JP3063042B2 - Antibacterial agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates not to a method in which a molded article made of various polymers is treated with a metal ion after molding,
The present invention relates to an antibacterial agent in which a metal is well mixed in a polymer by dissolving a metal in a monomer in advance and polymerizing the metal as it is.

[0002]

2. Description of the Related Art It is known that copper ions and silver ions exhibit excellent antibacterial properties. These metal ions are used in various fields as fungicides or disinfectants in the form of salts.
On the other hand, research is also being conducted to obtain antibacterial materials by bonding metal ions to polymers. For example, Japanese Patent Publication No. 60-4
No. 5643 is such. This is a proposal to form a polymer obtained by polymerizing a sulfonic acid group-containing alkyl acrylate and then treat it with an aqueous silver nitrate solution to bind silver ions. However, when used as a bactericide or disinfectant in the form of a salt, it can exist only in the form of a solution, and at present, its use is limited. or,
In Japanese Patent Publication No. 60-45643, etc., a molded product is molded and then treated with a metal solution to bind metal ions for the first time.
There is also a problem that the antibacterial property of the surface also causes a decrease in the effect due to falling off. Further, sulfonic acid groups generally have poor heat resistance, and it is difficult to contain many sulfonic acid groups in molding a resin, and as a result, it has been difficult to bond many metal ions. As a remedy, instead of treating the molded body with metal ions to give it antibacterial properties, if the resin before forming the molded body contains metal ions uniformly, then after molding, antibacterial properties can be obtained simply by molding. A molded product having the same is obtained. Therefore, there is a demand for a material in which a metal is dissolved in a monomer in advance and then polymerized as it is so that metal ions are uniformly mixed and dispersed in the polymer.

[0003]

The problem to be solved is that an antibacterial material is easily mixed with various polymers, is easy to mold, and is excellent in imparting antibacterial properties to the whole molded article only by mixing and molding. To develop antibacterial agents.

[0004]

The present invention is not a method of obtaining an antibacterial agent by treating a molded product of various polymers with a compound containing a metal ion after molding, but dissolving the metal ion in a monomer in advance. In addition, by polymerizing this as it is, the metal ions are mixed well and uniformly with the polymer, and by itself or by mixing this resin with other polymers, the antibacterial agent is easily mixed with various polymers. An object of the present invention is to provide an excellent antibacterial agent which is easy to mold and gives antibacterial properties to the whole molded article only by mixing and molding. The details of the present invention are described below.

[0005] The base of the antibacterial agent of the present invention is an acrylic resin. However, these metal compounds generally containing copper ions and silver ions exhibiting antibacterial properties are not easily mixed with the acrylic resin, and are unlikely to become a uniform material even when kneaded with a roll or the like for a long time under heating. . An antibacterial material or a molded article thereof is of low value as an antibacterial material unless any part is provided with antibacterial properties. Needless to say, uniformity is required. In the present invention, a specific acrylic monomer mixture to be described later is dissolved in an organic acid copper, or an organic acid silver, and copper ions or silver ions exhibiting antibacterial properties are uniformly mixed by radical copolymerization thereof. It has special features. The specific acrylic monomer used in the present invention is composed of an acrylate or methacrylate, acrylic acid or methacrylic acid, and a monomer copolymerizable therewith depending on the purpose. A resin obtained from a monomer mainly containing an acrylate or a methacrylate is known as a material having good moldability. However, a large amount of copper ions or silver ions cannot be dissolved in a monomer containing acrylate or methacrylate as a main component. Therefore, in the present invention, a specific amount of acrylic acid or methacrylic acid is used to dissolve a large amount of copper ions or silver ions, and copper and silver compounds which are easily dissolved in these mixed monomers are used as organic acid copper. Alternatively, an organic silver salt is used in the present invention.

[0006] The organic acid copper used in the present invention, or
Specific examples of the organic acid silver include the following compounds. Copper formate, copper acetate, copper butyrate, copper oxalate, copper citrate, copper acrylate, copper benzoate, copper cyclohexane butyrate, copper oleate, copper tartrate, copper naphthenate, copper stearate, copper toluene sulfonate, etc. Copper compounds of organic carboxylic acids and organic sulfonic acids, silver acetate, silver benzoate, silver citrate, silver cyclohexane butyrate,
Silver compounds of organic carboxylic acids such as silver decanoate and silver trifluoroacetate can be exemplified. In the present invention, in addition to these, hydrates of organic acid copper or organic acid silver can also be used. However, the invention is not limited to only these compounds. The amount of the organic acid copper or the silver organic acid used depends on the intended antimicrobial activity, but in the present invention, the amount of the organic acid copper or the organic silver silver used is 3 per 100 parts by weight of the total amount of the monomers. -50 parts by weight is used as a preferred range. If the amount is less than 3 parts by weight, remarkable antibacterial properties are not recognized. If the amount is more than 50 parts by weight, it may not be dissolved, and the polymerizability of the monomer may be undesirably reduced. In the present invention, 3 to 50 parts by weight per 100 parts by weight of the total amount of monomers is used as a preferable range.

Next, a specific acrylic monomer used in the present invention will be described. The acrylate or methacrylate used in the present invention is represented by the following chemical formula 1.
It is represented by (Structural formula 1). Here, X represents an H or CH ₃ group, and R represents an alkyl group of C ₈ or less. Here, the reason why the alkyl group having C ₈ or less is used is that if the alkyl group is larger than C ₈ , the heat resistance of the resin is reduced and the metal ion cannot be contained in a large amount.

[0008]

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Specific examples of the acrylate or methacrylate used in the present invention include methyl methacrylate (acrylate), ethyl methacrylate (acrylate), n-propyl methacrylate (acrylate), and iso-propyl methacrylate (acrylate). , N-butyl methacrylate (acrylate), is
o-butyl methacrylate (acrylate), t-butyl methacrylate (acrylate), n-hexyl methacrylate (acrylate), n-octyl methacrylate (acrylate), 2-ethylhexyl methacrylate (acrylate), and the like. However, it is not limited to these. However, the metal ions do not dissolve in these acrylates or methacrylates. Therefore, in the present invention, a specific amount of acrylic acid or methacrylic acid is used as an essential component in order to enhance the dissolving power. By adding and using acrylic acid or methacrylic acid, the organic acid copper or the organic acid silver can be easily dissolved in the acrylic acid ester or the methacrylic acid ester. The ratio of the acrylate or methacrylate to the acrylate or methacrylate varies depending on the type of the organic copper or silver used. And a relative ratio of 5 to 50 parts by weight of acrylic acid or methacrylic acid is used. 5 acrylic or methacrylic acid
If the amount is less than part by weight, the organic acid metal cannot be easily dissolved. If the amount exceeds 50 parts by weight, the solubility of the organic acid metal is improved, but copolymerization hardly occurs, and the moldability of the polymerized resin is extremely deteriorated.

In the present invention, in addition to these acrylic acid esters or methacrylic acid esters and acrylic acid or methacrylic acid, as long as the gist of the present invention is not impaired,
Depending on the purpose, a monomer copolymerizable with these monomers may be used.
Up to 0 parts by weight can be used as a component of the present invention. Specifically, the purpose is to improve copolymerizability, adjust the refractive index, increase compatibility with other resins, further improve heat resistance, improve moldability, and the like. Specific examples of monomers used for these purposes include vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, and vinyltoluene, and various acrylic monomers such as 2-hydroxyethyl methacrylate, phenyl methacrylate, and phenoxyethyl acrylate. It is. These are only examples, and the present invention is not limited thereto. Next, a specific amount of the organic acid copper or organic acid silver is added to an acrylic acid ester or methacrylic acid ester, acrylic acid or methacrylic acid and a monomer mixture copolymerizable therewith according to the purpose at room temperature or under heating. Dissolved in The antimicrobial resin of the present invention containing the metal ion can be obtained by adding an appropriate amount of a radical polymerization initiator to these monomer mixtures and heating the mixture. Here, the polymerization initiator may be a commonly used radical polymerization initiator, and is not particularly limited. The polymerization method can be any method. For example, a suspension polymerization method using a suspending agent,
In the present invention, an emulsion polymerization method using various emulsifiers, a solution polymerization method using an arbitrary solution, and a bulk polymerization method can also be performed in the present invention. A preferred polymerization method can be selected according to the purpose.

The metal ion-containing resin of the present invention thus obtained is washed and dried, and then formed into a desired shape. At this time, it is possible to form the resin containing the metal ion as it is and use it as an antibacterial agent, or to blend this resin with another resin to obtain an antibacterial agent. This is a feature of the invention. This is presumably because the resin of the metal ion-containing resin and the metal ion of the present invention are mixed very uniformly. For example, examples of other resins include polyethylene terephthalate resin, polyamide resin, various fluorine resins, and the like, but the present invention is not limited thereto. Thus, the present invention is not a method of obtaining an antimicrobial material by treating a molded article of various polymers with a metal ion after molding, but dissolving a metal ion in a monomer in advance and polymerizing the metal ion as it is to form a metal. The ions are mixed well with the polymer, and the antibacterial agent is easily mixed with various polymers by itself or by mixing this resin with other polymers. The present invention provides an excellent antibacterial agent which gives the following. Hereinafter, the present invention will be described with reference to examples.

[0012]

【Example】

Example (1) 65 parts by weight of methyl methacrylate, 25 parts by weight of acrylic acid, and 10 parts by weight of α-methylstyrene were mixed well, and 8 parts by weight of copper acetate (trihydrate) was dissolved at 50 ° C. to obtain a monomer solution. did. 0.15 parts by weight of benzoyl peroxide as a polymerization initiator was added to 100 parts by weight of the monomer solution, and the polymerization was started at 55 ° C. in a glass reactor after replacing with nitrogen. After about 8 hours, when the viscosity was about 400 cp, the reactor was cooled to stop the reaction, and 0.8 parts by weight of benzoyl peroxide was further added thereto. On the other hand, the above-mentioned monomer solution preliminarily polymerized was added to an aqueous solution for suspension polymerization in which 0.5 part by weight of polyvinyl alcohol was dissolved in 320 parts by weight of ion-exchanged water, and the mixture was replaced with nitrogen and strongly stirred at 60 ° C. for 16 hours. The polymerization reaction was carried out to obtain the suspended particles of the present invention. After washing and drying, the particles were press-molded at 200 ° C. to obtain a plate-like molded product having a thickness of 2 mm. The visible light transmittance of this plate-like molded product was determined to be 88%, indicating that the copper compound was relatively uniformly mixed.
The heat distortion temperature of this plate was measured in accordance with the ASTM standard (D648-56) and found to be 110 ° C. The same test was conducted using a commercially available acrylic resin.
showed that. It can be seen that the resins of the examples have sufficient heat resistance. Further, when the copper content of this plate was determined by fluorescent X-ray analysis, it was confirmed that the copper content was 2.4%. 10 parts by weight of this resin was replaced with a commercially available PMMA resin 9
It was blended with 0 parts by weight and press-molded to produce a transparent test piece having a thickness of about 1 mm. An antibacterial test was performed using this test piece. The test piece (100 mm disk) and
Using a normal PMMA 100 mm disk, bacteria (Escherichia coli. Staphyl) were used.
ococcus aureus and mold (Aspe)
rgillusniger). For bacteria, a culture solution cultured at 35 ° C. for 24 hours was added to an agar medium for measurement, and a disk was placed thereon,
After culturing at 35 ° C. for 24 hours and mold at 25 ° C. for 7 days, the spores were added to a 0.05% polysorbate aqueous solution for about 10 ^6.
To 10 ⁷ / ml become so liberated those added to the measurement agar pressurized glucose peptone medium Place the disk on it, after incubation for 5 days at 25 ° C., the presence or absence of inhibition zone formed around the disk As a result of observation, a band was formed around the disk according to the present invention.
No inhibition band was formed around the sample, and the excellent effect of the antibacterial material according to the present invention was confirmed.

Example (2) 50 parts by weight of methyl methacrylate, 20 parts by weight of isobutyl acrylate, 5 parts by weight of 2-ethylhexyl methacrylate, 10 parts by weight of methacrylic acid and α-methylstyrene 1
5 parts by weight, and 3 parts by weight of silver citrate are added to 5 parts by weight.
It was dissolved at 0 ° C. to obtain a uniform monomer solution. to this,
0.85 parts by weight of azobisisobutyronitrile was added as a polymerization initiator, and the mixture was heated at 40 ° C. under nitrogen in a glass container.
The mixture was heated at 50 ° C. for 18 hours, at 60 ° C. for 5 hours, and at 80 ° C. for 5 hours to perform bulk polymerization. The obtained polymer was pulverized, and this was hot-pressed to obtain a plate-like molded product having a thickness of 2 mm.
The visible light transmittance of this plate-like molded product was determined to be 85%.
And it was confirmed that the silver compounds were relatively uniformly mixed. In addition, this plate is compliant with the ASTM standard (D648-5
6) When the heat distortion temperature was measured, it was 110 ° C. It can be seen that the resin of Example (2) has sufficient heat resistance. Further, when the silver content of this plate was determined by fluorescent X-ray analysis, it was confirmed that the plate contained 0.6%. Using this test piece, an antibacterial test was performed in the same manner as in Example (1). It was confirmed that there was an effect superior to or better than that of Example (1).

[0014]

As described above, according to the present invention, an excellent antibacterial agent which is easily mixed with various polymers, is easy to mold, and imparts antibacterial properties to the whole molded article by simply mixing and molding. There are effects that can be developed.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A01N 55/02 A01N 59/16 A01N 59/20 A01N 25/10

Claims (1)

(57) [Claims] 1. A monomer solution containing at least 70 parts by weight of a mixed monomer comprising 50 to 95 parts by weight of an acrylate or methacrylate and 5 to 50 parts by weight of acrylic acid or methacrylic acid is copolymerized with 100 parts by weight of a monomer solution. Organic acid copper or organic acid silver per part 3-5
0 parts by weight are dissolved in a monomer solution, and this is polymerized as it is. An antibacterial agent in which metal ions are uniformly mixed.