JP2890871B2 - Antibacterial resin composition - Google Patents

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 antibacterial phosphate compound and a resin. More specifically, the present invention relates to an antibacterial resin composition which shows little and no deterioration over time during processing, storage and use, and exhibits a stable antibacterial effect. It can be used as plastic products and rubber products.

[0002]

2. Description of the Related Art Generally, when bacteria and molds proliferate on the surface of an object, a large amount of water is often present in the environment where the object is placed. May be in contact with an object. Also,
As in the case of food containers in particular, whether or not harmful components are eluted from the resin molded product when the resin molded product is brought into contact with an acidic liquid in order to evaluate the safety of the resin molded product. Is inspected. Therefore, when trying to use the processed product of the antibacterial resin composition for various uses, it is required that the antibacterial component is not eluted even when the antibacterial resin composition comes into contact with liquid water or an acidic liquid. You.

Hitherto, as an inorganic antibacterial agent, an antibacterial metal such as silver or copper supported on activated carbon, apatite, zeolite or the like has been known. These have higher safety than organic antibacterial agents, and are characterized by long lasting antibacterial effects 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 is processed into a fibrous, film, or pellet form using the composition, and is used for various purposes.

However, the antibacterial agent using activated carbon as a carrier has a problem in appearance that the antibacterial resin composition obtained by mixing with various polymers is colored because the antibacterial agent itself is black. Further, there is a problem that the antibacterial component is easily eluted when brought into contact with a liquid, and the antibacterial effect cannot be maintained for a long time. In addition, antibacterial agents using apatite and zeolite as carriers have relatively little elution of antibacterial components when contacted with a neutral liquid, and maintain antibacterial effects for a long time, compared to antibacterial agents using activated carbon as a carrier. Although these antibacterial agents are excellent in that they can be used, 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, so that the antibacterial metal is eluted. It is difficult to maintain the antibacterial effect for a long time, and there is a problem in safety. In addition, when mixed with various polymers, there is a problem that the resin discolors during storage or use, and causes deterioration of the resin.

As an 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 carried by ion exchange has been developed for the purpose of preventing discoloration. (Japanese Patent Laid-Open No. 64-
24860), discoloration is not completely prevented, and when a resin composition composed of the antibacterial agent and the resin is heated, the resin is foamed because ammonia is released, and the processability of the resin composition is increased. There is a problem that
The fundamental problem has not been solved.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a resin composition comprising an antibacterial agent and a resin. The resin composition is used in an environment where a large amount of water is present or is in a liquid state. An antibacterial component is not eluted from a resin molded product even when it comes into contact with water or an acidic liquid, and the antibacterial effect can be maintained for a long time. It is in.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and have found that silver, copper, zinc,
Specific phosphates having antibacterial metal ions (hereinafter referred to as antibacterial metal ions) of tin, mercury, lead, iron, cobalt, nickel, manganese, arsenic, antimony, bismuth, barium, cadmium and chromium ions The present inventors have found that an antibacterial resin composition comprising a compound and a resin extremely stably retains an antibacterial metal ion and exhibits long-term fungicidal and antibacterial properties, thereby completing the present invention. That is, the present invention relates to an antibacterial resin composition comprising a compound represented by the following general formula [1] and a resin. 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,
Nickel, manganese, arsenic, antimony, bismuth, barium, cadmium or at least one metal ion selected from chromium, A is an alkali metal ion,
Alkaline earth metal ions, at least one ion selected from ammonium ions or hydrogen ions,
M ² is a tetravalent metal, n is a number satisfying 0 ≦ n ≦ 6, a and b are both positive numbers, and c and d are la +
When mb = 1, c = 2, d = 3, and when la + mb = 2,
c = 1 and d = 2. Where l is the valence of M ¹ ,
m is the valence of A. )

Hereinafter, the present invention will be described in detail. ○ Phosphate compound The compound used in the present invention is 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,
Nickel, manganese, arsenic, antimony, bismuth, barium, cadmium or at least one metal ion selected from chromium, A is an alkali metal ion,
Alkaline earth metal ions, at least one ion selected from ammonium ions or hydrogen ions,
M ² is a tetravalent metal, n is a number satisfying 0 ≦ n ≦ 6, a and b are both positive numbers, and c and d are la +
When mb = 1, c = 2, d = 3, and when la + mb = 2,
c = 1 and d = 2. Where l is the valence of M ¹ ,
m is the valence of A. )

The compound represented by the above general formula [1]
When a + mb = 1, each coefficient has c = 2 and d = 3.
An amorphous or crystalline compound belonging to the space group R3c, in which each constituent ion represents a compound that forms a three-dimensional network structure, and when la + mb = 2, has each coefficient of c = 1 and d = 2; Represents a compound whose constituent ions form a layered structure. The phosphate compound used in the present invention has a low discoloration when exposed to sunlight.
A crystalline compound having an amorphous or three-dimensional network structure, having + mb = 1, c = 2, and d = 3, is preferred.

M ¹ in the general formula [1] is a metal which is known as a metal having antifungal, antibacterial and antialgal properties. ,
It is particularly effective as a metal that can enhance antibacterial properties and antialgal properties.

A in the general formula (1) is at least one ion selected from the group consisting of an alkali metal ion, an alkaline earth metal ion, an ammonium ion and a hydrogen ion. Preferred examples thereof include lithium, sodium and potassium. And the like, alkaline earth metal ions such as magnesium or calcium, or hydrogen ions. Among these, lithium, sodium, ammonium ions and hydrogen ions are preferable from the viewpoint of the stability of the compound and availability at low cost. It is an ion.

M ² in the general formula [1] is a tetravalent metal, and preferable specific examples include zirconium, titanium and tin. In view of the safety of the compound, zirconium and titanium are particularly preferable. It is a valent metal.

The following are specific examples of the phosphate compound represented by the 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 In} each of the above formulas, Ag was converted to Z while maintaining the same charge as that of silver ions per mole of Zr ₂ (PO ₄ ) ₃ and the compound.
Compound substituted with n, Mn, Ni, Pb, Hg, 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 compound 1 charge amount of silver ions per mole and While maintaining the same charge amount, Ag in each of the above equations is changed to Z
Compounds substituted with n, Mn, Ni, Pb, Hg, Sn, or Cu.

The method for synthesizing the phosphate compound used in the present invention includes a calcination method, a wet method, a hydrothermal method and the like, and can be easily obtained, for example, as follows.・ Synthesis of network structure phosphate In the case of synthesizing by the firing method, compounds containing alkali metals such as lithium carbonate (Li ₂ CO ₃ ) or sodium carbonate (Na ₂ CO ₃ ), zirconium oxide (ZrO ₂ ), etc. Compound containing zirconium and ammonium dihydrogen phosphate (NH ₄ H
A compound containing a phosphate group such as ₂ PO ₄ ) is mixed at a molar ratio of about 1: 4: 6, and the mixture is calcined at 1100 to 1400 ° C. to obtain a compound of the general formula [2] A ′ _x Zr ₂ (PO ₄ ) ₃ [2] (A ′ is at least one kind of metal ion selected from an alkali metal ion, an alkaline earth metal ion and an ammonium ion, and x represents a case where A ′ is monovalent. And A is divalent when A is divalent). This is immersed in an aqueous solution containing silver ions at an appropriate concentration at room temperature to 100 ° C. to obtain the compound represented by the general formula [1]. In addition, the compound in which the A ion in the general formula [1] is a hydrogen ion can be obtained by converting the compound represented by the above general formula [2] from room temperature to 100
Nitrate at ° C., by immersion in an aqueous mineral acid such as sulfuric acid and hydrochloric acid, the general formula _{H (1-z) A '} z M 2 (PO 4) 3
(Z is a number less than 0 or less than 1) to obtain a compound [3], which is further immersed in an aqueous solution containing silver ions at an appropriate concentration to obtain a compound represented by the general formula [1]. obtain. In the case of synthesizing by a wet method, oxalic acid is added to an aqueous solution of zirconium oxynitrate and sodium nitrate while stirring, and further phosphoric acid is added. The pH of the reaction solution was adjusted to 3.5 with an aqueous sodium hydroxide solution, and the mixture was heated under reflux for 78 hours. The precipitate was filtered, washed with water, dried, and dried.
Crushed and mesh zirconium phosphate [NaZr ₂ (P
O ₄ ) ₃ ]. By immersing this in an aqueous solution containing an antibacterial metal at an appropriate concentration, the compound represented by the general formula [1] is obtained.

Synthesis of a phosphate having a layered structure An oxychloride containing a zirconium such as zirconium oxychloride, titanium oxychloride or tin oxychloride, or a tetravalent metal such as titanium or tin in a concentrated aqueous solution of phosphoric acid. After heating under reflux for 24 hours, the precipitate was filtered, washed with water, dried and pulverized, and zirconium phosphate (Zr (HPO
₄ ) Phosphate such as ₂ · H ₂ O] is obtained, added to an aqueous solution of nitrate such as an alkali metal, stirred, washed with water, dried and pulverized to obtain a general formula [4] A _2x Zr (PO ₄ ) ₂ · nH ₂ O [4] (A, x and n have the same meanings as described above). By immersing this in an aqueous solution containing an antibacterial metal at an appropriate concentration, the compound represented by the general formula [1] is obtained.

The value of a in the general formula [1] represents the concentration of the antibacterial metal ion in the aqueous solution in which the compound represented by the general formula [2], [3] or [4] is immersed, and the value of the aqueous solution. By adjusting the time or temperature at which the compound represented by the general formula [2], [3] or [4] is immersed, it can be appropriately adjusted according to the required properties and use conditions. .

In order to exhibit the fungicidal, antibacterial and antialgal properties, the value of a in the general formula [1] is preferably large,
When the value of a is 0.001 or more, it is possible to sufficiently exhibit fungicide, antibacterial properties and antialgal properties. However, if the value of a is less than 0.001, it may be difficult to exhibit the antifungal, antibacterial and algal properties for a long time, so the value of a is set to 0.01 or more. Is preferred.
Also, in consideration of economy, the value of a is suitably 0.5 or less.

The phosphates used in the present invention are stable to exposure to heat and light, at 500 ° C.,
Even after heating at from 1 ° C. to 1100 ° C., the structure and composition do not change at all, and no discoloration occurs even when irradiated with ultraviolet rays. In addition, the phosphate used in the present invention does not come into contact with water in a liquid state or change in skeletal structure even in an acidic solution. Therefore, at the time of processing and storage when obtaining various molded products, and even at the time of use, like conventional antibacterial agents,
There is no restriction such as heating temperature or light shielding conditions.

The resin used in the present invention is a natural resin,
Any of a semi-synthetic resin and a synthetic resin may be used, and any of a thermoplastic resin and a thermosetting resin may be used.
Specific resins may be any of plastic, fiber and rubber, for example, 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, ethylene tetrafluoride resin, unsaturated polyester resin, epoxy resin, urethane resin and phenol resin; nylon, polyethylene, rayon, acetate,
Fibers such as acrylic, polyvinyl alcohol, polypropylene, cupra, triacetate, and vinylidene; natural rubber and silicone rubber, SBR (styrene / butadiene rubber), CR (chloroprene rubber), EPM (ethylene / propylene rubber), FPM (fluoro rubber), NBR
(Nitrile rubber), CSM (chlorosulfonated polyethylene rubber), BR (butadiene rubber), IR (synthetic natural rubber), IIR (butyl rubber), synthetic rubber such as urethane rubber and acrylic rubber.

The antibacterial resin composition of the present invention is obtained by heating and pressurizing the phosphate compound represented by the general formula [1] and the resin at an appropriate temperature or pressure in accordance with the characteristics of the resin used. Alternatively, it can be easily prepared by a method of mixing, mixing or kneading under reduced pressure, and the specific operation thereof may be carried out by a conventional method, and it can be formed into various forms.

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

The antibacterial resin composition of the present invention obtained in this manner has an excellent antibacterial property even when in an acidic solution because the antibacterial agent as a component thereof has excellent chemical and physical stability. Since it does not elute ions and has no hygroscopicity, it is extremely excellent in processability. In addition, it does not deteriorate at the time of mixing the antimicrobial agent and the resin, and at the time of storage or use of the antimicrobial resin composition thereafter, and has a long-term antifungal, antimicrobial and anti-algal properties even under severe environments .

The antibacterial resin composition of the present invention can be used in various fields requiring antifungal, antialgal and antibacterial properties, and is particularly effective for use in an environment where a large amount of water is present. It is. Specific applications include, for example, food containers, cutting boards, refrigerators, medical instruments, various packaging materials, brushes and water-related products for plastic products; sheets for textile products;
Towels, towels, masks, socks and gloves, etc .; rubber products include various tubes, packings and belts.

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

EXAMPLES First, a phosphate (a compound corresponding to the above general formula [2] or [4]) as a raw material of an antibacterial agent was synthesized.

REFERENCE EXAMPLE 1 (Preparation of Network Phosphate) Lithium carbonate, zirconium oxide and ammonium dihydrogen phosphate were charged in a molar ratio of 1: 4: 6, mixed well, and then mixed at 1300 ° C. Baking with LiZr ₂ (PO ₄ )
A compound having a composition formula of ₃ was obtained. Further, LiZr ₂ (PO ₄ ) ₃ obtained in powder form is added to a concentrated aqueous solution of sodium nitrate or ammonium nitrate, and the mixture is stirred, washed with water, dried and pulverized to obtain NaZr ₂ (PO ₄ ) ₃ and NH ₄
Zr ₂ (PO ₄ ) ₃ was obtained. Also, LiT was used in the same manner as above except that titanium oxide was used in place of zirconium oxide.
A compound having a composition formula of i ₂ (PO ₄ ) ₃ was obtained.

Reference Example 2 (Preparation of Layered Phosphate) Zirconium oxychloride was added to a concentrated aqueous phosphate solution, and
After heating and refluxing for 4 hours, the precipitate was filtered, washed with water, dried and pulverized to obtain zirconium phosphate H ₂ Zr (PO ₄ ) ₂ .H ₂ O.

REFERENCE EXAMPLE 3 (Preparation of antibacterial agent) Powders of various phosphates prepared in the above reference examples 1 and 2 were added to aqueous nitrate solutions of antibacterial metals having various concentrations. Stirred for hours. Then, after filtering these slurries, they were sufficiently washed with pure water. Furthermore, by heating and drying at 110 ° C. overnight, the desired antibacterial agent was obtained.
In addition, about zeolite, what carried out ion exchange in the coexistence of silver and ammonia was also prepared.

[0028] Comparative Example 1 (Preparation of antimicrobial hydroxyapatite and antibacterial zeolite) hydroxyapatite _{[Ca 10 (PO 4) 6 (} OH) 2 ] or A type zeolite [Composition: 0.94Na ₂ O · Al ₂ O ₃ · 1.92S
iO ₂ .xH ₂ O ^* ] is added to silver nitrate alone or an aqueous solution of silver nitrate and ammonium nitrate, stirred at room temperature for 10 hours, washed sufficiently with water, and dried at 110 ° C. to obtain antibacterial hydroxyapatite and antibacterial zeolite. I got Table 1 shows the antibacterial agents prepared by the above method.

[0029]

[Table 1] Note) Samples Nos. 1 to 5 were obtained according to Reference Example 3, Samples 6 to 8 were obtained according to Comparative Reference Example 1, and Sample No. 9 was a raw material of Sample No. 1. Zirconium phosphate that is not immersed in an aqueous antibacterial metal nitric acid solution.

Example 1 (Preparation of Antibacterial Resin Composition) Each of the various antibacterial agents prepared in Reference Example 3 and Comparative Reference Example 1 was subjected to high-density polyethylene powder (trade name: HIZEX 1300JP) manufactured by Mitsui Petrochemical Industries, Ltd. 5wt%
After mixing, various antibacterial pellets were prepared using a Labo Plastmill. This pellet and HIZEX 1300J
Was added to dilute the antibacterial agent content to 1 wt%, and the product was diluted with M-50AII-DM manufactured by Meiki Seisakusho Co., Ltd.
Injection molding was performed at 0 ° C. to prepare an antibacterial plate of 11 cm × 11 cm × 2 mm. In addition, only HIZEX 1300J containing no antibacterial agent was injection-molded in the same manner to obtain a blank.

Example 2 (Antibacterial test) The antibacterial activity of each antibacterial plate prepared in Example 1 was evaluated by the following method. Escherichia coli was used as the test bacterium.
The bacterial solution was uniformly inoculated on the surface so that the number of bacteria per cm × 5 cm was 10 ⁴ to 10 ⁵ and stored at 37 ° C. 0 hours after the start of storage (the number of theoretically added bacteria) and after storage for 24 hours, the surviving bacteria on the test piece were washed out with a culture medium for measuring the number of bacteria (SCDLP liquid medium), and this washing solution was used as a test solution. The viable cell count of this test solution was measured by a pour plate culture method (37 ° C. for 2 days) using a culture medium for cell count, and converted to the viable cell count per 5 cm × 5 cm of the antibacterial plate. Table 2 shows the results of the antibacterial test obtained as described above. In addition, it does not contain an antibacterial agent,
The viable cell count per 5 cm × 5 cm of the plate obtained by injection-molding only the cells was 1.2 × 10 ⁵ and 6.7 × 10 ⁴ at 0 hours and 24 hours after the start of storage, respectively. The numbers were 1.2 × 10 ⁵ and 1.1 × 10 ⁵ at 0 and 24 hours after the start of storage, respectively.

[0032]

[Table 2]

Example 3 "Weather Resistance Test" The various antibacterial plates prepared in Example 1 were measured for weather resistance using a weather resistance tester UC-1 manufactured by Toyo Seiki Seisaku-sho, Ltd.
The test conditions for UC-1 were such that one cycle was 2 hours and 60
It consists of a one-hour process of irradiating ultraviolet rays at 350 ° C. or less at 350 ° C. and a one-hour process of leaving at 40 ° C. in an atmosphere of 95% or more humidity. Nippon Denshoku Industries Co., Ltd. color difference meter SZ-
Using # 80, the color (L, a, b) after 0, 5, and 20 cycles of the weather resistance test was measured, and the color and the color immediately after molding a blank plate containing no antibacterial agent were measured. Were compared to determine the color difference ΔE. Table 3 shows the color difference between the various antibacterial plates immediately after molding (0 cycle) and after 5 and 20 cycles of the weather resistance test. As a result of the weather resistance test of the blank plate, the color difference was 0, 0.8, and 1.9 after 0 cycles, 5 cycles, and 20 cycles, respectively.

[0034]

[Table 3]

Example 4 (Dissolution test) 50 g of various antibacterial pellets (containing 5 wt% of antibacterial agent) prepared in Example 1 were immersed in 100 cc of nitric acid aqueous solution at pH 2, 3 and 4 for 10 hours, and then separated by filtration. The antimicrobial components eluted therein were measured with an atomic absorption spectrophotometer. Table 4 shows the results of the dissolution test obtained as described above.

[0036]

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

Example 5 (Acid Resistance Test) An antimicrobial polyethylene plate containing 5% by weight of the antimicrobial agent prepared in Example 1 was immersed in an aqueous acetic acid solution of pH 3.5 for 6 hours, washed well with water, and evaluated for antimicrobial activity. . The antibacterial activity was evaluated in the same manner as in Example 2, and the results are shown in Table 5. The bacterial solution was 1.7 × 10 ⁵ and 1.0 × 10 ⁵ after 0 hours and 24 hours of the action time, respectively.

[0038]

[Table 5]

[0039]

According to the antibacterial resin composition of the present invention, a resin molded article molded therefrom is used in an environment where a large amount of water is present, or is in contact with water in a liquid state. Even in such a case, even when it comes into contact with an acidic liquid, the antibacterial component is not eluted from the resin molded product, and is extremely useful as a material that can maintain the antibacterial effect for a long time.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideki Kato 1 east of Tokushima Plant, Tokushima City, Tokushima Prefecture No. 1 Toagosei Chemical Industry Co., Ltd., Nagoya Research Institute (72) Inventor Hiroki Korai 2-1, Minamijomishima-cho, Tokushima City, Tokushima Pref. JP-A-4-273803 (JP, A) JP-A-3-83906 (JP, A) JP-A-3-83905 (JP, A) JP-A-63-166813 (JP, A) (58) Fields investigated (Int .Cl. ⁶ , DB name) C08K 3/32 A01N 59/26

Claims (1)

(57) [Claims] 1. An antibacterial resin composition comprising a compound represented by the following general formula [1] and a resin. 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,
Nickel, manganese, arsenic, antimony, bismuth, barium, cadmium or at least one metal ion selected from chromium, A is an alkali metal ion,
Alkaline earth metal ions, at least one ion selected from ammonium ions or hydrogen ions,
M ² is a tetravalent metal, n is a number satisfying 0 ≦ n ≦ 6, a and b are both positive numbers, and c and d are la +
When mb = 1, c = 2, d = 3, and when la + mb = 2,
c = 1 and d = 2. Where l is the valence of M ¹ ,
m is the valence of A. )