JPH0578602A - Antibacterial resin or antibacterial coating - Google Patents

Abstract

PURPOSE:To provide an antibacterial resin not causing the change of its color with time, and to provide an antibacterial coating exhibiting an action to prevent the adhesion of algae, etc., for a long period, even when used in sea water. CONSTITUTION:An inorganic oxo acid salt (e.g. magnesium metasilicate aluminate) holding antibacterial metal ions (e.g. Ag ions, Cu ions) added in an amount of 0.1-60wt.%, preferably 1-50wt.%, to a resin such as a thermoplastic resin or thermosetting resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial resin or an antibacterial paint having an action of preventing the growth of bacteria and mold and the adhesion of algae.

[0002]

2. Description of the Related Art Conventionally, an antibacterial resin composition containing a zeolite carrying metal ions having a bactericidal action has been known. However, the antibacterial resin composition has a problem that it gradually discolors with the passage of time, and it is possible to add a discoloration inhibitor to a product whose commercial value decreases due to discoloration. It was necessary (Japanese Patent Laid-Open No. 63-265958).

Further, conventionally, an antibacterial coating composition containing a zeolite carrying a metal ion having a bactericidal action is also known. However, when this antibacterial coating composition is used as a coating for preventing the adhesion of algae and shellfish in fishing nets and ships, the cation in seawater and the metal ion having a bactericidal action carried on zeolite are Due to the ion exchange reaction, the elution of metal ions having a bactericidal action is accelerated, and there is a problem that the anti-adhesion effect disappears in a short period of time.

[0004]

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide an antibacterial resin which does not cause discoloration over time without using a discoloration inhibitor. Also,
It is an object of the present invention to provide an antibacterial coating which has a long-lasting anti-adhesive action against algae even when used in seawater.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The antibacterial resin and antibacterial coating material of the present invention are characterized by the addition of an inorganic oxo acid salt retaining metal ions having antibacterial properties. As the inorganic oxo acid salt, magnesium aluminometasilicate is particularly preferable.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below, but in this section, the term antibacterial resin is used to include an antibacterial paint. The inorganic oxo acid salt, which is the base material of the additive of the antibacterial resin, is a salt in which the dissociable hydrogen atom of the oxo acid is replaced with a metal ion, which has ion exchange ability and is soluble in water. Must be insoluble. This is because when it is water-soluble, the base material is dissolved in water and seawater and the antibacterial activity does not last.

As such an inorganic oxo acid salt,
Examples include silicates, aluminates, phosphates, titanates, and the like. Examples of silicates include magnesium metasilicate aluminate, calcium metasilicate aluminate, calcium silicate,
As magnesium silicate, silicate carbonate, aluminate, magnesium aluminate, calcium aluminate, as phosphate, calcium phosphate, zirconium phosphate, and as titanate, compounds such as potassium titanate and calcium titanate are preferable. From the viewpoint of safety, magnesium aluminate silicate and apatite containing calcium phosphate as the main component are preferable.

Magnesium aluminate metasilicate can be obtained by reacting basic magnesium aluminate with sodium silicate, and has a chemical formula of Al ₂ O ₃ .xMgO.ySi.
O ₂ · zH ₂ O [where x is 1 or 2, y and z are 1
The above integer]. Apatite is also called apatite and is a general term for fluoroapatite, chlorapatite, hydroxyapatite, and the like.

The metal ion having an antibacterial property to be ion-exchanged is usually a metal ion used as an antibacterial agent or a bactericidal agent, for example, Ag, Cu, Zn, Sn, Hg, P.
Metal ions such as b and Cd can be used. In particular, metal ions of Ag, Cu, Zn, and Sn are desirable in terms of safety for the human body. These metal ions are ion-exchanged with the metal ions of the salt of the oxo acid by a conventional method.

For example, ion exchange of Ag, Cu, Zn, Sn or the like is carried out in a region where the pH value is lower than the pH value for forming hydroxide and the salt of oxo acid is not dissolved. That is,
PH 9 to 4 for Ag, pH 6 to 4 for Cu, Z
In the case of n, the pH is in the range of 9 to 4, and the temperature range of 60 ° C. or higher is desirable. The metal ion can be used in the form of chloride or sulfate, but it is preferable to use nitrate which hardly causes anions.

In the inorganic oxo acid salt, a part of the metal ion is ion-exchanged by the metal ion having antibacterial property, and the ratio of the antibacterial metal ion to be ion-exchanged is possessed by the oxo acid salt. Ion exchange capacity of 0.1 to
90 mol% is suitable. Further, the amount of ion-exchanged metal ions in the base material is preferably 0.01 to 40% by weight of the base material. If the ratio of metal ions is less than the above minimum value, the antibacterial property is not sufficiently exerted, while if it exceeds the maximum value, the metal ions become unstable and the antibacterial effect is stable and durable. Will lack.

After the ion exchange operation, washing and
Dry to obtain the antibacterial resin additive. In addition, since the antibacterial metal ion is not firmly fixed and is easily eluted only by drying, it is desirable to bake at a temperature of 300 ° C. or higher after drying.

The antibacterial resin of the present invention contains the above additives in an amount of 0.
It is desirable to contain 1 to 60% by weight, preferably 1 to 50% by weight, in various resins such as thermoplastic resins and thermosetting resins. As the thermoplastic synthetic resin, for example, fluororesin, acrylic resin, polyamide resin, vinyl chloride resin, polycarbonate resin, polyolefin resin, epoxy resin, polyacetal resin, polyester resin,
Polyetherimide resin, polyethersulfone resin,
Polyether ether ketone resin, polyphenylene sulfide resin, polysulfone resin, polyarylate resin,
Examples thereof include polyethylene naphthalate resin, polymethylpentene resin, ABS resin, vinyl acetate resin and polystyrene resin.

As the thermosetting resin, for example, melamine resin, phenol resin, urea resin, furan resin, alkyd resin, unsaturated polyester resin, diallyl phthalate resin, epoxy resin, silicon resin, polyurethane resin, polyimide resin, Examples thereof include polyparabanic acid resin.

Further, as the coating film forming element which is the main component of the coating material, in addition to the above resins, oil-based coating materials and fibrin derivative coating materials can be mentioned. The antibacterial resin of the present invention can be used in an appropriate solvent or can be blended with a pigment component, and the use and the blending can be carried out by a usual method.

The above-mentioned additives have a particle size of 30 μm or less, especially 5 μm, in order to enhance the dispersibility when blended with a resin.
It is preferably m or less. This additive contains few metal ions in the free state and is less susceptible to oxidation effects by heating and light, so that the resin in which it is mixed does not discolor. INDUSTRIAL APPLICABILITY The antibacterial resin of the present invention can be used for daily sundries, furniture building materials, home electric appliances, fibers, packaging materials, etc. in addition to paints.

[0017]

EXAMPLES The present invention will be described in more detail with reference to the following examples. Preparation of additives 3.2 g of silver nitrate (AgNO ₃ ) and copper nitrate (Cu (NO ₃ ) ₂
・ 3H ₂ O) 38.0 g is dissolved in 5 liters of pure water,
The pH was adjusted to 5.0. In this aqueous solution, magnesium aluminometasilicate (manufactured by Fuji Chemical Industry Co., Ltd., trade name: Neusilin; Al ₂ O ₃ .MgO.2SiO ₂ .7H ₂ O,
125 g (average particle size 1.0 μm, water content 20% by weight) was added, the pH was adjusted again to 5.0, and the mixture was stirred at 60 ° C. for 1 hour. Then, it was washed with hot water in an amount 5 times the weight of the slurry, dried (110 ° C., 4 hours) and calcined (600 ° C.,
After 2 hours, the additive (A) was obtained. This additive (A)
The composition of is shown in Table 1.

3.2 g of silver nitrate (AgNO ₃ ) and copper nitrate (C
38.0 g of u (NO ₃ ) ₂ .3H ₂ O) was dissolved in 5 liters of pure water to adjust the pH to 5.0. A to this aqueous solution
Type zeolite (average particle size 2.0 μm, water content 23% by weight) 130 g was added, and the pH was adjusted to 5.0 again,
The mixture was stirred at 60 ° C for 1 hour. After that, it was washed with 5 equivalents of warm water, dried (110 ° C., 4 hours) and baked (600 ° C.,
After 2 hours, the additive (B) was obtained. This additive (B)
The composition of is shown in Table 1.

[0019]

[Table 1] Additive Base metal ion (wt%) (Ag) (Cu) A Magnesium metasilicate aluminate 2.0 10.0 B A-type zeolite 2.0 10.0

Example 1 The above additives (A) and (B) were mixed with polyethylene so as to have a concentration of 1.0% by weight, melt-drawn and molded into a plate having a thickness of 1 mm. The respective antibacterial resin plates are designated as (AP) and (BP). Evaluation of Antibacterial Composition The above antibacterial resin was evaluated by the following method.

(1) Antibacterial activity against bacteria (Halo Test) A suspension of 10 ⁹ test cells / ml in physiological saline was placed in a petri dish containing an agar medium in an amount of 0.1 ml, and applied with a conradi stick. .. After that, the plate (AP) (BP) has a diameter of 8
Place a disc cut into a circle of mm on a petri dish and keep at 32 ℃
The cells were cultured for 24 hours and the inhibition zone was measured. As test bacteria,
Escherichia coli (Escherichia coli), Pseudomonas aeruginosa (Pseudomonas aeruginosa),
Staphylococcus aur
eus), and the agar medium for general bacteria was used as the bacterial medium.

(2) Mortality of fungus A molded product of the antibacterial resin composition of the plates (AP) and (BP) cut into 1 mm x 2 mm x 5 mm, and 1 g of the solution added to 9 ml of sterile physiological saline. , Test bacteria Aspergillus niger
(Aspergillus niger) was mixed with 1 ml of a suspension of 10 ⁸ cells / ml and contacted at 28 ° C. for 24 hours, and the viable cell count was measured according to the viable cell count method. The above test results are summarized in Table 2. In addition, in both the tests (1) and (2), the evaluation results of the magnesium aluminometasilicate and the A-type zeolite themselves were all negative.

[0023]

[Table 2]Halo Test (mm)Viable count Death rate  Antibacterial resin Sta.aure Esc.coliPse.aeru (Pieces / ml) (%) AP 0.5 0.5-1.0 0.5-1.0 1 x 10^Five 99.9 BP 0.0 0.5 0.0 5 x 10⁷ 50.0 Control (* 1) − − − 10⁸ -(* 1) Resin without additives

(3) Discoloration test Test pieces of antibacterial resin (AP, BP) were exposed to sunlight for 30 days.
After being left for a day, the degree of discoloration of the test piece was observed. Similarly, the degree of discoloration of the test piece when the test piece was irradiated with carbon arc light for 300 hours and then irradiated with a xenon lamp for 300 hours was examined. The degree of discoloration was observed with the naked eye, and those without discoloration were indicated by ◯, and those with discoloration were indicated by x. Table 3 shows the evaluation results of the test.

[0025]

[Table 3] Discoloration Test Antibacterial Resin Solar Carbon Arc Light Xenon Lamp AP ○ ○ ○ BP × × ×

Example 2 10 parts by weight of the additives (A) and (B) were added to 450 parts by weight of a polyester resin having a solid content concentration of 20% by weight to obtain an antibacterial coating material. The test nets AQ and BQ were prepared by coating the paint on a polyester net by the dip method.

Example 3 In Example 2, the mixing ratio of the additives (A) and (B) was 40 parts by weight, and the mixing ratio of the polyester resin was 300.
Test networks AR and BR were prepared in exactly the same manner except that the parts by weight were used.

Example 4 Addition of 10 parts by weight of the additives (A) and (B) at a solid concentration of 3
Antibacterial paints were obtained by mixing with 300 parts by weight of 0% by weight of acrylic resin, and test nets AS and BS were prepared in the same manner as in Example 2 using these antibacterial paints.

Example 5 10 parts by weight of additives (A) and (B) were added to give a solid concentration of 3
Antibacterial paints were obtained by mixing with 300 parts by weight of 0% by weight nylon resin, and these antibacterial paints were coated on a nylon net by the dip method to obtain test nets AT and BT.
Was prepared.

Reference Example 1 A test net Qp was prepared by coating a polyester net with a solid content of 20% by weight without adding any additives on a polyester net by the dip method.

Reference Example 2 A test net Tn was prepared by coating a nylon net with a solid content of 30% by weight without adding any additives on a nylon net by a dip method.

Example 6 Using the test nets of Examples 2 to 5 and Reference Examples 1 and 2, an algae control evaluation test was conducted. In the evaluation test, each test net was immersed in the sea of Ariake Sea, and the algae adhesion state was visually observed over time, and evaluated in the following three stages. ○ ・ ・ ・ Algae is not attached △ ・ ・ ・ Algae is attached a little × ・ ・ ・ Algae is attached a lot

[0033]

[Table 4] Algal adhesion state (change over time ) Test net 1 month 2 months 3 months 5 months Example 2 AQ ○ ○ ○ △ Example 2 BQ ○ △ × × Example 3 AR ○ ○ ○ ○ Example 3 BR ○ ○ △ × Example 4 AS ○ ○ ○ △ Example 4 BS ○ △ × × Example 5 AT ○ ○ ○ ○ Example 5 BT ○ × × × Reference Example 1 Qp △ × × × Reference Example 2 Tn △ × × ×

[0034]

INDUSTRIAL APPLICABILITY The antibacterial resin of the present invention does not cause discoloration over time without using a discoloration inhibitor. Moreover, since it is insoluble, it has no problems of environmental pollution and toxicity, and is highly safe for the human body. The antibacterial coating composition of the present invention has antiseptic, antifungal, algae, and shellfish-preventing effects, and particularly when used in seawater, the effect of preventing the adhesion of algae or the like lasts for a long time.

Claims (2)

[Claims] 1. An antibacterial resin or an antibacterial coating material, to which an inorganic oxoacid salt retaining metal ions having antibacterial properties is added. 2. The antibacterial resin or antibacterial paint according to claim 1, wherein the inorganic oxo acid salt is magnesium aluminometasilicate.