Cosmetic container

Abstract

To provide a cosmetic container which does not contain copper and silver in a molding material, causes properties for dissipation of bacteria on a cosmetic itself stored in the cosmetic container, and reduces affection of secondary pollution of the cosmetic.SOLUTION: A container body 20 of a cosmetic container contains only zinc oxide as a component of metal, and a content of a molding material of powder of the zinc oxide is regulated as a prescribed ratio as a ratio of the powder of the zinc oxide to a resin, and the prescribed ratio is regulated as a necessary and sufficient ratio for causing properties for dissipation of bacteria in a cosmetic stored in the cosmetic container, in a prescribed condition.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cosmetic container. [Background technology]

[0002] Bacterial contamination during the manufacturing process of cosmetics is called "primary contamination," while bacterial contamination after the cosmetic container containing the cosmetics is opened and the cosmetic is used by the user is called "secondary contamination."

[0003] In order to reduce the effects of the above-mentioned secondary contamination, preservatives (e.g., paraben) and additives such as phenoxyethanol, which has a preservative effect, are generally added to cosmetics. However, from the viewpoint of the health of the user, it is preferable not to use preservatives or additives. In this regard, a technology has been proposed in which cosmetics are filled into small-capacity containers that correspond to the amount used in one use (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4627562 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, when considering the amount of cosmetics used in one month, if the entire amount is not stored in one container, but rather a small-capacity container is used to store only the amount used in one go, a large number of containers will be required. For example, if the cosmetics are used once a day, 30 containers will be required. Furthermore, the amount used in one go may vary depending on the user, and even for the same person, the amount may vary depending on the situation, so there may be an excess or deficiency of cosmetics in the container, which may ultimately result in the cosmetics being wasted.

[0006] In response to this, a technology is known that reduces bacteria contaminating cosmetics by utilizing the bactericidal action of metal ions (called "trace metal action"). Copper and silver are known as metals that have a significant trace metal action. When a cosmetic container is formed by including copper or copper in a molding material, bacteria contaminating the cosmetics stored in the cosmetic container are annihilated (dead) or reduced by the bactericidal action of the copper ions or silver ions. However, when a cosmetic container is formed by dispersing copper in a molding material, there is a problem that the cosmetics are colored blue due to the influence of the copper ions. When a cosmetic container is formed by dispersing silver in a molding material, the concentration of silver ions continues to increase even after a relatively long time has passed, and the silver ions may have adverse effects on the human body. When a cosmetic container is formed by dispersing both silver and copper in a molding material, the increase in the concentration of silver ions can be suppressed, but there is still a problem that the cosmetics are colored blue due to the influence of the copper ions.

[0007] In light of the above, the present invention provides a cosmetic container that can impart bacteria-eliminating properties to the cosmetics stored in the cosmetic container itself without including copper or silver in the molding material, thereby reducing the effects of secondary contamination of the cosmetics. [Means for solving the problem]

[0008] The first invention is a cosmetic container having a container body for storing liquid cosmetic, wherein the container body is formed from a molding material whose main component is resin, the molding material contains only zinc oxide as a metal component, the zinc oxide being in the form of a powder, the content of the zinc oxide powder in the molding material is specified as a predetermined ratio as the proportion of the zinc oxide powder in the molding material, and the predetermined ratio is specified as the ratio that is necessary and sufficient for the cosmetic stored in the cosmetic container formed from the molding material to impart the property of eliminating bacteria that have become contaminated in the cosmetic under specified conditions.

[0009] Based on the basic technical concept of imparting to the cosmetic itself stored in the cosmetic container the property of destroying or killing bacteria that may be mixed in the cosmetic, the inventor of the present invention has come up with a technical idea of ​​reducing the impact of secondary contamination of the cosmetic while avoiding the adverse effects of copper (Cu) and silver (Ag) by deliberately including only a specified amount of zinc oxide (ZnO), which is known to have a relatively weak bactericidal effect, as a metal component in the molding material that forms the container body. The content of zinc oxide (ZnO) is specified as the ratio of zinc oxide in the molding material (the "predetermined ratio"), and is limited to a necessary and sufficient ratio for imparting to the cosmetic stored in the cosmetic container the property of destroying bacteria under specified conditions.

[0010] Zinc oxide is also a metal that has trace metal properties, but its bactericidal properties are weaker than those of copper and silver. For this reason, there are no prior art examples that embody the technical idea of ​​forming a cosmetic container with only zinc oxide in the molding material and imparting the bacteria-killing properties to the cosmetics stored in the cosmetic container itself.

[0011] However, cosmetic containers made of molding materials containing zinc oxide have existed for some time. However, the purpose of using zinc oxide in these cosmetic containers is to color them white or to block ultraviolet rays from the outside, and the content in the molding materials is about 0.5% to 3% by weight. Alternatively, a technology is known in which a molding material in which zinc oxide is dispersed is formed into a thin film to reduce bacteria on the surface of the thin film, but unlike the present invention, this technology does not impart a bactericidal effect to the cosmetics stored in the cosmetic container itself, and does not eliminate bacteria mixed in the cosmetics by the bactericidal effect of the cosmetics themselves, so the technical idea is fundamentally different.

[0012] The inventor of the present invention confirmed through experiments that, under certain conditions, when the ratio of zinc oxide in the molding material reaches a certain ratio ("certain ratio"), the cosmetics stored in the cosmetics container formed from the molding material have a bactericidal effect that eliminates bacteria. Furthermore, when the content of zinc oxide exceeds a certain ratio, the zinc ion concentration in the cosmetics increases, but no significant difference was observed in the bactericidal effect. In other words, in order to reduce the effects of secondary contamination, it was found that there is no point in increasing the content of zinc oxide beyond the certain ratio, and the certain ratio is necessary and sufficient. In light of the above, in the present invention, the certain ratio is defined as a necessary and sufficient ratio for endowing the cosmetics stored in the cosmetics container with the property of eliminating bacteria under certain conditions, not that the greater the amount of zinc ions eluted into the cosmetics when the liquid cosmetics is placed in the container body, the better, nor that the higher the zinc ion concentration in the cosmetics, the better. This makes it possible to provide a cosmetics container that can reduce the effects of secondary contamination of cosmetics stored in the cosmetics container without including copper or silver in the molding material.

[0013] The second invention is a cosmetic container configured as in the first invention, wherein the specified condition is that the cosmetic, which does not contain preservatives, additives or other ingredients for reducing the number of bacteria, has been stored in the container body for 24 hours, and then a specified number of bacteria is mixed into the cosmetic and another 24 hours are allowed to pass at a temperature favorable for the proliferation of the bacteria.

[0014] There is a time lag of at least 24 hours between the time when the cosmetic product is stored in the cosmetic container and the time when the product is actually sold. If the cosmetic product is used after the product is sold and bacteria are mixed in, it is desirable that the bacteria have disappeared by the time the cosmetic product is used next time. The frequency of use of the cosmetic product is typically about every 24 hours, for example, the morning of one day and the morning of the following day. According to the configuration of the second invention, the influence of secondary contamination of the cosmetic product stored in the cosmetic container can be reduced even if the temperature is favorable for bacterial growth during the typical frequency of use of the cosmetic product.

[0015] A third invention is a cosmetic container in which, in the configuration of the first or second invention, the specified ratio is determined by the specific surface area of ​​the container body, which is defined as the ratio of the area of ​​the inner surface of the container body to the volume of the container body, and the particle diameter of the powder.

[0016] The inventors of the present invention have confirmed that, when the particle size of the zinc oxide powder is fixed, the larger the specific surface area of ​​the container body, defined as the area of ​​the inner surface of the container body relative to the volume of the container body, the greater the amount of zinc ions eluted into the cosmetic product, and the higher the zinc ion concentration in the cosmetic product. This can be rationally understood as being because the larger the specific surface area of ​​the container body, the larger the area of ​​the cosmetic product stored in the container body that comes into contact with the inner surface of the container body, and the higher the efficiency of elution of zinc ions into the cosmetic product. In other words, the specific surface area is the area of ​​the inner surface of the container body relative to the unit volume of the container body.

[0017] The inventors of the present invention have also confirmed that the smaller the particle size of zinc oxide powder, the greater the amount of zinc ions dissolved in the cosmetic product, and the higher the zinc ion concentration in the cosmetic product. This can be reasonably understood as being because the smaller the particle size of the particles, the greater the specific surface area, and therefore the greater the total surface area of ​​the powder consisting of many particles.

[0018] Therefore, the above-mentioned "predetermined ratio" is determined by the specific surface area of ​​the container body and the particle diameter of the zinc oxide powder. As described above, the inventor of the present invention has confirmed through experiments that when the content of zinc oxide reaches a predetermined ratio, the cosmetics stored in the cosmetic container formed from the molding material have a bactericidal effect that eliminates bacteria. As described above, the relationship between the specific surface area of ​​the container body and the amount of zinc ions eluted, and the relationship between the particle diameter of the zinc oxide powder and the amount of zinc ions eluted have also been confirmed, so that a person skilled in the art can determine a specific "predetermined ratio" based on the above relationships. For example, if the particle diameter of zinc oxide is determined, the larger the specific surface area of ​​the container body, the smaller the predetermined ratio. Also, if the specific surface area of ​​the container body is determined, the smaller the particle diameter of zinc oxide, the smaller the predetermined ratio. For this reason, a person skilled in the art will not need to make excessive errors in carrying out the present invention.

[0019] A fourth invention is a cosmetic container having the configuration of the third invention, wherein when the maximum width of each particle constituting the powder is the particle diameter of each particle and the maximum value of the particle size distribution of the powder is the particle diameter of the powder, the particle diameter of the powder is 1 micrometer or more and 10 micrometers or less.

[0020] The present invention does not exclude ultrafine particles at the nano level as the particle diameter of the powder. However, when the particle diameter of the powder is ultrafine particles at the nano level, aggregation will occur unless a process is performed to prevent the phenomenon of multiple particles agglomerating with each other in the manufacturing process of the cosmetic container. As a result of aggregation, the surface area of ​​the powder consisting of a large number of ultrafine particles as a whole may be smaller than that in the case where aggregation does not occur. Therefore, the smaller the particle diameter of the powder provided by the zinc oxide manufacturer, the greater the amount of zinc ions eluted into the cosmetic product, and the higher the zinc ion concentration in the cosmetic product. For this reason, the particle diameter of the zinc oxide powder is limited to 1 micrometer or more and 10 micrometers or less. Within this range, it can be rationally understood that the smaller the particle diameter of the powder, the greater the amount of zinc ions eluted into the cosmetic product and the higher the zinc ion concentration in the cosmetic product. In addition, by limiting the particle diameter of the powder to 1 micrometer or more and 10 micrometers or less, an advantageous effect is obtained in that a process to prevent aggregation of the zinc oxide powder is not required in the manufacturing process of the cosmetic container. Effect of the Invention

[0021] According to the cosmetic container of the present invention, the cosmetics stored in the cosmetic container itself can be given the property of destroying bacteria without the need to include copper or silver in the molding material, thereby reducing the effects of secondary contamination of the cosmetics. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic perspective view of a cosmetic container according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic perspective view of a container body. [Diagram 3] FIG. [Figure 4] FIG. 2 is a schematic side view of a container body. [Diagram 5] FIG. 2 is a schematic plan view of a container body. [Figure 6] FIG. 2 is a schematic cross-sectional view of a container body. [Figure 7] 4 is a conceptual diagram showing an enlarged view of a portion of the peripheral wall of the container body. FIG. [Figure 8] 1 is a schematic cross-sectional view showing a state in which cosmetics are stored in a container body. [Figure 9] 5 is a schematic diagram showing the operation of the container body when cosmetics are stored in the container body. FIG. [Figure 10] 10 is a schematic diagram showing the action of the container body when the amount of cosmetic stored in the container body is reduced. [Figure 11] FIG. 13 is a diagram showing the results of an experiment using the container body. [Figure 12] FIG. 13 is a diagram showing the results of an experiment using the container body. [Figure 13] FIG. 13 shows supplementary experimental results using pellets. [Figure 14] 4 is a conceptual diagram showing the specific surface area of ​​a container body and a predetermined ratio of zinc oxide in a molding material. [Figure 15] 2 is a conceptual diagram showing the particle size of zinc oxide powder and a predetermined ratio of zinc oxide in a molding material. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that the description of configurations that can be implemented by those skilled in the art will be omitted, and only the basic configuration of the present invention will be described.

[0024] As shown in FIG. 1, the cosmetic container 1 is composed of a lid 10 and a container body 20. The cosmetic container 1 has an overall cylindrical outer shape. As shown in FIGS. 2 and 6, the container body 20 has a hollow structure, and the cosmetic 100 is stored in the internal space S1 (see FIG. 6) (see FIG. 8). In this embodiment, the space S1 is a cylindrical space that is open at the top. In other words, the container body 20 and the space S1 are substantially similar in shape. Unlike this embodiment, the outer shape and internal space of the container body are not limited to a cylindrical shape, and may be, for example, an approximately conical shape, a cube, or a rectangular parallelepiped.

[0025] The volume B1 of the container body 20 is the volume B1 of the space S1 (see FIG. 6). The volume B1 of the space S1 can be calculated as the volume of a cylinder with a diameter W1 (see FIG. 6) of the bottom surface 20e and a height H1 (see FIG. 6) of the peripheral wall 20d. The volume B1 is also the volume of the cosmetic 100 when the cosmetic 100 is filled to the fullest in the space S1 (hereinafter, also referred to as the "full filling amount") (see FIG. 8). The inner surface area A1 of the space S1 can be calculated as the sum of the area of ​​the bottom surface 20e, which is a circle with a diameter W1, and the area of ​​the inner surface of the peripheral wall 20d with a height H1. The inner surface area A1 is also the area where the full amount of the cosmetic 100 comes into contact with the inner surface of the container body 20. The ratio of the inner surface area A1 to the volume B1 is defined as the specific surface area C1 (A1 / B1) of the container body 20. In other words, the specific surface area C1 is the area of ​​the inner surface of the container body 20 per unit volume of the container body 20.

[0026] The cosmetic product 100 is a liquid cosmetic product. In this specification, "liquid" includes a state of low viscosity close to that of water to a state of relatively high viscosity. "Liquid cosmetic products" include, for example, creams, milky lotions, gels, and lotions. Specific examples of liquid cosmetic products include, but are not limited to, mascara, eye shadow, foundation, skin lotion, facial cleanser, hair dye, hair styling product, and the like.

[0027] The cosmetic product 100 stored in the space S1 does not contain any preservatives (such as paraben) or additives such as phenoxyethanol that have a preservative effect. In other words, the cosmetic product 100 does not contain any preservatives, additives or other ingredients for reducing the number of bacteria.

[0028] As shown in Fig. 3, the lid 10 also has a hollow structure. In this specification, the direction connecting the lid 10 and the container body 20 in Fig. 1 is referred to as the "vertical direction", the direction of the lid 10 is referred to as the "upward direction", and the direction of the container body 20 is referred to as the "downward direction". In this specification, the term "sterilization" refers to the property and / or action of reducing or eliminating bacteria and / or viruses, and is used as a term including sterilization, sterilization, and disinfection. In addition, "the property and / or action of eliminating bacteria or viruses" is synonymous with "the property and / or action of killing bacteria or viruses".

[0029] The container body 20 is formed from a molding material whose main component is resin. In this embodiment, the container body 20 is formed by injection molding the molding material. As the resin constituting the container body 20, for example, a polyolefin-based resin such as polypropylene, a polystyrene-based resin, or a polyester-based resin can be used. In this embodiment, the resin is polypropylene.

[0030] The main components of the molding material forming the container body 20 are resin and metal powder. The molding material is a mixture of resin and metal powder, as well as an appropriate coupling material such as a silane coupling material, and other additives as necessary. The container body 20 is formed by injection molding the molding material. The metal powder is zinc oxide powder. That is, the molding material constituting the container body 20 contains a predetermined amount of zinc oxide (ZnO). The molding material contains only zinc oxide as a metal, and does not contain any other types of metals.

[0031] During the molding process, some of the components of the molding material evaporate, but in the context of the present invention, the amount is negligibly small, so the proportion of zinc oxide powder in the molding material can be considered to be the same as the proportion of zinc oxide powder in the container body 20.

[0032] In the container body 20, the zinc oxide powder is dispersed throughout the resin. That is, the zinc oxide powder is not concentrated on any one surface of the container body 20, nor concentrated toward the center in the thickness direction of the bottom or side walls of the container body 20, but is dispersed substantially uniformly throughout.

[0033] Generally, the content of each component in the molding material is specified to a predetermined value. However, in the actual manufacturing process, even if the error is within the allowable range, measurement errors in the amount of each component occur, so the more types of components there are, the more likely it is that the composition of the actual molded product will deviate from the designed composition. In this regard, in the present embodiment, the molding material forming the container body 20 contains only zinc oxide powder as the metal powder, so that the composition of the container body 20 is less likely to deviate from the designed composition than when multiple types of metal powder are contained.

[0034] Furthermore, even if the objective of reducing the impact of secondary contamination of the cosmetic product 100 stored in the container body 20 is achieved, it is desirable from the viewpoint of controlling the manufacturing process that there be as few changes as possible to the manufacturing process and that the components used are the same as those used when forming the container body 20 by normal resin molding. In this regard, in this embodiment, the molding material constituting the container body 20 contains only zinc oxide powder as the metal powder, and as described below, no treatment is required to prevent the aggregation of the zinc oxide powder, which has the advantage of avoiding complication of the manufacturing process.

[0035] Furthermore, zinc oxide is used in sunscreen products, makeup products, body powder, skin care products, etc., and its safety to the human body has already been confirmed. For this reason, containing only zinc oxide as the metal powder in the molding material constituting the container body 20 is also advantageous from the viewpoint of ensuring safety to the human body.

[0036] As shown in Figures 2 and 4, the container body 20 is composed of a base portion 20a and a connection portion 20b. As shown in Figure 2, a male screw portion 20c is formed in the connection portion 20b. Note that the male screw portion 20c is not shown in Figure 4.

[0037] As shown in Fig. 3, a female thread portion 10c is formed on the inner surface 10b of the lid body 10. The male thread portion 20c of the connection portion 20b of the container body 20 engages with the female thread portion 10c formed on the inner surface 10b of the lid body 10, thereby detachably engaging the lid body 10 and the container body 20. The lid body 10 is formed by injection molding a molding material. The molding material forming the lid body 10 may be the same as that of the container body 20, or may be a molding material different from that of the container body 20. For example, the molding material forming the lid body 10 may be a material that does not contain zinc oxide powder.

[0038] Fig. 5 is a schematic plan view of the container body 20 in Fig. 4 as viewed from the direction of arrow Z1. Fig. 6 is a schematic cross-sectional view of the container body 20 shown in Fig. 5 along line AA. As shown in Fig. 6, the inside of the container body 20 is a cylindrical space S1 with a diameter W1 and a height H1. The space S1 is open only at the top. In this embodiment, the diameter W1 is 5.0 centimeters (cm) and the height H1 is 4.0 centimeters (cm). Therefore, the volume of the container body 20 (the volume of the space S1) is approximately 78.5 cubic centimeters (cm 3 ) and the surface area (area of ​​the inner surface of the container body 20) is approximately 82.43 square centimeters (cm 2 ).

[0039] Fig. 7 is a conceptual diagram showing an enlarged view of a portion T1 of the peripheral wall of the container body 20 of Fig. 6. In the container body 20, zinc oxide fine particles 28 are substantially uniformly dispersed throughout the resin 26. Since Fig. 7 is a conceptual diagram, for ease of explanation, fine particles 28 of a single particle diameter L1 are shown, but in reality, a particle group consisting of a large number of fine particles 28 having a predetermined particle size distribution (typically, for example, a normal distribution) is dispersed in the container body 20.

[0040] Here, the meaning of "particle diameter" in this specification will be explained. Zinc oxide powder is a particle group composed of many fine particles 28. In this specification, a particle group composed of many fine particles 28 is called "powder." And, a representative value of the particle diameter of many fine particles 28 is called "particle diameter L1 of fine particles 28." And, since particle diameter L1 is a representative value of the particle diameters of many fine particles 28 constituting "powder," it is also called "particle diameter L1 of powder."

[0041] In this embodiment, the maximum width of each fine particle 28 is the particle diameter of the fine particle 28. That is, the particle diameter of each fine particle 28 is the Krumbein diameter. A sieving method is adopted as a method for measuring the particle diameter distribution of a particle group (powder) consisting of a large number of fine particles 28. In addition, the maximum value of the particle distribution is adopted as the particle diameter L1. In this specification, a large number of fine particles 28 are normally distributed, and the particle diameter L1 of the fine particles 28 means the maximum value in the normal particle size distribution. The definition of the particle diameter and the method for measuring the particle diameter distribution are not limited to the above. For example, unlike this embodiment, the particle diameter L1 may be a sphere equivalent diameter measured using a laser diffraction / scattering type particle size distribution measuring device, and the median diameter (d50) may be used. The median diameter means a diameter at which the larger side and the smaller side are equal when a powder is divided into two from a certain particle diameter. Also, unlike this embodiment, the particle diameter L1 may be an average particle diameter.

[0042] The particle diameter L1 of the fine particles 28 is set to a predetermined numerical range, for example, 1 micrometer or more and 10 micrometers or less. In this embodiment, the particle diameter L1 is 4 micrometers. That is, a group of fine particles in which a large number of fine particles 28 having a maximum particle diameter L1 are normally distributed is dispersed in the container body 20. In the present invention, the particle diameter L1 is not limited to 1 micrometer or more and 10 micrometers or less, and fine particles less than 1000 nanometers, for example, ultrafine particles such as 10 nanometers or more and less than 100 nanometers, can be adopted and are not excluded from the present invention. However, in the case of ultrafine particles, it is necessary to prevent aggregation of the fine particles in the molding process. In this regard, if the particle diameter L1 is 1 micrometer or more, aggregation of the fine particles is not a big problem in the molding process, and there is an advantage that no treatment to prevent aggregation is necessary. Furthermore, if the particle diameter L1 is 1 micrometer or more, there is an advantage that there is no need to consider the influence of aggregation, so that a person skilled in the art can more rationally estimate the difference in the sterilization action due to the difference in the particle diameter L1.

[0043] The reason why the particle size L1 is limited to 10 micrometers or less is that if the powder particle size is too large, the specific surface area of ​​each fine particle becomes small, and the surface area of ​​the powder as a whole also becomes small. If the surface area of ​​the powder as a whole becomes small, the efficiency of elution of zinc ions into the cosmetic 100 decreases when the cosmetic 100 is stored in the container body 20.

[0044] In this embodiment, the content of zinc oxide in the molding material is specified as a predetermined ratio as the ratio of zinc oxide powder in the molding material. The predetermined ratio is specified as a necessary and sufficient ratio for the cosmetic 100 stored in the container body 20 formed from the molding material to produce a property of eliminating bacteria mixed in the cosmetic 100 under predetermined conditions. In other words, the content of the fine particles 28 does not mean that the amount of zinc ions eluted into the cosmetic 100 when the liquid cosmetic 100 is placed in the container body 20 is large, nor does it mean that the zinc ion concentration in the cosmetic 100 is high. The higher the content of the fine particles 28 in the molding material, the higher the zinc ion concentration in the cosmetic 100 stored in the container body 20, and the stronger the bactericidal action, but excessive bactericidal effect is not necessary. In addition, since the cost per unit amount is generally higher for zinc oxide powder than for polypropylene, the higher the content of the fine particles 28, the higher the cost of the molding material. Furthermore, although polypropylene molded products have appropriate properties including mechanical strength, there is a problem that the higher the content of the fine particles 28, the more the properties are impaired. In this regard, in the present embodiment, the content of the microparticles 28 is set to a value that is just enough to reduce the effects of secondary contamination when a liquid cosmetic is poured into the container body 20. Although the particle size in this embodiment is the Krumbein diameter, it will be naturally understood by those skilled in the art that since the content of the microparticles 28 is set in this way, it is also possible to use other definitions of particle size.

[0045] In this embodiment, the "predetermined condition" is a condition in which the liquid cosmetic 100 is stored in the container body 20 for 24 hours, a predetermined number of bacteria is mixed into the cosmetic 100, and another 24 hours are allowed to pass at a temperature favorable for bacterial growth. In general, there is a time lag of at least 24 hours between the time when the cosmetic is stored in a cosmetic container and the product is completed and the time when the product is actually sold. In addition, the typical frequency of use of a cosmetic is considered to be approximately every 24 hours, for example, when a cosmetic is used in the morning of one day, the next time the cosmetic is used in the morning of the following day. In this regard, by defining the "predetermined condition" as described above, it is possible to reduce the influence of secondary contamination of the cosmetic stored in the container body 20 even if the temperature is favorable for bacterial growth during the typical frequency of use of the cosmetic.

[0046] As described above, the content of zinc oxide in the molding material is a necessary and sufficient content for imparting to the cosmetic 100 stored in the container body 20 itself the property of eliminating bacteria that have become mixed into the cosmetic 100 under predetermined conditions. As shown in FIG. 14, the parameters that define the content are the specific surface area C1 of the container body 20 and the particle diameter L1 of the microparticles 28. Here, the specific surface area C1 of the container body 20 is defined as the ratio of the area A1 of the inner surface of the container body 20 to the capacity B1 of the container body 20, i.e., the capacity B1 of the space S1 (see FIG. 6, etc.). In other words, the specific surface area C1 is the surface area of ​​the inner surface per unit capacity of the container body 20.

[0047] 14, the inventors of the present invention confirmed that, when the particle diameter of the microparticles 28 is fixed, the larger the specific surface area C1 (A1 / B1) of the container body, the smaller the predetermined ratio D1. This can be reasonably understood as being because, as the specific surface area C1 of the container body 20 is larger, the area of ​​the cosmetic 100 stored in the container body 20 that comes into contact with the inner surface of the container body 20 becomes larger, and the efficiency of elution of zinc ions into the cosmetic 100 increases.

[0048] 15, the inventors of the present invention confirmed that when the specific surface area C1 (A1 / B1) of the container body is fixed, the smaller the particle diameter L1 of the microparticles 28, the smaller the predetermined ratio D1. This can be reasonably understood as being because the smaller the particle, the larger the specific surface area, and therefore the particle group with a smaller maximum value in the particle size distribution has a larger surface area of ​​the powder as a whole, and the efficiency of elution of zinc ions from the inner surface of the container body 20 into the cosmetic product 100 increases.

[0049] Therefore, the predetermined ratio D1 can be determined by the specific surface area C1 of the container body 20 and the particle diameter L1 of the microparticles 28. As described above, the inventor of the present invention has confirmed through experiments that when the content of zinc oxide in the molding material reaches a predetermined ratio under predetermined conditions, the cosmetic product 100 stored in the container body 20 formed from the molding material has a bactericidal effect that eliminates contaminating bacteria, and has also confirmed the relationship between the specific surface area C1 of the container body 20 and the predetermined ratio D1, and the relationship between the particle diameter L1 and the predetermined ratio D1, so that the specific content of zinc oxide can be determined based on these relationships, and a person skilled in the art would not need to make excessive errors in carrying out the present invention.

[0050] As described above, in this embodiment, the particle diameter L1 of the zinc oxide powder is 4 micrometers, and a large number of fine particles 28 having a maximum value of 4 micrometers are dispersed in the container body 20 in a normally distributed fine particle group. In the container body 20 of this embodiment, the predetermined ratio of the zinc oxide fine particles 28 in the molding material is set in the range of more than 11 weight % and not more than 15 weight %. Desirably, the predetermined ratio is 12 weight % or more and 15 weight % or less. More desirably, the predetermined ratio is 13 weight % or more and 15 weight % or less.

[0051] The above-mentioned predetermined ratio is significantly different from the content of zinc oxide contained in a cosmetic container for the conventional purpose of coloring the cosmetic container white or blocking ultraviolet rays. Therefore, in the first place, the technical ideas of the prior art and the present invention are fundamentally different, and the content of zinc oxide in the container body is also different.

[0052] As shown in Figure 8, when a full amount of cosmetic product 100 is stored in the container body 20, zinc ions are dissolved into the cosmetic product 100 from the inner peripheral portion 20d and the bottom portion 20e of the container body 20, as shown by the arrows in Figure 9, and the zinc ions act on bacteria that have become mixed into the cosmetic product 100, eliminating the bacteria.

[0053] As shown in FIG. 10, even if the amount of the cosmetic 100 is reduced and becomes less than the full amount, the action of the container body 20 to impart sterilizing power to the cosmetic 100 itself is maintained. Generally, the larger the volume, the smaller the ratio of the surface area to the volume. Conversely, the smaller the volume, the larger the ratio of the surface area to the volume. Therefore, when the amount of the cosmetic 100 is reduced, the volume of the cosmetic 100 is reduced and the ratio of the surface area to the volume of the cosmetic 100 is increased. This means that the area of ​​the inner surface of the container body 20 in contact with the cosmetic 100 is increased per unit volume of the cosmetic 100. Therefore, even if the amount of the cosmetic 100 is reduced, the action of the container body 20 to impart to the cosmetic 100 itself the property of eliminating bacteria that have become mixed in the cosmetic 100 under specified conditions is maintained.

[0054] The inventors of the present invention have confirmed that the predetermined ratio can be reduced by configuring the zinc oxide powder to be composed of fine particles and ultrafine particles, unlike this embodiment. For example, the particle diameter of the fine particles is 4 micrometers, and the particle diameter of the ultrafine particles is 35 to 200 nanometers. The content of the fine particles is made larger than the content of the ultrafine particles. For example, the total ratio of the zinc oxide powder in the molding material is 11% by weight, of which the fine particles are 10% by weight, and the ultrafine particles are 1% by weight.

[0055] [Experimental example using the container body 20] [Zinc oxide content and zinc ion concentration] FIG. 11 shows the results of an experiment in which water was stored in the container body 20 and the transition of the zinc ion concentration in the water was measured at room temperature (25 degrees Celsius). The measurement was performed for up to 480 hours. The container body 20 was made of a molding material mainly made of polypropylene resin, and the ratio of zinc oxide powder in the molding material was compared at 0 weight %, 10 weight %, 20 weight %, 30 weight %, 40 weight %, 50 weight %, and 60 weight %. The polypropylene resin used was a material manufactured by LOTTE CHEMICAL, and the grade was SB-520. The zinc oxide used was a material manufactured by HKK SOLUTION, with a particle diameter (maximum width) of 4 micrometers (μm).

[0056] As shown in Figure 11, the greater the zinc oxide content, the higher the zinc ion concentration in the water at any point in time. And, at any zinc oxide content, the increase in zinc ion concentration becomes slower with time, and the zinc ion concentration becomes constant at some point in time.

[0057] [Bactericidal effect of cosmetics stored in the container body 20] 12 shows the results of an experiment to confirm the bactericidal effect of the liquid cosmetic 100 stored in the container body 20. First, six types of container bodies 20 were prepared by molding a molding material containing zinc oxide powder, the main component of which is polypropylene (hereinafter referred to as "Container Body A", "Container Body B", "Container Body C", "Container Body D", "Container Body E" and "Container Body F"). The ratio of zinc oxide in the container bodies A to F is 5% by weight for Container Body A, 10% by weight for Container Body B, 15% by weight for Container Body C, 20% by weight for Container Body D, 25% by weight for Container Body E and 30% by weight for Container Body F. The particle diameter (maximum width) of the fine particles of the zinc oxide powder is 4 micrometers, and the particle size distribution of the fine particle group is a normal distribution.

[0058] Next, the lotions were placed in container bodies A to F as shown in Figure 8 and stored at 25 degrees Celsius for 24 hours (hereinafter referred to as "storage treatment"). The lotions used did not contain preservatives or other additives to reduce bacteria and viruses. The lotion before the storage treatment is called "initial lotion." After the storage treatment, 9 milliliters (ml) of lotion was removed from each of container bodies A to F. The lotions removed from container bodies A to F are called "treated lotions A to F," respectively.

[0059] Next, 1 milliliter (ml) of the concentrated bacterial liquid was added to 9 milliliters of the treated lotion A to prepare the lotion A for incubation. The bacteria in the concentrated bacterial liquid were Escherichia coli, and the number of bacteria was 1,000,000 CFU / mL (colony forming unit / mL). In other words, the number of bacteria in the lotion A for incubation was 100,000 CFU / mL (colony forming unit / mL). The lotion A for incubation was then incubated at 37 degrees Celsius for 24 hours. The treated lotions B to F were also treated in the same manner to produce lotions B to F for incubation, which were incubated under the same conditions as the lotion A for incubation.

[0060] Next, the initial lotion was used to dilute the incubation lotions A to F after incubation 1000 times, respectively, to obtain sample solutions A to F. Each of the sample solutions A to F was inoculated into a Compact Dry (registered trademark), model 06744CF (2-8998-04: for measuring coliform bacteria count) from Nissui Pharmaceutical Co., Ltd. (3-23-9 Ueno, Taito-ku, Tokyo), and the number of bacteria was measured. Compact Dry (registered trademark) is a culture medium for measuring the number of bacteria, and the inoculated sample solution is designed to naturally spread evenly.

[0061] The number of bacteria measured with Compact Dry (registered trademark) in container body A was reduced by less than one digit compared to the bacterial count of 100,000 CFU / mL (colony forming unit / mL) before incubation, which was diluted 1,000 times to 100 CFU / mL. In container body B, the number of bacteria was reduced by one digit. The number of bacteria could not be measured in containers C, D, E, and F. That is, E. coli had disappeared in containers C to F.

[0062] The above experiment confirmed that under specified conditions, when the ratio of zinc oxide in the molding material is 10% by weight or less, the bactericidal effect of the lotion stored in the cosmetic container 20 does not destroy bacteria, when it is 15% by weight, the bacteria are destroyed, and when it exceeds 15% by weight, no significant difference in the bactericidal effect is found. In this experiment, the particle diameter of the zinc oxide powder was 4 micrometers. Therefore, when the particle diameter of the zinc oxide powder is 4 micrometers, there is a predetermined ratio of zinc oxide that is necessary and sufficient to give the cosmetic stored in the container body 20 the property of destroying bacteria under specified conditions in the range of more than 10% by weight and less than or equal to 15% by weight.

[0063] [Supporting experimental examples] Fig. 13 shows the experimental results of a supplementary experimental example in which pellets of polypropylene resin (hereinafter referred to as "PP resin") containing zinc oxide powder were used instead of the container body 20. In the experimental example of Fig. 13, P1 is a PP resin pellet containing 10% by weight of zinc oxide. P2 is a PP resin pellet containing 15% by weight of zinc oxide. P3 is a PP resin pellet containing 20% ​​by weight of zinc oxide. The particle diameter of the zinc oxide powder is 4 micrometers in all cases.

[0064] First, nine petri dishes were prepared, each containing 30 milliliters of lotion. Three of the petri dishes were filled with 0.5 grams, 1.0 grams, and 1.5 grams of P1, respectively. Similarly, 0.5 grams, 1.0 grams, and 1.5 grams of P2 were placed in three petri dishes, and 0.5 grams, 1.0 grams, and 1.5 grams of P3 were placed in three petri dishes. Since P1, P2, and P3 are pellets, an increase in weight (grams) means an increase in the number of pellets, and the surface area of ​​the pellets as a whole increases in proportion to the weight. And since the lotion is 30 milliliters in each case, the specific surface area as the ratio of the area of ​​the lotion in contact with the pellets to the volume of the lotion (area of ​​the lotion in contact with the pellets / volume of the lotion: hereinafter referred to as the "specific surface area of ​​the pellets") increases in proportion to the number of pellets.

[0065] They were then stored at 25 degrees Celsius for 24 hours (hereafter referred to as "storage treatment"). The lotion used did not contain preservatives or other additives to reduce bacteria and viruses. The lotion before storage treatment is called "initial lotion." After storage treatment, 9 milliliters (ml) of lotion was removed from each petri dish. The lotions removed from each petri dish at this stage are each referred to as "reference lotion after treatment."

[0066] Next, 1 milliliter (ml) of concentrated bacterial liquid was added to the treated reference lotion taken out from each petri dish to prepare a reference lotion for incubation. The bacteria in the concentrated bacterial liquid were Escherichia coli, and the number of bacteria was 1,000,000 CFU / mL (colony forming unit / mL). In other words, the number of bacteria in the reference lotion for incubation was 100,000 CFU / mL (colony forming unit / mL). Then, each reference lotion for incubation was incubated at 37 degrees Celsius for 24 hours.

[0067] Next, the initial lotion was used to dilute the reference lotion for incubation after incubation by 1000 times to prepare sample solutions. Each of sample solutions A to F was inoculated into a Compact Dry (registered trademark), model 06744CF (2-8998-04: for measuring coliform bacteria count) manufactured by Nissui Pharmaceutical Co., Ltd. (3-23-9 Ueno, Taito-ku, Tokyo), and the number of bacteria was counted.

[0068] The number of bacteria measured with Compact Dry (registered trademark) was low for 0.5 and 1.0 grams of P1, and double-digit reduction in the number of bacteria for 1.5 grams. The number of bacteria was low for 0.5 grams of P2, triple-digit reduction in the number of bacteria for 1.0 grams, and quadruple-digit reduction in the number of bacteria for 1.5 grams. The number of bacteria was double-digit reduction for 0.5 grams of P3, and quadruple-digit reduction in the number of bacteria for 1.0 and 1.5 grams.

[0069] The auxiliary experimental results are as above. It is considered that the surface area of ​​each PP resin pellet is substantially the same. Therefore, a larger weight of the pellet means a larger number of pellets. And, in all of P1, P2 and P3, the larger the number of pellets, the greater the reduction in the number of bacteria. In other words, the larger the specific surface area of ​​the pellets, the greater the reduction in the number of bacteria.

[0070] From the above, it can be reasonably understood that the larger the specific surface area C1 of the container body 20 is, as shown in FIG. 14, the smaller the proportion (predetermined proportion) of zinc oxide in the resin may be.

[0071] In addition to the above experiment, the inventor of the present application has confirmed through an experiment that, in the container body 20 of this embodiment, when the ratio of zinc oxide in the molding material is set to 10% by weight, ultrafine particles at the nano level are further contained at a ratio of 1% by weight, and the ratio of zinc oxide in the molding material is set to 11% by weight, the cosmetic 100 itself has a property of eliminating bacteria that have been mixed into the cosmetic 100 under specified conditions. In this experiment, the particle diameter of the fine particles was 4 micrometers, and the particle diameter of the ultrafine particles was 35 nanometers. This suggests that by adding ultrafine particles at a relatively small ratio compared to the ratio of fine particles in the molding material, the specified ratio of zinc oxide becomes smaller than when the zinc oxide in the molding material is only fine particles.

[0072] As described above, even if a metal powder having a trace metal effect is added to a normal molding material, it is ideal to add one type of metal powder. In order to minimize the change in the properties of the molding material whose main component is resin and to optimize the cost-effectiveness, it is desirable to add as little metal powder as possible. In this regard, in the present invention, only zinc oxide is added as a metal to the molding material, and the predetermined ratio in the molding material is limited to a necessary and sufficient ratio to give the cosmetic a property of destroying bacteria within a predetermined time. After a relatively long time has passed, the concentration of zinc ions does not exceed a certain concentration. In addition, there is no problem of the cosmetic being colored by zinc ions. This makes it possible to avoid the complication of management of the manufacturing process, suppress the change in the properties of the molding material, and optimize the cost-effectiveness, while giving the cosmetic stored in the cosmetic container itself a bactericidal effect without mixing preservatives into the cosmetic, and reducing the impact of secondary contamination.

[0073] The cosmetic container of the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the scope of the present invention. Furthermore, the above-mentioned embodiments can be combined as appropriate as long as no technical contradiction occurs. [Explanation of symbols]

[0074] 1. Cosmetic container 10 Lid 20 Container body 26 Resin 28 Zinc oxide particles 100 Cosmetics

Claims

1. A cosmetic container having a container body for storing liquid cosmetic, The container body is formed from a molding material mainly composed of resin, The molding material contains only zinc oxide as a metal component, The zinc oxide is a powder, The content of the zinc oxide powder in the molding material is specified as a predetermined ratio as a ratio of the zinc oxide powder in the molding material, A cosmetic container, wherein the specified ratio is defined as the ratio necessary and sufficient to impart to the cosmetic stored in the cosmetic container formed from the molding material the property of eliminating bacteria that have become contaminated in the cosmetic under specified conditions.

2. The predetermined condition is that the cosmetic product, which does not contain any preservatives, additives or other ingredients for reducing the number of bacteria, is stored in the container body for 24 hours, and then a predetermined number of bacteria is mixed into the cosmetic product and another 24 hours are allowed to pass at a temperature favorable for the proliferation of the bacteria. The cosmetic container according to claim 1.

3. 3. The cosmetic container according to claim 1, wherein the predetermined ratio is determined by a specific surface area of ​​the container body, which is defined as a ratio of an inner surface area of ​​the container body to a volume of the container body, and a particle diameter of the powder.

4. The cosmetic container according to claim 3, wherein the particle diameter of the powder is 1 micrometer or more and 10 micrometers or less, when the maximum width of each particle constituting the powder is the particle diameter of each particle and the maximum value of the particle size distribution of the powder is the particle diameter of the powder.

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