = 9 N is a positive number equal to or less than 2.
(2) The silver-based inorganic antibacterial agent according to 1 above, obtained by hydrotreating a silver zirconium phosphate compound represented by the following formula [2].
_{Ag a Na b H C1 Zr e} Hf f (PO 4) 3 (2)
In the formula [2], a, b, c1, and e are positive numbers, f is 0 or a positive number, and a number satisfying 1.75 <(e + f) <2.25 and a + b + c1 + 4 (e + f) = 9 It is.
(3) After containing silver using an aqueous solution containing 0.6b1 mol to 0.99b1 mol of silver nitrate per 1 mol of the zirconium phosphate compound represented by the following formula [3], this was obtained by firing. 2. The silver-based inorganic antibacterial agent according to 1 above, obtained by hydrotreating a zirconium phosphate silver-based compound represented by the formula [2].
_{Na b1 A c1 Zr e Hf f} (PO 4) 3 · nH 2 O [3]
In the formula [3], A is an ammonium ion and / or a hydrogen ion, b1, c1, and e are positive numbers, f is 0 or a positive number, and 1.75 <(e + f) <2.25 , B1 + c1 + 4 (e + f) = 9.
(4) An antibacterial product containing the silver-based inorganic antibacterial agent according to any one of 1 to 3 above.

  The silver-based inorganic antibacterial agent containing an oxonium group of the present invention is superior in antibacterial activity and anti-discoloration resistance compared to existing zirconium phosphate antibacterial agents.

The present invention will be described below. In addition,% is weight%.
The silver-based inorganic antibacterial agent of the present invention is represented by the above general formula [1].

  In the formula [1], a is a positive number, preferably 0.01 or more, more preferably 0.03 or more, and a is preferably 1 or less, more preferably 0.6 or less. If a in formula [1] is less than 0.01, antibacterial properties may not be sufficiently exhibited, which is not preferable.

  In the formula [1], b is a positive number, preferably 0.01 or more. B is less than 0.6, preferably less than 0.55, more preferably 0.5 or less, and still more preferably 0.35 or less. When the value of b is large, the antibacterial agent of the present invention tends to be discolored when blended with the resin, and when b is 0.6 or more, discoloration tends to occur, which is not preferable.

  In the formula [1], c is a positive number, preferably 0.01 or more, and more preferably 0.05 or more. Further, c is less than 0.9, preferably less than 0.8, and more preferably 0.7 or less.

  In the formula [1], d is a positive number, preferably 0.01 or more, more preferably 0.05 or more, and particularly preferably 0.1 or more. C is less than 0.8, preferably less than 0.7, and more preferably 0.6 or less. If the value of c is less than 0.01 or 0.8 or more, discoloration tends to occur when the antibacterial agent of the present invention is blended with a resin.

In the formula [1], e and f are 1.75 <(e + f) <2.25, e is preferably less than 2.20, more preferably less than 2.15, and more preferably 1.80 or more, 1.85 or more is more preferable, and 1.90 or more is still more preferable. Further, f is preferably 0.2 or less, more preferably 0.001 or more and 0.15 or less, and more preferably 0.005 or more and 0.10 or less.
When e + f is 1.75 or less or 2.25 or more, it may be difficult to obtain homogeneous zirconium phosphate represented by the formula [1], which is not preferable.

In the formula [1], n is preferably 1 or less, more preferably 0.01 to 0.5, and still more preferably in the range of 0.03 to 0.3. When n is more than 2, the absolute amount of water contained in the silver-based inorganic antibacterial agent of the present invention is large, and foaming or hydrolysis may occur during processing, which is not preferable.
The following can be illustrated as a silver type inorganic antibacterial agent shown by Formula [1].
Ag _0.05 Na _0.02 H _0.3 (H ₃ O) _0.55 Zr ₂ Hf _0.02 (PO ₄ ) ₃ · 0.15H ₂ O
Ag _0.1 Na _0.02 H _0.25 (H ₃ O) _0.47 Zr _2.01 Hf _0.03 (PO ₄ ) ₃ · 0.1H ₂ O
Ag _0.17 Na _0.02 H _0.35 (H ₃ O) _0.3 Zr _2.03 Hf _0.01 (PO ₄ ) ₃・ 0.05H ₂ O
Ag _0.17 Na _0.04 H _0.2 (H ₃ O) _0.55 Zr _1.99 Hf _0.02 (PO ₄ ) ₃・ 0.25H ₂ O
Ag _0.17 Na _0.05 H _0.2 (H ₃ O) _0.3 Zr _1.92 Hf _0.15 (PO ₄ ) ₃ · 0.15H ₂ O
Ag _0.17 Na _0.1 H _0.35 (H ₃ O) _0.5 Zr _1.92 Hf _0.05 (PO ₄ ) ₃ · 0.15H ₂ O
Ag _0.17 Na _0.1 H _0.34 (H ₃ O) _0.43 Zr _1.99 (PO ₄ ) ₃ · 0.15H ₂ O
Ag _0.45 Na _0.12 H _0.2 (H ₃ O) _0.35 Zr _1.95 Hf _0.02 (PO ₄ ) ₃・ 0.05H ₂ O
Ag _0.55 Na _0.1 H _0.1 (H ₃ O) _0.25 Zr _1.99 Hf _0.01 (PO ₄ ) ₃ · 0.15H ₂ O

The silver-based inorganic antibacterial agent of the present invention is a silver-based inorganic antibacterial agent described in the above formula [1] obtained by hydrolyzing the following formula [2].
_{Ag a Na b H C1 Zr e} Hf f (PO 4) 3 (2)
In the formula [2], a, b, c1, e, and f are positive numbers, and are numbers satisfying 1.75 <(e + f) <2.25 and a + b + c1 + 4 (e + f) = 9.

  In the formula [2], a and b are the same as a and b in the formula (1). In the formula [2], e and f are the same as e and f in the formula (1).

  In the formula [2], c1 is c1 = c + d (c and d are those of the formula (1)), preferably 0.02 or more, and more preferably 0.1 or more. C1 is less than 1.7, preferably less than 1.5, and more preferably 1.3 or less.

The method of hydrating the zirconium phosphate compound represented by the formula [2] is performed at a temperature of less than 220 ° C., preferably 200 ° C. or less (however, at room temperature or more), and a relative humidity of 1% or more, more preferably a relative humidity. It can be carried out by standing or stirring the zirconium phosphate compound represented by the formula [2] in an atmosphere of 5% or more, preferably under normal pressure. The time for the hydrolysis treatment is preferably 10 minutes or more, more preferably 1 hour or more, still more preferably 3 hours or more, and preferably 30 hours or less. It is preferable for the conditions of the above-mentioned hydrolysis treatment because the product of the present invention can be efficiently produced.
Although the water | moisture content which hydrolyzed exists in part as crystal water, it is used for a hydrogen ion to change to an oxonium ion according to the quantity of the hydrogen ion contained in a zirconium phosphate. The distinction between hydrogen ions and oxonium ions can be confirmed by a decrease in the infrared absorption spectrum vibration peak at 820 cm ⁻ caused by hydrogen ions. For confirmation of this oxonium group, see J Materials Sci. , 19, 2691-5 (1984).

The following can be illustrated as a silver type inorganic antibacterial agent shown by Formula [2].
Ag _0.05 Na _0.02 H _0.85 Zr ₂ Hf _0.02 (PO ₄ ) ₃
Ag _0.1 Na _0.02 H _0.72 Zr _2.01 Hf _0.03 (PO ₄ ) ₃
Ag _0.17 Na _0.02 H _0.65 Zr _2.03 Hf _0.01 (PO ₄ ) ₃
Ag _0.17 Na _0.04 H _0.75 Zr _1.99 Hf _0.02 (PO ₄ ) ₃
Ag _0.17 Na _0.05 H _0.5 Zr _1.92 Hf _0.15 (PO ₄ ) ₃
Ag _0.17 Na _0.1 H _0.85 Zr _1.92 Hf _0.05 (PO ₄ ) ₃
Ag _0.17 Na _0.1 H _0.77 Zr _1.99 (PO ₄ ) ₃
Ag _0.45 Na _0.12 H _0.55 Zr _1.95 Hf _0.02 (PO ₄ ) ₃
Ag _0.55 Na _0.1 H _0.35 Zr _1.99 Hf _0.01 (PO ₄ ) ₃

Further, the silver-based inorganic antibacterial agent of the present invention is ion-exchanged with an aqueous solution containing 0.6b1 mol to 0.99b1 mol of silver nitrate per mol of the zirconium phosphate compound represented by the following formula [3]. A silver-based inorganic antibacterial agent of formula [2] obtained by firing.
_{Na b1 A c1 Zr e Hf f} (PO 4) 3 · nH 2 O [3]
In the formula [3], A is an ammonium ion and / or a hydrogen ion, b1, c1, e and f are positive numbers, and 1.75 <(e + f) <2.25, b1 + c1 + 4 (e + f) = 9 It is a number that satisfies.

  In the formula [3], e and f are the same as e and f in the formula (1).

  In the formula (3), c1 is c1 = c + d (c and d are those of the formula (1)), preferably 0.02 or more, and more preferably 0.1 or more. C1 is less than 1.7, preferably less than 1.5, and more preferably 1.3 or less.

  In the formula [3], b1 is b1 = a + b (a and b are those of the formula (1)), and preferably 0.02 or more.

  The method for synthesizing zirconium phosphate represented by the formula [3] is a wet method or a hydrothermal method in which various raw materials are reacted in an aqueous solution. A specific method for synthesizing zirconium phosphate in which A in Formula [3] is an ammonium ion contains a predetermined amount of zirconium compound, ammonia or a salt thereof, oxalic acid or a salt thereof, and phosphoric acid or a salt thereof. The aqueous solution is adjusted to pH 4 or less with caustic soda or ammonia water, and then heated at a temperature of 70 ° C. or higher for synthesis. In addition, a specific method for synthesizing zirconium phosphate in which A in formula [3] is a hydrogen ion includes an aqueous solution containing a predetermined amount of a zirconium compound, oxalic acid or a salt thereof, and phosphoric acid or a salt thereof. Then, after adjusting the pH to 4 or less, the zirconium phosphate obtained by heating at a temperature of 70 ° C. or higher is further agitated in an aqueous solution of hydrochloric acid, nitric acid, sulfuric acid or the like to carry hydrogen ions to synthesize. The hydrogen ions can be supported simultaneously with the silver ions supported by silver nitrate or after the silver ions are supported. The synthesized zirconium phosphate is further filtered off, washed thoroughly with water, dried and lightly pulverized to obtain white particulate zirconium phosphate. Moreover, if it is the hydrothermal method synthesize | combined under the pressurization over 100 degreeC, the zirconium phosphate represented by Formula [3] is compoundable, without using an oxalic acid or its salt.

As the zirconium compound that can be used as a raw material for the synthesis of zirconium phosphate represented by the formula [3], a water-soluble or acid-soluble zirconium salt can be used. For example, zirconium nitrate, zirconium acetate, zirconium sulfate, basic zirconium sulfate, zirconium oxysulfate, and zirconium oxychloride are exemplified, and zirconium oxychloride is preferable in consideration of reactivity and economy.
Hafnium compounds that can be used as a raw material for the synthesis of zirconium phosphate represented by the formula [3] are water-soluble or acid-soluble hafnium salts such as hafnium chloride, hafnium oxychloride, and hafnium ethoxide. Also, zirconium compounds containing hafnium can be used. The hafnium content contained in the zirconium compound is preferably 0.1% to 5%, more preferably 0.3% to 4%. In the present invention, it is preferable to use zirconium oxychloride containing such a small amount of hafnium in view of reactivity, economy, and the like.

  Examples of oxalic acid or a salt thereof that can be used as a raw material for the synthesis of zirconium phosphate represented by the formula [3] include oxalic acid dihydrate, sodium oxalate, ammonium oxalate, sodium hydrogen oxalate, and ammonium hydrogen oxalate. Etc., and preferably oxalic acid dihydrate.

  As ammonia or a salt thereof that can be used as a raw material for the synthesis of zirconium phosphate represented by the formula [3], ammonium chloride, ammonium nitrate, ammonium sulfate, aqueous ammonia, ammonium oxalate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, Examples thereof include ammonium phosphate, and ammonium chloride or aqueous ammonia is preferable.

  As phosphoric acid or a salt thereof that can be used as a raw material for the synthesis of zirconium phosphate represented by the formula [3], a soluble or acid-soluble salt is preferable, and these include phosphoric acid, sodium phosphate, sodium hydrogen phosphate, and phosphoric acid. Examples include ammonium hydrogen and ammonium phosphate, and phosphoric acid is more preferable. The concentration of phosphoric acid is preferably about 60% to 85%.

When synthesizing the zirconium phosphate represented by the formula [3], the molar ratio of phosphoric acid or a salt thereof to the zirconium compound (with the zirconium compound being 1) is more than 1.3 to less than 2, more preferably 1. More than .31 to less than 1.71, more preferably more than 1.4 to less than 1.67, and particularly preferably more than 1.5 to less than 1.65.
That is, the method for synthesizing zirconium phosphate represented by the formula [3] is a wet method or a hydrothermal method in which the mole of phosphoric acid or a salt thereof is in the range of more than 1.3 to less than 2 per mole of the zirconium compound. .

Further, the molar ratio of phosphoric acid or a salt thereof to ammonia or a salt thereof when synthesizing the zirconium phosphate represented by the formula [3] (ammonia or a salt thereof is 1) is preferably 0.3 to 10. Further, 1 to 10 is preferable, and 2 to 5 is particularly preferable.
That is, the method for synthesizing zirconium phosphate represented by the formula [3] is a wet method or a hydrothermal method containing ammonia or a salt thereof.

When the zirconium phosphate represented by the formula [3] is synthesized, the molar ratio of phosphoric acid or a salt thereof to oxalic acid or a salt thereof (where oxalic acid or a salt thereof is 1) is preferably 1 to 6, more preferably Preferably it is 1.5-5, More preferably, it is 1.51-4, Most preferably, it is 1.52-3.5.
That is, the method for synthesizing zirconium phosphate represented by the formula [3] is a wet method or hydrothermal method containing oxalic acid or a salt thereof. However, in the case of the hydrothermal method, it is not necessary to contain oxalic acid or a salt thereof.

  The solid content concentration in the reaction slurry when synthesizing the zirconium phosphate represented by the formula [3] is preferably 3% or more, and more preferably 7% to 15% in view of efficiency such as economy.

  The pH during the synthesis of the zirconium phosphate represented by the formula [3] is preferably 1 or more and 4 or less, more preferably 1.3 to 3.5, still more preferably 1.8 to 3.0, particularly Preferably it is 2.0-3.0. If the pH is more than 4, it is not preferable because zirconium phosphate represented by the formula [3] may not be synthesized. If the pH is less than 1, it may not be possible to synthesize the zirconium phosphate represented by the formula [3]. For adjusting the pH, sodium hydroxide, potassium hydroxide or aqueous ammonia is preferable, and sodium hydroxide is more preferable.

  Further, the synthesis temperature when synthesizing the zirconium phosphate represented by the formula [3] is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, still more preferably 90 ° C. or higher, particularly preferably 95 ° C. or higher. . Moreover, as a synthesis temperature, 150 degrees C or less is preferable and 120 degrees C or less is more preferable. If the temperature is less than 70 ° C., the zirconium phosphate of the present invention may not be synthesized, which is not preferable. Further, if the temperature is higher than 150 ° C., it is not preferable because it is disadvantageous in terms of energy.

When synthesizing the zirconium phosphate represented by the formula [3], it is desirable that the raw materials are mixed homogeneously and stirred so that the reaction proceeds uniformly.
The synthesis time of the zirconium phosphate represented by the formula [3] varies depending on the synthesis temperature. For example, the synthesis time of the zirconium phosphate of the present invention is preferably 4 hours or longer, more preferably 8 hours to 72 hours, further preferably 10 hours to 48 hours.

  The median diameter of zirconium phosphate represented by the formula [3] can be synthesized between 0.1 and 5 μm. The median diameter of the zirconium phosphate represented by the formula [3] is preferably 0.1 to 5 μm, more preferably 0.2 to 3 μm, and still more preferably 0.3 to 2 μm. In addition, considering the workability to various products, not only the median diameter but also the maximum particle diameter is important. From this, the maximum particle diameter of the zirconium phosphate represented by the formula [3] is preferably 10 μm or less, more preferably 8 μm or less, and particularly preferably 6 μm or less because the effect can be exhibited. .

Examples of the zirconium phosphate represented by the formula [3] that can be used as a raw material for the silver-based inorganic antibacterial agent of the present invention include the following.
Na _0.07 (NH ₄ ) _0.85 Zr ₂ Hf _0.02 (PO ₄ ) ₃ · 0.65H ₂ O
Na _0.12 (NH ₄ ) _0.72 Zr _2.01 Hf _0.03 (PO ₄ ) ₃ · 0.85H ₂ O
Na _0.19 (NH ₄ ) _0.65 Zr _2.03 Hf _0.01 (PO ₄ ) ₃ · 0.75H ₂ O
Na _0.21 (NH ₄ ) _0.75 Zr _1.99 Hf _0.02 (PO ₄ ) ₃ · 0.6H ₂ O
Na _0.22 (NH ₄ ) _0.50 Zr _1.92 Hf _0.15 (PO ₄ ) ₃ · 0.75H ₂ O
Na _0.27 (NH ₄ ) _0.85 Zr _1.92 Hf _0.05 (PO ₄ ) ₃・ 0.5H ₂ O
Na _0.27 (NH ₄ ) _0.77 Zr _1.99 (PO ₄ ) ₃ · 0.25H ₂ O
Na _0.57 (NH ₄ ) _0.55 Zr _1.95 Hf _0.02 (PO ₄ ) ₃ · 0.35H ₂ O
Na _0.65 (NH ₄ ) _0.35 Zr _1.99 Hf _0.01 (PO ₄ ) ₃ · 0.4H ₂ O
Na _0.07 H _0.85 Zr ₂ Hf _0.02 (PO ₄ ) ₃ · 0.65H ₂ O
Na _0.12 H _0.72 Zr _2.01 Hf _0.03 (PO ₄ ) ₃ · 0.85H ₂ O
Na _0.19 H _0.65 Zr _2.03 Hf _0.01 (PO ₄ ) ₃ · 0.75H ₂ O
Na _0.21 H _0.75 Zr _1.99 Hf _0.02 (PO ₄ ) ₃ · 0.6H ₂ O
Na _0.22 H _0.5 Zr _1.92 Hf _0.15 (PO ₄ ) ₃ · 0.75H ₂ O
Na _0.27 H _0.85 Zr _1.92 Hf _0.05 (PO ₄ ) ₃ · 0.5H ₂ O
Na _0.27 H _0.77 Zr _1.99 (PO ₄ ) ₃・ 0.25H ₂ O
Na _0.57 H _0.55 Zr _1.95 Hf _0.02 (PO ₄ ) ₃ · 0.35H ₂ O
Na _0.65 H _0.35 Zr _1.99 Hf _0.01 (PO ₄ ) ₃ · 0.4H ₂ O

In order to obtain the silver-based inorganic antibacterial agent of the formula [2], it is obtained by performing silver ion exchange on the zirconium phosphate represented by the formula [3] and then firing. This method of exchanging silver ions is carried out in an aqueous solution containing from 0.6 b1 mol to 0.99 b1 mol, preferably from 0.7 b1 mol to 0.98 b1 mol of silver nitrate per mol of zirconium phosphate compound. ] It can carry out by immersing the zirconium phosphate represented. If the content of silver nitrate is 0.6 b1 mol or less, the discoloration at the time of compounding with the resin is not preferable. On the other hand, if it is 0.99b1 mol or more, silver nitrate is not used for ion exchange and remains in the ion exchange solution, which is not economical. Moreover, it is preferable to make the state mixed uniformly by stirring etc. at the time of the said immersion. The amount to be immersed may be a concentration that can be uniformly mixed with the aqueous solution. For that purpose, the zirconium phosphate represented by the formula [3] is preferably 20% by weight or less.
For the adjustment of the aqueous solution containing silver ions, it is preferable to use an aqueous solution in which silver nitrate is dissolved in ion-exchanged water. The temperature of the aqueous solution at the time of ion exchange can be 0 to 100 ° C, and preferably 20 to 80 ° C. Since this ion exchange is performed promptly, the immersion time can be within 5 minutes, but 30 minutes to 5 hours is preferable in order to obtain a uniform and high silver ion exchange rate. Even if immersion is performed for 5 hours or more, the exchange of silver ions does not proceed further.
After completion of the silver ion exchange, the silver-based inorganic antibacterial agent represented by the formula [2] can be obtained by thoroughly washing it with ion-exchanged water and then baking it.

  The firing temperature is preferably 550 ° C. to 1000 ° C., more preferably 600 ° C. to 900 ° C., and firing at 650 ° C. to 800 ° C. is still more preferable for improving discoloration resistance. The firing time is preferably 1 hour or longer, more preferably 2 hours or longer, and further preferably 3 hours or longer for improving discoloration resistance. The firing time is preferably 48 hours or less, and more preferably 36 hours or less. Moreover, since the particles of the silver-based inorganic antibacterial agent of the present invention may be solidified after firing, it is better to crush the solidified one using a pulverizer.

  There is no restriction | limiting in particular in the usage type of the silver-type inorganic antibacterial agent of this invention, According to a use, it can be mixed with another component suitably or can be combined with another material. For example, it can be used in various forms such as powder, powder-containing dispersion, powder-containing particles, powder-containing paint, powder-containing fiber, powder-containing paper, powder-containing plastic, powder-containing film, powder-containing aerosol, etc. Accordingly, various additives or materials such as deodorants, flameproofing agents, anticorrosion, fertilizers and building materials can be used in combination.

  In order to improve kneading into a resin and other physical properties, various additives can be mixed in the silver-based inorganic antibacterial agent of the present invention as necessary. Specific examples include pigments such as zinc oxide and titanium oxide, inorganic ion exchangers such as zirconium phosphate and zeolite, dyes, antioxidants, light stabilizers, flame retardants, antistatic agents, foaming agents, impact strengthening agents, Lubricants such as glass fibers, metal soaps, moisture-proofing agents and extenders, coupling agents, nucleating agents, fluidity improvers, deodorants, wood powder, antifungal agents, antifouling agents, rust preventives, metal powders, UV rays There are absorbers, UV shielding agents and the like.

  An antibacterial resin composition can be easily obtained by blending the silver-based inorganic antibacterial agent of the present invention with a resin. The type of resin that can be used is not particularly limited, and may be any of a natural resin, a synthetic resin, and a semi-synthetic resin, and may be any of a thermoplastic resin and a thermosetting resin. Specific resins may be molding resins, fiber resins, and rubber-like resins. For example, polyethylene, polypropylene, vinyl chloride, ABS resin, AS resin, MBS resin, nylon resin, polyester, polychlorinated resin. Vinylidene, polystyrene, polyacetal, polycarbonate, PBT, acrylic resin, fluororesin, polyurethane elastomer, polyester elastomer, melamine, urea resin, tetrafluoroethylene resin, unsaturated polyester resin, rayon, acetate Mold, acrylic, polyvinyl alcohol, cupra, triacetate, vinylidene and other molding or fiber resins, natural rubber, silicone rubber, styrene butadiene rubber, ethylene propylene rubber, fluorine rubber, nitrile rubber, chlorosulfonated polyethylene Rubber, Tajiengomu, synthetic natural rubber, butyl rubber, there is a rubber resin such as urethane rubber and acrylic rubber. Further, the silver-based inorganic antibacterial agent of the present invention can be combined with natural fiber to produce an antibacterial fiber.

  The blending ratio in the antibacterial resin composition of the silver-based inorganic antibacterial agent of the present invention is preferably 0.03 to 10 parts by weight and more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the antibacterial resin composition. . If the amount is less than 0.03 parts by weight, the antibacterial property of the antibacterial resin composition may be insufficient. In some cases, the physical properties of the resin deteriorate significantly.

  Any known method can be adopted as a processing method for blending the silver-based inorganic antibacterial agent of the present invention into a resin to obtain a resin molded product. For example, (1) using an additive for making silver-based inorganic antibacterial powder and resin easily adhere to each other and a dispersing agent for improving the dispersibility of the antibacterial powder, and mixing the pellet-like resin or powder-like resin with a mixer (2) Mixing as described above, forming into pellets with an extrusion molding machine, and then blending the molded product into pellet resin, (3) Silver-based inorganic antibacterial agent After molding into a high-concentration pellet using wax, and then blending the pellet-shaped molding into a pellet-shaped resin. (4) Dispersing and mixing the silver-based inorganic antibacterial agent into a high-viscosity liquid such as polyol. There is a method of blending this paste into a pellet-shaped resin after preparing the paste-like composition.

  For forming the antibacterial resin composition, known processing techniques and machines can be used in accordance with the characteristics of various resins. That is, it can be easily prepared by a method of mixing, mixing or kneading at an appropriate temperature or pressure, for example, heating and pressurizing or depressurizing. These specific operations may be carried out by ordinary methods, and can be molded into various forms such as a lump, sponge, film, sheet, thread, pipe, or a composite thereof.

  There is no restriction | limiting in particular in the usage form of the silver-type inorganic antibacterial agent of this invention, It is not limited to mix | blending with a resin molded product or a high molecular compound. Depending on the application requiring antifungal, antialgal and antibacterial properties, it can be appropriately mixed with other components or combined with other materials. For example, it can be used in various forms such as powder form, powder dispersion liquid form, granular form, aerosol form or liquid form.

○ Use The silver-based inorganic antibacterial agent of the present invention is used in various fields that require antifungal, algal and antibacterial properties, that is, electrical appliances, kitchen products, textile products, residential building materials products, toiletry products, paper products, toys. It can be used as leather products, stationery and other products.
To further illustrate specific uses, electrical appliances include dishwashers, dish dryers, refrigerators, washing machines, pots, televisions, personal computers, radio cassettes, cameras, video cameras, water purifiers, rice cookers, vegetable cutters, and registers. , Futon dryer, FAX, ventilation fan, air conditioner, etc. Kitchen products include tableware, chopping board, push-cut, tray, chopsticks, tea dispenser, thermos, kitchen knife, stalk pattern, fry back, lunch box, There are rice paddles, balls, draining bowls, triangular corners, scrubbers, garbage bowls, draining bags, etc.

  Textile products include shower curtains, futon cotton, air conditioner filters, pantyhose, socks, towels, sheets, duvet covers, pillows, gloves, apron, curtains, diapers, bandages, masks, sportswear Housing and building material products include decorative boards, wallpaper, floor boards, window films, handles, carpets, mats, artificial marble, handrails, joints, tiles, waxes, and the like. In addition, toiletries include toilet seats, bathtubs, tiles, pots, filth, toilet brushes, bath lids, pumice stones, soap containers, bath chairs, clothing baskets, showers, and washstands. Paper products include wrapping paper , Wrapping paper, medicine box, sketch book, chart, notebook, origami, and toys include dolls, stuffed animals, paper clay, blocks, puzzles, etc.

In addition, leather products include shoes, bags, belts, watch bands, interior items, chairs, gloves, hanging leather, and stationery items include ball pens, sharp pens, pencils, erasers, crayons, paper, There are notebook, flexible disk, ruler, post-it, stapler, etc.
Other products include insoles, cosmetic containers, scrubbers, makeup puffs, hearing aids, musical instruments, cigarette filters, cleaning adhesive paper sheets, hanging leather grips, sponges, kitchen towels, cards, microphones, barber supplies Vending machines, razors, telephones, thermometers, stethoscopes, slippers, clothes cases, toothbrushes, sandbox sand, food packaging films, antibacterial sprays, paints, and the like.

<Example>
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this.
The median diameter and maximum particle diameter were measured on a volume basis using a laser diffraction particle size distribution.
The amount of zirconium was calculated by measuring the sample with an ICP emission spectrometer after dissolving the specimen using a strong acid. The amount of phosphorus was calculated by dissolving the sample using a strong acid and then measuring this solution with an ICP emission spectrometer. The amount of sodium was calculated by dissolving the specimen with a strong acid and measuring the liquid with an atomic absorption photometer. The amount of ammonia was calculated by dissolving the sample using a strong acid and measuring this solution by the indophenol method. The amount of oxonium ions was calculated by measuring the weight loss of 160 to 190 ° C. by thermal analysis.

<Example 1>
0.1 mol of oxalic acid dihydrate, 0.2 mol of zirconium oxychloride octahydrate containing 0.18% hafnium and 0.1 mol of ammonium chloride were dissolved in 300 ml of pure water, and phosphoric acid was added in an amount of 0. 3 moles were added. The solution was adjusted to pH 2.7 using a 20% aqueous sodium hydroxide solution and then stirred at 98 ° C. for 14 hours. Thereafter, the resulting precipitate was washed thoroughly and dried at 120 ° C. to synthesize a zirconium phosphate compound.
When the amount of each component of this zirconium phosphate was measured, the composition formula was
Na _0.6 (NH ₄ ) _0.4 Zr _1.98 Hf _0.02 (PO ₄ ) ₃ · 0.09H ₂ O
Met.
450 ml of an ion exchange aqueous solution in which 0.05 mol of silver nitrate (Ag / Na = 0.93) was dissolved in 0.09 mol of the obtained zirconium phosphate was added, and the mixture was stirred at 60 ° C. for 2 hours to carry silver. Then, it was washed thoroughly and dried at 120 ° C. and baked at 650 ° C. for 4 hours.
When the amount of each component of this zirconium phosphate was measured, the composition formula was
Ag _0.55 Na _0.05 H _0.4 Zr _1.98 Hf _0.02 (PO ₄ ) ₃
Met.
The fired powder was lightly pulverized and then allowed to stand for 6 hours in an atmosphere with a relative humidity of 40% and a temperature of 55 ° C., followed by hydrotreatment to obtain a silver-based inorganic antibacterial agent of the present invention. When the amount of each component of this silver-based inorganic antibacterial substance was measured, the composition formula was
Ag _0.55 Na _0.05 H _0.2 (H ₃ O) _0.2 Zr _1.98 Hf _0.02 (PO ₄ ) ₃ · 0.2H ₂ O
Met. Then, the median diameter (μm), maximum particle diameter (μm) and minimum inhibitory concentration (MIC, μg / ml) against Escherichia coli of this silver-based inorganic antibacterial substance were measured, and the results are shown in Table 1.

<Example 2>
In 300 ml of pure water, 0.1 mol of oxalic acid dihydrate, 0.19 mol of zirconium oxychloride octahydrate containing 0.18% hafnium and 0.10 mol of ammonium chloride were dissolved, and then phosphoric acid was added in an amount of 0. 3 moles were added. The solution was adjusted to pH 2.7 using a 20% aqueous sodium hydroxide solution and then stirred at 98 ° C. for 14 hours. Thereafter, the resulting precipitate was washed thoroughly and dried at 120 ° C. to synthesize a zirconium phosphate compound.
When the amount of each component of this zirconium phosphate was measured, the composition formula was
Na _0.5 (NH ₄ ) _0.8 Zr _1.91 Hf _0.015 (PO ₄ ) ₃ · 0.11H ₂ O
Met.
To 450 ml of 1N aqueous nitric acid solution in which 0.035 mol of silver nitrate (Ag / Na = 0.78) was dissolved in 0.09 mol of zirconium phosphate obtained, was added and stirred at 60 ° C. for 2 hours to support silver. It was. Then, it was washed thoroughly and dried at 120 ° C. and calcined at 720 ° C. for 4 hours.
When the composition formula of this zirconium phosphate was measured, the composition formula was
Ag _0.39 Na _0.11 H _0.8 Zr _1.91 Hf _0.015 (PO ₄ ) ₃
Met. The fired powder was lightly pulverized and then allowed to stand for 6 hours in an atmosphere having a relative humidity of 5% and a temperature of 110 ° C., followed by water treatment to obtain a silver-based inorganic antibacterial agent of the present invention. When the amount of each component of this silver-based inorganic antibacterial substance was measured, the composition formula was
Ag _0.39 Na _0.11 H _0.21 (H ₃ O) _0.59 Zr _1.91 Hf _0.015 (PO ₄ ) ₃ · 0.19H ₂ O
Then, the median diameter (μm), maximum particle diameter (μm) and minimum inhibitory concentration (MIC, μg / ml) against Escherichia coli of this silver-based inorganic antibacterial substance were measured, and the results are shown in Table 1.

<Example 3>
After dissolving 0.195 mol of hafnium 0.18% zirconium oxychloride octahydrate and 0.12 mol of ammonium chloride in 300 ml of pure water, 0.3 mol of phosphoric acid was added with stirring. The solution was adjusted to pH 2.7 using a 20% aqueous sodium hydroxide solution and then stirred at 140 ° C. under saturated vapor pressure for 4 hours. Thereafter, the resulting precipitate was washed thoroughly and dried at 120 ° C. to synthesize a zirconium phosphate compound.
When the amount of each component of this zirconium phosphate was measured, the composition formula was
Na _0.25 (NH ₄ ) _0.95 Zr _1.93 Hf _0.02 (PO ₄ ) ₃ · 0.09H ₂ O
Met.
Silver was supported by adding it to 450 ml of ion-exchanged water in which 0.018 mol of silver nitrate was dissolved in 0.09 mol of the obtained zirconium phosphate and stirring at 60 ° C. for 2 hours. Then, it was washed thoroughly and dried at 120 ° C. and calcined at 700 ° C. for 4 hours.
When the amount of each component of this zirconium phosphate was measured, the composition formula was
Ag _0.18 Na _0.07 H _0.95 Zr _1.93 Hf _0.02 (PO ₄ ) ₃
Met. The fired powder was lightly pulverized and then hydrotreated by stirring in an atmosphere of 50% relative humidity and 35 ° C. for 24 hours to obtain a silver-based inorganic antibacterial agent of the present invention. When the amount of each component of this silver-based inorganic antibacterial substance was measured, the composition formula was
Ag _0.18 Na _0.07 H _0.45 (H ₃ O) _0.5 Zr _1.93 Hf _0.02 (PO ₄ ) ₃ 0.27 H ₂ O
Met. Then, the median diameter (μm), maximum particle diameter (μm) and minimum inhibitory concentration (MIC, μg / ml) against Escherichia coli of this silver-based inorganic antibacterial substance were measured, and the results are shown in Table 1.

<Example 4>
In 300 ml of pure water, 0.1 mol of oxalic acid dihydrate and 0.193 mol of zirconium oxychloride octahydrate containing 0.18% hafnium were dissolved, and 0.3 mol of phosphoric acid was added with stirring. This solution was adjusted to pH 2.9 using a 20% aqueous sodium hydroxide solution and stirred at 98 ° C. for 14 hours. The resulting precipitate was washed thoroughly, ion-exchanged using a 1N aqueous nitric acid solution, and dried at 120 ° C. to synthesize zirconium phosphate.
When the amount of each component of this zirconium phosphate was measured, the composition formula was
Na _0.27 H _0.75 Zr _1.97 Hf _0.025 (PO ₄ ) ₃ · 0.37H ₂ O
Met.
The synthesized silver salt was added to 450 ml of 1N nitric acid solution in which 0.018 mol of silver nitrate (Ag / Na = 0.8) was dissolved in 0.09 mol of the obtained zirconium phosphate, and silver was added by stirring at 60 ° C. for 2 hours. Supported. Then, it was washed thoroughly and dried at 120 ° C. and calcined at 700 ° C. for 4 hours.
When the amount of each component of this zirconium phosphate was measured, the composition formula was
Ag _0.2 Na _0.07 H _0.75 Zr _1.97 Hf _0.025 (PO ₄ ) ₃
Met.
The baked powder was lightly pulverized and then allowed to stand for 24 hours in an atmosphere at a temperature of 35 ° C. and a relative humidity of 50%, followed by a hydrotreatment to obtain a silver-based inorganic antibacterial agent of the present invention.
When the amount of each component of this silver-based inorganic antibacterial substance was measured, the composition formula was
Ag _0.2 Na _0.07 H _0.3 (H ₃ O) _0.45 Zr _1.91 Hf _0.02 (PO ₄ ) ₃ · 0.22H ₂ O
Met. Then, the median diameter (μm), maximum particle diameter (μm) and minimum inhibitory concentration (MIC, μg / ml) against Escherichia coli of this silver-based inorganic antibacterial substance were measured, and the results are shown in Table 1.

<Comparative Example 1>
A comparative silver-based inorganic antibacterial agent was obtained by the same operation as in Example 3 except that the water treatment was not performed. The composition formula of this comparative silver-based inorganic antibacterial substance is
Ag _0.18 Na _0.07 H _0.95 Zr _1.93 Hf _0.02 (PO ₄ ) ₃
Met. Then, the median diameter (μm), the maximum particle diameter (μm) and the minimum inhibitory concentration (MIC, μg / ml) against Escherichia coli were measured for these comparative silver-based inorganic antibacterial substances. The results are shown in Table 1.

<Comparative example 2>
A comparative silver-based inorganic antibacterial agent was obtained by the same operation as in Example 3 except that the baking was not performed. The composition formula of this comparative silver-based inorganic antibacterial is
Ag _0.18 Na _0.07 (NH ₄ ) _0.95 Zr _1.93 Hf _0.02 (PO ₄ ) ₃ · 0.43H ₂ O
Met. Then, the median diameter (μm), the maximum particle diameter (μm) and the minimum inhibitory concentration (MIC, μg / ml) against Escherichia coli were measured for these comparative silver-based inorganic antibacterial substances. The results are shown in Table 1.

<Comparative Example 3>
Silver nitrate 0.015 mol (Ag / Na = 0.33) A comparative silver-based inorganic antibacterial agent was obtained in the same manner as in Example 2 except that silver was supported by dissolved ion-exchanged water. The composition formula of this comparative silver-based inorganic antibacterial substance is
Ag _0.16 Na _0.34 H _0.24 (H ₃ O) _0.56 Zr _1.91 Hf _0.015 (PO ₄ ) ₃ · 0.16H ₂ O
Met. Then, the median diameter (μm), the maximum particle diameter (μm) and the minimum inhibitory concentration (MIC, μg / ml) against Escherichia coli were measured for these comparative silver-based inorganic antibacterial substances. The results are shown in Table 1.

<Comparative Example 4>
450 ml of an ion exchange aqueous solution in which 1.2 g of silver nitrate was dissolved in 40 g of a commercially available A-type zeolite was added, and silver was supported by stirring at 60 ° C. for 2 hours. The median diameter (μm), the maximum particle size (μm) and the minimum inhibitory concentration (MIC, μg / ml) against Escherichia coli were measured for these comparative silver-based inorganic antibacterial substances. The results are shown in Table 1.

<Example 5: Evaluation with molded product>
0.1% of the silver-based inorganic antibacterial agent obtained in Example 1 was blended with nylon 6 resin manufactured by Ube Industries, and a 2 mm thick plate was injection molded at 280 ° C. to obtain a molded product a. The color difference ΔE immediately after molding with a plate formed by blending 0.1% of zirconium phosphate obtained by performing the same operation as in Example 1 except that the molded product a and silver were not substituted was measured with a color difference meter. Table 2 shows the measurement results. Also, Table 2 shows the results of measuring the color difference ΔE of the plate exposed to 0.1% saline solution at 90 ° C. for 1 hour and then exposing it outdoors using a color difference meter. Furthermore, an antibacterial test was performed by a test method such as JIS Z2801 5.2 plastic product using this injection molded plate. The results of the antibacterial activity values obtained are also shown in Table 2.
Similarly, molded products b to d and comparative molded products e to h were prepared using the silver-based inorganic antibacterial agents and comparative silver-based inorganic antibacterial agents prepared in Examples 2 to 4 and Comparative Examples 1 to 4. These molded products were also measured for color difference and antibacterial activity, and the results are shown in Table 2.

<Example 6: Nylon spinning test>
A silver-based inorganic antibacterial agent prepared in Example 1 was blended with nylon resin so as to be 10 wt%, thereby preparing a master batch. And this masterbatch and nylon resin pellet were mixed, and the antibacterial resin was prepared so that a silver type inorganic antibacterial agent might be 0.15 wt%. This antibacterial resin was melt-spun at a spinning temperature of 285 ° C. using a multifilament spinning machine to obtain a 24 filament antibacterial agent-containing nylon fiber (fiber a). Similarly, fibers b to d and comparative fibers e to h were prepared using the comparative silver-based inorganic antibacterial agents prepared in Examples 2 to 4 and Comparative Examples 1 to 4. Table 3 shows the results of measuring the presence or absence of yarn breakage during spinning and the color difference ΔE of the washed three times using a color difference meter. The obtained antibacterial agent-containing nylon fiber was evaluated for antibacterial properties by JIS L 1902 ^-1998 quantitative test using Staphylococcus aureus after scouring and after washing 3 times, and the results are shown in Table 3.

  From these results, the silver-based inorganic antibacterial agent of the present invention is excellent in processability such as spinnability and excellent in resistance to discoloration when blended in a plastic product. In addition, the silver-based inorganic antibacterial agent of the present invention was recognized to have antibacterial effect durability as compared with existing silver-based inorganic antibacterial agents.

  The novel silver-based inorganic antibacterial agent of the present invention is excellent in processability because it is uniform and fine particles, and also has excellent discoloration resistance and antibacterial properties of plastic products. Therefore, it can be used as an antibacterial agent having high applicability in applications where workability of thin fibers and paints is important.

Claims (4)

A silver-based inorganic antibacterial agent represented by the following formula [1].
_{Ag a Na b H c (H} 3 O) d Zr e Hf f (PO 4) 3 · nH 2 O [1]
In the formula [1], a, b, c, d, and e are positive numbers, f is 0 or a positive number, and 1.75 <(e + f) <2.25, a + b + c + d + 4 (e + f) = 9 N is a positive number equal to or less than 2. The silver-based inorganic antibacterial agent according to claim 1, obtained by hydrotreating a zirconium phosphate silver-based compound represented by the following formula [2].
_{Ag a Na b H C1 Zr e} Hf f (PO 4) 3 (2)
In the formula [2], a, b, c1, and e are positive numbers, f is 0 or a positive number, and a number satisfying 1.75 <(e + f) <2.25 and a + b + c1 + 4 (e + f) = 9 It is. The above formula obtained by baking silver after containing silver using an aqueous solution containing 0.6b1 mol to 0.99b1 mol of silver nitrate per 1 mol of the zirconium phosphate compound represented by the following formula [3] The silver-based inorganic antibacterial agent according to claim 1 obtained by hydrotreating the zirconium phosphate silver-based compound represented by 2].
_{Na b1 A c1 Zr e Hf f} (PO 4) 3 · nH 2 O [3]
In the formula [3], A is an ammonium ion and / or a hydrogen ion, b1, c1, and e are positive numbers, f is 0 or a positive number, and 1.75 <(e + f) <2.25 , B1 + c1 + 4 (e + f) = 9.   An antibacterial product containing the silver-based inorganic antibacterial agent according to any one of claims 1 to 3.