JPH09183863A - Antimicrobial agent excellent in durability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antimicrobial agent simultaneously satisfying durable antimicrobial activity and moldability, suitable for resin composition. SOLUTION: At least one metal ion selected from among silver, copper, zinc, gold and platinum in an amount of 0.1-20wt.% is supported on a phosphate particle which has <=5μm average particle diameter and comprises at least one metal salt selected from among magnesium, calcium, titanium and zirconium and at least one cation selected from among hydrogen and an alkali metal as constituent components to give the objective antimicrobial agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial agent, and more particularly to an antibacterial agent composed of phosphate particles having an excellent antibacterial action with excellent durability.

[0002]

2. Description of the Related Art Synthetic fibers such as polyester, nylon, and acrylic are widely used for clothing, industrial materials, bedding, etc. because of their excellent heat resistance and chemical resistance.

In recent years, in these fiber applications, there has been an increasing demand for fibers having antibacterial properties as one of the comfort functions.

Generally, as a method for imparting antibacterial properties to fibers, a method of adhering an aromatic halogen compound, an organic silicon quaternary ammonium salt, an organic nitrogen compound, etc. to the fibers is adopted. There is a problem with durability because it is easily dropped off by washing or the like. Therefore, as an antibacterial agent, SiO ₂ / carrying silver, copper and zinc ions
Al ₂ O ₃ molar ratio is 14 or less, specific surface area is 150 m ² /
Resin containing zeolite particles of g or more (Japanese Patent Publication No. Sho 6)
No. 3-54013) has been proposed. This resin has an excellent antibacterial effect and durability. However, since the particles easily absorb moisture, foaming occurs when the particles are blended with a resin, and even after blending with the resin, the particles are likely to adsorb moisture, resulting in a decrease in moldability, or when the resin is aged with time. There was a problem of coloring. Therefore, a method of improving the moldability of the resin by coating the zeolite particles with liquid paraffin, a silicone-based coating agent or a fluorine-based resin and subjecting it to a hydrophobic treatment (Japanese Patent Laid-Open No. 62-62-62).
No. 7746, No. 62-7747, No. 62-7748), or a method of blending zeolite particles holding metal ions and ammonium ions with a discoloration inhibitor (Japanese Patent Laid-Open No. 63-265958). ) Is proposed. However, these improvement effects were not sufficient. Further, in JP-A-63-88109, an oxide such as titanium oxide is used as a support, and an antibacterial silver compound containing an antibacterial silver compound attached to the support is attached. , Fell off easily, and the durability was not enough.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have the drawbacks of the above-mentioned conventional methods and have a durable antibacterial action,
And, as a result of the investigation for the purpose of providing an antibacterial agent having an excellent antibacterial action, the average particle size is within a specific range, and the phosphate particles having specific metal ions and cations as constituents have antibacterial properties. It has been found that it can be solved by an antibacterial agent carrying metal ions by an ion exchange method.

[0006]

The above-mentioned object of the present invention is a phosphate particle having an average particle size of 5 μm or less, wherein the particle is at least one selected from magnesium, calcium, titanium and zirconium. 0.1 to 20 metal ions and at least one cation selected from hydrogen and alkali metals as constituent components, and at least one metal ion selected from silver, copper, zinc, gold and platinum by an ion exchange method. This can be achieved by an antibacterial agent having excellent durability, which is supported by weight%.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The phosphate particles used in the present invention are required to have an average particle size of 5 μm or less and 3 μm.
The following is more preferred. If the average particle diameter exceeds 5 μm, the dispersibility of the phosphate particles in the resin becomes insufficient, and the moldability of the obtained resin deteriorates. For example, in the case of fiber, if the average particle diameter is large, yarn breakage easily occurs, and also in the case of film, tearing easily occurs.

The specific surface area of the phosphate particles is 3 m ² /
It is preferably at least g, more preferably at least 10 m ² / g.
When the specific surface area is less than 3 m ² / g, the amount of metal ions carried by the phosphate particles decreases, and the antibacterial effect of the obtained resin tends to decrease, which is not preferable.

The phosphate particles used in the present invention are silver, copper,
0.1 to 0.1% metal ions selected from zinc, gold and platinum
20 wt% Ion exchange method must be supported,
0.3 to 15% by weight is preferable, and 0.5 to 12% by weight is more preferable. If the supported amount of metal ions is less than 0.1% by weight, the durability of the antibacterial effect is not sufficient, and if it exceeds 20% by weight, the antibacterial effect of the obtained antibacterial agent is saturated, which is not economical. The metal ions can be supported on the phosphate particles by an ion exchange method which is a conventionally known method.

Specific examples of the phosphate particles include NaCa.
Calcium phosphate compounds such as PO ₄ , NaCa ₄ (PO ₄ ) ₃ and LiCaPO ₄ , NaMgPO ₄ , NaMg ₄
Magnesium phosphate-based compounds such as (PO ₄ ) ₃ and LiMgPO ₄ , titanium phosphate-based compounds such as Ti (HPO ₄ ) ₂ and Ti (NaPO ₄ ), Zr (HPO ₄ ) ₂ and NaZr
Examples thereof include zirconium phosphate-based compounds such as ₂ P ₃ O ₁₂ , Zr (H _0.5 Li _0.5 PO ₄ ) _{2 and the} like, which may be crystalline or amorphous, natural products or synthetic products. However, a synthetic product is preferable because particles of uniform quality can be obtained.

In order to support the metal ions on the phosphate particles by an ion exchange method or the like, the phosphate particles contain a cation which is an alkali metal ion such as H ion, Li, Na or K as a constituent component. It is necessary. Antibacterial ions are easily supported by using the cation as a constituent component,
The durability of the antibacterial agent is improved by the ionic interaction.
A zirconium phosphate-based compound is particularly preferable from the viewpoint of exhibiting high antibacterial properties with a small amount of metal ion supported.

The phosphate particles used in the present invention may further carry other ions such as ammonium ions in addition to the above-mentioned specific metal ions depending on the purpose.

The content of the antibacterial agent in the present invention contained in the resin is preferably 0.01 to 20% by weight, more preferably 0.05 to 15% by weight, and 0.1
Particularly preferred is from 10 to 10% by weight. When the content of the phosphate particles in the resin group is less than 0.01% by weight, the antibacterial effect is not sufficiently exhibited, and when it exceeds 20% by weight, the antibacterial effect is saturated and not only economical, but also the moldability is improved. It is not preferable because it tends to decrease. For example, in the case of fibers, yarn breakage and in the case of films tend to occur. The phosphoric acid particles can be added to the resin in any manufacturing process.

In the present invention, when the antibacterial agent comprising the above-mentioned specific phosphate particles is blended with the resin, the resin is not limited, and specifically, polyamides such as nylon 6, nylon 66, polyethylene terephthalate, polybutylene, etc. Examples thereof include polyesters such as terephthalate, polyolefins such as polyethylene and polypropylene, synthetic resins such as polyvinyl alcohol, acrylic resins and urethane resins. The more hydrophilic the resin, the greater the antibacterial effect of the obtained resin, so in the case of a hydrophobic resin,
It is preferable to copolymerize a copolymerization component having a hydrophilic functional group or to blend a hydrophilic resin.

In addition to the antibacterial agent in the present invention, the resin contains
Add additives such as matting agents, deodorants, colorants, ultraviolet absorbers, infrared absorbers, flame retardants, fluorescent brighteners, other ion adsorbents, and other antibacterial agents according to the purpose. You can

Since the molded article containing the antibacterial agent of the present invention has not only antibacterial properties but also deodorant properties and freshness-retaining properties, fibers such as futon cotton and socks, as well as fibers for hospital curtains and carpets, etc. It can be used for applications and film applications such as packaging films. When it is used as a fiber or a film, the surface area becomes large and the effect of exhibiting antibacterial properties is enhanced. In particular, the fiber is a preferable shape because it has the highest surface area.

When used for fiber applications, it can also be used as a composite fiber such as a core-sheath type composite used for a fiber core or sheath, and may be mixed fiber, mixed woven, mixed knitted or mixed spun. .

[0018]

The present invention will be described in detail below with reference to examples. In addition, each characteristic value in the examples was obtained according to the following methods.

(A) Average particle size of particles: Determined by electron micrograph of particles.

(B) Amount of metal ion supported on particles: quantified by atomic absorption method.

(C) Evaluation of antibacterial properties of tubular knitted fabric: A suspension buffer of a test bacterium (Escherichia coil NIHJ and Staphylococcus aereus IFO12732) was added to the tubular knitted fabric, and the suspension was added 150 times in a closed container. / Min, the viable cell count after shaking for 1 hour was measured, and the reduction rate with respect to the bacterial count of the poured suspension was determined (shake-flask method).

Example 1 100 parts by weight of Zr (H _0.5 Li _0.5 PO ₄ ) ₂ particles were _{added to} 0.1 wt.
It was placed in 400 parts by weight of a 05 mol / l silver nitrate aqueous solution and stirred at room temperature for 2 hours. The particles separated by the centrifugal separation method were slowly added with 5000 parts by weight of deionized water on the filter paper to completely wash off the metal ions physically adsorbed on the surface of the particles. The obtained particles were vacuum dried at 150 ° C. for 15 hours to obtain Zr (H _0.5 Li _0.5 PO ₄ ) ₂ (average particle diameter 0.8 μm) carrying 3.2% by weight of silver ions.
m) Particles were obtained. When 30 parts by weight of the particles and 970 parts by weight of Nylon 6 were mixed by an extruder,
Nylon 6 pellets containing 3.0% by weight of particles could be obtained without causing foaming.

The pellets are spun by a usual melt spinning method and then stretched to prevent the yarn from breaking.
A drawn yarn of 75 denier 24 filaments could be obtained.

The antibacterial properties of the drawn and refined yarns which had been cylindrically knitted and further washed 100 times were evaluated.

The reduction rate of the number of bacteria was 99.9% for E. coli and 97.6 for S. aureus in the sample after scouring.
%, 99.9% against E. coli and 98.1% against Staphylococcus aureus in the samples after washing, and it was found that all samples have an excellent antibacterial effect. .

Examples 2 to 10 and Comparative Examples 1 and 2 Using various phosphate particles, the same operations as in Example 1 were carried out to prepare phosphate particles having different amounts of silver ions carried and different average particle diameters. This was mixed with nylon 6. Next, a stretched yarn was prepared in the same manner as in Example 1, and the stretched yarn was cylindrically knitted to evaluate antibacterial properties. Table 1 shows the evaluation results of the moldability and antibacterial property of the resin.

With respect to Examples 2 to 10, high antibacterial properties are exhibited even if any of the phosphate particles is used. Especially,
When the zirconium phosphate salt is used as in Examples 5 to 10, it has a high antibacterial property before and after washing as well as excellent durability when the amount of the carried zirconium salt is about the same as that of particles of other compositions.

[0028]

[Table 1] Example 11 Zr (HPO ₄ ) ₂ holding silver ions obtained in Example 7
When 30 parts by weight of particles and 970 parts by weight of modified polyethylene terephthalate (polyethylene terephthalate having a number average molecular weight of 18,000 obtained by copolymerizing a 5-sodium sulfoisophthalic acid component with 5 mol% of all dicarboxylic acid components) were mixed by an extruder. A modified polyethylene terephthalate pellet containing 3.0% by weight of particles could be obtained without causing foaming.

These pellets are spun by a usual melt spinning method and then stretched to prevent yarn breakage.
A drawn yarn of 75 denier 24 filaments could be obtained.

The antibacterial properties of the drawn and refined products obtained by cylindrically knitting and those washed further 100 times were evaluated.

The reduction rate of the number of bacteria was 99.5% for E. coli and 96.0 for S. aureus in the sample after scouring.
%, 96.2% against Escherichia coli and 92.6% against Staphylococcus aureus in the samples after washing, and it was found that all samples had excellent antibacterial effect.

Example 12 100 parts by weight of Zr (HPO ₄ ) ₂ particles was added in an amount of 0.05 mol / mol.
It was put into 400 parts by weight of an aqueous zinc chloride solution of 1 and stirred at room temperature for 2 hours. The particles separated by the centrifugal separation method were slowly added with 5000 parts by weight of deionized water on the filter paper to completely wash off the metal ions physically adsorbed on the surface of the particles. The obtained particles were vacuum dried at 150 ° C. for 15 hours to obtain Zr carrying 1.3% by weight of zinc ions.
(HPO ₄ ) ₂ (average particle size 1.6 μm) was obtained. When 30 parts by weight of the particles were mixed with 970 parts by weight of nylon 6 by an extruder, foaming did not occur,
Nylon 6 pellets containing 3.0% by weight of particles could be obtained.

The pellets are spun by a usual melt spinning method and then stretched to prevent the yarn from breaking.
A drawn yarn of 75 denier 24 filaments could be obtained.

The antibacterial properties of the drawn and refined products obtained by cylindrical knitting and those washed 100 times were evaluated.

The reduction rate of the number of bacteria was 90.1% for E. coli and 88.2 for S. aureus in the sample after scouring.
%, 89.2% against S. aureus and 85.0% against S. aureus in the samples after washing, and all samples had excellent antibacterial effect.

[0036]

Since the antibacterial agent of the present invention has durable antibacterial properties, its industrial value is extremely high.

Claims (2)

[Claims] 1. A phosphate particle having an average particle diameter of 5 μm or less, wherein the particle is at least one metal ion selected from magnesium, calcium, titanium and zirconium, and at least one selected from hydrogen and an alkali metal. Consists of species cations, and silver, copper, zinc,
An antibacterial agent having excellent durability, which carries 0.1 to 20% by weight of at least one metal ion selected from gold and platinum by an ion exchange method. 2. The antibacterial agent having excellent durability according to claim 1, wherein the metal ion of the phosphate is zirconium.