JPH0557002A - Antibacterial nonwoven fabric - Google Patents

Abstract

PURPOSE:To improve the persistance of an antibacterial, antifungus and anti- alga effect by holding an antibacterial material comprising a phosphate compound expressed by a specific general formula. CONSTITUTION:A phosphate compound expressed by the general formula I is held in a nonwoven fabric such as nylon cloth. In the formula I, M<1> is one type of a metal ion selected from silver, copper, zinc, mercury, lead, iron, cobalt, nickel, manganese, arsenic, antimony, bismuth, cadmium and chromium. Also, A stands for one of an alkali metal ion, an alkaline earth metal ion, anmonium ion and hydrogen ion, and M<2> stands for a quadrivalent metal. Furthermore, the (n) stands for a value between 0 and 6, both inclusive, and (a) and (b) stand for positive numbers. The (c) and (d) have a relationship where (c)= 2 and (d)= 3 when la+mb= 1, and (c)= 1 and (d)= 2 when la+ mb= 2, where lis a valence for M<1> and (m) is a valence for A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial nonwoven fabric composed of a specific phosphate compound having antibacterial properties and a nonwoven fabric. More specifically, it relates to an antibacterial non-woven fabric capable of exhibiting a stable antibacterial effect over a long period of time, such as packaging materials for medical supplies and food products requiring high hygiene management, air filters, water filtration, etc. The present invention relates to an antibacterial nonwoven fabric that can be used for various purposes such as sterilization of air or sterilization of water by using it as various filters.

[0002]

2. Description of the Related Art Nonwoven fabrics are inexpensive, have high strength, and have high filterability, and are therefore used as various packaging materials and filters. In recent years, in order to prevent mold and bacteria from propagating on the nonwoven fabric used as a filter, organic bactericidal agents such as TBZ and Kolgasan and inorganic antibacterial agents such as zeolite carrying antibacterial metal ions such as silver ions have been used. A retained non-woven fabric has been proposed (JP-A-2-2191).
6). Inorganic antibacterial agents are more safe than organic bactericides, and are less likely to volatilize or decompose, so that they have excellent antibacterial effect durability and excellent heat resistance. Therefore, it is effective to retain the inorganic antibacterial agent in the non-woven fabric when the antibacterial effect is required to have long-lasting antibacterial effect and heat resistance. However, the zeolite-based antibacterial agent has a high reactivity of the metal contained as an antibacterial component, and has a problem of discoloring the fibers constituting the nonwoven fabric,
Since zeolite has a weak skeletal structure, it cannot stably support antibacterial metal ions.For example, when it comes in contact with a weakly acidic solution, the antibacterial metal ions are easily eluted and a permanent antibacterial effect can be exhibited. There is a problem that you can not.
Further, since some zeolite-based antibacterial agents have an average particle size of several μm, and the maximum exceeds several tens to 100 μm, kneading the antibacterial agent into the fibers reduces the strength of the fibers and forms a nonwoven fabric. When spinning a fiber, there is a problem that the fiber breaks and the antibacterial agent comes off particularly noticeably in a thin fiber.

[0003]

The present invention comprises a non-woven fabric holding a chemically and physically stable antibacterial agent, does not cause discoloration, and effectively exhibits antibacterial properties by using a small amount of antibacterial agent. Moreover, it is an object of the present invention to provide an antibacterial non-woven fabric having antibacterial, antifungal and algae-proofing effects for a long time even under severe conditions.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have retained a specific phosphate carrying a metal ion having antibacterial properties such as silver ion. It has been found that the non-woven fabric does not cause discoloration with time and has a permanent antibacterial, antifungal and algaeproof effect under a severe environment even with a small amount of antibacterial agent, and has completed the present invention. That is, the present invention is an antibacterial non-woven fabric characterized by holding a compound represented by the following general formula [1]. M ¹ _{a Ab} M ² _c (PO ₄ ) _d · nH ₂ O [1] (M ¹ is silver, copper, zinc, tin, mercury, lead, iron, cobalt,
At least one metal ion selected from nickel, manganese, arsenic, antimony, bismuth, barium, cadmium, or chromium, and A is at least one metal ion selected from alkali metal ions, alkaline earth metal ions, ammonium ions, or hydrogen ions. Is the ion of M ²
Is a tetravalent metal, n is a number satisfying 0 ≦ n ≦ 6,
Both a and b are positive numbers, and c and d are la + mb
= 1, c = 2, d = 3, la + mb = 2, c =
1 and d = 2. However, l is the valence of M ¹ and m is the valence of A. )

The present invention will be described in detail below. O Phosphate Compound The compound used as the antibacterial agent in the present invention is a phosphate compound represented by the following general formula [1]. M ¹ _{a Ab} M ² _c (PO ₄ ) _d · nH ₂ O [1] (M ¹ is silver, copper, zinc, tin, mercury, lead, iron, cobalt,
At least one metal ion selected from nickel, manganese, arsenic, antimony, bismuth, barium, cadmium, or chromium, and A is at least one metal ion selected from alkali metal ions, alkaline earth metal ions, ammonium ions, or hydrogen ions. Is the ion of M ²
Is a tetravalent metal, n is a number satisfying 0 ≦ n ≦ 6,
Both a and b are positive numbers, and c and d are la + mb
= 1, c = 2, d = 3, la + mb = 2, c =
1 and d = 2. However, l is the valence of M ¹ and m is the valence of A. )

The compound represented by the above general formula [1] is
When a + mb = 1, each coefficient of c = 2 and d = 3,
Amorphous or a crystalline compound belonging to the space group R3c, in which each constituent ion forms a three-dimensional network structure, and when la + mb = 2, each coefficient of c = 1 and d = 2, amorphous or Each constituent ion is a compound that forms a layered structure. As the phosphate compound used in the present invention, since it can be easily obtained in the form of fine particles and has little discoloration when exposed to sunlight and has excellent weather resistance, la + mb = 1 and c = 2, d = A crystalline compound having a three-dimensional network structure having a coefficient of 3 is preferable.

M ¹ in the above general formula [1] is known as a metal exhibiting antifungal, antibacterial and antialgal properties. Among them, silver is not only safe but also antifungal. ,
It is particularly effective as a metal that can remarkably enhance antibacterial and antialgal properties.

A in the above general formula [1] is at least one ion selected from an alkali metal ion, an alkaline earth metal ion, an ammonium ion and a hydrogen ion, and preferable specific examples include lithium, sodium and potassium. There is an alkali metal ion such as, an alkaline earth metal ion such as magnesium or calcium, an ammonium ion or a hydrogen ion, and among these, lithium, sodium, an ammonium ion and hydrogen are preferred from the viewpoint of the stability of the compound and low cost. Ions are the preferred ions.

M ² in the above general formula [1] is a tetravalent metal, and preferable specific examples thereof include zirconium, titanium or tin. Considering the safety of the compound, zirconium is a particularly preferable tetravalent metal. is there.

The following are specific examples of the phosphate compound of the above general formula [1]. Ag _0.005 Li _0.995 Zr ₂ (PO ₄ ) ₃ Ag _0.01 (NH ₄ ) _0.99 Zr ₂ (PO ₄ ) ₃ Ag _0.05 Na _0.95 Zr ₂ (PO ₄ ) ₃ Ag _0.2 K _0.8 Ti ₂ (PO ₄ ) ₃ Ag _0.1 H _0.9 Zr ₂ (PO ₄ ) ₃ and some of the Ag in each of the above formulas are replaced with Zn, Mn, Ni, Pb, Hg while maintaining the same charge amount as that of silver ions per mol of the compound. Compound substituted with Sn or Cu, Ag _0.001 Li _1.999 Zr (PO ₄ ) ₂ Ag _0.01 Na _1.99 Zr (PO ₄ ) ₂ Ag _0.01 K _1.99 Sn (PO ₄ ) ₂ 1.2H ₂ O Ag _0.1 (NH ₄ ) _1.9 Ti (PO ₄ ) ₂ .4H ₂ O Ag _0.02 H _1.98 Zr (PO ₄ ) ₂ .1.7H ₂ O and the amount of silver ion per 1 mol of the compound, while maintaining the same charge amount as described above. Part or all of Ag in each formula is Zn, Mn, or Ni. Pb, Hg, Sn, or compounds substituted with Cu.

The average particle size of the phosphate compound used in the present invention is preferably 1 μm or less in order to uniformly disperse it in the nonwoven fabric.

The phosphate compound used in the present invention is synthesized.
Known methods such as firing method, wet method and hydrothermal method
Either method can be used, but it is economical and has a high degree of purity.
For the synthesis of fine particulate zirconium phosphate
The hydrothermal method is the most suitable. Hydrothermal method as a concrete synthesis method
An example of the method is shown below. Aqueous solution of zirconium sulfate
Slowly add ammonium dihydrogen phosphate with stirring.
, A precipitate is formed. After that, with a caustic soda solution
Adjust the pH value of the reaction solution to 2 and keep it at 130 ℃
After heating the precipitate in a vessel under saturated vapor pressure for 32 hours,
The precipitate is filtered, washed with water, dried and crushed to obtain crystalline zirconium phosphate.
Konium NH 4 Zr 2 (PO Four) Get three. Furthermore, this result
Amorphous zirconium phosphate in silver nitrate aqueous solution of appropriate concentration
In addition, by stirring, the average particle size is 1 μm or less
Antibacterial phosphate Ag_X(NH Four) 1_-XZr 2 (PO Four) Get 3
(X is a positive number less than 1).

The value of a in the general formula [1] is the concentration of the antibacterial metal ion in the aqueous solution for supporting the antibacterial metal ion, and the time for immersing the compound supporting the antibacterial metal ion in the aqueous solution. Alternatively, by adjusting the temperature and the like, the temperature and the like can be appropriately adjusted according to the required characteristics and use conditions.

The value of a in the general formula [1] can exhibit antifungal properties and antibacterial properties even when it is extremely small, but if it is less than 0.001, it can exhibit antifungal properties and antibacterial properties for a long time. Considering the possibility of difficulty and the economical efficiency, the value is preferably 0.01 or more and 0.5 or less.

The phosphate compound used in the present invention is stable to exposure to heat and light, and its structure and composition do not change at all even after heating at 500 ° C. or higher, and in some cases 800 ° C. It does not cause any discoloration even when exposed to ultraviolet rays. Moreover, it does not come into contact with water in a liquid state or change in the skeleton structure even in an acidic solution. As described above, since the phosphate compound used in the present invention is chemically and physically stable, it is very safe even when used in the fields of food industry and medical care. Further, the antibacterial nonwoven fabric of the present invention is not subject to restrictions such as heating temperature or light shielding, unlike the conventional antibacterial nonwoven fabric, during the manufacturing process, storage, and use.

Further, since the phosphate compound used in the present invention can be easily obtained in the form of fine particles having an average particle size of 1 μm or less and a narrow particle size distribution, the phosphate compound is contained in the fiber. However, the problem of yarn breakage due to spinning and the problem of dispersibility when mixed with the resin forming the fiber do not occur. Also, when a phosphate compound is attached to the fiber surface of a non-woven fabric using a binder, the phosphate compound is uniformly and firmly retained in the resin, so that the phosphate compound particles due to physical factors such as friction are Very few dropouts. Since non-woven fabrics are usually characterized by high strength, their usage conditions are difficult. Therefore, in consideration of the dropout of particles due to friction or the like, and in consideration of use in a water filter, for example, the elution property becomes a problem.
Inorganic antibacterial agents are difficult to dissolve in organic solvents, but may slightly dissolve in acidic aqueous solutions. When the antibacterial metal that is a component elutes, the antibacterial effect decreases and the life becomes a problem, but the antibacterial agent used in the present invention has a strong acid resistance and does not dissolve in an acidic solution, so the antibacterial effect is Is highly sustainable.

Nonwoven fabric The material of the raw material fibers of the nonwoven fabric used in the present invention is not particularly limited, and specifically, for example, nylon, acrylic, rayon, polyester, cellulose ester, vinylon,
In addition to synthetic fibers such as polypropylene and natural fibers, inorganic fibers such as glass fibers, carbon fibers and alumina fibers can be used. These materials are not particularly limited and can be appropriately selected depending on the usage of the nonwoven fabric. For example,
In order to exert the antibacterial effect to a high degree, rayon and vinylon having high hydrophilicity are preferable, and rayon which is a resin having high water absorption is particularly preferable. Further, when moisture permeability and chemical resistance are required, polypropylene nonwoven fabric is preferable.

○ Method for Preparing Nonwoven Fabric The method for manufacturing the nonwoven fabric is not limited, and any known method such as a dry method or a wet method can be adopted. Specifically, for example, the fibers are entangled with each other using a needle punch machine, Examples of the method include a mechanical binding method such as sewing with a thread, and an adhesion method using heat, pressure or a binder.

The method of holding the antibacterial agent on the nonwoven fabric is not particularly limited, and for example, it is kneaded in advance by a conventional method at the stage of spinning the raw material fibers of the nonwoven fabric, or the raw material fibers are bonded using a binder containing an antibacterial agent. Thus, there is a method of processing into a non-woven fabric or a post-processing in which an antibacterial agent is attached to the surface of the resulting non-woven fabric with a binder. Among these methods, the post-processing is the most preferable processing method because it is easy to hold and the effect can be exhibited with a small amount of antibacterial agent. Preferred binders include water-soluble adhesives, solvent-soluble adhesives, viscose liquids, aqueous emulsions and synthetic resin powders. Among them, particularly preferred binders are aqueous emulsions, which effectively exhibit antibacterial properties. Therefore, it is desirable to use a material having a highly hydrophilic component.

The amount of the antibacterial agent added to the non-woven fabric is
The type of material, porosity, fineness, processing method, usage conditions, etc.
It may be adjusted more appropriately, for example, the spinning stage of the raw material fiber.
When added in 0.1% to 10% by weight to the fiber
It is appropriate to use a binder etc. by post-processing.
When attaching a fungus agent to the solid content of the binder
Mixing 10 to 60 wt% into a cloth-like relatively thin non-woven fabric
On the other hand, 0.1 g / m About 2 for thick non-woven fabric
1 g / m Adhesion of about 2 gives a sufficient antibacterial effect
It However, the antibacterial effect is persistent, fast-acting, or stronger.
When it is desired to obtain the fruit, the addition amount can be appropriately increased.

The antibacterial nonwoven fabric of the present invention can be used by laminating it with a film or paper. Further, the deodorizing effect can be enhanced by using an adsorbent such as activated carbon in addition to the antibacterial agent.

The antibacterial nonwoven fabric of the present invention can be used in various fields requiring antifungal, algae and antibacterial properties, and can also be used for deodorization. Specific applications include various filters, carpets, wiping cloths, various packaging materials such as food or medical products, bedding, clothing, absorbent hygiene products such as paper diapers and sanitary products, towels, masks, insoles, Examples include sportswear, various sports goods, various fillings, cushions and bandages for transporting fruits and the like.

Hereinafter, the present invention will be specifically described with reference to examples.

【Example】

 Reference example "Preparation of antibacterial agent" Aqueous solution of zirconium sulfate and ammonium dihydrogen phosphate
The ratio of zirconium to phosphorus in the aqueous solution of aluminum becomes 2: 3.
A precipitate is formed by mixing the
After adjusting the pH to 2 with an aqueous solution of lithium, seal it in a sealed volume.
Transfer to a container and heat under hydrothermal conditions at 150 ° C for 24 hours.
Thus, crystalline zirconium phosphate was obtained. As above
The crystalline zirconium phosphate obtained in
After stirring for 4 hours at room temperature, wash thoroughly with water and dry.
An antibacterial agent was obtained by drying and crushing. Antibacterial obtained
The agent is a white powder with an average particle size of 0.47 μm and has a composition
Ag_0.013(NH Four)_0.987Zr₂ (PO_Four )₃ And
It was

Example 1 "Preparation of antibacterial non-woven fabric" The anti-bacterial agent prepared in the reference example was mixed with a urethane emulsion binder at a ratio of 30 parts per 100 parts of solid content, and this was mixed with rayon fiber non-woven fabric and polypropylene fiber non-woven fabric. To give an antibacterial non-woven fabric having an anti-bacterial agent attached to the non-woven fabric. Table 1 shows the antibacterial nonwoven fabric obtained as described above.

[0025]

[Table 1]

Example 2 "Antibacterial activity test" The nonwoven fabric obtained in Example 1 was tested for antibacterial activity as follows.
It was. The number of bacteria is 10 per sheet 4-10 So that there are 5
Uniformly spread the E. coli bacterial solution on the surface of the non-woven fabric (5 cm x 5 cm)
The number of bacteria was inoculated immediately after inoculation and after storage for 6 hours at 37 ° C
The surviving bacteria were washed with the measurement medium (SCDLP liquid medium)
Then, this washing solution was used as a test solution. Measure the number of bacteria in the test solution
By pour plate culture method (37 ℃, 24 hours)
Measure the viable cell count and convert it to the viable cell count per sample.
It was The obtained results are shown in Table 2.

[0027]

[Table 2]

Example 3 "Water treatment test" Using the nonwoven fabric obtained in Example 1, a water treatment test was conducted as follows.
Test was carried out. After putting it in a beaker and leaving it for a week, the large intestine
2 x 10 fungi Do not add 2 tap water (100cc)
The woven fabric (5 cm x 5 cm) was submerged. Store at 25 ° C for 1 week
The number of viable bacteria after 2 hours, 1 day and 7 days after inoculation of E. coli.
It was measured by the pour plate culture method using a culture medium for measuring the number of bacteria.
The results obtained are shown in Table 3.

[0029]

[Table 3]

[0030]

The antibacterial non-woven fabric of the present invention is composed of a non-woven fabric holding a chemically and physically stable uniform fine particle antibacterial agent, does not cause discoloration, and is effectively antibacterial with a small amount of antibacterial agent used. It is extremely useful as a material that exhibits antibacterial, antifungal, and algae-proofing effects for a long period of time even under severe conditions.

Claims (1)

[Claims] 1. An antibacterial non-woven fabric, which holds an antibacterial agent represented by the following general formula [1]. M ¹ _{a Ab} M ² _c (PO ₄ ) _d · nH ₂ O [1] (M ¹ is silver, copper, zinc, tin, mercury, lead, iron, cobalt,
At least one metal ion selected from nickel, manganese, arsenic, antimony, bismuth, barium, cadmium, or chromium, and A is at least one metal ion selected from alkali metal ions, alkaline earth metal ions, ammonium ions, or hydrogen ions. Is the ion of M ²
Is a tetravalent metal, n is a number satisfying 0 ≦ n ≦ 6,
Both a and b are positive numbers, and c and d are la + mb
= 1, c = 2, d = 3, la + mb = 2, c =
1 and d = 2. However, l is the valence of M ¹ and m is the valence of A. )