JP2000247805A - Inorganic composition having antibacterial and mildew resistant activity, and resin composition having the same activity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare the subject inorganic composition excellent in heat resistance and weather resistance, not causing discoloration and capable of sustainedly exhibiting antibacterial and mildew resistant activity by including a reaction product of a salt of silver, copper or zinc with an alkaline salt of tungstic acid as an active principle. SOLUTION: This inorganic composition contains at least one kind of tungstates of the formula [wherein, X is Ag, Cu or Zn; (n) is 2 when X is Ag and 1 when X is Cu or Zn] as an active principle. The tungstate of the formula is obtained by reacting a salt of silver, copper or zinc with an alkaline salt of tungstic acid (e.g. sodium tungstate, potassium tungstate or the like). This resin composition having antibacterial and mildew resistant activity is prepared by including 0.001-30 wt.% inorganic composition mentioned above and 99.99-70 wt.% resin (e.g. polyethylene resin, polypropylene one, polyvinyl chloride one or the like). The inorganic composition can impart heat resistance, weather resistance and highly antibacterial and mildew resistant activities to a resin product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic antibacterial and fungicidal composition for imparting antibacterial and antifungal properties to resin products such as polyethylene, polypropylene, ABS resin and vinyl chloride resin, and an antibacterial and antifungal composition containing the same. The present invention relates to a water-soluble resin composition, and has excellent heat resistance and weather resistance, and exhibits a continuous antibacterial and antifungal activity without causing discoloration.

[0002]

2. Description of the Related Art It has long been known that inorganic metal salts and organic metal salts such as silver, copper and zinc are excellent in antibacterial and bactericidal properties. Inorganic metal salts containing silver ions have attracted attention as inorganic antibacterial agents because of their high safety and remarkable antibacterial activity. Among such inorganic antibacterial agents, a silver compound containing a sparingly soluble salt, for example, a silicate as an active ingredient (Japanese Unexamined Patent Publication (Kokai) No. 2-2)
15704), a silver compound containing a borate as an active ingredient (JP-A-4-134006), an antibacterial agent obtained by adding silver ions to calcium phosphate (JP-A-5-148116), other aluminum phosphate-based and zirconium phosphate-based antibacterial agents Etc. are known. However, silver ions are susceptible to light, heat, coexisting substances, etc., and are difficult to use as they are as inorganic antibacterial agents. On the other hand, inorganic antibacterial agents have remarkable antibacterial properties against a wide range of microorganisms. It is an antibacterial agent that has excellent properties, has no problem with resistant bacteria, and has no problem with safety, so it can solve the above problems and be applicable to a wide range of applications It was desired. Therefore, in recent years, it has been studied to support and react silver ions with various inorganic compounds in order to overcome such shortcomings of silver ions, and new properties such as heat resistance and moderate silver elution have been provided along with overcoming the shortcomings. Therefore, it is used in various fields.

On the other hand, with respect to the antifungal performance, conventional inorganic antibacterial agents show almost no efficacy, and it was practically impossible to use them as antifungal agents. Therefore, in order to impart mold resistance to resin products such as polyethylene, polypropylene, ABS resin and vinyl chloride resin, it is necessary to use an organic fungicide such as an imidazole compound, isothiazoline compound or pyridine compound. I didn't get it. But,
These organic fungicides have the drawback that they have high toxicity and poor heat stability as compared with inorganic antibacterial agents. Further, in connection with poor heat stability, the use of these organic fungicides often causes discoloration to yellow, brown, or the like, and their use has been limited.

[0004]

The silver-based inorganic antibacterial agents, for example, the above-mentioned insoluble silver salts, which are excellent in antibacterial and bactericidal properties, have the disadvantage that they discolor when irradiated with ultraviolet rays or heated. When used in a paint or plastic, a white silver-based antibacterial agent causes foaming during kneading, deterioration, coloring, and discoloration of the resin in a heat and weather resistance test, making it difficult to use for a long period of time. However, while having antibacterial properties, it was industrially severely restricted.

[0005]

Means for Solving the Problems The present inventor has conducted intensive studies to solve such problems, and as a result, at least one kind of tungstate represented by the general formula (1) XnWO4 (1) is obtained. The present inventors have found that an inorganic antibacterial / mildew-proof composition containing, as an active ingredient, is excellent in antibacterial / mildew-proof and excellent in discoloration resistance of a resin, and completed the present invention.

That is, the present invention relates to a tungsten oxide represented by the general formula (1) (where X is Ag, Cu or Zn, n = 2 for Ag, and n = 1 for Cu and Zn) XnWO4 (1) An inorganic antibacterial and fungicidal composition comprising at least one kind of salt as an active ingredient, and a compound represented by the general formula (1) (where X is Ag, Cu or Z
n = 2 in the case of Ag and n = 1 in the case of Cu and Zn) 0.001 to 30% by weight of an inorganic antibacterial and antifungal composition represented by XnWO4 (1) and 99.99 to 70% by weight of a resin. An antibacterial and antifungal resin composition.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The inorganic antibacterial and antifungal composition of the present invention is prepared by reacting a salt of silver, copper or zinc with an alkali salt of tungstic acid. Silver nitrate as a silver salt,
Copper compounds such as silver acetate and silver sulfate can be used such as copper nitrate, copper acetate, copper sulfate and copper chloride, and zinc compounds such as zinc nitrate, zinc acetate, zinc sulfate and zinc chloride can be used. Further, as an alkali salt of tungstic acid, sodium tungstate, potassium tungstate, or the like can be used. The reaction may be carried out by adding an aqueous solution of an alkali salt of tungstic acid to an aqueous solution of a metal salt or vice versa. The particle size of the antibacterial and antifungal composition of the present invention can be adjusted by changing the concentration, the stirring speed, and the addition speed of the aqueous metal salt solution and the aqueous alkali salt solution of tungstic acid. After the reaction, water can be obtained by filtering off water from the reaction solution slurry and drying. Drying methods include heat drying or freeze drying.

[0008] The resin to which the antibacterial and antifungal composition of the present invention is added includes polyethylene resin, polypropylene resin,
Vinyl chloride resin, acrylic / butadiene / styrene (A
BS) resin, epoxy resin, unsaturated polyester resin,
Phenol resin, urea resin, melamine resin, polyurethane resin and the like can be mentioned. It can also be applied to rubbers and fibers. The amount of the inorganic antibacterial and antifungal composition of the present invention added to the resin may be set to 0.1 when used for antibacterial use.
001 to 1.0% by weight is preferable, and 0.01 to 30% by weight is preferable when used for fungicide use. When the addition amount is less than 0.001% by weight, a sufficient effect cannot be obtained, so that it is not preferable. When the addition amount exceeds 30% by weight, the effect is saturated, which is economically disadvantageous and is not preferable. The antibacterial and antifungal resin of the present invention may contain, as necessary, fillers, stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, metal deactivators, and the like, which are commonly used as other additives. It does not matter. In addition, the shape of the antibacterial and antifungal resin of the present invention is a film, a sheet, a molded product, a fiber,
Examples include paper and paint, but the production method and shape are not particularly limited.

[0009]

Next, the present invention will be described with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 Method for Preparing Silver Tungstate (Antimicrobial and Antifungal Composition of the Present Invention) 33 g of sodium tungstate dihydrate was dissolved in 500 g of ion-exchanged water, and 34 g of silver nitrate was stirred with this solution.
Was dissolved in 200 g of an ion exchange aqueous solution to obtain a silver tungstate particle suspension. The pH of this suspension was 7.8. Stirring was further continued for 2 hours, and after the suspension was aged, it was filtered and washed with ion-exchanged water. The obtained silver tungstate cake was dried with a freeze dryer to obtain a white powder.

Example 2 Method for Preparing Zinc Tungstate (Antimicrobial and Antifungal Composition of the Present Invention) 33 g of sodium tungstate was replaced with deionized water 200
g of zinc nitrate hexahydrate 30 with stirring.
g was dissolved in 200 g of an ion exchange aqueous solution to obtain a zinc tungstate particle suspension. PH of this suspension
Was 5.6. Stirring was further continued for 2 hours, and after the suspension was aged, it was filtered and washed with ion-exchanged water. The obtained zinc tungstate cake was dried with a freeze dryer to obtain a white powder.

Example 3 Method for Preparing Copper Tungstate (Antimicrobial and Antifungal Composition of the Present Invention) 33 g of sodium tungstate was replaced with deionized water 200
g of zinc nitrate trihydrate 24 with stirring.
g was dissolved in 200 g of an ion exchange aqueous solution to obtain a copper tungstate particle suspension. The pH of this suspension was 6.2. Stirring was further continued for 2 hours, and after the suspension was aged, it was filtered and washed with ion-exchanged water. The obtained zinc tungstate cake was dried with a freeze dryer to obtain a pale green-blue powder.

Comparative Example 1 Method for Preparing Silver Silicate Sodium Metasilicate Nonahydrate (Wako Pure Chemical Industries, Ltd.)
9.9 g was dissolved in 100 ml of ion-exchanged water, and a solution of 11.9 g of silver nitrate (Kanto Chemical Co., Ltd.) in 100 ml of ion-exchanged water was added dropwise to form a precipitate.
The mixture was stirred for 2 hours, aged, filtered, washed with ion-exchanged water, and dried with a freeze dryer.

Comparative Example 2 Preparation Method of Calcium Phosphate-Based Silver Antibacterial Agent 3 g of calcium hydroxide was suspended in 100 ml of ion-exchanged water, and an 8% aqueous solution of phosphoric acid was gradually added dropwise. When it reached 6, it was aged for 30 minutes. 0.3 ml each of silver nitrate and aluminum nitrate in 10 ml of ion exchange water
g, and a solution in which each was dissolved was adjusted.
After aging for a time, the precipitate was washed, filtered, and dried.

[Preparation of Sheet] Polypropylene resin (A
W-630V: 1500 parts by weight, an ultraviolet absorber (Smisorb 300: manufactured by Sumitomo Chemical Co., Ltd.)
1.5 parts by weight, 0.75 parts by weight of an antioxidant (Sumilyzer P-16: manufactured by Sumitomo Chemical Co., Ltd.) and 0.75 parts by weight of calcium stearate as a stabilizer were mixed, and a mixing roll (Yasuda Seiki Seisakusho Co., Ltd.) ), The roll was first mixed at a surface temperature of about 190 ° C. For 50 g of this mixture,
0.02% by weight of the antibacterial / fungicidal composition of Example 1, 0.2% by weight of the antibacterial / fungicidal compositions of Examples 2 and 3, and 0.02% by weight of the antibacterial agent of Comparative Example were added and mixed for 15 minutes. Kneaded.
Next, using an electrothermal press sheet molding machine (Kansai Roll Co., Ltd.), melting at a temperature of 230 ° C. for 3 minutes, pressing for 2 minutes, cooling
A resin sheet was molded in minutes. These sheets were subjected to a weather resistance test, an antibacterial force test and a mold resistance test.

Test Example 1 Weathering Test A weathering test (J) was conducted using a sunshine weatherometer.
IS A1415) was performed for 180 hours, and the sheet was observed for discoloration. Those that hardly discolored were represented by O, and those that discolored remarkably in brown were represented by X. As a result, as shown in Table 1, almost no discoloration was observed in the case of using the antibacterial and antifungal compositions of Examples 1 and 2 even at the time of molding and after the weather resistance test.

[0017]

[Table 1]

[Test Example 2] Antibacterial activity test Cultured test bacteria were sterilized with sterilized purified water to which 1/200 NB medium was added to 2.0 × 10 5 to 1.0 × 10 6 (cells / ml).
Adjust to The polypropylene sheet obtained above (5
(cm × 5 cm) was placed in a sterile petri dish, and 0.5 ml of the bacterial solution was inoculated on the sheet, covered with a coating film, sealed with a Petri dish, and stored at 35 ° C. SCDLP after 24 hours
The cells were washed out with 9.5 ml of the medium, and the number of viable cells was measured by an agar plate culture method. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were used as test bacteria. as a result,
As shown in Table 2, the antibacterial and antifungal compositions of Examples 1 and 2 exhibited higher antibacterial performance than the comparative examples.

[0019]

[Table 2]

[Test Example 3] Mold-proof test A sample sheet was cut into a size of 5 x 5 cm, and the test was performed according to JIS Z2911.
The mixture was placed on an inorganic salt agar medium, and 1 ml of a mold mixed spore suspension was sprinkled evenly. These samples were cultured at 28 ° C. for 28 days and observed every 7 days. Mold mixed spore suspension is As
pergillusniger. , Penicilli
um citrinum, Chaetomiugmlo
bosum, Cladosporium clados
poroides, Rhizopus stolon
5 strains of ifer were mixed. The antifungal effect was evaluated according to the following criteria. As a result, as shown in Table 3, those using the antibacterial and antifungal compositions of Examples 1 to 3 exhibited higher antifungal performance than the comparative examples.

-······················································· Mold does not grow on 1/4 or less of the sample piece. Mold growth on 1/2 ~ 3/4 on sample piece +++++ ... mold growth on 3/4 or more on sample piece

[0022]

[Table 3]

[0023]

As described above, the antibacterial and fungicidal compositions containing at least one of silver, copper and zinc tungstates of the present invention and the antibacterial and fungicidal resins containing these antibacterial and antifungal compositions are Has high weather resistance, high antibacterial and antifungal properties.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 101/16 C08L 101/00

Claims (2)

[Claims] (1) wherein X is Ag, Cu or Zn and n = 2 for Ag and n = 1 for Cu and Zn, at least the tungstate represented by XnWO4 (1) An inorganic antibacterial and antifungal composition containing one kind as an active ingredient. 2. An inorganic antibacterial and fungicide represented by the general formula (1) (where X is Ag, Cu or Zn, n = 2 for Ag and n = 1 for Cu and Zn) XnWO4 (1) An antibacterial and antifungal resin composition comprising 0.001 to 30% by weight of a composition and 99.99 to 70% by weight of a resin.