JP3154365B2 - Antibacterial resin molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved antibacterial resin molding.

[0002]

2. Description of the Related Art In recent years, when synthetic resin products are frequently used, or when used in a field that requires attention to hygiene such as kitchen utensils, contamination of the surface of the synthetic resin by bacteria is a problem. It is becoming. In addition, there are problems such as fungi and mold growing on the surface of the caulking material used as a building material, resulting in hygiene or poor appearance. As a countermeasure, a method has been used in which an antibacterial agent such as a silver salt is mixed into a synthetic resin and the component is eluted on the surface of the synthetic resin to sterilize the resin surface.

[0003]

When a silver salt is used as an antibacterial agent and is dispersed in a base resin of a molded product, an appropriate amount of the silver salt is not disclosed. When the content of the silver salt is large, it is easily reduced to silver by light or the like, and does not function as an antibacterial agent. On the other hand, if the content of silver salt is small, the antibacterial effect cannot be obtained. Furthermore, the antibacterial effect varies depending on the solubility of the silver salt used. Therefore, the present invention
An object of the present invention is to clarify an effective amount of silver acting as an antibacterial agent in a surrounding liquid when a resin molded article is used, and to provide a resin molded article exhibiting an antibacterial action.

[0004]

Antibacterial resin molded body of the present invention, in order to solve the problem] is a resin molded body obtained by dispersing the silver salt, the concentration of the silver salt of the ambient liquid in contact with the molded body, the silver amount It contains silver salt in such an amount as to be 1 ppb or more and 2000 ppb or less in conversion.

Specifically, the antibacterial resin molded article has a matrix resin of an ABS resin, a silver salt of a thiosulfatosilver complex supported on silica gel, and converts the silver salt into a silver amount. 1 × 10 ⁻⁵ wt% or more and 1 × 10 ⁻³ wt%
% Or less in the base resin. Further , the base resin is an olefin resin, the silver salt is a silver thiosulfato complex salt supported on silica gel, and the silver salt is 1 × 10 ⁻⁴ wt% or more in terms of silver and 2 × 10 ⁻⁴ wt% or more. ^-3 wt% or less contained in base resin.

[0006]

In the past, when a silver salt was dissolved in a liquid such as water, it was considered that the higher the concentration, the greater the antibacterial effect. The present invention is based on the finding that the antibacterial effect is not exhibited not only when the concentration of the silver salt is lower than the limit but also when the concentration is high to some extent. That is, as described above, the concentration of the silver salt in the liquid is 1 pp.
The antibacterial effect is exhibited in the case of b or more and 2000 ppb or less. Note that an antibacterial effect can be obtained even at about 70 ppm or more. However, in order to obtain such a high concentration, the content of the silver salt in the base resin must be increased, which increases the amount reduced by light or the like, which is uneconomical.

Various silver salts are known, and they can be used in the present invention.
The silver thiosulfato complex described below exhibits an antibacterial effect without becoming clouded even when it comes in contact with tap water containing chloride ions, and is therefore convenient for use in resin moldings around kitchens.

[0008]

The preferred method for producing the antibacterial agent used in the present invention will be described below. First, since CH ₃ COOAg as a raw material has low solubility, 7.7 g / l close to the solubility is converted to 60 ° C.
Dissolve in pure water at the following temperatures. This dissolving step is performed at 60 ° C.
When heated to a temperature exceeding 60 ° C., CH ₃ COOAg is decomposed. Next, in the thiosulfato complex salt forming step, K ₂ SO ₃ : CH ₃ COOA
g = 2.7 g: K ₂ SO ₃ was first added at a ratio of 1 g, and after sufficient dissolution, K ₂ S ₂ O ₃ : CH ₃ COOAg = 6.6.
g: K ₂ S ₂ O ₃ is added and dissolved at a ratio of 1 g. The melting step at this time is preferably in a temperature range of 40 ° C. to room temperature.

Next, in the adsorption step, a water-containing amorphous silicon dioxide having an equilibrium water content of 10% or less, so-called silica gel having a desired particle size, preferably 1 to 100 μm, is used as a carrier, and a silver thiosulfato complex is used as a carrier. Adsorb and impregnate sufficiently to obtain a concentration. Here, Carplex CS-5 (average particle diameter: 2.3 μm) manufactured by Shionogi Pharmaceutical Co., Ltd. was used as the silica gel. This step involves 40
C. to room temperature are preferred. Next, in the drying step, the pressure is from normal pressure to 1 to prevent decomposition of the silver thiosulfato complex.
It is preferable that the temperature is 0 ^-2 Torr and the temperature is 40 to 120 ° C. Next, an outer shell coating layer is formed on the surface of the carrier supporting the silver thiosulfato complex by a sol-gel method. This coating layer has a role of adjusting the duration of the antibacterial and virus-suppressing pharmacological effects of the silver thiosulfato complex. That is, it is possible to control the persistence of the drug treatment effect by the area and thickness of the coating layer.

The alkoxysilane and alcohol used here preferably have an alkyl group having 1 to 4 carbon atoms. Here, the standard formulation of tetraethoxysilane (CH
₃ CH ₂ O) ₄ Si and ethyl alcohol are used. 1 g of the silica gel particles supporting the above silver thiosulfato complex were added to a mixture of 1 ml of each, and after mixing well, about 0.2 ml of pure water was added dropwise to hydrolyze the tetraethoxysilane. To form a coating layer of silicon dioxide. The reaction proceeds further by absorbing the moisture in the air. Heating at a temperature less than about 60 ° C. accelerates the reaction. Next, in the drying step, the pressure is set to 760 mmHg to 10 ^-2 T so that the silver thiosulfato complex is not decomposed.
The orr and the temperature are preferably from 120C to 40C. As described above, an antibacterial agent is obtained.

At the time of resin molding, a hydrocarbon such as calcium stearate or a derivative thereof is often added as a resin property improving agent. When these are added in a large amount as well as a growth source of the bacterium, they cover the surface of the silica gel supporting the above-mentioned silver complex salt and hinder the antibacterial effect. Therefore, when adding these resin property improvers, it is preferable to limit the addition ratio to 1 wt% or less of the base resin.

Example 1 An antibacterial agent containing 3% by weight of silver thiosulfato complex in terms of silver was prepared as described above. An aqueous dispersion containing this antibacterial agent in various ratios was prepared, Staphylococcus aureus was added thereto, and after culturing for 18 hours, the turbidity of the culture solution was measured instead of the number of viable bacteria to determine the antibacterial effect. Table 1 shows the relationship between the concentration of the antibacterial agent in terms of the amount of silver and the presence or absence of the antibacterial effect (presence; 印, no; ×). As is clear from Table 1, the concentration of silver salt in terms of silver amount is 1 ppb.
Although the antibacterial effect is obtained as described above, the antibacterial effect cannot be obtained at 2 ppm or more to about 60 ppm.

[0013]

[Table 1]

Example 2 The same antibacterial agent as in Example 1 was used as A
0.01 for BS resin and polypropylene resin respectively
The mixture was kneaded at 0 to 7.0 wt% and molded into a test plate having a thickness of 2 mm. An experiment was conducted on these test plates by a dropping method using staphylococci, and the antibacterial properties were evaluated in the same manner as in Example 1. Table 2 shows the results.
It can be seen that there is an optimum concentration of the antibacterial agent in the resin molding.

[0015]

[Table 2]

[0016]

According to the present invention, a resin molded product exhibiting good antibacterial performance can be obtained.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroaki Oka 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-6-73196 (JP, A) JP-A-2-292201 (JP, A) JP-A-3-84066 (JP, A) JP-A-5-17617 (JP, A) JP-A-5-201817 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 1/00-101/16 C08K 3/00-13/08 A01N 59/16

Claims (2)

(57) [Claims] 1. A consists supported silver thiosulfate complex ABS resin dispersed with the sheet Rikageru resin molded body der
I, in terms of silver amount 1 × 10 ^-5 wt% or more 1 × 10 ^-3
including antibacterial resin molded body wt% or less of the silver complex in the ABS resin. 2. A consists supported silver thiosulfate complex salt olefin resin dispersed in shea Rikageru resin molding
A ^{body, 2 × 1 × 10 -4 wt} % or more in terms of silver amount
Including antibacterial resin molded body in a 10 ^-3 wt% or less of the silver complex in the olefin resin.