JP6405348B2 - UV sterilization method - Google Patents

Description

  The present invention relates to a sterilization method using ultraviolet rays.

  Unlike sterilization with chemicals, ultraviolet sterilization has no residue, is highly safe, and hardly changes the irradiated object. Therefore, it is suitable as a sterilization method for foods and medical products that require safety and security. And it is proposed to use ultraviolet sterilization for sterilization in various scenes.

  For example, Patent Document 1 discloses that “a flow path through which an object to be sterilized made of fluid flows, the periphery of which is made of a material having permeability to deep ultraviolet rays having a wavelength of 200 to 350 nm having a bactericidal action, A light source that emits the deep ultraviolet light that is disposed outside the flow path and has a bactericidal action, and sterilizes the object to be sterilized that circulates in the flow path by irradiating the deep ultraviolet light emitted from the light source The light source includes a plurality of “ultraviolet light emitting elements that emit deep ultraviolet light” on a side surface of a cylindrical or polygonal column substrate, and an optical axis of each ultraviolet light emitting element is cylindrical or An ultraviolet light emitting element-arranged base disposed so as to pass through the central axis of a polygonal columnar base so that the deep ultraviolet rays are emitted radially with respect to the central axis, and a cover formed from a deep ultraviolet transparent material When And the cover is airtightly attached to the ultraviolet light emitting element arrangement substrate so as to cover the ultraviolet light emitting element arrangement substrate and enclose an inert gas or dry air therein, and is cylindrical or polygonal. It comprises a deep ultraviolet light emitting module in which a cooling medium flow path is formed inside a columnar base and the cooling medium is circulated through the cooling medium flow path. Alternatively, the light source is disposed on a focal axis of a rectangular mirror and includes a condensing deep ultraviolet emitting unit that condenses and emits the deep ultraviolet rays emitted radially from the light source. There is described an “ultraviolet sterilization apparatus characterized by irradiating the object to be sterilized with the condensed deep ultraviolet light emitted from the ultraviolet emission unit”.

  Patent Document 2 states that “a method for sterilizing microorganisms in a target object, the step of generating a broad spectrum large intensity short duration polychromatic light pulse, and a pulse of light generated on the target object. Inactivating microorganisms in the target object by illuminating, receiving a part of the light pulse as a measure of the amount of the light pulse irradiating the target object, and the part of the light pulse. Generating an output signal in response to light reception, and determining whether the light pulse is sufficient to inactivate a predetermined level of microorganisms in the target object in response to the generation of the output signal. The method characterized by including "." Here, the broad spectrum polychromatic light is, for example, from the far ultraviolet region (200 to 300 nanometers) to the near ultraviolet region (300 to 380 nanometers), visible light (380 to 780 nanometers), and infrared region (780 to 780 nanometers). 1100 nanometers), and its energy distribution is approximately 25% ultraviolet, 45% visible, and 30% infrared, respectively. The target object is, for example, a so-called parenteral solution, enema solution, or contact lens filled and sealed in a flexible pouch made of an ultraviolet light transmissive resin such as vinyl chloride or polyolefin. “Parenteral or enema package” or “contact lens package”. In this method, for example, a thick portion of the above various packages (specifically, around the addition port and / or administration port) and around the center of the package where there are many objects to be sterilized that require processing. In such places, sterilization or inactivation of microorganisms suspended in the product contained in the package by distributing a large amount of the broad-spectrum large-intensity short-duration polychromatic light pulse using a reflector or the like It is carried out.

  In Patent Document 3, “in a liquid sterilization method in which a liquid is passed in front of an ultraviolet irradiator and sterilized by irradiating the liquid with ultraviolet rays, the thickness of the liquid at the location irradiated with the ultraviolet rays is determined by the surface of the liquid. UV irradiation in which the survival rate of microorganisms to be sterilized is not more than a predetermined value while limiting the illuminance ratio, which is the ratio of the ultraviolet illuminance at the surface and the ultraviolet illuminance at the farthest point from the surface, to 20% or more. A liquid sterilization method characterized by irradiating ultraviolet rays at an irradiation line intensity or irradiation time obtained at an irradiation site of the ultraviolet rays is described.

  In the liquid sterilization method described above, a pair of ultraviolet irradiators having a straight tube lamp that irradiates light having a wavelength of 254 nm, disposed opposite to each other with a drinking water channel interposed therebetween, and drinking water provided in the channel. A sterilizer having a slit nozzle that is sprayed between a pair of ultraviolet irradiators is used. And the control of the thickness of the liquid in the place irradiated with the ultraviolet ray is such that the drinking water introduced from the inlet of the slit nozzle has a film thickness corresponding to the slit width of the slit, and a liquid film having a length corresponding to the slit length. It is done by injecting as

  Further, Patent Document 4 includes a light source and a light guide plate having the light source disposed on a side surface, and at least one of the front surface or the back surface of the light guide plate is a light emitting surface that emits light from the light source. A surface light emitting device is described in which a surface other than a light emitting surface of a light plate and a side surface on which a light source is disposed is formed as a light shielding surface, and emits light having a peak wavelength of 388 nm or less.

JP 2014-87544 A Special Table 2000-511497 Japanese Patent Laying-Open No. 2015-62902 JP 2006-237563 A

  It is known that the transmittance of ultraviolet rays varies depending on the type of substance. For example, although the UV transmittance of pure water is relatively high, the UV transmittance is decreased in aqueous solutions in which solutes that absorb UV rays are dissolved and suspensions that contain suspended substances that absorb or scatter UV rays. Varies significantly depending on the type and content of solutes and suspended solids. Specifically, the thickness (light path length: the length of light transmitted through the sample) is 300 mm when the transmittance for ultraviolet rays of 253.7 nm is 10% in distilled water, whereas milk and juice Are known to be 0.07 mm and 0.5-1 mm, respectively.

  Therefore, there is a concern that sterilization may be insufficient when the solution or suspension is subjected to ultraviolet sterilization using the conventional technique described in Patent Document 1. Further, even if the sterilization can be sufficiently performed by the method described in Patent Document 1, there is a risk of re-contamination in a process after ultraviolet sterilization (for example, a filling process in a container).

  In Patent Document 2, by irradiating a wide spectrum large intensity short-time multicolor light emission pulse, and in Patent Document 3, by injecting an object to be sterilized as a liquid film having a film thickness according to the slit width from the slit nozzle. By controlling the film thickness, it is possible to sterilize even an object to be sterilized with a low ultraviolet transmittance. Moreover, in patent document 2, since the object to be sterilized is filled and sealed in a container and then sterilized with ultraviolet rays, the above-mentioned problem of recontamination can be prevented.

  However, the method disclosed in Patent Document 2 requires not only a special control system to perform light distribution, but even if such a system is used, the thickness unevenness of the container or the object to be sterilized, Due to the complexity of the system, such as the complexity of the spectrum of the irradiated light and the intensity changes due to pulsing, it is very difficult to perform uniform UV irradiation, especially for large-capacity packages containing a large amount of sterilized materials. is there. In fact, the capacity of the object to be sterilized in the example of Patent Document 2 is often 10 ml or less, and is 120 ml at the maximum.

  Moreover, in the method described in Patent Document 3, the film thickness is controlled by spraying the liquid to be sterilized as a liquid film having a film thickness corresponding to the slit width from the slit nozzle. It is difficult to control the flow rate of the liquid to be sterilized and it is difficult to control the flow rate of the liquid to be sterilized. There is. In addition, there is the problem of recontamination.

  Furthermore, in the methods disclosed in Patent Documents 2 and 3, since an ultraviolet lamp having a wide emission spectrum is used as an ultraviolet light source, short-wavelength ultraviolet irradiation is unavoidable. It became clear that deterioration was a concern.

  It is a well-known fact that when ultraviolet irradiation is applied for a long period of time, the bonds of molecules constituting the substance are broken by the energy of the ultraviolet rays, resulting in deterioration of the synthetic resin. In ultraviolet sterilization in which only ultraviolet irradiation is performed, the effect has hardly been regarded as a problem. In addition, in the method of sterilizing water using ultraviolet rays, there are many conventional techniques using a photocatalyst (for example, JP 2000-42382 A, JP 2012-223670 A, JP 2006-237563 A, etc.). As is clear from the existence, active species such as hydroxyl radical (OH radical) and ozone generated by ultraviolet irradiation have been considered effective.

  Even if there is a problem due to the active species, it is considered that the problem can be easily avoided if the photocatalyst is not used. When irradiating ultra-short wavelength ultraviolet rays, even in the absence of a photocatalyst, the ultraviolet rays directly act on water and oxygen to generate a small amount of active species, but the lifetime of such active species is very high. It is known to be short, and it is usually difficult to think that these trace amounts of active species will have an adverse effect in normal UV sterilization.

  However, even if it is such a small amount of active species with a short life, its activity (oxidizing power) is very strong, so when organic substances are present in the sterilized body, there is no problem in health or hygiene. It can cause slight changes in the amount that are not at the same level, resulting in subtle changes in taste and aroma. The sensitivity to human taste and olfaction is extremely high, and even slight alteration of its active ingredients can be detected, so the quality of beverages and seasonings characterized by subtle flavors is reduced by UV sterilization. It is fully assumed that

Such problems can occur in J. of Photochemistry and Photobiology A: Chemistry, Vol.137, pp177-184, 2000 and Chem.Eng.Technol. Vol. 21, pp187-191, 1998.
In addition, it is shown that water (H ₂ O) and Fe (OH) ²⁺ generate OH radicals by ultraviolet irradiation, and that quantum efficiency increases when short wavelength ultraviolet rays are used in these OH radical generation reactions. In Japanese Patent No. 4332107, a water retaining surface capable of holding water on the surface in a granular state is wetted with water droplets and irradiated with short wavelength ultraviolet rays from a short distance to generate OH radicals, and the water retaining surface It can also be understood from the description of a method for reforming ethylene into ethane and water by ventilating a gas containing ethylene gas.

  And the probability that such a problem will occur is that ultraviolet rays with extremely short wavelengths are more irradiated to the sterilized body by increasing the intensity of ultraviolet rays or narrowing the flow path width. Will definitely increase.

  Therefore, the present invention solves the above-mentioned problems peculiar to ultraviolet sterilization of solutions and suspensions containing organic substances such as beverages and liquid seasonings in which taste, fragrance or flavor is important, and does not reduce the quality. In addition to providing the method and apparatus, in addition to having such characteristics, there is also provided an ultraviolet sterilization method capable of uniformly and reliably irradiating an object to be sterilized without worrying about recontamination. The task is to do.

  In the present invention, in order to prevent re-contamination as much as possible, the concept shown in Patent Document 2 in which UV irradiation is performed in a state where the object to be sterilized is filled in the container, and UV irradiation is ensured by reducing the thickness of the object to be sterilized. In addition to combining the concepts shown in Patent Document 3 to perform and further developing these, it is possible to generate ultraviolet rays having a very short wavelength (high energy) such as 250 nm or less, and further 220 nm or less, which has a high ability to generate the active species, as much as possible. This is based on the concept of not irradiating and the concept of enabling a large amount of objects to be sterilized to be processed efficiently on an industrial scale.

That is, the sterilization method of the present invention comprises:
A method for sterilizing an object to be sterilized filled with a fluid containing an organic substance, filled in a container,
A filling step of filling the container to be sterilized;
From the outside of the container filled with the object to be sterilized by the filling step, a wavelength region of 260 nm or more and 280 nm or less in the spectrum in which the horizontal axis represents the wavelength and the vertical axis represents the relative emission intensity with respect to the object to be sterilized . a sealing step of sealing the container the sum of the relative intensity ultraviolet irradiation step and the object to be sterilized body to shot an ultraviolet irradiation is 70% or more of the sum of the relative intensities of the entire wavelength range is filled ultraviolet airtightly Comprising
The container has an ultraviolet light transmitting portion made of a material that transmits ultraviolet light in a wavelength region of 253 nm or more and 280 nm or less and having a uniform thickness,
In the ultraviolet irradiation step, the ultraviolet rays that have passed through the ultraviolet transmitting portion are irradiated to the sterilized body,
The sealing step is performed between the end of the filling step and the end of the ultraviolet irradiation step, or is performed in the same sterile environment as the ultraviolet irradiation step after the end of the ultraviolet irradiation step. It is characterized by that.

  Here, selectively irradiating ultraviolet rays in a wavelength region of 253 nm or more and 280 nm or less, preferably 260 nm or more and 280 nm or less means that in the spectrum of the irradiated ultraviolet rays, the horizontal axis indicates the wavelength and the vertical axis indicates the relative emission intensity. The sum of the relative intensities of ultraviolet rays in the wavelength region of 280 nm or less, preferably 260 nm or more and 280 nm or less is 70% or more, preferably 80% or more, and most preferably 90% or more of the sum of the relative intensities of all wavelength regions. means. At this time, the sum of the relative intensities in the wavelength region of 250 nm or less is preferably 10% or less, preferably 5% or less, more preferably 3% or less, and the sum of the relative intensities in the wavelength region of 220 nm or less is 7%. % Or less, preferably 3% or less, more preferably 1% or less.

  In the sterilization method of the present invention, from the viewpoint that the sealing step can be easily performed and the risk of re-contamination is low, the container has an ultraviolet transparent film having a uniform thickness made of a heat-sealable resin. A flexible bag formed from a bag, or a flexible bag formed from a UV-permeable laminated resin film having a uniform thickness including a heat-sealable resin layer, wherein the sealing step is the It is preferably performed by heat-sealing the opening of the flexible bag, and it is preferable that the object to be sterilized is liquid, paste, jelly, or mousse because of its high industrial value.

  Moreover, it is preferable to make the temperature of the to-be-sterilized body in the said ultraviolet irradiation process more than 0 degreeC and 10 degrees C or less from the reason of suppressing generation | occurrence | production of the said active species more.

Further, from the viewpoint of reliably sterilizing ultraviolet rays even when an ultraviolet light emitting diode whose output intensity is weaker than that of an ultraviolet lamp is used as a light source, in the ultraviolet irradiation step, the ultraviolet rays are applied to an area irradiated with ultraviolet rays. Irradiation from one direction or two directions opposite to each other, and further the width of the irradiated ultraviolet light in the optical axis direction in at least a part of the region, the transmitted ultraviolet light when the irradiated ultraviolet light passes through the layer to be sterilized When the thickness of the layer to be sterilized with an irradiance of 0.01 mW / cm ² is defined as an effective optical path length, the total effective optical path length of ultraviolet rays irradiated from the one or two directions is equal to or less than It is preferable to do.

  In this case, from the viewpoint that the width in the optical axis direction can be reliably controlled, in the ultraviolet irradiation step, a pair of partition walls arranged to face each other with a gap having a width equal to or less than the sum of the effective optical path lengths. 1 or 2 provided on one or both of the two opposing surfaces of the pair of partition walls, with the surface of the container filled with the object to be sterilized disposed in the space between It is preferable to irradiate the ultraviolet rays from the ultraviolet light emitting surface or ultraviolet transmissive window.

  In addition, from the viewpoint of the storage stability of the object to be sterilized, it is preferable that the method further includes an ultraviolet shielding process for performing an ultraviolet shielding process on the outer surface of the container sealed by the sealing process.

  In these sterilization methods of the present invention, an ultraviolet light-emitting diode (hereinafter also referred to as UV-LED) is used as an ultraviolet light source because there is no waiting time at startup, mercury is not used, maintenance is easy, and the life is long. It is preferable to use a UV-LED having a main peak of the emission wavelength in the wavelength region of 253 nm to 280 nm.

  Another aspect of the present invention is a method for producing a container-packed article in which a UV-sterilized food, cosmetic, quasi-drug, or pharmaceutical is enclosed in a container, and the fluid food, cosmetic, pharmaceutical Packing the container to be sterilized consisting of an quasi-drug or a pharmaceutical product by the steps of filling the container to be sterilized by the sterilization method of the present invention, irradiating with ultraviolet rays, and sealing the container. This is a method for manufacturing an article.

  In the ultraviolet sterilization method of the present invention, the object to be sterilized is filled in a container, and sterilization is performed by irradiating ultraviolet rays from the outside of the container, so that recontamination can be prevented. Furthermore, the object to be sterilized does not come into contact with the window material of the ultraviolet irradiation device or the ultraviolet sterilization device, and the window material is not soiled. Therefore, it is not necessary to perform disassembly and cleaning, and it is possible to always maintain a clean state (a state in which the ultraviolet ray transmission is high) by a simple operation such as a wiping operation for light dirt such as adhesion of dust.

  In addition, since the ultraviolet rays in the wavelength region of 253 nm or more and 280 nm or less are selectively irradiated, the taste and scent of the solution or suspension containing organic matter such as beverages and liquid seasonings in which taste, fragrance or flavor is important Alternatively, ultraviolet sterilization can be performed without impairing the flavor.

  Furthermore, by performing ultraviolet irradiation through the “ultraviolet transmitting portion having a uniform thickness” of the container, uniform ultraviolet irradiation can be performed without using a complicated control system. In addition, when the ultraviolet transmitting part is composed of a thin flexible film or sheet, it is easy to control the thickness (width) of the object to be sterilized in the ultraviolet irradiation region, and the ultraviolet irradiation is performed by reducing the thickness. be able to. Therefore, even if UV-LED is used, it can be reliably irradiated with ultraviolet rays.

  Furthermore, in the method of the present invention, when an ultraviolet shielding process for applying an ultraviolet shielding process to the outer surface of the container sealed by the sealing process is added, a sterilized object to be sterilized enclosed in the container In the case of storing for a long time, it is possible to prevent the contents (sterilized material to be sterilized) from being deteriorated and the container from being deteriorated by ultraviolet rays from nature.

  In so-called retort foods, it is necessary to sterilize under pressure and heat after enclosing the food in a retort pouch, whereas the sterilization method of the present invention does not require pressure or heating, so raw milk, fermented milk, etc. It is also possible to sterilize objects to be sterilized that cannot be heated or pressurized, such as fresh food, raw soy sauce, and sake.

  In addition, according to the method for producing a container-packed article (an article packed in a container) of the present invention, while obtaining the effect of the sterilization method of the present invention as described above, fluid food, cosmetics, quasi-drugs The product or medicine can be filled in a container, UV sterilized, and the container can be sealed. And compared with the case where heat-and-pressure sterilization is performed, there exists an advantage that an apparatus is simple, energy cost is small, and the time which manufacture can be shortened.

This figure is a cross-sectional view of an ultraviolet sterilization apparatus that can be suitably used in the ultraviolet irradiation step of the sterilization method of the present invention. This figure is a transverse sectional view and a longitudinal sectional view of an ultraviolet light emitting module that can be suitably used in the ultraviolet sterilization apparatus shown in FIG. This figure is a schematic diagram for explaining a preferred embodiment of the ultraviolet irradiation step of the sterilization method of the present invention. This figure is the schematic of the ultraviolet irradiation unit used suitably by the aspect shown in FIG. This figure is the schematic of another ultraviolet irradiation unit used suitably with the aspect shown in FIG. This figure is the schematic of another ultraviolet irradiation unit used suitably by the aspect shown in FIG. This figure is a cross-sectional view of a light source (condensing modularized light source) in the ultraviolet irradiation unit shown in FIG. This figure is a side view of a light source (condensing modularized light source) in the ultraviolet irradiation unit shown in FIG.

The sterilization method of the present invention is a method for sterilizing an object to be sterilized, which is filled in a container and made of a fluid containing organic matter, and includes a filling step for filling the container to be sterilized, and the object to be treated by the filling step. From the outside of the container filled with a sterilized body, the sum of the relative intensities of ultraviolet rays in a wavelength region of 260 nm or more and 280 nm or less in the spectrum in which the horizontal axis represents the wavelength and the vertical axis represents the relative emission intensity with respect to the sterilized body. There comprises a sealing step of sealing hermetically the container ultraviolet irradiation step and the object to be sterilized body is morphism irradiation with ultraviolet rays is at least 70% of the sum of the relative intensities of the entire wavelength range is filled, the container Is composed of a material that transmits ultraviolet rays in a wavelength region of 253 nm or more and 280 nm or less and has a uniform thickness and an ultraviolet transmitting portion. In the ultraviolet irradiation step, the ultraviolet transmitting portion is The ultraviolet light that has passed is irradiated onto the object to be sterilized, and the sealing step is performed between the completion of the filling step and the completion of the ultraviolet irradiation step, or the ultraviolet light after the ultraviolet irradiation step is completed. It is performed in the same aseptic environment as the irradiation step.

  The object to be sterilized in the present invention is composed of a fluid containing an organic substance and is not particularly limited as long as it can be filled in a container, but the effect of the sterilization method of the present invention is remarkable. For reasons, taste, fragrance and / or flavor are important. Sterilized liquid, paste, jelly or mousse containing aqueous solutions and aqueous suspensions containing organic substances such as various sugars and ester compounds that become aromatic components. The body to be sterilized has a thickness (optical path length: the length of light transmitted through the sample) of 100% or less and 0.001 mm or more when the transmittance for ultraviolet rays of 253.7 nm is 10%. It is preferable that In particular, the thickness is particularly preferably 10 mm or less and 0.001 mm or more.

  Examples of such an object to be sterilized include fluid foods (including beverages), cosmetics, quasi drugs, and pharmaceuticals. Specifically, examples of the food include liquid foods, liquid seasonings, edible oils, alcoholic beverages, beverages, yogurt, ice cream, and jelly. Examples of cosmetics include cosmetics for skin, such as cosmetic liquids, lotions, creams, milky lotions, face wash, cosmetics for finishing such as foundations and makeup bases, perfumes, and colognes. Examples of quasi-drugs include nutritional drinks, toothpastes, and hair care products. Examples of pharmaceuticals include eye drops, various drops, various injections, and various ointments. Among these, those that are not suitable for pressure heat sterilization, such as those containing active ingredients that are decomposed or altered by pressure heating, such as raw milk, fresh juice, fresh sake, draft beer, raw soy sauce, etc., and further promote the generation of OH radicals It is particularly preferable to apply the sterilization method of the present invention to tomato juice, vegetable juice and the like containing a nitrate nitrogen compound having an effect.

  The container used in the present invention is not particularly limited as long as it has a uniform thickness and is composed of a material that transmits ultraviolet rays in a wavelength region of 253 nm or more and 280 nm or less and has an ultraviolet transmission part. Moreover, the said container should just be the said ultraviolet permeation | transmission part in the part which contacts the to-be-sterilized body irradiated with an ultraviolet-ray in the said ultraviolet irradiation process, The whole does not necessarily need to be comprised with a ultraviolet-ray transmissive material. . As the ultraviolet transmissive material, it is preferable to use an ultraviolet transmissive resin from the viewpoint of easy manufacture of the container.

The ultraviolet transmissive resin may be any resin that is transparent to ultraviolet rays having a wavelength of 253 nm or more and 280 nm or less. Examples of such a resin include polyolefin resins such as polyethylene, polypropylene, and polymethylterpene, and polyolefin-based copolymers. Fluorine resin such as coalescence resin, polytetrafluoroethylene, tetrafluoroethylene perfluoroalkyl vinyl ether copolymer, methacryl resin, polytetrafluoroethylene, epoxy resin, alicyclic polyimide resin, polyamide resin, polyvinyl chloride, polyvinyl alcohol Resins and the like (all of which preferably do not contain additives such as ultraviolet absorbers and plasticizers that absorb ultraviolet rays irradiated in the ultraviolet irradiation step) can be exemplified. Among these resins, it is preferable to use a polyolefin resin or a polyolefin-based copolymer resin having high heat sealability. These ultraviolet light transmitting resins may be used alone or in a composite form such as a laminate. Regarding the ultraviolet transmittance of the resin film, “Touzo Matsui, Yoshihiro Shimizu,“ UV Transmissivity of Plastic Film II ”, Toyo Foods Institute, Toyo Food Research Laboratory, 102-111 (1967)” , "Daikin Industries, Ltd. Technical Document GX-27e" Neofrene _TM Film "", and
Data is described in http://jp.mitsuichem.com/service/functional_polymeric/polymers/tpx/spec.htm.

  The shape of the container is not particularly limited, and may be any of a bag-shaped container, a box-shaped container, and a bottle-shaped container, and may have other shapes. However, the ultraviolet transmissive part needs to have a uniform thickness. The uniformity of the thickness is preferably ± 10% or less, particularly ± 5% or less in terms of the variation rate with respect to the average thickness. The average thickness of the ultraviolet light transmitting portion is preferably thinner as long as it has a strength capable of holding the contents. A preferable thickness of the container material is 5 μm or more and 1 mm or less, a more preferable thickness is 10 μm or more and 500 μm or less, and a particularly preferable thickness is 20 μm or more and 300 μm or less. In addition, the transmittance of the ultraviolet light transmitting portion to the irradiated ultraviolet light is preferably 50% or more, more preferably 70% or more, and most preferably 75% or more.

  Among these containers, from the viewpoint that heat sealing is possible in the sealing step, an ultraviolet ray including a flexible bag or a heat sealable resin layer formed by making an ultraviolet ray transmissive film made of a heat sealable resin. A flexible bag formed by making a permeable laminated resin film is preferable. In addition, as an ultraviolet permeable laminated resin film which consists of a heat-sealable resin layer, what is disclosed by Unexamined-Japanese-Patent No. 2013-534874 can be mentioned, for example.

  The form of the flexible bag is not limited as long as it has an opening for filling an object to be sterilized. Two-sided bag, three-sided bag, gusset bag, bottom gusset bag, stand bag, side seal bag A known form such as a bottom seal bag can be employed. These bags may have a spout, a zipper or a chuck.

  The filling step is not particularly different from the conventional filling step except that the container having the ultraviolet light transmitting portion is used as the container, and can be performed using, for example, an automatic pouch filling machine or an automatic bottle filling machine.

  In the sterilization method of the present invention, in the ultraviolet irradiation step, from the viewpoint of suppressing the generation of the active species such as OH radicals and ozone and further reducing the reactivity of the inevitably generated activity. The temperature of the object to be sterilized is preferably more than 0 ° C. and 10 ° C. or less, and further includes a step of reducing or removing dissolved oxygen contained in the object to be sterilized as a pre-process of the ultraviolet irradiation process. It is preferable.

  In these steps, for example, the temperature of the object to be sterilized is controlled within the above range through a heat exchanger or the like, and further, for example, dissolved oxygen is reduced or removed by a method of bubbling nitrogen gas or hydrogen gas, a decompression process, or the like.

  In the ultraviolet irradiation step, ultraviolet rays having a wavelength region of 253 nm or more and 280 nm or less, preferably 260 nm or more and 280 nm or less are selectively emitted from the outside of the container filled with the object to be sterilized in the filling step. To do. By selectively irradiating ultraviolet rays in a wavelength region of 253 nm or more and 280 nm or less, preferably 260 nm or more and 280 nm or less, high-energy ultraviolet rays are applied to the liquid to be sterilized while maximizing the bactericidal effect of damaging bacterial DNA. It is possible to suppress the generation of active species such as OH radicals and ozone by acting on the contained water and dissolved oxygen as much as possible, and it becomes possible to maintain the quality of the sterilized object.

  Here, selectively irradiating ultraviolet rays in a wavelength region of 253 nm or more and 280 nm or less, preferably 260 nm or more and 280 nm or less means that in the spectrum of the irradiated ultraviolet rays, the horizontal axis indicates the wavelength and the vertical axis indicates the relative emission intensity. The sum of the relative intensities of ultraviolet rays in the wavelength region of 280 nm or less, preferably 260 nm or more and 280 nm or less is 70% or more, preferably 80% or more, and most preferably 90% or more of the sum of the relative intensities of all wavelength regions. means. At this time, the sum of the relative intensities in the wavelength region of 250 nm or less is preferably 10% or less, preferably 5% or less, more preferably 3% or less of the sum of the relative intensities in all the wavelength regions, and 220 nm or less. The sum of the relative intensities in the wavelength region is 7% or less, preferably 3% or less, more preferably 1% or less, of the sum of the relative intensities in all the wavelength regions. Furthermore, from the viewpoint of preventing so-called photorecovery or reactivation, the sum of the ultraviolet intensities in the wavelength region of 300 nm or more is 7% or less, preferably 3% or less, more preferably 1% of the sum of the relative intensities in all the wavelength regions. % Or less is preferable. In addition, although ultraviolet rays may contain visible light, it is more preferable not to contain visible light.

  That is, the spectrum of the irradiated ultraviolet rays becomes more preferable from (1) to (6) below.

  (1) The sum of the relative intensities of ultraviolet rays in the wavelength region of 253 nm or more and 280 nm or less is 70% or more of the sum of the relative intensities of all the wavelength regions, and the sum of the relative intensities of the wavelength regions of 250 nm or less is relative to all the wavelength regions A spectrum that is 10% or less of the sum of intensities, and the sum of UV intensities in the wavelength region of 300 nm or more is 7% or less of the sum of relative intensities in all wavelength regions; (2) UV in the wavelength region of 260 nm or more and 280 nm or less The total sum of relative intensities is 70% or more of the sum of relative intensities in all wavelength regions, the sum of relative intensities in the wavelength regions of 250 nm or less is 10% or less of the sum of relative intensities in all wavelength regions, and is 300 nm or more. The sum of the ultraviolet intensities in the wavelength region is a spectrum that is 7% or less of the sum of the relative intensities in all the wavelength regions; (3) the ultraviolet rays in the wavelength region from 253 nm to 280 nm. The sum of the pair strengths is 80% or more of the sum of the relative intensities in the whole wavelength region, the sum of the relative intensities in the wavelength region of 250 nm or less is 5% or less of the sum of the relative intensities in all the wavelength regions, and is 300 nm or more. A spectrum in which the total sum of ultraviolet intensities in the wavelength region is 3% or less of the sum of relative intensities in all wavelength regions; (4) The sum of the relative intensities of ultraviolet rays in the wavelength region of 260 nm or more and 280 nm or less is the relative intensity of all wavelengths. 80% or more of the total sum, the sum of relative intensities in the wavelength region of 250 nm or less is 5% or less of the sum of the relative intensities in all the wavelength regions, and the sum of the ultraviolet intensities in the wavelength region of 300 nm or more is the total wavelength region (5) The sum of the relative intensities of ultraviolet rays in the wavelength region of 253 nm or more and 280 nm or less is 90% or more of the sum of the relative intensities of all the wavelength regions. , The sum of the relative intensities in the wavelength region of 250 nm or less is 3% or less of the sum of the relative intensities in all the wavelength regions, and the sum of the ultraviolet intensities in the wavelength region of 300 nm or more is 1 of the sum of the relative intensities in all the wavelength regions. (6) The sum of the relative intensities of ultraviolet rays in the wavelength region of 260 nm or more and 280 nm or less is 90% or more of the sum of the relative intensities of all wavelength regions, and the sum of the relative intensities in the wavelength region of 250 nm or less is A spectrum in which the sum of relative intensities in all wavelength regions is 3% or less and the sum of ultraviolet intensities in wavelength regions of 300 nm or more is 1% or less of the sum of relative intensities in all wavelength regions.

  In order to selectively irradiate ultraviolet rays in such a wavelength region, a method using an optical filter that absorbs or reflects ultraviolet rays in a wavelength region other than the wavelength region to be irradiated, or irradiates by extracting ultraviolet rays having a specific wavelength with a monochromator. The method uses an ultraviolet light emitting diode (UV-LED, which is also a deep ultraviolet light emitting diode: DUV-LED because the ultraviolet light in the above wavelength region is also a deep ultraviolet light) designed to emit ultraviolet light in a specific wavelength region. A method etc. can be adopted. Among these methods, the advantages of UV-LED (DUV-LED), such as excellent features such as instantaneous start-up, low power drive, long life, no mercury, etc. Therefore, it is preferable to use a UV-LED (DUV-LED) having a main peak in a wavelength region of 253 nm or more and 280 nm or less, preferably 260 nm or more and 280 nm or less and having an emission spectrum as described above as a light source. .

  The sealing step is performed by hermetically sealing the container. As the sealing method, heat sealing or adhesion using an adhesive can be suitably employed when the container is in a bag shape, and capping can be suitably employed when the container is in a bottle shape. In sealing, a gas replacement process or a deaeration process can also be performed. These treatments can be easily performed using a dedicated device generally used in so-called vacuum packaging or gas-filled packaging.

  In the sterilization method of the present invention, the sealing step is performed between the end of the filling step and the end of the ultraviolet irradiation step (details will be described later), or after the end of the ultraviolet irradiation step. It is performed in the same aseptic environment as in the ultraviolet irradiation step. Here, performing in the same aseptic environment means that an object to be sterilized is filled in a sterilized space such as an indoor space in which sufficiently sterilized air is supplied with positive pressure. This means that the ultraviolet ray irradiation step and the sealing step are performed without taking the container out of the space. At this time, the sealing step can be performed after the ultraviolet irradiation.

  In the ultraviolet irradiation step, the ultraviolet light that has passed through the ultraviolet transmitting portion is irradiated to the sterilized body. When using an object to be sterilized with a low UV transmittance, the intensity of the irradiated UV light attenuates rapidly as the length of the object to be sterilized becomes longer (depth becomes deeper), and the inner object to be sterilized. It will not reach the body. Therefore, in order to make the ultraviolet rays reach the inside, the width (maximum length of the optical axis of the irradiated ultraviolet rays across the container, for example, W in FIG. 3) of the container is reduced (thinned) or irradiated. It is necessary to increase the UV intensity.

In the method of the present invention, the irradiance of ultraviolet rays at an arbitrary position of the article to be sterilized filled in the container is controlled to 0.01 mW / cm ² or more, particularly preferably 0.8 by controlling the width of the container or the ultraviolet intensity. It is preferable to be 03 mW / cm ² or more, most preferably 0.05 mW / cm ² or more. The higher the irradiance, the better, and there is no special meaning in setting the upper limit, but it is generally 1 W / cm ² or less.

The value of the irradiance: 0.01 mW / cm ² , 0.03 mW / cm ^2, or 0.05 mW / cm ² is not critical for the numerical value itself, and is an industrially practical treatment. It is an index determined from the viewpoint that an effective bactericidal effect can be obtained in time (ultraviolet irradiation time). For example, when considering the sterilization of Escherichia coli whose ultraviolet irradiation amount (integrated irradiation amount) necessary for inactivation of 99.9% is about 10 mJ / cm ² (= mW · sec / cm ² ), 0.01 mW / cm ^For irradiance of ² , 0.03 mW / cm ² and 0.05 mW / cm ² , 1,000 seconds (16 minutes 40 seconds), 333 seconds (5 minutes 33 seconds) and 200 seconds (3 minutes 20 seconds), respectively. 99.9% inactivation becomes possible by irradiation. Incidentally, the retort food is sterilized under pressure and heat at a center temperature of 120 ° C. for 4 minutes or more.

In the sterilization method of the present invention, from the viewpoint of reliably irradiating ultraviolet rays even when a low-intensity ultraviolet light-emitting diode is used as a preferable light source, in the ultraviolet irradiation step, the ultraviolet ray is applied to the region irradiated with ultraviolet rays. Irradiated from the direction or two directions facing each other, and further, the irradiated ultraviolet ray (having a specific intensity at the time of emission) is irradiated with the width in the optical axis direction of the irradiated ultraviolet ray in at least a part of the region. The thickness of the layer of the object to be sterilized so that the irradiance of the transmitted ultraviolet light when transmitted through the layer is 0.01 mW / cm ² is defined as the effective optical path length of the ultraviolet light (having a specific intensity when emitted). It is preferable that the total length of the effective optical path lengths of the ultraviolet rays irradiated from the one direction or the two directions is not more than the total.

  In addition, when emitting ultraviolet rays of a specific intensity from a light source or its ultraviolet light emitting surface and performing ultraviolet irradiation, the effective optical path length is also referred to as an effective optical path length of the light source or its ultraviolet light emitting surface.

In order to satisfy such a condition, (i) the ultraviolet light emitting surface of the ultraviolet light source is disposed so as to face the ultraviolet transmitting portion on one side of the container, and ultraviolet rays are irradiated from one direction And (ii) the ultraviolet light emitting surfaces of the two ultraviolet light sources are arranged so as to face the ultraviolet transmitting parts on the two front and back sides of the container, and ultraviolet rays are irradiated from two directions facing each other on the same optical axis. For each case, it is preferable to do as follows. That is, (i) when irradiating ultraviolet rays from one direction, the irradiance of the transmitted ultraviolet rays when the ultraviolet ray transmitting part and the sterilizing material layer of the container filled with the sterilizing material are transmitted is 0 0.01 mW / cm ² or more, preferably 0.03 mW / cm ² or more, and most preferably 0.05 mW / cm ² or more. In addition, (ii) when simultaneously irradiating ultraviolet rays having the same intensity from two directions facing each other on the same optical axis, the irradiance of ultraviolet rays at the central portion in the container is 0.01 mW / cm ² or more. Preferably, it is 0.03 mW / cm ² or more, and most preferably 0.05 mW / cm ² or more.

  About the to-be-sterilized body actually used, for example, by examining the relationship between the optical path length and the radiant intensity of transmitted ultraviolet rays in advance by the procedure as shown in the following steps (a) to (d), In the case of (ii), the irradiance at each position can be easily estimated.

(A) Step S ₁₀₁ for filling an object to be sterilized inside an ultraviolet transmissive optical measurement cell having a predetermined optical path length (hereinafter sometimes simply referred to as “cell”);
(B) The ultraviolet light emitting surface of the ultraviolet irradiation device is placed in close contact with the cell with a film or sheet of the same material and thickness as the ultraviolet light transmitting portion of the container, and the same light emission as in the sterilization treatment is made from the ultraviolet light emitting surface. Irradiating ultraviolet rays emitted under conditions toward the inside of the cell _S102 ;
(C) Step S ₁₀₃ of measuring the irradiance (unit: mW / cm ² ) of the transmitted ultraviolet light that has passed through the cell;
(D) the steps (a) to the _{(c) (S 101 ~S 103} ), by performing a plurality of cells having different optical path lengths, the step _{S 104} to determine the relationship between the irradiance and the optical path length of the transmitted ultraviolet ;
In the steps (a) to (d) (S _{101 to} S ₁₀₄ ), the relationship between the irradiance of transmitted ultraviolet light and the optical path length follows Lambert-Beer's law. That is, the irradiance I ₁ of transmitted ultraviolet rays is in the relationship of the following equation (1) with respect to the optical path length L.
log (I ₁ / I ₀ ) = − αL (1)
In equation (1), I ₀ is the irradiance of ultraviolet light having a wavelength λ before entering the medium, and α is a proportionality constant (absorption coefficient) determined corresponding to the sterilized object and the wavelength λ _peak . In general, since the peak width of the emission spectrum of the light emitting diode is extremely narrow, in discussing the dependence of the irradiance of transmitted ultraviolet light on the optical path length, only the extinction coefficient α (λ _peak ) at the emission peak wavelength λ _peak of the deep ultraviolet light emitting diode. Is enough. Equation (1) can be transformed into the following equation (2).
logI ₁ = −αL + logI ₀ (2)
Therefore, by obtaining a plurality of pairs of the logarithm of the transmitted ultraviolet irradiance I _{1 at} the main peak wavelength λ _peak and the optical path length L of the cell, the transmitted ultraviolet irradiance I ₁ and the optical path length L at the main peak wavelength λ _peak Can be obtained (step (d) above, step S ₁₀₄ ). For example, a known method such as a least square method can be used to calculate the regression line.

  In the step (b), a film or sheet having the same material and thickness as the ultraviolet transmissive part of the container is interposed in the actual ultraviolet irradiation process. The ultraviolet ray is a container material (a partition wall and a sheet separating the outside and the inside of the container). This is because, by passing through the film), the material to be sterilized is attenuated and irradiated.

In this way, for the light source actually used (referred to as light source a), the irradiance I ₁ of transmitted ultraviolet light and the optical path length L are determined for each intensity of ultraviolet light emitted from the ultraviolet light exit surface (referred to as exit surface a). The relationship is investigated, and from this relationship, the optical path length L when the irradiance I ₁ when emitting ultraviolet rays with the intensity actually irradiated in the ultraviolet irradiation step is 0.01 mW / cm ² is the effective optical path under the conditions. it comes to the length _{L a.}

In the above case (i) is the width of the optical axis of the ultraviolet rays irradiated at least part of a region where ultraviolet rays are irradiated, following one effective optical length when using an ultraviolet light-emitting surface a L _a and In the case of (ii), the effective optical path when the two ultraviolet light emitting surfaces a and b are used is defined as the width in the optical axis direction of the irradiated ultraviolet rays in at least a part of the region irradiated with the ultraviolet rays. The length may be equal to or less than the sum of the lengths L _a and L _b (L _a + L _b ).

  Although such a method seems to enable estimation with considerably high accuracy, it is preferable to finally perform confirmation under actual use conditions in an actual machine. As long as the conditions are stable, the results will not change.Therefore, it is not necessary to make such a check every time. It may be performed periodically after a period of.

  When a thin container cannot be used and the thickness (width) cannot be controlled because the container is not deformed, it is preferable to increase the intensity of the irradiated ultraviolet rays to increase the effective optical path length.

  Ultraviolet light emitting diodes (UV-LEDs), particularly deep ultraviolet light emitting diodes (DUV-LEDs) that emit deep ultraviolet rays, are not only weaker in light output than ultraviolet lamps, but also have high directivity of emitted ultraviolet rays. The irradiation area becomes narrower. Therefore, it is difficult to control the width of the container, and when a UV-LED or DUV-LED is used as a light source, strong ultraviolet light is irradiated over the entire surface of the container to be irradiated with ultraviolet light. There is a need to.

  As a method of irradiating strong ultraviolet rays over the entire surface of the container to be irradiated with ultraviolet rays, a method of increasing the irradiance using condensing or a high forward current using a step-up DC-DC converter or a charge pump. It is preferable to adopt a method in which the light emission output is increased by flowing the light (in this case, pulse light emission may be performed if necessary).

  For example, the container is a hollow object such as a bottle and is difficult to deform (deformation that returns to its original shape by removing the force or applying a restoring force by applying a force temporarily) In such cases, the following method can be suitably employed.

  That is, firstly, as shown in FIG. 4 or FIG. 5 of Patent Document 1, “a sterilized body made of a fluid having a periphery made of a material having a sterilizing action and having a permeability to ultraviolet rays is distributed. A light source disposed outside the flow channel and emitting ultraviolet light having a sterilizing effect, and irradiating the sterilized body flowing through the flow channel with the ultraviolet light emitted from the light source The light source is composed of a plurality of “ultraviolet light emitting elements that emit ultraviolet light having a sterilizing effect”, and condenses the ultraviolet light emitted from each ultraviolet light emitting element. The ultraviolet ray sterilized apparatus is characterized by irradiating the object to be sterilized with the ultraviolet light condensed by the light collecting device (instead of the flow path, the flow path is disposed). To be sterilized) Place Hama containers (also referred to as method 1.) Method with ultraviolet irradiation is preferably employed.

  Second, a large number of DUV-LEDs are aligned over the entire inner surface facing the container of a cylindrical base material that can accommodate the container, and a high forward direction using a step-up DC-DC converter and a charge pump. A method (also referred to as method 2) in which an ultraviolet ray is irradiated at a high output by passing an electric current can be suitably employed.

  In addition, when the shape of the container can be set freely, a thin container (for example, a flat plate) may be used, and the intensity of ultraviolet rays may be increased as necessary. For example, when the container is a flexible bag, it is preferable that the bag shape is a thin elliptical columnar shape (including one having a gradually decreasing thickness in the height direction) or a rectangular columnar shape (or a flat plate shape), Further, it is preferable to perform ultraviolet irradiation by the following method (also referred to as Method 3). That is, in the method 3, the surface of the container filled with the object to be sterilized approaches or comes into contact with the space between a pair of partition walls arranged to face each other with a gap having a predetermined width. It arrange | positions in this way, and an ultraviolet-ray is irradiated from the 1 or 2 ultraviolet-ray light emission surface provided in one or both of the two surfaces where the said pair of partition faces. At this time, when only the surface of one partition is an ultraviolet light emitting surface, the surface of the other partition (the surface facing the ultraviolet light emitting surface) is preferably an ultraviolet reflecting mirror.

  Further, in the above method 3, the surface of the container filled with the object to be sterilized is arranged so that an area of 50% or more is close to or in contact with the partition wall, and the two surfaces of the pair of partition walls face each other. A method of irradiating ultraviolet light from two provided ultraviolet light emitting surfaces (also referred to as method 3-1) is preferable, and the ultraviolet light emitting surface has a shape corresponding to the shape of the surface of the container filled with an object to be sterilized. It is particularly preferable to employ a method (also referred to as method 3-2) in which ultraviolet irradiation is performed so that an area of 80% or more of the surface of the container is close to or in contact with the partition wall.

  In addition, a flexible bag or a heat-sealable resin layer in which the object to be sterilized is liquid, paste-like, jelly-like, or mousse-like, and the container is made of an ultraviolet-permeable film made of a heat-sealable resin. In the case of a flexible bag formed by making an ultraviolet transmissive laminated resin film comprising, the flexible bag filled with the object to be sterilized, from the front side and / or the back side, It is preferable to adopt a method (also referred to as method 3-3) in which ultraviolet irradiation is performed by deforming the flexible bag so that the thickness of the flexible bag is reduced by clamping with an ultraviolet light emitting surface.

  Hereinafter, the method 1 and the method 3-3 will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view of an ultraviolet sterilizer 100 used in Method 1. The apparatus is basically the same as the apparatus shown in FIG. 4 of Patent Document 1, and the sterilization target is disposed at the position where the quartz tube or the sapphire pipe constituting the flow path in the apparatus shown in FIG. A bottle-like container 300 filled with the body 200 is disposed. The ultraviolet sterilization apparatus 100 shown in FIG. 1 is arranged such that “a plurality of deep ultraviolet light emitting elements are arranged on the side surface of a cylindrical base body so that the optical axis of each deep ultraviolet light emitting element passes through the central axis of the base body. A light source including an ultraviolet light emitting module 110 configured to emit the deep ultraviolet rays radially with respect to the central axis; and a condensing device including an oblong reflection mirror 120, the oblong reflection mirror 120. The ultraviolet light emitting module 110 is disposed on the focal axis of the light source, and a “condensed ultraviolet light emitting unit” 130 that collects and emits the ultraviolet light emitted radially from the ultraviolet light emitting module 110 is provided. In the ultraviolet sterilizer 100, the four condensing ultraviolet ray emitting units 130 are arranged so that the respective condensing axes coincide with each other, and the condensing axes coincide with the symmetry axis (center axis) of the bottle-shaped container 300. A container 300 is arranged.

  In the ultraviolet light emitting module 110, as shown in FIG. 2, a plurality of DUV-LEDs 112 are arranged on the surface of the cylindrical substrate 111, and a cooling medium flow channel 113 is disposed inside the cylindrical substrate. Is formed. Further, the cylindrical substrate 111 on which the DUV-LED 112 is mounted is covered with a cover 116 formed of an ultraviolet light transmissive material such as quartz or sapphire. The cover 116 is airtightly or watertightly attached to the cylindrical substrate using a sealant 117 such as a sealant, packing, o-ring, and the like, and an inert gas such as nitrogen and a gas such as dry air are enclosed therein. Has been.

  The DUV-LED is arranged in a state where the element is mounted on a submount or accommodated in a package, and ultraviolet rays are emitted in a certain direction. Although not shown, the submount or the package is provided with wiring for supplying power to the deep ultraviolet light emitting element from the outside, a circuit for operating the DUV-LED normally, and the like. Electric power is supplied to the circuit through wiring formed on or in the surface of the cylindrical substrate 111.

  On the side surface of the cylindrical substrate 111, a plurality of DUV-LEDs 112 are arranged along the circumferential direction of the substrate so that the optical axis 115 of each DUV-LED 112 passes through the central axis 114 of the substrate 111. As a result, deep ultraviolet rays emitted from the DUV-LED are emitted radially with respect to the central axis 114.

  As described above, since the symmetry axis (center axis) of the container 300 is arranged so as to coincide with the condensing axes of the four condensing ultraviolet ray emitting units 130, the depth emitted radially from each ultraviolet light emitting module 110. All of the ultraviolet rays are collected so as to converge on the symmetry axis (center axis) of the container 300. Thus, in principle, the ultraviolet sterilizer 100 can irradiate the container 300 with all of the deep ultraviolet rays radiated from the ultraviolet light emitting module 110 in a direction that is not directed toward the container 300 (for example, the opposite direction). The ultraviolet rays emitted in the direction and the lateral direction can also be effectively used. As a result, high-intensity ultraviolet rays can be irradiated.

  FIG. 3 is a schematic diagram for explaining the method 3-3, in which the lower stage (A) is a bottom view and the upper stage (B) is a front view. In Method 3-3, a flexible bag formed by using a liquid, paste-like, jelly-like or mousse-like object to be sterilized 210 and making a container made of a UV-permeable film made of a heat-sealable resin. Alternatively, a flexible “stand bag having an elliptical bottom surface” formed by bag-making a UV-permeable laminated resin film including a heat-sealable resin layer is used. First, in a filling step and a sealing step (not shown), the container 310 is filled with the object to be sterilized 210 and further sealed. After that, as shown in FIG. 3, when the container 310 is disposed at the center of the space between the ultraviolet irradiation units 400a and 400b, which are a pair of partition walls arranged to face each other with a gap of a predetermined width. The ultraviolet irradiation units 400a and 400b automatically move in the direction of the container 310, and the containers 310 are clamped by the ultraviolet light emitting surfaces 410a and 410b of the respective ultraviolet irradiation units. Then, the ultraviolet rays are irradiated while being deformed so as to be thin.

  The ultraviolet irradiation units 400a and 400b basically have the same structure except that they are mirror images of each other, and the light emitting surfaces 410a and 410b have a shape corresponding to the shape of the sandwiched container 310. ing. The light emitting surfaces 410a and 410b of the ultraviolet irradiation unit used in FIG. 3 are concave curved surfaces that are inclined corresponding to the shape of the stand bag (container 310) having an elliptical bottom surface. What is necessary is just to change suitably the shape of a light emission surface according to the shape of a container, for example, when a container is a flat bag (plate-shaped container), it is set as a plane.

  Ultraviolet irradiation units 401, 402, and 403 that are preferably used in the method shown in FIG. 3 are shown in FIGS. Each of these ultraviolet irradiation units has a housing 420 having an opening, an inner surface 431 and an outer surface 432 opposite to the inner surface, and the inner surface of the housing is closed so as to close the opening of the housing. An ultraviolet ray transmitting window 430 that transmits ultraviolet rays and an ultraviolet light source 440 arranged toward the inside, and an object covered (filled inside the container) that is arranged to face the outer surface 432 of the ultraviolet ray transmitting window. Sterilization is performed by irradiating the sterilized body with ultraviolet rays. Therefore, the outer side surface 432 of the ultraviolet ray transmitting window 430 becomes the light emitting surface 410a (410b) in FIG.

  The material constituting the housing 420 is not particularly limited as long as it does not transmit ultraviolet light. For example, metal, resin, or the like can be used. However, it is preferable that the inner surface of the housing 420, more specifically, the surface of the portion visible from the outside of the ultraviolet light transmitting window 430, be made of an ultraviolet reflecting material. Examples of the ultraviolet reflecting material that can be suitably used in the present invention include chromium (ultraviolet reflectance: about 50%), platinum (ultraviolet reflectance: about 50%), rhodium (ultraviolet reflectance: about 65%), barium sulfate. (UV reflectivity: about 95%), magnesium carbonate (UV reflectivity: about 75%), calcium carbonate (UV reflectivity: about 75%), magnesium oxide (UV reflectivity: about 90%), aluminum (UV reflectivity) Rate: about 90%). Among these, it is particularly preferable to use rhodium, platinum, or aluminum as the ultraviolet reflecting material because the surface can be made highly reflective by surface treatment such as plating or vapor deposition. In addition, when a metal material is used as the ultraviolet reflective material, ultraviolet rays such as quartz, sapphire, and polytetrafluoroethylene film are used from the viewpoint of preventing the reflectance from being lowered due to oxidation or scratching of the surface. It is preferable to coat the surface of the ultraviolet reflective material with a transparent material.

  The ultraviolet transmissive window 430 has an inner surface 431 and an outer surface 432 opposite to the inner surface, and is provided so as to close the opening of the housing 420 so that the inner surface faces the inside of the housing 420. The ultraviolet light emitted from 440 is transmitted through the ultraviolet light transmission window 430 and the partition wall (or sheet or film) of the container 310 to irradiate the object to be sterilized 210. For example, sapphire, quartz, or the like can be preferably used as the material constituting the ultraviolet transmitting window 430. In addition, the ultraviolet transmissive window 12 can be suitably configured by a molded body or a flexible sheet (or film) made of an ultraviolet transmissive resin. Examples of such UV transmissive resins include polytetrafluoroethylene, polyethylene, polypropylene, methacrylic resin, epoxy resin, alicyclic polyimide resin, polyamide resin, polyvinyl chloride, and polyvinyl alcohol resin (absorbing irradiated UV light And the like that do not contain additives such as ultraviolet absorbers and plasticizers).

  In the case where the window ultraviolet transmissive window is made of an ultraviolet transmissive resin, the resin may be deteriorated by the ultraviolet irradiation. From the viewpoint of facilitating replacement of the ultraviolet transmissive window, the ultraviolet transmissive window is not included in the casing. It is preferable to attach with such a detachable structure.

  In the ultraviolet irradiation units 401, 402, and 403 shown in FIGS. 4 to 6, as described above, the ultraviolet transmission window 430 is a concave curved surface that is inclined corresponding to the shape of the stand bag (container 310).

  The light source 440 is different in each of the ultraviolet irradiation units 401, 402, and 403, and the ultraviolet irradiation unit 401 shown in FIG. 4 uses a plurality of ultraviolet lamps 441 as light sources. The ultraviolet lamps 441 are arranged at predetermined intervals along the inner side surface 431 of the ultraviolet transmission window 430, and an ultraviolet reflection mirror (not shown) is installed behind the ultraviolet lamps 430, and is emitted backward from the ultraviolet lamp 441. The ultraviolet light thus reflected is reflected by the mirror and travels toward the ultraviolet lamp 441 through the gap between the lamps.

  In the ultraviolet irradiation unit 402 shown in FIG. 5, a plurality of DUV-LEDs 442 are used as light sources. The plurality of DUV-LEDs 442 are opposed to the inner side surface 431 of the ultraviolet ray transmitting window 430 in a form mounted on a substrate (not shown) mainly made of a metal or ceramic having high thermal conductivity such as copper or aluminum. Are arranged so that The DUV-LED 442 is usually packaged or modularized and emits light with enhanced directivity such as parallel light, but has a certain emission angle so that the light intensity distribution is more uniform. It is preferable that the light is emitted radially. The number of DUV-LEDs 442 may be sufficient if the emitted ultraviolet light irradiates the entire inner surface 431 of the ultraviolet light transmitting window 430. Note that the greater the number of DUV-LEDs 442, the stronger the ultraviolet intensity. Similarly to the method 2, it is possible to increase the output by flowing a high forward current using a step-up DC-DC converter or a charge pump.

  In the ultraviolet irradiation unit 403 shown in FIG. 6, the ultraviolet light emitting module 110 shown in FIG. 2 is incorporated as a light source, and the ultraviolet light emitted radially with respect to the central axis 114 of the ultraviolet light emitting module 110 is condensed to form a belt shape. A light source (hereinafter also referred to as a “light-collecting modularized light source”) 443 that emits as a luminous flux of the same is used. Since the length of the ultraviolet light emitting module 110 is set so as to coincide with the width (length of the short side) of the ultraviolet transmitting window 430, the condensing modular light source 443 is disposed in the housing 420 to transmit the ultraviolet light. By sliding and moving along the window 430, the belt-shaped light beam can be scanned to irradiate the entire surface of the inner side surface 431 of the ultraviolet transmitting window 430 with ultraviolet rays.

  The condensing modular light source 443 is described in Japanese Patent No. 5591305 as an ultraviolet light emitting device, the contents of which are incorporated herein by reference.

  7 and 8 show a cross-sectional view and a side view of a light collecting module-formed light source 443 having a rod-like light source 110. FIG. The condensing modular light source 443 includes an output-side casing 125 whose inner surface is an output-side reflecting mirror 120 made of an ellipsoidal reflecting mirror, and a condensing-side reflecting mirror 123 whose inner surface is made of an ellipsoidal reflecting mirror. In addition, a condensing side housing 126 in which a deep ultraviolet light emitting opening 130 is formed and a main body 150 including a collimating optical system 140 disposed in the deep ultraviolet light emitting opening 130. A rod-shaped light source 110 is disposed inside. In the main body 150, it is preferable that the emission side casing 125 and the condensing side casing casing 126 are detachable from each other or can be opened and closed using a hinge or the like. 4 and 5 of the main body 150 are provided with covers (not shown) for preventing ultraviolet rays from leaking to the outside.

  7 and 8, the exit-side reflecting mirror 120 and the condensing side reflecting mirror 123 are substantially elliptical reflecting mirrors having substantially the same shape. The shape of the internal space formed by coupling with the side housing 126 is an elliptical cross-section with two axes of the focal axis 121 of the exit-side reflecting mirror and the condensing axis 122 of the exit-side reflecting mirror, respectively. However, a portion corresponding to the opening 130 is missing.) The surfaces of the exit-side reflecting mirror 120 and the condensing-side reflecting mirror 123 are made of a material having a high reflectivity with respect to deep ultraviolet light, for example, a platinum group metal such as Ru, Rh, Pd, Os, Ir, and Pt, Al, Ag, Ti, It is preferably composed of an alloy containing at least one of these metals or magnesium oxide, and is formed of Al, a platinum group metal or an alloy containing a platinum group metal, or magnesium oxide because of its particularly high reflectance. It is particularly preferable.

  The condensing-side reflecting mirror 123 and the condensing-side casing 126 are provided with a deep ultraviolet light emission opening 130 in a slit shape, and the collected ultraviolet light is parallel or substantially parallel to the opening 130. A collimating optical system 140 for converting to is arranged. The collimating optical system 140 is preferably made of a material having high ultraviolet transparency such as synthetic or natural quartz, sapphire, or ultraviolet transmissive resin. The collimating optical system 140 is preferably detachably attached to the deep ultraviolet ray emitting opening 130.

  In the condensing modular light source 443, the rod-shaped light source 110 is arranged so that the central axis 114 thereof coincides with the focal axis 121 of the exit side reflection mirror. Since the rod-shaped light source 110 is disposed at such a position, the deep ultraviolet light emitted radially from the rod-shaped light source 110 is reflected by the emitting-side reflecting mirror 120 and the collecting-side reflecting mirror 123, and the collecting-side reflecting mirror. The condensed deep ultraviolet light is converged so as to converge on the focal axis 124 (that is, the condensing axis 122 of the exit-side reflecting mirror), and the condensed deep ultraviolet light is emitted toward the inner side surface 431 of the ultraviolet transmission window 430.

  Thus, in principle, the condensing modular light source 443 can condense all of the deep ultraviolet light emitted radially from the rod-shaped light source 110 onto the focal axis 124 of the condensing side reflection mirror 123, and deep ultraviolet Ultraviolet rays emitted in a direction not directed toward the light emitting opening 130 (for example, in the opposite direction or the lateral method) can also be used effectively. That is, in the rod-shaped light source 110, it is not necessary to arrange all the deep ultraviolet LEDs 112, 112,... On the same plane so that the optical axis 115 is directed toward the deep ultraviolet light emitting opening 130, in the lateral direction or in the opposite direction. It is also possible to arrange them facing. Therefore, in the rod-shaped light source 110, the number of ultraviolet light emitting elements arranged per unit space can be greatly increased, and the condensing modular light source 443 can emit ultraviolet light having a stronger intensity. Further, the condensing modular light source 443 does not need to use a large-diameter field lens. Further, in the condensing modular light source 443, the ultraviolet rays are emitted as a band-shaped light beam, and the irradiation region is not a narrow spot shape but can irradiate the rectangular region having a long long side with uniform intensity.

  In the ultraviolet irradiation unit 403, the condensing modular light source 443 is disposed in the housing 420 so as to emit a strip-shaped light beam toward the inner side surface 431 of the ultraviolet transmission window 430. In addition, an electric motor 450 and a set of guide rails 460 are disposed in the housing 420, and the light collecting module-formed light source 443 is held by the guide rails 460 and is driven by the electric motor 450 to move on the guide rails. It reciprocates (slides) in the direction of the arrow in the lower diagram of FIG. As a mechanism (not shown) for converting the rotational driving force of the electric motor 450 into a driving force of linear motion along the guide rail 460, a known mechanism such as a rack and pinion mechanism, a crank mechanism, a cam mechanism, or a belt mechanism is known. A rotational motion-linear motion conversion mechanism can be employed without any particular limitation. The condensing modular light source 443 performs such reciprocating movement (sliding), whereby the ultraviolet rays are scanned, and the entire inner side surface 431 of the outer line transmission window 430 can be irradiated with the ultraviolet rays.

  As described above, the ultraviolet irradiation unit has been described by taking as an example the case where the container is a stand bag having an elliptical bottom surface, but the condensing ultraviolet emission unit is not limited to this. For example, as described above, the shape of the light emitting surface may be appropriately changed according to the shape of the container. For example, when the container is a flat bag (plate-shaped container), it is flat. Moreover, the surface emitting device as disclosed in Patent Document 5 can be used as the ultraviolet irradiation unit.

  What is obtained in the ultraviolet sterilization method of the present invention and in which an object to be sterilized by ultraviolet sterilization is enclosed in a container is a container-packed article (for example, a container-packed food, a container-packed cosmetic, a container-packed medicine outside of a pharmacy) In order to prevent deterioration of the sterilized body and deterioration of the container due to ultraviolet rays from the natural world during storage and distribution process, the sealing step can be performed as it is. It is preferable that the method further includes an ultraviolet shielding step of performing an ultraviolet shielding treatment on the outer surface of the container sealed by the step.

  As a method for applying an ultraviolet shielding treatment to the outer surface of the container, the ultraviolet transmissive portion of the container may be covered with an ultraviolet opaque material. Examples of the coating method include a method of printing using ultraviolet impermeable ink, a method of surface coating with an ultraviolet impermeable coating agent, and a method of attaching (laminating) an ultraviolet impermeable film.

  The ultraviolet sterilization method of the present invention can be suitably applied to a method for producing a container-packed article in which a food, cosmetic, quasi-drug, or pharmaceutical product that has been sterilized with ultraviolet rays and is sealed in a container. .

DESCRIPTION OF SYMBOLS 100 ... Ultraviolet sterilizer 110 ... Ultraviolet light emitting module 111 ... Cylindrical base | substrate 112,442 ... Deep ultraviolet light emitting element (DUV-LED)
113 ... Cooling medium flow path 114 ... Center axis of cylindrical substrate 115 ... Optical axis of deep ultraviolet light emitting element 116 ... Cover 117 ... Seal member 118 ... Cooling medium 120 ... The exit-side reflection mirror 121 composed of an elliptical reflection mirror 121... The focal axis of the exit-side reflection mirror 122... The condensing axis of the exit-side reflection mirror 123. ... Focus axis of condensing side reflection mirror 125 ... Exit side housing 126 ... Condensing side case 130 ... Condensed ultraviolet ray emitting unit (combination of 110 and 120)
140 ... collimating optical system 150 ... main body 200, 210 ... object to be sterilized 300, 310 ... container 400a, 400b, 401, 402, 403 ... ultraviolet irradiation unit 420 ... housing 430・ ・ ・ UV transmission window 431 ・ ・ ・ Inside surface 432 ・ ・ ・ Outside surface 440 ・ ・ ・ Light source 441 ・ ・ ・ Ultraviolet lamp 443 ・ ・ ・ Condensed modular light source 450 ・ ・ ・ Electric motor 460 ・ ・ ・ Guide rail

Claims (8)

A method for sterilizing an object to be sterilized filled with a fluid containing an organic substance, filled in a container,
A filling step of filling the container to be sterilized,
From the outside of the container filled with the object to be sterilized by the filling step, a wavelength region of 260 nm or more and 280 nm or less in the spectrum in which the horizontal axis represents the wavelength and the vertical axis represents the relative emission intensity with respect to the object to be sterilized. Including an ultraviolet irradiation step of irradiating ultraviolet rays in which the sum of relative intensities of ultraviolet rays is 70% or more of the total sum of relative intensities in all wavelength regions, and a sealing step of hermetically sealing the container filled with the object to be sterilized. And
The container has an ultraviolet light transmitting portion made of a material that transmits ultraviolet light in a wavelength region of 253 nm or more and 280 nm or less and having a uniform thickness,
In the ultraviolet irradiation step, the ultraviolet rays that have passed through the ultraviolet transmitting portion are irradiated to the sterilized body,
The sealing step is performed between the end of the filling step and the end of the ultraviolet irradiation step, or is performed in the same sterile environment as the ultraviolet irradiation step after the end of the ultraviolet irradiation step. bacteria how killing, characterized in that.   An ultraviolet transmissive laminated resin film having a uniform thickness including a flexible bag or a heat-sealable resin layer formed by bag-making an ultraviolet transmissive film having a uniform thickness made of a heat sealable resin. The sterilization method according to claim 1, wherein the bag is a flexible bag, and the sealing step is performed by heat-sealing the opening of the flexible bag.   The sterilization method according to claim 1 or 2, wherein the temperature of the object to be sterilized in the ultraviolet irradiation step is set to exceed 0 ° C and not more than 10 ° C. In the ultraviolet irradiation step, the ultraviolet ray is irradiated to the region irradiated with the ultraviolet ray from one direction or two directions opposite to each other, and the width of the irradiated ultraviolet ray in the optical axis direction in at least a part of the region is irradiated. When the thickness of the layer to be sterilized is defined as the effective optical path length, the irradiance of the transmitted ultraviolet light is 0.01 mW / cm ² when the applied ultraviolet light passes through the layer to be sterilized. The sterilization method according to any one of claims 1 to 3, wherein the sterilization method is less than or equal to a sum of effective optical path lengths of ultraviolet rays irradiated from one direction or two directions.   In the ultraviolet irradiation step, the surface of the container filled with the object to be sterilized in a space between a pair of partition walls arranged to face each other with a gap having a width equal to or less than the sum of the effective optical path lengths. The ultraviolet light is radiated from one or two ultraviolet light emitting surfaces or ultraviolet transmissive windows provided on one or both of two surfaces facing each other of the pair of partition walls. 4. The sterilization method according to 4.   Since the object to be sterilized is liquid, paste-like, jelly-like, or mousse-like, and the container includes a flexible bag or a heat-sealable resin layer formed by making an ultraviolet transmissive film made of a heat-sealable resin. 6. The sterilization method according to claim 5, which is a flexible bag formed by bag-making an ultraviolet transparent laminated resin film.   The sterilization method according to any one of claims 1 to 6, further comprising an ultraviolet shielding process for performing an ultraviolet shielding process on an outer surface of the container sealed by the sealing process.   A method for producing a container-packed article in which a food, cosmetic, quasi-drug, or pharmaceutical product sterilized by ultraviolet rays is enclosed in a container, comprising a food, cosmetic, quasi-drug or pharmaceutical product having fluidity A method for producing a packaged packaged article comprising the steps of filling a sterilized body into a container with a sterilized body, irradiating with ultraviolet rays and sealing the container by the method according to any one of claims 1 to 7. .

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