Antibacterial resin composition and antibacterial resin molded article, and container for liquid for external use

Abstract

To provide an antibacterial plastic which is usable in a container capable of preventing propagation of microorganisms in liquid containing metal ions.SOLUTION: An antibacterial resin composition contains a metal ion sealing agent, and a resin material, wherein the metal ion sealing agent has one kind of ligand selected from the group consisting of O2-, OH-, H2O, CO32-, NO3-, NH3, RNH2, RCOO-, RO-, ROH, N2H4, PO43-, ROPO32-, (RO)2 PO2-, Cl-, R2O, NO2-, imidazole, pyridine, N2, SO32-, Br-, N3-, S2-, R2S, R3 P, RS-, CN-, RSH, RNC, SCN-, CO, NO, (RS)2 PO2-, H-, R-, (RO)2 P(O)S- and I-, as a ligand bonded to metal ions in the molecule.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an antibacterial resin composition containing a metal ion sequestering agent, an antibacterial resin molded article, and a container for external use liquid agent.

Background Art

[0002] On the surface of the human body, skin resident bacteria exist at 1.0×10 3 cells / cm 2 ~6.0×10 6 cells / cm 2 and there are about 1.0×10 13 cells of skin resident bacteria throughout the body. The presence of skin resident bacteria in the epidermis, particularly in the stratum corneum, which is the outermost layer of the skin, prevents the invasion of pathogenic bacteria and allergens into the skin and further prevents the evaporation of moisture from the skin. Such a function of skin resident bacteria is called the skin barrier function.

[0003] When the skin comes into contact with bactericidal components such as methylparaben, propylparaben, and benzalkonium chloride contained in handwashing bactericides, the number of skin resident bacteria decreases, and the skin barrier function by autologous skin resident bacteria decreases. A decrease in the skin barrier function is said to cause an increase in the incidence of atopic dermatitis. Such bactericidal components are formulated (in a free state) as preservatives not only in handwashing bactericides but also in external use liquid agents such as cosmetics, shampoos, body soaps, and detergents. Since the antibacterial boom after 1990, the number of external use liquid agents containing bactericidal components as preservatives has increased, and accordingly, the number of patients with allergic diseases such as atopic dermatitis, asthma, and allergic rhinitis has been increasing.

[0004] Therefore, instead of formulating a bactericidal component in the external use liquid agent, an attempt has been made to prevent the growth of microorganisms in the external use liquid agent by using an antibacterial plastic made of an antibacterial resin for part or all of the container for the external use liquid agent (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] International Publication No. WO2015 / 083466 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] Conventional antibacterial plastics exhibit an antibacterial effect on those in contact with the plastics. Therefore, in order to suppress the growth of microorganisms in an external preparation placed in a container made of conventional antibacterial plastic, it is sometimes necessary to stir the external preparation so that the external preparation comes into uniform contact with the container, which is inconvenient in actual use.

[0007] The problem to be solved by the present invention is to provide an antibacterial plastic that can be used for a container capable of preventing the growth of microorganisms in a liquid containing metal ions. [Means for Solving the Problems]

[0008] The present inventor prepared plastics blended with hundreds of antibacterial components and repeatedly conducted experiments to confirm each antibacterial effect. Then, the inventor considered that it might be possible to suppress the growth of the microorganisms by changing the growth environment of the microorganisms rather than the microorganisms themselves. In particular, since the external preparation contains metal ions necessary for the growth of microorganisms, the inventor considered that it might be possible to suppress the growth of microorganisms by avoiding the contact between metal ions and microorganisms, and as a result of searching for a method therefor, came up with the idea of using a metal ion sequestering agent.

[0009] Therefore, the present inventor prepared a plastic blended with a metal ion sequestering agent, placed a medium containing microorganisms thereon, and performed static culture. Surprisingly, the microorganisms in the medium hardly grew at all. The present invention has been made based on the above findings, and can provide a novel antibacterial plastic that exhibits an antibacterial effect by avoiding the contact between microorganisms and metal ions.

[0010] That is, according to the present invention, there are provided a resin composition, a molded article, and a container for external liquid agent in the following embodiments. [1] An antibacterial resin composition containing a metal ion sequestering agent and a resin material. [2] The metal ion sequestering agent has, as a ligand that binds to a metal ion in the molecule, O2 - , OH - , H2O, CO3 2- , NO3 - , NH3, RNH2, RCOO - , RO - , ROH, N2H4, PO4 3- , ROPO3 2- , (RO)2PO2 - , Cl - , R2O, NO2 - , imidazole, pyridine, N2, SO3 2- , Br - , N3 - , S 2- , R2S, R3P, RS - , CN - , RSH, RNC, SCN - , CO, NO, (RS)2PO2 - , H - , R - , (RO)2P(O)S - and I - The antibacterial resin composition according to [1], having one ligand selected from the group consisting of. [3] The metal ion sequestering agent is one or more metal ion sequestering agents selected from the group consisting of benzoylacetone, acetylacetone, ethylenediaminetetraacetic acid, trimetaphosphoric acid, iminodiacetic acid, nitropentaamminecobalt, gluconic acid, aminoethanol, ethylenediamine, zirconium carbonate, glycolic acid, bipyridine, imidazole, thiocyanic acid, diethylenetriaminepentaacetic acid, and acetylpenicillamine. The antibacterial resin composition according to [1]. [4] The resin material contains an ultraviolet curable resin component and a photopolymerization initiator. The antibacterial resin composition according to any one of [1] to [3]. [5] The antibacterial resin composition according to any one of [1] to [4], wherein 6 to 8 parts by mass of the sequestering agent is contained per 100 parts by mass of the antibacterial resin composition. [6] The antibacterial resin composition according to any one of [1] to [5], wherein the sequestering agent is dispersed in the resin material.

[0011] [7] An antibacterial resin molded article comprising the antibacterial resin composition according to any one of [1] to [6].

[0012] [8] A container for an external preparation liquid, comprising a container body having an opening and a lid portion detachably attached to the container body so as to close the opening, The container for an external preparation liquid, wherein at least the inner surface portion of the container body is formed of the antibacterial resin molded article according to [7].

Advantages of the Invention

[0013] According to the present invention, it is possible to provide an antibacterial resin molded article capable of preventing the growth of microorganisms in a liquid containing metal ions. Therefore, at least the inner surface portion of a container for an external preparation liquid for containing an external preparation liquid containing metal ions such as cosmetics, shampoos, body soaps, and detergents is formed of the antibacterial resin molded article, so that the growth of microorganisms in the external preparation liquid can be suppressed even if the external preparation liquid does not contain an antibacterial component.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described in detail. It should be noted that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Furthermore, the assumptions and theories made in this specification are based on the inventor's knowledge and experience so far, and thus the present invention is not limited only by such assumptions and theories.

[0016] <Antibacterial resin composition> The antibacterial resin composition according to the present invention contains a metal ion sequestering agent and a resin material.

[0017] "Composition" is used in its commonly used meaning and means a substance formed by combining two or more components. Also, "comprising" means that elements other than the elements explicitly stated as being included can be added (synonymous with "at least comprising"), and includes "consisting of" and "essentially consisting of".

[0018] The metal ion sequestering agent is a compound that captures the metal ion in the molecule by forming a coordination bond with the metal ion through the ligand in the molecule, and is also called a chelating agent. The metal ion captured in the molecule of the metal ion sequestering agent is inactivated. The metal ions chelated by the metal ion sequestering agent contained in the antibacterial resin composition according to the present invention are not particularly limited as long as they are metal ions necessary for the growth or maintenance of microorganisms. Examples include metal ions such as sodium, magnesium, potassium, calcium, iron, aluminum, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, and molybdenum. In other words, the metal ion sequestering agent contained in the antibacterial resin composition according to the present invention is a compound having a ligand that forms a coordination bond with these metal ions.

[0019] Since metal ions are cations, the ligands of the metal ion sequestering agent act as bases. The ligands of the metal ion sequestering agent may be any of hard bases, intermediate bases, and soft bases, and can be appropriately set according to the properties of the metal ions to be captured (chelated) by the binding of the ligands contained in the metal ion sequestering agent. For example, when chelating heavy metal ions such as iron, chromium, nickel, zinc, and molybdenum, the base contained in the metal ion sequestering agent is preferably a hard base.

[0020] Here, a hard base refers to a base having properties such as a small atomic radius, being difficult to polarize, and a high electronegativity. A soft base refers to a base having properties such as a large atomic radius, being easy to polarize, and a low electronegativity. An intermediate base is a base having properties intermediate between those of a hard base and a soft base. Generally, a hard base easily reacts with a soft acid (metal ion) to form a strong bond. A soft base easily reacts with a hard acid to form a strong bond. Also, a hard base tends to bind to a metal ion by an ionic bond, and a soft base tends to bind to a metal ion by a covalent bond.

[0021] Examples of hard bases include, for example, O2 - , OH - , H2O, CO3 2- , NO3 - , NH3, RNH2, RCOO - , RO - , ROH, N2H4, PO4 3- , ROPO3 2- , (RO)2PO2 - , Cl - and the like. Examples of soft bases include R2S, R3P, RS - , CN - , RSH, RNC, SCN - , CO, NO, (RS)2PO2 - , H - , R - , (RO)2P(O)S - , I - and the like. Examples of intermediate bases include R2O, NO2 -, imidazole, pyridine, N2, SO3 2- , Br - , N3 - , S 2- and the like.

[0022] Specific examples of the sequestering agent for metal ions contained in the antibacterial resin composition according to the present invention include, for example, benzoylacetone, acetylacetone, ethylenediaminetetraacetic acid, tripolyphosphoric acid, iminodiacetic acid, nitropentaamminecobalt, gluconic acid, aminoethanol, ethylenediamine, zirconium carbonate, compounds having a hard base such as glycolic acid, compounds having an intermediate base such as bipyridine and imidazole, and compounds having a soft base such as thiocyanic acid and acetylpenicillamine, but are not limited thereto.

[0023] The antibacterial resin composition according to the present invention may contain one type of sequestering agent for metal ions, or may contain two or more types of sequestering agents for metal ions.

[0024] The content of the sequestering agent for metal ions contained in the antibacterial resin composition according to the present invention is not particularly limited as long as it is effective in exerting the function as a sequestering agent for metal ions (that is, the function of the ligand binding to the metal ion) when a molded article is produced from the antibacterial resin composition. For example, when the antibacterial resin composition is 100 parts by mass, the content of the sequestering agent for metal ions is preferably 0.1 part by mass to 20 parts by mass, more preferably 1 part by mass to 10 parts by mass, and even more preferably 4 parts by mass to 8 parts by mass.

[0025] Here, the "content" is synonymous with the concentration and the amount used (the added amount), and means the ratio of the amount of the component to the total amount of the antibacterial resin composition.

[0026] The resin material contained in the antibacterial resin composition according to the present invention can be appropriately selected according to the use, place of use, etc. of the antibacterial resin molded article formed using the antibacterial resin composition. For example, when the antibacterial resin molded article is used for a container that houses external liquid agents such as cosmetics, shampoos, and body soaps, the resin material may include polyethylene, polypropylene, polymethylpentene, polybutene-1, ethylene·tetracyclododecene copolymer, polyacetal, acrylonitrile·styrene resin, acrylonitrile·butadiene·styrene resin, polyphenylene ether, fluororesin, polyhydroxybenzoic acid polyester, polyetherimide, methacrylic resin, polyethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene naphthalate, polyarylate, polyacrylonitrile, polyallyl sulfone, polystyrene, polyamide, polycarbonate, polyvinyl alcohol, polymethacrylic styrene, butadiene resin, polybutylene terephthalate, polyester carbonate, polylactic acid, polybutylene succinate, ethylene·2-norbornene resin, 3-hydroxybutyric acid·3-hydroxyhexanoic acid copolymer, dimethyl 2,6-naphthalenedicarboxylate·ethylene glycol·1,4-cyclohexanedimethanol·spiroglycol copolymer, etc. (resin powders, resin pellets, etc.) or raw material components of the resin (monomers, oligomers, etc.).

[0027] Here, terms such as shampoos and body soaps are used in the meaning usually used by those skilled in the technical fields such as the toiletry field, cosmetics field, and chemical field, unless otherwise specified, and should not be construed as having an unduly limited meaning.

[0028] When the resin material contains raw material components of the resin (monomers, oligomers, etc.), the resin material may preferably contain a polymerization initiator according to the type of polymerization reaction of the raw material components. Specifically, when the raw material component is an ultraviolet curable resin component, it may preferably contain a photoinitiator. In addition, the resin material may contain a crosslinking agent or an additional monomer component to make the strength and properties of the resin preferable.

[0029] In addition, in the antibacterial resin composition, it is preferable that the metal ion sequestering agent is dispersed in the resin material. When the metal ion sequestering agent is dispersed in the resin material, when the antibacterial resin molded article is formed by the polymerization reaction of the resin material, the metal ion sequestering agent is dispersed in the entire antibacterial resin molded article, and the chelating action of the metal ion sequestering agent becomes effective. Here, "dispersion" includes a state in which the metal ion sequestering agent is uniformly dispersed in the resin material (when the metal ion sequestering agent is in particulate or powder form and the resin material is in particulate, powder or liquid form), and a state in which the metal ion sequestering agent is uniformly dissolved in the resin material (when both the metal ion sequestering agent and the resin material are in liquid form).

[0030] <Antibacterial resin molded article> The antibacterial resin molded article according to the present invention is manufactured using the above-described antibacterial resin composition.

[0031] The manufacturing method of the antibacterial resin molded article is not particularly limited, but basically, an antibacterial resin molded article is manufactured by molding a polymer (resin) obtained by the polymerization reaction of the resin material (resin raw material component) contained in the antibacterial resin composition.

[0032] For example, a metal ion sequestering agent is added to the resin material and stirred, shaken, etc. to obtain a mixture in which the metal ion sequestering agent is uniformly dissolved or uniformly dispersed in the resin material. This mixture corresponds to the antibacterial resin composition according to the present invention. Note that a blend obtained by simply blending a metal ion sequestering agent with a resin material (that is, a state in which the metal ion sequestering agent is not uniformly dissolved / dispersed in the resin material) may also be included in the antibacterial resin composition according to the present invention.

[0033] Next, by subjecting the resin raw material component contained in the obtained mixture to a polymerization reaction, an antibacterial resin as a polymer is obtained, and by molding the antibacterial resin, an antibacterial resin molded article is obtained. The polymerization reaction is appropriately set according to the types of the resin raw material component and the polymerization initiator, etc. For example, when the resin raw material component is an ultraviolet curable resin component or a thermosetting resin component, a polymer is formed by a polymerization reaction by external stimuli such as light such as ultraviolet rays and heat. Further, examples of the method for obtaining an antibacterial resin molded article from the antibacterial resin include injection molding, blow molding, extrusion molding, vacuum molding, and the like.

[0034] For example, FIG. 1 shows a container for external liquid agent according to the present invention (hereinafter referred to as container 1), FIG. 1(a) is a side view, and (b) is a cross-sectional view. This container 1 includes a bottle 10 having an opening 101 at the upper end (corresponding to the container body of the present invention), and a cap 11 attached to the upper end of the bottle 10 to close the opening 101 (corresponding to the lid of the present invention). A screw thread 102 is formed on the outer peripheral surface of the neck portion 101 at the upper part of the bottle 10, and a screw groove (not shown) is formed on the inner peripheral surface of the cap 11. By screwing the screw groove of the cap 11 onto the screw thread 102 of the bottle 10, the cap 11 is detachably attached to the bottle 10.

[0035] The bottle 10 is a container having a thickness of about 1.0 mm to 3.0 mm, and a thin layer portion (inner surface portion) having a thickness of 0.5 mm to 1.5 mm on the inner surface side in contact with the external liquid agent as a whole is made of an antibacterial resin molded article formed using the antibacterial resin composition according to the present invention. That is, the antibacterial resin molded article according to the present invention includes molded articles having various shapes such as a container shape, a sheet shape, and a film shape. Since at least the inner surface portion of the bottle 10 is formed of an antibacterial resin molded article, the growth of microorganisms in the external liquid agent stored in the bottle 10 is suppressed.

[0036] Since such a bottle 10 is mainly composed of a conventional resin material, it is easy to mold and is useful, for example, as a container for containing external-use liquid agents such as cosmetics, shampoos, conditioners, body soaps, etc. The container for external-use liquid agents according to the present invention can be applied to containers of various shapes other than the bottle 10. For example, when the external-use liquid agent is a skin cream, toothpaste, oral rinse, eye drops, etc., it is preferable to use a container having a shape suitable for each storage. It should be noted that the external-use liquid agents include those in the form of cream (semi-liquid).

[0037] The degree of antibacterial property of the antibacterial resin molded article according to the present invention is not particularly limited. Taking the evaluation described in the examples below as an example, when Pseudomonas aeruginosa and mold are inoculated into the medium in contact with the antibacterial resin molded article and allowed to stand for 2 days and 2 weeks respectively, the antibacterial property is such that no growth of microorganisms is visually observed.

[0038] It has not been recognized that a sequestering agent elutes into the external-use liquid agent contained in the container for external-use liquid agents according to the present invention. Therefore, it can be said that the container for external-use liquid agents according to the present invention is excellent in safety, and is very beneficial for users who have developed or are likely to develop allergic diseases such as atopic dermatitis, asthma, and allergic rhinitis due to antibacterial components contained in conventional external-use liquid agents.

[0039] Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples, and the present invention can take various forms as long as the problems of the present invention can be solved.

[0040] It should be noted that the unit "vol%" used in the following description is synonymous with "%(v / v)" and "volume%". The unit "wt%" is synonymous with "%(w / w)" and "mass%". The unit "%(w / v)" is synonymous with "mass / volume%".

[0041] In addition, the "~" in a numerical range represents a range that includes the numerical values before and after it. For example, "0 mass% ~ 100 mass%" means a range that is 0 mass% or more and 100 mass% or less.

[0042] The number of digits of an integer value coincides with the number of significant figures. For example, the significant figure of 1 is 1 digit, and the significant figure of 10 is 2 digits. Also, for a decimal value, the number of digits after the decimal point coincides with the number of significant figures. For example, the significant figure of 0.1 is 1 digit, and the significant figure of 0.10 is 2 digits.

Example

[0043] [Test 1] [Manufacture of Novel Antibacterial Plastic] To 3 g of a commercially available ultraviolet curable resin material (trade name: "Taiyono Shizuku Hard Type", manufactured by Paji Co., Ltd.), 15 types of metal ion sequestering agents (Examples 1 to 15) described in Table 1 were added to a concentration of 8% (w / v), and the mixture was thoroughly mixed until dissolution or uniform dispersion of the metal ion sequestering agent was confirmed. Among the metal ion sequestering agents, solid ones were made into powder or fine powder and then dissolved or dispersed in the resin material. After pouring the obtained mixture into a petri dish (φ60 mm), it was irradiated with ultraviolet light to be cured, and an antibacterial plastic (corresponding to the antibacterial resin molded article according to the present invention) was obtained. Next, the antibacterial plastic in the petri dish was washed three times with sterilized water at 60°C to remove the uncured resin material and the metal ion sequestering agent that was not mixed with the resin material.

[0044] [Verification Experiment of Antibacterial Effect] To verify the antibacterial effect of the antibacterial plastic against test microorganisms, a culture medium was poured onto the antibacterial plastic in a washed petri dish, and the microorganisms specified in the preservative effectiveness test stipulated by the Ministry of Health, Labor and Welfare were cultured. The bacteria Pseudomonas aeruginosa ATCC9097, Escherichia coli ATCC8739, Staphylococcus aureus ATCC6538, and the fungi Candida albicans ATCC10231 and Aspergillus brasiliensis ATCC16404 were used in the verification experiment. The bacteria were cultured in a medium containing 1.0 x 10 8 Add 5 mL of general bacterial medium (peptone 5 g / L, yeast extract 2.5 g / L, glucose 1 g / L; pH 6.8) containing CFU / mL, and add 1.0 × 10 5 5mL of Sabouraud agar medium (peptone 10g / L, glucose 40g / L, agar 15g / L; pH 6.0) smeared with conidia was used for each medium. As a control, plastic obtained by hardening an ultraviolet-curable resin material without adding a metal ion sequestering agent was used. The culture period was 30 days, and the degree of microbial growth at the end of the culture was examined. Although there was a difference in the content of Mg as a metal ion in both general bacterial medium and Sabouraud agar medium, both media contained Mg as a metal ion. 2+ , Ca 2+ , Mn 2+ , Zn 2+ , Na + , K + The culture medium used in the tests described below also contains metal ions.

[0045] In addition to the bacterial and fungal cultures mentioned above, in order to verify the antibacterial effect against airborne bacteria, a petri dish filled with only a general bacterial culture medium was prepared, the lid was removed indoors for three hours, the lid was then replaced, and the dish was cultured for 30 days, and the extent of proliferation of airborne bacteria was examined.

[0046] By comparing the degree of microbial growth in Examples 1 to 15 and the control, the antibacterial effect of the antibacterial plastic of each example was evaluated. The degree of microbial growth was confirmed by counting the number of microorganisms (CFU / ml) for bacteria and visually observing for fungi. When the growth of microorganisms was observed to be at the same level as the control, it was marked as "+", and when the degree of microbial growth was smaller than that of the control or no growth was confirmed, it was marked as "-". The evaluation results are shown in Table 1.

[0047] Note that Table 1 shows the metal ion sequestering agents used in each example and the ligands possessed by those metal ion sequestering agents. As shown in Table 2, ligands are classified into hard bases, soft bases, and intermediate bases. Hard bases bind to metal ions by ionic bonds, and soft bases bind to metal ions by covalent bonds.

[0048]

Table 1

[0049]

Table 2

[0050] As shown in Table 1, it was found that the antibacterial plastics of Examples 1 to 15 exhibited sufficient antibacterial effects against bacteria, fungi, and airborne bacteria.

[0051] [Test 2] [Comparative Evaluation with Conventional Antibacterial Plastics] A test was conducted to compare the antibacterial effects between the antibacterial plastic according to the present invention and a conventional antibacterial plastic (Comparative Example 1). As Comparative Example 1, benzalkonium chloride was mixed into an ultraviolet-curing resin material to a concentration of 6% (w / v). This mixture was placed in a cylindrical culture tube (φ22 mm) and cured by irradiating with ultraviolet light to produce an antibacterial plastic. Also, as Example 16, benzoylacetone was mixed into an ultraviolet-curing resin material to a concentration of 6% (w / v). This mixture was similarly placed in a cylindrical culture tube (φ22 mm) and cured by irradiating with ultraviolet light to produce an antibacterial plastic. In both Comparative Example 1 and Example 1, after curing the resin material, it was washed three times with sterilized water at 60 °C to remove the uncured resin material and the antibacterial components not mixed with the resin material.

[0052] Subsequently, 5 mL of a general bacterial medium was poured into the culture tube containing the antibacterial plastic. Then, 1.0×10 4 CFU of Pseudomonas aeruginosa was inoculated, covered, and cultured at 37 °C for 2 days under static or shaking (120 revolutions / min) conditions. Also, as a control, Pseudomonas aeruginosa was cultured under the same conditions using a culture tube without any antibacterial plastic.

[0053] The antibacterial effects of the antibacterial plastics of Comparative Example 1 and Example 16 were evaluated as follows. That is, the degree of growth of Pseudomonas aeruginosa in the culture solution in the culture tube after culturing was visually confirmed. When the growth was observed to be similar to that of the control, it was marked as “+”. When the degree of growth of the microorganism was smaller than that of the control or no growth was confirmed, it was marked as “-”. The results are shown in Table 3.

[0054]

Table 3

[0055] As shown in Table 3, the antibacterial plastic of Comparative Example 1 did not exhibit antibacterial activity unless it was under shaking conditions, whereas the antibacterial plastic of Example 16 exhibited antibacterial activity under both shaking and static conditions. From these results, it is expected that simply containing an external preparation such as a cosmetic in a container employing the antibacterial plastic of Example 16 can suppress the spoilage of the external preparation without adding an antibacterial agent or a preservative.

[0056] As Example 17, a mixture obtained by mixing acetylacetone into a UV-curable resin material at 6% (w / v) was placed in a culture tube, irradiated with ultraviolet rays for curing to prepare an antibacterial plastic, and the culture of Pseudomonas aeruginosa was carried out and the antibacterial effect was evaluated in the same manner as Comparative Example 1 and Example 16 described above. The results are shown in FIG. 2. FIG. 2 is a photograph showing the antibacterial effects of the antibacterial plastic of Comparative Example 1, the antibacterial plastic of Example 17, and a control plastic. In the control, Pseudomonas aeruginosa was cultured using a culture tube without any antibacterial plastic. As shown in FIG. 2, the antibacterial plastic of Comparative Example 1 exhibited antibacterial activity only when cultured under shaking conditions, whereas for the antibacterial plastic of Example 17, the culture solution remained clear under both shaking and static conditions, and an antibacterial effect was confirmed.

[0057] [Test 3] [Elution test of antibacterial component] For the antibacterial plastics of Example 16 and Example 17, an elution test of a metal ion sequestering agent (benzoylacetone, acetylacetone) incorporated in the UV-curable resin material was conducted. The elution test was carried out as follows. First, the antibacterial plastics of Example 16 and Example 17 were prepared in a petri dish, 5 mL of distilled water was dispensed onto this antibacterial plastic, and it was allowed to stand at 37 °C for 2 days. Next, a general bacterial medium was prepared using this distilled water, transferred to a culture tube, inoculated with 1.0×10 4 CFU of Pseudomonas aeruginosa, and cultured by allowing it to stand at 37 °C for 2 days. As a control, a general bacterial medium was prepared using distilled water that had not been in contact with the antibacterial plastic, and Pseudomonas aeruginosa was cultured in the same manner.

[0058] As a result, when culturing using the medium prepared with distilled water that had been in contact with the antibacterial plastics of Example 16 and Example 17, and when culturing using the medium prepared with distilled water that had not been in contact with the antibacterial plastics, growth of Pseudomonas aeruginosa was confirmed in both cases. From this, it was presumed that no metal ion sequestering agent eluted from the antibacterial plastics of Example 16 and Example 17 into the distilled water.

[0059] [Test 4] [Application as a coating agent] A mixture in which acetylacetone or benzalkonium chloride was blended into the ultraviolet curable resin material to a concentration of 6% (w / v) was applied to the surface of a petri dish made of polypropylene 2 at 0.05 g / cm², and irradiated with ultraviolet light to be cured to form an antibacterial plastic coating layer.

[0060] 5 mL of a general bacterial medium was poured into the petri dish with the antibacterial plastic coating layer formed thereon for Pseudomonas aeruginosa and airborne bacteria, and 5 mL of Sabouraud agar medium was poured for fungi. Each microorganism was inoculated and cultured under the same conditions as the above-described test.

[0061] As a result, even when an antibacterial plastic coating layer was formed on the petri dish, Pseudomonas aeruginosa, airborne bacteria, and fungi did not grow, and a sufficient antibacterial effect was observed. From this, it was presumed that if the inner surface, which is the contact surface with the contents such as external liquid preparations, of the container was made of antibacterial plastic, it would be possible to suppress the growth of microorganisms in the contents without making the entire container of antibacterial plastic. As a result, it became possible to develop skin care products (including shampoos, etc.) without added preservatives.

[0062] [Test 5] [Relationship between the blending amount (%) of the metal ion sequestering agent and the thickness of the coating layer and the antibacterial effect] To the ultraviolet-curable resin material used in Test 1 ( "Sun's Drop Hard Type"; manufactured by Pajico), benzoylacetone as a metal ion sequestering agent was added to 4 - 8% (w / w), and the mixture was thoroughly mixed until dissolution or uniform dispersion was confirmed. The resulting mixture was applied to the bottom of a petri dish (55 mm in diameter), irradiated with ultraviolet light to cure the mixture, and coat layers with thicknesses of 0.1 mm, 0.4 mm, 1.0 mm, and 5.0 mm were formed on the bottom of the petri dish.

[0063] Next, 3 mL of medium was poured into the petri dish with the coat layer of each thickness formed, and bacteria or mold were inoculated therein and cultured for 28 days. The medium for bacteria was LB liquid medium, and three types of bacteria (Esherichia coli, Pseudomonas aeruginosa, Staphyloccocus aureus) were statically cultured at 36°C in this medium. Also, the medium for mold was Sabouraud agar medium, and two types, Candida albicans and Aspergillus brasiliensis, were statically cultured at 25°C on this medium, respectively.

[0064] Whether bacteria or mold grew after 28 days of culture was visually confirmed. The results are shown in Table 4. In Table 4, "+" indicates good growth, and "-" indicates no growth. As can be seen from Table 4, no influence on the antibacterial effect due to the coating thickness was observed.

Table 4

[0065] [Test 6] A mixture was prepared by adding 5% (w / w) of diethylenetriaminepentaacetic acid to resin pellets of polyethylene terephthalate (PET) and resin pellets of polypropylene (PP) respectively. Using this mixture, containers with a capacity of 30 mL (PET resin container, PP resin container) were produced by blow molding. 20 mL of culture medium was injected into the PET resin container and the PP resin container respectively, and bacteria or fungi were inoculated therein for culturing. The culture medium for bacteria was a soy-bean casein digest medium, and three types of bacteria (Escherichia coil DH5α strain, Pseudomonas aeruginosa PAO1 strain, Staphylococcus aureus NBRC100910 strain) were statically cultured at 37 °C in this medium. Also, the culture medium for fungi was a Sabouraud dextrose liquid medium, and two types of fungi (Candida albicans NBRC1594 strain, Aspergillus brasiliensis NBRC9455 strain) were statically cultured at 25 °C in this medium.

[0066] On the 7th day, 14th day, and 28th day from the start of culturing, the degree of growth of each bacterium and each fungus was visually confirmed. As a result, no growth was confirmed for any of the three types of bacteria and two types of fungi. Since an equivalent antibacterial effect was obtained even when diethylenetriaminepentaacetic acid was added to either PET resin or PP resin to produce the container, it was speculated that the influence of the resin material on the antibacterial effect was small.

Industrial Applicability

[0067] The antibacterial resin according to one aspect of the present invention can be used to prevent the growth of microorganisms in a topical liquid preparation that does not contain an antibacterial component even in a static state, and can contribute to the maintenance of healthy skin. Also, since the conventional resin material can be adopted, the antibacterial resin according to one aspect of the present invention can be manufactured economically and on an industrial scale.

Explanation of Signs

[0068] 1... Container 10... Bottle 11... Cap

Claims

1. An antibacterial resin composition comprising a metal ion sequestering agent and a resin material.

2. The metal ion sequestering agent has, as a ligand that binds to a metal ion in the molecule, O ２ － , OH － , H ２ O, CO ３ ２－ , NO ３ － , NH ３ , RNH ２ , RCOO － , RO － , ROH, N ２ H ４ , PO ４ ３－ , RO PO ３ ２－ , (RO) ２ PO ２ － , Cl － , R ２ O, NO ２ － , imidazole, pyridine, N ２ , SO3 ２－ , Br － , N ３ － , S ２－ , R ２ S, R ３ , RP, RS － , CN － , RSH, RNC, SCN － , CO, NO, (RS) ２ PO ２ － , H － , R － , (RO) ２ P(O)S － and I － The antibacterial resin composition according to claim 1, having one kind of ligand selected from the group consisting of

3. The antibacterial resin composition according to Claim 1, wherein the metal ion sequestering agent is one or more metal ion sequestering agents selected from the group consisting of benzoylacetone, acetylacetone, ethylenediaminetetraacetic acid, tripolyphosphoric acid, iminodiacetic acid, nitropentaamminecobalt, gluconic acid, aminoethanol, ethylenediamine, zirconium carbonate, glycolic acid, bipyridine, imidazole, thiocyanic acid, diethylenetriaminepentaacetic acid, and acetylpenicillamine.

4. The antibacterial resin composition according to Claim 1, wherein the resin material contains an ultraviolet curable resin component and a photopolymerization initiator.

5. The antibacterial resin composition according to Claim 1, wherein 6 to 8 parts by mass of the metal ion sequestering agent is contained per 100 parts by mass of the antibacterial resin composition.

6. The antibacterial resin composition according to Claim 1, wherein the metal ion sequestering agent is dispersed in the resin material.

7. An antibacterial resin molded article comprising the antibacterial resin composition according to any one of Claims 1 to 6.

8. A container for an external preparation liquid, comprising a container body having an opening and a lid portion detachably attached to the container body so as to close the opening, The container for an external preparation liquid, wherein at least the inner surface portion of the container body is formed of the antibacterial resin molded article according to Claim 7.

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