JPH06212019A - Antimicrobial resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition comprising a specific antimicrobial agent and a resin, not eluting silver ions, excellent in weather resistance and antimicrobial persistence and useful for fiber products, etc. CONSTITUTION:The objective composition comprises 100 pts.wt. of a resin such as PE and an antimicrobial agent of the formula [A is alkali(alkaline earth) metal ion, ammonium ion; (q) is the valency of A; (a), (c) are positive numbers; (b) is 0, a positive number; a+qb+c=1; (n) is 0-6] preferably in an amount of 0.5-10 pts.wt., the antimicrobial agent of the formula being produced by carrying silver ions and hydrogen ions on the alkali(alkaline earth) metal salt or ammonium salt of zirconium phosphate having a phosphate ion/zirconium ion ratio of 3/2 and subsequently calcining the carried product at 500-1300 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition comprising a specific zirconium phosphate salt having antibacterial properties and a resin.
More specifically, the present invention relates to an antibacterial resin composition exhibiting a stable antibacterial effect with little deterioration over time during processing, storage, and use, and a fiber product that requires antifungal, algae, and antibacterial properties. It can be used as a plastic product and a rubber product.

[0002]

2. Description of the Related Art Generally, when bacteria or fungi propagate on the surface of an object, a large amount of water is often present in the environment where the object is placed, and sometimes the water is in a liquid state such as dew condensation. , May be in contact with an object. Also,
In order to evaluate the safety of resin molded products, as is the case especially for food containers, whether harmful components are eluted from the resin molded product when the resin molded product is contacted with an acidic liquid. Is inspected. Therefore, when the processed product of the antibacterial resin composition is to be used for various purposes, it is required that the antibacterial component does not elute even when the antibacterial resin composition is brought into contact with liquid water or acidic liquid. It

Conventionally, as an inorganic antibacterial agent, one in which silver is supported on activated carbon, apatite, zeolite or the like is known. These are more safe than organic antibacterial agents, have a long lasting antibacterial effect because they do not volatilize or decompose, and have excellent heat resistance. Therefore, an antibacterial resin composition is prepared by mixing these antibacterial agents and various polymer compounds, and the composition is processed into fibrous, film-like or pellet-like forms and used for various purposes.

However, since the antibacterial agent using activated carbon as a carrier has a black color, the antibacterial resin composition obtained by mixing with various polymers has a problem in appearance. Further, when brought into contact with a liquid, there is a problem that the antibacterial component is easily eluted and the antibacterial effect cannot be maintained for a long time. In addition, antibacterial agents that use apatite and zeolite as carriers have relatively less elution of antibacterial components when contacted with a neutral liquid compared to antibacterial agents that use activated carbon, and the antibacterial effect lasts for a long time. However, all of these antibacterial agents have low acid resistance, and the skeleton structure is easily destroyed in a dilute acidic aqueous solution of about PH4 to elute the antibacterial metal. It is difficult to maintain the antibacterial effect for a long time, and there are also safety problems. Further, when mixed with various polymers, there is a problem that the resin discolors during subsequent storage or use, causing deterioration of the resin.

As for the antibacterial agent using zeolite as a carrier, an antibacterial agent having silver as an antibacterial component and ammonia or amine as a discoloration preventing component supported by ion exchange has been developed for the purpose of preventing discoloration. (JP-A-64-
24860), discoloration is not completely prevented, and when the resin composition comprising this antibacterial agent and the resin is subjected to heat processing, the resin is foamed due to the release of ammonia and the processability of the resin composition is increased. Has the problem that
The underlying problem has not been resolved.

Recently, an antibacterial agent having silver supported on a special zirconium phosphate-based compound has been developed.
No. 83905), which synthesizes a zirconium phosphate salt-based compound by a calcination method, so that the compound obtained by calcination had to be pulverized into fine particles in order to uniformly mix the antibacterial agent with the resin.

[0007]

DISCLOSURE OF THE INVENTION The present invention is a resin composition in which an antibacterial agent in the form of fine particles and a resin are uniformly mixed, and silver ions are not eluted from the antibacterial agent, and at the time of processing,
It is an object of the present invention to provide a product that does not discolor during storage and use, has very little deterioration over time, and can maintain an antibacterial effect for a long time.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a specific zirconium phosphate salt obtained by synthesis by a wet method contains silver ions and hydrogen ions. It was found that an antibacterial resin composition composed of an antibacterial agent and a resin, which is supported and baked at a temperature of 500 to 1300 ° C., retains antibacterial metal ions extremely stably and exhibits antifungal and antibacterial properties for a long time. The present invention has been completed. That is, according to the present invention, an alkali metal salt, an alkaline earth metal salt or an ammonium salt of zirconium phosphate having a ratio of phosphate ion to zirconium ion of 3/2 is loaded with silver ion and hydrogen ion, and
An antibacterial resin composition comprising an antibacterial agent represented by the following general formula [1] and a resin, which is obtained by firing at 00 to 1300 ° C. Ag _{a Ab} H _c Zr ₂ (PO ₄ ) ₃ · nH ₂ O [1] (A is at least one ion selected from alkali metal ions, alkaline earth metal ions and ammonium ions, and q is A Valence, a and c are positive numbers, b is 0 or a positive number, and q, a, b and c are a +
It is a number that satisfies qb + c = 1. Further, n is a number that satisfies 0 ≦ n ≦ 6. )

The present invention will be described in detail below. Antibacterial Agent The antibacterial agent used in the present invention is a compound having a composition represented by the following general formula [1]. Ag _{a Ab} H _c Zr ₂ (PO ₄ ) ₃ · nH ₂ O [1] (A is at least one ion selected from alkali metal ions, alkaline earth metal ions and ammonium ions, and q is A Valence, a and c are positive numbers, b is 0 or a positive number, and q, a, b and c are a +
It is a number that satisfies qb + c = 1. Further, n is a number that satisfies 0 ≦ n ≦ 6. )

The compound represented by the above general formula [1] represents an amorphous or crystalline compound in which each constituent ion forms a three-dimensional network structure and belongs to the space group R3c, and any compound may be used in the present invention. However, it is preferable to use a crystalline compound in order to more stably support the antibacterial metal ion.

A in the above general formula [1] is at least one ion selected from alkali metal ions, alkaline earth metal ions and ammonium ions, and preferred specific examples of the alkali metal ions and alkaline earth metal ions are: Include lithium, sodium, potassium, magnesium and calcium. Preferred ions as A in the general formula [1] are lithium, sodium, and ammonium ions, and nasodium ion is a particularly preferred ion, from the viewpoint of stability of the compound and availability at low cost.

In order to exhibit antifungal, antibacterial and antialgal properties, the larger the value of a in the general formula [1] is, the better.
When the value of a is 0.001 or more, antifungal, antibacterial and antialgal properties can be sufficiently exhibited. However, if the value of a is less than 0.001, it may be difficult to exert the antifungal, antibacterial and antialgal properties for a long time. Therefore, the value of a is set to 0.01 or more. It is preferable.
Further, in consideration of economy, the value of a is preferably 0.5 or less.

The value of a in the general formula [1] can be adjusted by adjusting the concentration of silver ions in the aqueous solution in which the zirconium phosphate salt is dipped, and the time or temperature of dipping, and the required characteristics and operating conditions. It can be appropriately adjusted according to the above.

The compound represented by the above general formula [1] [hereinafter referred to as compound (1). ] Is characterized in that it has a hydrogen ion, which allows the compound (1) to be an extremely stable antibacterial agent without discoloration. The hydrogen ion coefficient c in the general formula [1] is not particularly limited as long as it is a positive number less than 1, but is preferably 0.1 or more in order to obtain a stable compound without discoloration. It is preferably 0.2 or more, and most preferably 0.25 or more.

The following are preferred specific examples of the antibacterial agent represented by the above general formula [1]. _{Ag 0.005 Li 0.505 H 0.49 Zr 2} (PO 4) 3 · 1.1H 2
0 Ag _0.01 (NH ₄ ) _0.59 H _0.40 Zr ₂ (PO ₄ ) ₃・ 1.2
H ₂ O Ag _0.05 H _0.95 Zr ₂ (PO ₄ ) ₃ · 1.5H ₂ O Ag _0.05 Na _0.50 H _0.45 Zr ₂ (PO ₄ ) ₃ · 1.1 H ₂ O Ag _0.05 Na _0.60 K _0.11 H _0.24 Zr ₂ ( PO _{4) 3} · 1.
2H ₂ O Ag _0.05 Ca _0.10 H _0.75 Zr ₂ (PO ₄ ) ₃ · 1.2H ₂ O Ag _0.10 Na _0.50 H _0.40 Zr ₂ (PO ₄ ) ₃ · 1.1H ₂ O Ag _0.20 Na _0.30 H _0.50 Zr ₂ ( PO _{4) 3} · 1.1H ₂ O

The antibacterial agent used in the present invention is made of a zirconium phosphate salt produced by a so-called wet method in which phosphate ions and zirconium ions are reacted in water to obtain fine particles having a uniform particle size. .

A preferred method for producing the zirconium phosphate salt is to allow the phosphate ion and the zirconium ion to be present in water in the presence of at least one ion selected from alkali metal ions, alkaline earth metal ions and ammonium ions. It is a method of obtaining a zirconium phosphate salt by reacting at a ratio of 0.4 to 4.0 equivalents of zirconium ion per 1 equivalent of ion.

Alkali metal ions present in water when reacting phosphate ions and zirconium ions,
The alkaline earth metal ion and the ammonium ion are ions to be the A ion in the general formula [1]. The compound used in the reaction is not particularly limited as long as it is a compound having these ions, but as a preferred compound,
There are hydroxides, sulfates, nitrates, chlorides, carbonates, hydrogencarbonates, phosphates, borates and the like, and hydroxides are particularly preferable compounds.

In order to react the phosphate ion with the zirconium ion, a compound containing these ions may be reacted. In order to promote this reaction, a carboxylic acid or a salt thereof is added to the compound containing zirconium ions (zirconium compound). It is preferable to react a mixture of [a raw material (A)] with a compound having a phosphate ion [a raw material (B)]. Preparation of Raw Material (A) The raw material (A) used in the above-mentioned production method contains a zirconium compound and a carboxylic acid or a salt thereof, and an aqueous solution of the zirconium compound and a carboxylic acid or the same are prepared in advance in order to react uniformly. It is preferably prepared by mixing an aqueous solution of salt. The preferable mixing ratio of the carboxylic acid or its salt and the zirconium compound is 1 of the zirconium compound.
The ratio is preferably 1 equivalent (molecular weight per carboxyl group) of the carboxylic acid or a salt thereof per equivalent (formula weight per Zr atom). (Zirconium compound) As the zirconium compound which can be used in the above-mentioned production method, those which are water-soluble or acid-soluble are suitable, and specific examples of preferable compounds include zirconium nitrate, zirconium acetate, zirconium sulfate and basic sulfuric acid. Zirconium, zirconium oxysulfate, zirconium oxychloride and the like.

(Carboxylic acid or salt thereof) The carboxylic acid or salt thereof is an aliphatic polycarboxylic acid having two or more carboxyl groups and a salt thereof, and preferable specific examples thereof include the following compounds. That is, oxalic acid, maleic acid,
Aliphatic dibasic acids such as malonic acid and succinic acid, salts of aliphatic dibasic acids such as sodium oxalate, sodium hydrogen oxalate, lithium hydrogen oxalate, ammonium oxalate, ammonium hydrogen oxalate, citric acid and tartaric acid , Aliphatic oxyacids such as malic acid, and salts thereof. Of these, oxalic acid and its sodium and ammonium salts are particularly preferred compounds.

Preparation of Raw Material (B) In the above production method, it is preferable to previously prepare an aqueous solution containing phosphoric acid or a salt thereof as the raw material (B). (Phosphate) Preferred phosphates are water-soluble or acid-soluble salts such as ammonium phosphate and alkali metal phosphate, and specific examples thereof include sodium dihydrogen phosphate, disodium hydrogen phosphate, Examples include trisodium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate and dipotassium hydrogen phosphate.

Equivalent ratio of zirconium ion to phosphate ion (α) When the raw material (A) and the raw material (B) are mixed, the zirconium ion is added in an amount of 0.4 equivalent to 1 equivalent of phosphate ion.
It is preferably 4.0 equivalents, more preferably 0.
6 equivalents to 2.0 equivalents, most preferably 0.6 equivalents to 0.
Set to 8 equivalents. If the equivalent ratio (α) is smaller than 0.4 or larger than 4.0, a compound having a structure different from that of the zirconium phosphate salt used in the present invention may be produced.

PH value By mixing the raw material (A) and the raw material (B), they react with each other to precipitate fine particles of zirconium phosphate salt to form a reactant slurry. Then, p of the reactant slurry
It is preferable to adjust the H value to 7 or less, more preferably to adjust the pH to 1 to 6, and further preferably to 3 to 6,
It is subjected to a heating reaction.

Reaction temperature The reactant slurry is preferably heated at 80 ° C. or higher in the reaction vessel, more preferably at 95 ° C. or higher. If heated below 80 ° C., a compound different from the zirconium phosphate salt used in the present invention tends to be produced as an impurity. When heated at 95 ° C. or higher, crystallization proceeds in a short time, and the crystallization rate increases at higher temperatures, so 97 ° C. to 100 ° C. is more preferable. In this temperature range, crystallization is usually completed within 10 to 50 hours.

Solid Content Concentration of Reactant Slurry The solid content concentration of the reactant slurry is preferably in the range of 15 wt% or less in consideration of the stirring property of the reactant slurry.

○ Separation / Washing / Drying The product is separated from the liquid phase by known separation means such as filtration, decantation, centrifugation and filter press,
After washing, it is dried by a conventional method, and if it is solidified, it is loosened as necessary to obtain a zirconium phosphate salt.

Supporting and firing of silver ions and hydrogen ions In order to obtain the antibacterial agent in the present invention, the zirconium phosphate salt obtained as described above is treated in the following steps A, B and C. Need to be applied. Step A: a step of supporting silver ions on the zirconium phosphate salt. Step B: a step of supporting hydrogen ions on the zirconium phosphate salt. Step C: Zirconium phosphate salt at a temperature of 500 to 130
Step of firing at 0 ° C.

Step A A preferable method for supporting silver ions on the zirconium phosphate salt is a method by an ion exchange reaction. That is, by immersing the zirconium phosphate salt obtained as described above in an aqueous solution containing an appropriate concentration of silver ions,
A zirconium phosphate salt carrying silver ions is obtained. The temperature of the aqueous solution at this time may be in the range of 0 to 100 ° C., and the immersion time may be several minutes to several tens of minutes,
The immersion may be continued for a longer time (for example, several hours).

Step B As a preferable method of supporting hydrogen ions on the zirconium phosphate salt, there is a method of immersing the zirconium phosphate salt in an acid solution having an appropriate concentration. Acid solutions that can be used include solutions of hydrochloric acid, sulfuric acid, nitric acid and the like. The acid concentration of the solution, the temperature, and the time are not particularly limited, but generally, the higher the acid concentration, the higher the temperature and the longer the time, the hydrogen ions can be supported in a shorter time, so that the preferable acid concentration is 0.1 N or more, and the preferable processing temperature is 40
The temperature is not lower than 0 ° C, more preferably not lower than 60 ° C and not higher than 100 ° C, and the preferable treatment time is not shorter than 10 minutes, more preferably not shorter than 60 minutes. In order to carry hydrogen ions, a zirconium phosphate salt having ammonium ions is added at 600 to 1100 ° C. in addition to the dipping treatment in an acid solution.
There is also a method of baking. The step of supporting hydrogen ions may be performed before or after step A or simultaneously with step A.

Step C By passing through this firing step, the chemical and physical stability of the antibacterial agent can be remarkably improved, and an antibacterial agent having no discoloration and extremely excellent weather resistance can be obtained. In addition, since the water adhering to the resin before firing hardly exists, the processability of the resin is improved. In this step, 500 to 130
It is necessary to bake at 0 ° C., preferably 600 to
Baking at 1000 ° C., and more preferably 700 to 900 ° C. is good. It is difficult to sufficiently exert the effect of improving the chemical and physical stability of the antibacterial agent when calcined at a temperature lower than 500 ° C, and the antibacterial property is lowered when calcined at a temperature higher than 1300 ° C. There's a problem. The firing time is not particularly limited, and the effects of the present invention can be sufficiently exhibited by firing for usually 1 to 20 hours. The rate of temperature increase and the rate of temperature decrease are not particularly limited, and can be appropriately adjusted in consideration of the capacity and productivity of the firing furnace.

The calcining step may be carried out either before the silver ions are carried on the zirconium phosphate salt or after the silver ions are carried. The specific examples of the order of carrying out the steps A to C are as follows. Is the street. That is, (process A → process B → process C), (process B → process A → process C),
(Process A → Process C → Process B), (Process A and Process B → Process C), (Process C → Process A → Process B), (Process C → Process B)
→ step A), (step B → step C → step A) and (step C)
→ Process A and process B), etc. In order to improve the chemical and physical stability of the antibacterial agent and obtain an antibacterial agent without discoloration, it is preferable to carry out the firing step after supporting silver ions on the zirconium phosphate salt.

The antibacterial agent obtained as described above is in the form of fine particles having an average particle size of several μm or less, often 1 μm or less, is stable to exposure to light, and undergoes no color change even when irradiated with ultraviolet rays. Does not cause As is clear from the fact that the manufacturing process goes through a firing step, the antibacterial agent used in the present invention has extremely excellent heat resistance. In addition, the skeleton structure is not changed even in an acidic solution.
Therefore, unlike the conventional antibacterial agents, there is no restriction on the heating temperature or the light-shielding conditions during processing and storage when obtaining various molded products.

The resin used in the present invention is a natural resin,
It may be either a semi-synthetic resin or a synthetic resin, and may be a thermoplastic resin or a thermosetting resin.
The specific resin may be any of plastic, fiber and rubber, and examples thereof include polyethylene, polypropylene, vinyl chloride, ABS resin, nylon, polyester, polyvinylidene chloride, polyamide, polystyrene, polyacetal, polycarbonate, acrylic resin, Plastics such as fluorine resin, polyurethane elastomer, polyester elastomer, melamine resin, urea resin, tetrafluoroethylene resin, unsaturated polyester resin, epoxy resin, urethane resin and phenol resin; nylon, polyethylene, rayon, acetate,
Fibers such as acrylic, polyvinyl alcohol, polypropylene, cupra, triacetate, vinylidene; natural rubber and silicone rubber, SBR (styrene / butadiene rubber), CR (chloroprene rubber), EPM (ethylene / propylene rubber), FPM (fluorine rubber), NBR
There are synthetic rubbers such as (nitrile rubber), CSM (chlorosulfonated polyethylene rubber), BR (butadiene rubber), IR (synthetic natural rubber), IIR (butyl rubber), urethane rubber and acrylic rubber.

The antibacterial resin composition of the present invention is obtained by heating and pressurizing or depressurizing the antibacterial agent represented by the general formula [1] and the resin at an appropriate temperature or pressure according to the characteristics of the resin used. However, it can be easily prepared by a method of mixing, mixing or kneading, and the specific operation thereof may be carried out by an ordinary method, and various shapes can be formed.

The preferred blending ratio of the antibacterial agent is 0.1 per 100 parts by weight of the antibacterial resin composition (hereinafter simply referred to as "part").
The amount is 05 to 50 parts, and more preferably 0.5 to 10 parts in consideration of antibacterial effect and economy.

The antibacterial resin composition of the present invention thus obtained has an antibacterial agent, which is a component thereof, having excellent chemical and physical stability, so that the antibacterial metal composition can be used even in an acidic solution. It does not elute ions and has no hygroscopicity, so it is extremely workable. Moreover, when the antibacterial agent and the resin are mixed, and when the antibacterial resin composition is stored or used thereafter, there is no deterioration such as discoloration or deterioration of the antibacterial property, and it is fungicidal and antibacterial for a long time even in a severe environment. It possesses phytotoxicity and algal resistance.

The antibacterial resin composition of the present invention can be used by being molded into various forms in various fields requiring antifungal, antialgal and antibacterial properties, and in particular, it contains a large amount of water. It is effective for use in the environment. Specific applications include food containers, cutting boards, and plastic products.
Refrigerators, medical equipment, various packaging materials, brushes and water-related products; for textiles, sheets, towels, towels, masks,
Socks and gloves; various rubber products such as tubes, packings and belts.

Hereinafter, the present invention will be described more specifically by way of examples.

[Examples and Comparative Examples] First, zirconium phosphate salt, which is a raw material of an antibacterial agent, was synthesized.

Reference Example 1 (Preparation of reticulated zirconium phosphate salt) While stirring an aqueous solution of zirconium oxychloride (0.2 mol), oxalic acid (0.1 mol) was added thereto, and phosphoric acid ( 0.3 mol) is added (1 of phosphate ion)
The equivalent of zirconium ion per equivalent is 0.67).
Adjust the pH of the reaction solution to 3.5 with a caustic potash solution, and
After heating under reflux at 5 ° C. for 20 hours, the precipitate is filtered, washed with water, dried and pulverized to give a meshy potassium zirconium phosphate [KZ
r ₂ (PO ₄ ) ₃ · 1.2H ₂ O] was obtained (K-type zirconium phosphate salt. Average particle size: 0.4 μm). Similarly, while stirring an aqueous solution of zirconium oxychloride (0.2 mol), ammonium chloride and oxalic acid (0.1 mol) are added thereto, and phosphoric acid (0.3 mol) is further added. The pH of the reaction solution was adjusted to 4.0 with an aqueous ammonia solution, and 9
After 48 hours of heating under reflux at 5 ° C., the precipitate is filtered, washed with water, dried, and pulverized to obtain a reticulated zirconium phosphate ammonium _{[NH 4 Zr 2 (PO 4} ) 3 · 1.1H 2 O] (NH 4
Type zirconium phosphate salt. Average particle size: 0.7 μm). Further, while stirring the aqueous solution of zirconium oxychloride (0.2 mol), oxalic acid (0.1 mol) is added thereto, and phosphoric acid (0.3 mol) is further added. Adjust the pH of the reaction solution to 3.5 with an aqueous solution of caustic soda, and add 2 at 95 ° C.
After heating under reflux for 0 hours, the precipitate was filtered, washed with water, dried and pulverized to give a mesh of sodium zirconium phosphate [NaZr ₂
(PO ₄ ) ₃ · 1.1H ₂ O] was obtained (Na-type zirconium phosphate salt. Average particle size: 0.8 μm).

Synthesis Example 1 (Preparation of antibacterial agent and firing) The powders of the K-type and Na-type zirconium phosphate salts prepared in Reference Example 1 above were added to a 1N nitric acid solution containing silver ions, and the mixture was added at 60 ° C. It was stirred for 10 hours. Then, these slurries were filtered and then thoroughly washed with pure water. further,
An antibacterial agent was obtained by heating and drying at 110 ° C. overnight and baking at 750 ° C. for 4 hours (Sample No. 1 and No. 1).
3 antibacterial agent).

Synthesis Example 2 (Preparation of antibacterial agent and calcination) The NH ₄ type zirconium phosphate powder prepared in Reference Example 1 was calcined at 700 ° C. for 4 hours to give hydrogen type zirconium phosphate [ HZr ₂ (PO ₄ ) ₃ ] was obtained, this was added to a 1N nitric acid solution containing silver ions, and the mixture was stirred at 60 ° C. for 10 hours. Then, these slurries were filtered and then thoroughly washed with pure water. Furthermore, 11
An antibacterial agent was obtained by heating and drying at 0 ° C overnight and baking at 750 ° C for 4 hours (antibacterial agent of sample No. 2).

Synthesis Example 3 (Preparation of Antibacterial Agent and Firing) The powder of the Na-type zirconium phosphate salt prepared in Reference Example 1 above was added to a 0.1N nitric acid solution containing silver ions, and the mixture was added at 10 ° C. at 10 ° C. Stir for hours. Then, these slurries were filtered and then thoroughly washed with pure water. Furthermore, 11
An antibacterial agent was obtained by heating and drying at 0 ° C overnight and baking at 750 ° C for 4 hours (antibacterial agent of sample No. 4).

Comparative Synthesis Example 1 (Preparation and Firing of Antibacterial Agent) The powder of the Na-type zirconium phosphate salt prepared in Reference Example 1 was added to an aqueous solution in which nitric acid was not contained and only a predetermined amount of silver nitrate was dissolved. Then, the mixture was stirred at 60 ° C. for 10 hours. Then, these slurries were filtered and then thoroughly washed with pure water. Furthermore, after heating and drying at 110 ° C overnight, it is dried at 750 ° C for 4
By firing for a time, the coefficient c in the general formula [1]
Was 0, and an antibacterial agent which does not carry hydrogen ions was obtained (antibacterial agent of sample No. 5).

Comparative Synthesis Example 2 (Preparation of Antibacterial Agent) The powder of the Na-type zirconium phosphate salt prepared in Reference Example 1 above was added to a 1N nitric acid solution containing a predetermined amount of silver nitrate and stirred at 60 ° C. for 10 hours. did. Then, these slurries were filtered and then thoroughly washed with pure water. Then 11
An antibacterial agent was obtained without heating and drying overnight at 0 ° C. (antibacterial agent of sample No. 6).

Comparative Synthesis Example 3 (Preparation of Antibacterial Hydroxyapatite and Antibacterial Zeolite) Hydroxyapatite [Ca ₁₀ (PO ₄ ) ₆ (OH)
₂ ] or A-type zeolite [composition: 0.94 Na ₂ O · A]
1 ₂ O ₃ · 1.92 SiO ₂ · xH ₂ O ^* ] was added to silver nitrate alone or an aqueous solution of silver nitrate and ammonium nitrate, stirred at room temperature for 10 hours, washed thoroughly with water, and dried at 110 ° C. Hydroxyapatite (average particle size: 1.2 μm) and antibacterial zeolite (average particle size:
2.6 μm) was obtained (antibacterial agents of sample Nos. 7 to 9)
(*: X = 1 to 4). The antibacterial agents prepared by the above method are shown in Table 1 below.

[0046]

[Table 1] Note) Sample No. 10 is the raw material of Sample No. 3, and is sodium zirconium phosphate that has not been immersed in a nitric acid aqueous solution containing silver ions.

Example 1 (Preparation of antibacterial resin composition) Various antibacterial agents prepared in Synthetic Examples 1 to 3 and Comparative Synthetic Examples 1 to 3 were respectively used as high density polyethylene powder (commercial product) 5 wt% was mixed with Hi-Zex 1300JP) and various antibacterial pellets were produced using a Labo Plastomill. This pellet and Hi-Zex 1300J were added to dilute the antibacterial agent content to 1 wt%, and M-50AII-DM manufactured by Meiki Seisakusho Co., Ltd.
Injection molded at 200 ° C using
A 2 mm antibacterial plate was made. Further, only Hi-Zex 1300J containing no antibacterial agent was injection-molded in the same manner to obtain a blank.

Test Example 1 (Antibacterial Test) The antibacterial activity of the various antibacterial plates prepared in Example 1 was evaluated by the following method. Escherichia coli was used as the test bacteria, and the number of bacteria per 5 cm × 5 cm of the antibacterial plate was 10 ⁴ to 1
0 ⁵ become as the bacterial suspension was evenly inoculated on the surface, 37 ° C.
Saved in. After 0 hours from the start of storage (theoretical number of added bacteria) and after storing for 24 hours, the culture medium for measuring the number of bacteria (SCDLP
The surviving bacteria on the test piece were washed out with a liquid medium), and this washing solution was used as a test solution. The viable cell count of this test solution was measured by the pour plate culture method (37 ° C. for 2 days) using a culture medium for cell count measurement and converted into the viable cell count per 5 cm × 5 cm of the antibacterial plate. The results of the antibacterial test obtained as described above are shown in Table 2 below. In addition, it contains no antibacterial agent,
The viable cell count per 5 cm × 5 cm of the plate injection-molded with Hi-Zex 1300J was 1.2 × 10 ⁵ and 6.7, respectively, at 0 hours and 24 hours after the start of storage.
× 10 ^4, and viable cell count of the bacterial suspension each at 0 hours and 24 hours after initiation storage, 1.2 × 10 ⁵ and 1.
It was 1 × 10 ⁵ .

[0049]

[Table 2]

Test Example 2 "Weather resistance test" The weather resistance of each of the antibacterial plates produced in Example 1 was measured using a weather resistance tester UC-1 manufactured by Toyo Seiki Seisaku-sho, Ltd. The test condition of UC-1 is 2 cycles per cycle.
It is a time, and consists of a 1-hour process of irradiating ultraviolet rays of 350 nm or less at 60 ° C. and a 1-hour process of leaving at 40 ° C. in an atmosphere having a humidity of 95% or more. Using a color difference meter SZ-Σ80 manufactured by Nippon Denshoku Industries Co., Ltd.
And after 20 cycles, the color (L, a, b) was measured, and this color was compared with the color immediately after forming a blank plate containing no antibacterial agent to obtain a color difference ΔE.
I asked. Immediately after molding (0
Cycle) and the color difference after 5 and 20 cycles of weather resistance test are shown in Table 3 below. As a result of the weather resistance test of the blank plate, the color differences were 0, 0.8 and 1.9 after 0 cycle, 5 cycles and 20 cycles, respectively.

[0051]

[Table 3]

Test Example 3 (dissolution test) Various antibacterial pellets prepared in Example 1 (antibacterial agent 5w
(containing t%) 50 g of nitric acid aqueous solution of pH 2, 3 and 4
After soaking in 0 cc for 10 hours, the mixture was filtered and the antibacterial component eluted in the filtrate was measured by an atomic absorption spectrophotometer. The results of the dissolution test obtained as described above are shown in Table 4 below. Further, with respect to Sample No. 3 (calcined product) and Sample No. 6 (uncalcined product), the elution properties of silver ions into water were evaluated as follows. 1 g of each sample was weighed in a 200 ml polypropylene pack, and 100 ml of pure water was put therein. Cover it and shake it well by hand, then put it in a dark place at room temperature for 24 hours.
Let stand for hours. Then, the supernatant was filtered with a 0.20 μm membrane filter. The silver ion in the filtrate was measured by ICP mass spectrometry. The results are shown in Table 5 below.

[0053]

[Table 4] Note) ND indicates that it is below the detection limit (0.1 ppm).

[0054]

[Table 5]

Test Example 4 (acid resistance test) The antibacterial polyethylene plate containing 5 wt% of the antibacterial agent prepared in Example 1 was immersed in an aqueous acetic acid solution having a pH of 3.5 for 6 hours and then thoroughly washed with water to evaluate the antibacterial activity. did. The antibacterial activity was evaluated in the same manner as in Test Example 1, and the results are shown in Table 6 below. The number of bacteria in the bacterial solution was 1.7 × 10 ⁵ and 1.0 ×, respectively, after 0 hour and 24 hours of action.
It was 10 ⁵ .

[0056]

[Table 6]

[0057]

INDUSTRIAL APPLICABILITY The antibacterial resin composition of the present invention is a uniform mixture of a fine particle antibacterial agent and a resin, and silver ions do not elute even when contacted with water or an acidic liquid. In addition, since it has excellent weather resistance, it is extremely useful as a material that has no discoloration and can maintain the antibacterial effect for a long time.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideki Kato 1-1 Funami-cho, Minato-ku, Nagoya-shi, Aichi Toagosei Chemical Industry Co., Ltd. Nagoya Research Institute

Claims (1)

[Claims] 1. An alkali metal salt of zirconium phosphate having a ratio of phosphate ion to zirconium ion of 3/2,
An antibacterial resin composition comprising an antibacterial agent represented by the following general formula [1] and a resin, which is obtained by supporting silver ions and hydrogen ions on an alkaline earth metal salt or ammonium salt and baking at 500 to 1300 ° C. Ag _{a Ab} H _c Zr ₂ (PO ₄ ) ₃ · nH ₂ O [1] (A is at least one ion selected from alkali metal ions, alkaline earth metal ions and ammonium ions, and q is A Valence, a and c are positive numbers, b is 0 or a positive number, and q, a, b and c are a +
It is a number that satisfies qb + c = 1. Further, n is a number that satisfies 0 ≦ n ≦ 6. )