JP2000203876A - Antimicrobial glass and resin composition containing the glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a silver-containing antimicrobial glass hardly causing discoloration of a resin when the silver-containing glass is added to the resin. SOLUTION: This glass is a borosilicate-based silver-containing antimicrobial glass containing 0-4.9 wt.% alkali metal oxide, and preferably comprises 0-4.9 wt.% (Na2O+K2O+Li2O), 10-60 wt.% B2O3, 10-60 wt.% SiO2, 0-20 wt.% Al2O3, 0-20 wt.% (CaO+MgO+BaO), 0-30 wt.% ZnO, and 0.05-5.0 wt.% Ag2O.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass having a property of suppressing the growth of bacteria and reducing the number of bacteria (hereinafter referred to as antibacterial property), and a resin composition containing the glass.

[0002]

2. Description of the Related Art Since silver or silver ions have an excellent property of destroying bacteria in contact with them, a technique has been developed in which silver is held in glass and silver or silver ions are eluted when necessary.

For example, an inorganic antibacterial agent containing borosilicate glass containing silver can be used. The above-mentioned inorganic antibacterial agent is usually used in the form of flakes or powder in combination with a product, particularly a thermosetting resin or a thermoplastic resin. When water adheres to the surface of the antibacterial resin product, silver in the inorganic antibacterial agent gradually dissolves in the water, and silver or silver ions are present on the surface of the resin product. As a result, the surface of the resin product exhibits antibacterial properties against attached bacteria.

However, the above-mentioned antibacterial resin has a problem that discoloration due to silver occurs when heated in molding or used in hot water.

In order to prevent the discoloration of the appearance of the product due to the silver, an antibacterial agent which does not use silver, that is, has carried ammonia or amine by ion exchange has been developed (Japanese Patent Laid-Open No. 24860/1989).

Japanese Patent Application Laid-Open No. 8-231800 discloses a silver-free antibacterial glass in weight% in order to prevent discoloration of the antibacterial resin during and after molding with time. _{SiO 2 25~60, B 2 O 3} 18~60, Al 2 O 3 0~20, R 2 O 8~30, (R is Li, Na and K, the total of R ₂ O these oxides) R′O 0-20 (R ′ is Ca, Mg, Zn, and Ba;
Is the total of these oxides) Water-soluble glass powder having a composition of Ag ₂ O + CuO 0 or less than 0.05, and an antibacterial agent in which the glass powder is dispersed and contained in a resin at a ratio of 0.1 to 15% by weight. A hydrophilic resin composition is described.

[0007]

However, the above-mentioned antibacterial agent carrying ammonia or amine and the above-mentioned antibacterial glass not containing silver prevent discoloration of the antibacterial resin, but have the antibacterial property of the silver. It is not enough compared to the contained inorganic antibacterial agent.

The present invention has been made by paying attention to the problems existing in the prior art as described above. It is an object of the present invention to provide a resin composition having less discoloration in appearance when a glass exhibiting good antibacterial properties by containing silver ions is contained in the resin.

[0009]

SUMMARY OF THE INVENTION The present inventor has set the content of an alkali metal oxide such as sodium oxide, which has been conventionally added to facilitate melting of a borosilicate silver-containing antibacterial glass, from 0 to 0. It has been found that by reducing the amount to 4.9% by weight, discoloration of the antibacterial resin containing the antibacterial glass is prevented. That is, the present invention is a borosilicate silver-containing antibacterial glass containing 0 to 4.9% by weight of an alkali metal oxide.

The borosilicate silver-containing antibacterial glass of the present invention comprises:
And in _{weight%, Na 2 O + K 2} O + Li 2 O 0~4.9 B 2 O 3 10~60 SiO 2 10~60 Al 2 O 3 0~20 CaO + MgO + BaO 0~20 ZnO 0~30 Ag 2 O 0 0.05 to 5.0 is preferably contained.

In the present invention, the SiO ₂ component is an essential component constituting the skeleton of glass, and its content is preferably from 10 to 60% by weight, more preferably from 25 to 5% by weight.
5% by weight. If the amount is less than 10% by weight, the amount of silver ions, zinc ions and glass components eluted is too large, and the life (or durability) of the composition for antibacterial glass becomes extremely short. On the other hand, if it exceeds 60% by weight, the viscosity increases and it becomes difficult to melt the glass, and the amount of silver ions eluted is too small, and the antibacterial properties are not sufficient.

The boron oxide (B ₂ O ₃ ) component is an essential component, forms a glass skeleton, promotes the elution of glass, and provides boron ions that combine with silver ions to contribute to the stability of silver ions. Its content is 10-60% by weight
And more preferably 20 to 50% by weight. If the amount is less than 10% by weight, the elution amount of silver ions is too small, so that the antibacterial property is weak and metal silver tends to precipitate in the glass. If it exceeds 60% by weight, the amount of glass eluted is too large and the life is extremely shortened, and if it is contained more than this, silver ion stabilization is not so effective.

Although the aluminum oxide (Al ₂ O ₃ ) component is not an essential component, it suppresses the elution of glass,
It contributes to stabilization of silver ions by providing aluminum ions that bind to silver ions, and its content is 0 to 20% by weight, preferably 2 to 15% by weight. If the content exceeds 20% by weight, the amount of glass eluted is too small, so that the antibacterial property is weakened. In addition, the viscosity of the glass is increased, and it is difficult to melt the glass.

In general, alkali metals such as sodium, potassium and lithium have a low primary ionization enthalpy value and tend to ionize themselves. Since silver exists as silver ions in the silver-containing glass,
The glass is initially colorless. However, when this glass is kneaded into a thermoplastic resin or the like in the form of a powder, for example, it is exposed to a high temperature of 200 ° C. or more, and water existing in a trace amount in the thermoplastic resin is reduced by silver from the glass. It promotes the elution of ions and alkali metal ions, and the eluted silver ions are reduced to silver atoms, probably at the glass surface. This reduction of silver ions is promoted by the presence of alkali metal ions coexisting therewith. Then, the reduced silver atoms are further aggregated to form silver colloid, and this silver colloid absorbs visible light, thereby causing discoloration of the resin. On the other hand, when this glass is kneaded into a thermosetting resin, the heat treatment temperature during molding is low, so that discoloration during resin molding is unlikely to occur, but when used in hot water as a resin product, By the hot water taken into the resin product, silver ions are similarly reduced and aggregated to form silver colloid, and the resin is discolored. As in the present invention, in the silver-containing borosilicate antibacterial glass, if the alkali metal ions are not contained or have a small content, promotion of the reduction of silver ions by the above-mentioned alkali metal ions is hindered. As a result, discoloration of the resin is prevented.
Therefore, Na ₂ O, K ₂ O and Li ₂ O (hereinafter referred to as R ₂ O
In order to prevent the discoloration, the content of O is preferably zero or as small as possible. On the other hand, an alkali metal oxide is a component that promotes melting and elution of glass. Alkali metal _{oxides, Li 2 O, Na 2 O} , and the total content of K ₂ O is 0 to 4.9 wt%, preferably 0
４4.5% by weight. If it exceeds 4.9% by weight, discoloration due to silver is likely to occur during heating of the antibacterial resin containing it or during use in hot water.

Calcium oxide (CaO), magnesium oxide (MgO), and barium oxide (BaO) (hereinafter referred to as R'O) are not essential components, but R2O
MgO, Ca
The total content of O and BaO is preferably 0 to 20% by weight, and more preferably 5 to 15% by weight. When the content exceeds 20% by weight, the amount of glass eluted decreases, and the antibacterial property is weakened.

The zinc oxide (ZnO) component is not an essential component, but it is a component that becomes zinc ions exhibiting antibacterial property, particularly antibacterial property in glass, and its content is preferably 0 to 30% by weight. Preferably, more preferably 0 to 20% by weight
It is. When the content exceeds 30% by weight, the amount of glass eluted is reduced, and the antibacterial property is weakened.

The silver oxide (Ag ₂ O) component is an essential component that becomes antibacterial silver ions in glass, and its content is preferably 0.05 to 5.0% by weight, and more preferably 0.05 to 5.0% by weight. 0.1 to 2.0% by weight. If the content is less than 0.05% by weight, the elution amount of silver ions is too small and the antibacterial property is poor.
If the content exceeds 5.0% by weight, silver colloid or metallic silver having a low antibacterial property increases, and silver is expensive. Therefore, the upper limit is 5.0% by weight.

As other components, SO ₃ and Fe
_It may contain ₂ O ₃ or the like. SO ₃ has the effect of keeping the glass in an oxidized state until the temperature becomes high by raising the temperature during glass melting or re-melting, thereby preventing the precipitation of silver colloid or metallic silver.
The content is 1% by weight, more preferably 0 to 0.03% by weight. Fe ₂ O ₃ is contained in the glass as an impurity in the glass raw material. However, if the content is too large, silver colloid or metallic silver is likely to be precipitated.
The content is 0.2% by weight, more preferably 0 to 0.1% by weight. Components other than SO ₃ and Fe ₂ O ₃ may be contained as long as the glass is not colored or devitrified and the dissolution of the glass is not significantly reduced.

The antibacterial glass of the present invention is preferably used in the form of microscopic bodies. The fine particles have a shape of powder, flakes, fibers, or the like, and have an average particle diameter of 0.1 to 50 μm, more preferably 0.5 to 30 μm.
Powder having an average thickness of 0.3 to 20 μm and an average major axis of 1
Flakes with a mean diameter of 0.3 to
A 30 μm fiber or the like is preferably used. The antimicrobial glass microparticles are used by being dispersed and contained in resin, gypsum, cement and the like. In particular, the antibacterial glass microparticles are preferably 0.05 to 10% by weight, more preferably 0.1 to 5% by weight.
The antibacterial resin composition in which the weight percentage is dispersed and contained is most useful.

The resin may be any of a natural resin, a semi-synthetic resin, and a synthetic resin, and may be a thermoplastic resin, a thermosetting resin, an inorganic fiber reinforced thermoplastic resin, or an inorganic fiber reinforced thermosetting resin. Any of these may be used in the form of various molded articles, films, paints and the like.

Specific resins include polyethylene, polypropylene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), acrylonitrile-styrene copolymer resin (AS resin), polyvinylidene chloride, polyamide, polystyrene, Saturated polyester resin, polyacetal, polyvinyl alcohol,
Thermoplastic resins such as polycarbonate, acrylic resin, fluororesin, urethane resin, ethylene / vinyl acetate copolymer resin (EVA resin); unsaturated polyester resin, vinyl ester resin, silicone resin, modified silicone resin, phenol resin, urea resin, Thermosetting resins such as melamine resin and epoxy resin; natural rubber; synthetic rubber; and these resins reinforced with fiber reinforced material, for example, fiber reinforced polyethylene, fiber reinforced polypropylene, fiber reinforced vinyl chloride, fiber reinforced ABS resin, fiber reinforced AS resin, fiber reinforced nylon, fiber reinforced polyester, fiber reinforced polyvinylidene chloride, fiber reinforced polyamide, fiber reinforced polystyrene, fiber reinforced polyacetal,
Fiber reinforced polycarbonate, fiber reinforced acrylic resin, fiber reinforced fluororesin, fiber reinforced polyurethane, fiber reinforced phenol resin, fiber reinforced urea resin, fiber reinforced melamine resin, fiber reinforced unsaturated polyester resin, fiber reinforced vinyl ester resin, fiber reinforced epoxy resin And fiber-reinforced urethane resins.

Examples of the reinforcing fibers include inorganic fibers such as glass fibers, carbon fibers, and ceramic fibers and organic fibers such as polyamide fibers and aramid fibers.
Among them, glass fibers are preferably used. These fibers are usually blended in an amount of 1 to 50% by weight with respect to the resin. Some of these fibers can be replaced with the above-mentioned borosilicate silver-containing antibacterial glass fibers. In addition to the fibers, fillers such as calcium carbonate, aluminum hydroxide, and mica may be added to the resin composition.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. The performance of the glass powders produced in Examples and Comparative Examples of the present invention and the resin compositions containing the same are determined by the following measurement, determination methods and criteria.

(1) Judgment of antibacterial performance of resin composition (a) Type of bacterial strain used Escherichia coli: IFO3972 Staphylococcus aureus: IFO12732 (b) Judgment of antibacterial activity (C) Judgment Criteria The criteria for the antibacterial activity are shown in Table 1 below. Here, ND and logD in Table 1 are the results of "Test method 1 for antibacterial activity of antibacterial processed product (1996 supplementary version)", where ND: viable cell count after culture is zero, logD: viable cell count after culture The number is a value expressed in common logarithm. ND or l
Based on the ogD value, “○” (excellent antibacterial property), “Δ” (good antibacterial property), and “×” (poor antibacterial property) are determined.

(2) Judgment of discoloration performance (a) Judgment method For the resin molded article containing no antibacterial glass and the resin molded article containing glass produced in Examples or Comparative Examples,
The color difference (ΔE) before and after the color change test described later was measured with a colorimetric color difference meter (model Z-1001DP manufactured by Nippon Denshoku Industries Co., Ltd.), and the color change was calculated according to the following equation. ΔE1 = ΔE * −ΔEX Here, ΔE1: discoloration of the glass-containing resin molded product, ΔE
*: Color difference of glass-containing resin molded body, ΔEX: Color difference of glass-free resin molded body. (B) Criteria The criteria are shown in Table 1 for each type of thermosetting resin and PBT resin. Depending on the value of ΔE1, “○” (excellent discoloration),
“Δ” (good discoloration) and “X” (discoloration poor) are determined.

[0026]

[Table 1] ================================== Judgment ○ △ × −−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−− Antibacterial ND 0 <logD ≦ 2 2 <logD Discoloration 1 (thermosetting resin) △ E1 ≦ 10 10 <ΔE1 ≦ 15 15 <ΔE1 Discoloration property 2 (PBT resin) ΔE1 ≦ 55 5 <ΔE1 ≦ 10 10 <ΔE1 ==================== ==================

[Examples 1 to 6, Comparative Examples 1 to 4] Glass materials were melted in an electric furnace at 1400 to 1500 ° C. for 2 hours and then pulverized in a ball mill to contain borosilicate silver having an average particle size of 10 μm. An antibacterial glass powder was obtained. The composition of this glass is
Table 2 shows the results. In Comparative Example 4, no glass powder was used.

(Evaluation of thermosetting resin) This glass powder was prepared by using a commercially available bis-based vinyl ester resin (Showa Kogaku KK)
"Lipoxy R-802"): Aluminum hydroxide:
Glass powder was mixed so as to have a weight ratio of 100: 150: 1. To this mixture, cobalt naphthenate as a reaction accelerator and methyl ethyl ketone peroxide as a curing agent were added, and molded to a thickness of 3 mm.
After standing for 4 hours, the mixture was cured by heating at 90 ° C. for 3 hours to obtain a resin molded plate. The resin molded product obtained by this operation was cut into 5 cm squares, and the discoloration was evaluated by the change after immersion in a high-temperature water bath at 90 ° C. for 100 hours. The antibacterial properties were evaluated on a molded plate immediately after molding.

The results of the evaluation are shown in Table 3. In Examples 1 to 6 containing 0 to 4.9% by weight of alkali metal, discoloration was prevented while maintaining excellent antibacterial properties, as compared with Comparative Examples 1 to 3 containing 6 to 10% by weight of alkali metal. You can see that it is.

[Examples 7, 8 and Comparative Examples 5 to 7] Glass materials were melted in an electric furnace at 1400 to 1500 ° C. for 2 hours, and then pulverized in a ball mill to contain borosilicate silver having an average particle size of 10 μm. An antibacterial glass powder was obtained. The composition of this glass was as shown in Table 4. In Comparative Example 7, no glass powder was used.

(Evaluation with Thermoplastic Resin) One part by weight of the above glass powder was kneaded into 99 parts by weight of a commercially available polybutylene terephthalate resin (PBT resin) by extrusion at a cylinder temperature of 260 ° C.
A 60 mm × 60 mm × 3 mm resin molded plate was produced by injection molding at 0 ° C. The degree of discoloration after the molding was compared with that of the glass powder-free product. The antibacterial properties were also evaluated using this resin molded plate.

Table 5 shows the results of the evaluation. Even in the thermoplastic resin, Examples 7 and 8 containing 0 to 4.9% by weight of the alkali metal maintain excellent antibacterial properties as compared with Comparative Examples 5 and 6 containing 6 to 10% by weight of the alkali metal. Further, it can be seen that discoloration was prevented.

[0033]

[Table 2] =============================== Example No. Comparative Example No. Component −−−−−−−−− ------------------------------- 12-3 4 5 6 1 2 3 ---------------------------------------------------- −−−−− Na ₂ O 0 2.0 4.0 2.0 0 0 6.0 8.0 8.0 K ₂ O 0 0 0 0 2.0 0 0 0 0 Li ₂ O 0 0 0 0 0 2.0 0 0 2.0 B ₂ O ₃ 45.5 44.5 43.5 38.0 38.0 38.0 42.5 35.0 40.5 SiO ₂ 40.0 39.0 38.0 38.5 38.5 38.5 37.0 35.5 35.0 Al ₂ O ₃ 10.0 10.0 10.0 5.0 5.0 5.0 10.0 5.0 10.0 CaO 4.0 4.0 0 8.0 0 8.0 4.0 8.0 4.0 MgO 0 0 0 0 8.0 0 0 0 0 BaO 0 0 4.0 0 0 8.0 0 0 0 ZnO 0 0 0 8.0 8.0 0 0 8.0 0 Ag ₂ O 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 ==================== ===========

[0034]

[Table 3] ================================== Example Comparative Example -------------------- ------------------------------------ 12 3 4 5 6 6 1 2 3 4 ------------------------------------------------------------------------ −−−−−−−−−−− Phenyl polyester (parts by weight) 100 Same as on the left 〃 〃 〃 〃 〃 〃 〃 〃 (Al (OH) ₃ (parts by weight) 150 Same as on the left 〃 〃 〃 〃 〃 〃 〃 〃 Accelerator (by weight)同 左 〃 〃 〃 〃 〃 硬化 剤 硬化 硬化 硬化 硬化 剤 硬化 同 同 硬化 同 硬化 同 同 抗菌 抗菌 硬化 硬化 同 抗菌 同 抗菌 同 抗菌 抗菌 抗菌 抗菌 硬化 抗菌 抗菌 抗菌 抗菌 〃 〃 抗菌 〃 抗菌 〃 抗菌 抗菌−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Discoloration (△ E1) ○ ○ ○ ○ ○ ○ × × △ ○ Antibacterial Escherichia coli ○ ○ ○ ○ ○ ○ ○ ○ ○ × Yellow Staphylococcus aureus ○ ○ ○ ○ ○ ○ ○ ○ ○ × ===================================

[0035]

[Table 4]

[0036]

[Table 5]

[0037]

By incorporating the borosilicate silver-containing antibacterial glass of the present invention into a thermoplastic resin or a thermosetting resin, discoloration during molding of the resin and during use of the resin product is prevented, and excellent. An antibacterial resin having antibacterial properties is obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C03C 3/093 C03C 3/093 14/00 14/00 C08K 3/40 C08K 3/40 C08L 101/00 C08L 101/00 F term (reference) 4G062 AA09 AA15 BB05 DA04 DA05 DA06 DB01 DB02 DB03 DB04 DC04 DC05 DC06 DD01 DE01 DE02 DE03 DE04 DF01 EA01 EA02 EA03 EA10 EB01 EB02 EB03 EC01 EC02 EC03 ED01 ED02 ED03 EE03 EE03 EE04 EE03 EG04 FA01 FA10 FB01 FC01 FD01 FE01 FF01 FG01 FH01 FJ01 FK01 FL01 GA01 GB01 GC01 GD01 GE01 HH01 HH03 HH04 HH05 HH07 HH09 HH11 HH13 HH15 HH17 HH20 JJ01 JJ03 JJ05 JJ1 KK1 NN01 KK1 KK1 FD186

Claims (7)

[Claims] 1. An alkali metal oxide of 0 to 4.9% by weight
Antimicrobial glass containing borosilicate silver. 2. Na ₂ O + K ₂ O + Li ₂ O 0-4.9 B ₂ O ₃ 10-60 SiO ₂ 10-60 Al ₂ O ₃ 0-20 CaO + MgO + BaO 0-20 ZnO 0 antimicrobial glass according to claim 1 containing 30 Ag ₂ O 0.05~5.0. 3. The antibacterial glass according to claim 1, which is a minute body. 4. An antibacterial resin composition comprising a thermoplastic resin or a thermosetting resin containing the antibacterial glass according to claim 2. 5. The content of the antibacterial glass is 0.05
The antibacterial resin composition according to claim 4, wherein the amount is 10 to 10% by weight. 6. The antibacterial resin composition according to claim 4, wherein an inorganic fiber is contained as a reinforcing material. 7. The antibacterial resin composition according to claim 6, wherein the inorganic fibers are glass fibers.