JP2020121252A - Photoreaction device, photoreaction method using the same, and method for manufacturing lactam - Google Patents

Abstract

To provide a photoreaction device achieving more desirable light irradiation with higher light transmittance by further suppressing light reflection in a light irradiation path between a light-emitting diode light source and a target photoreaction substance separated from each other by a light transmissive container: to provide a photoreaction method using the photoreaction device: and to provide a method for manufacturing lactam using the photoreaction method.SOLUTION: A photoreaction device irradiates a photoreaction substance introduced to the periphery of a light irradiation device with light from a light irradiation device having a light source comprising light-emitting diode, a first light transmissive container covering the light source, and a second light transmissive container covering the first light transmissive container. In the photoreaction device, light transmissive insulation liquid is filled in the inside of the first light transmissive container and light transmissive liquid is filled in a space between the first light transmissive container and the second light transmissive container. A photoreaction method uses the photoreaction device. A method for manufacturing lactam uses the photoreaction method.SELECTED DRAWING: Figure 1

Description

The present invention relates to a photoreaction device for irradiating a photoreactive substance with light from a light irradiation device using a light emitting diode as a light source, a photoreaction method using the photoreaction device, and a method for producing a lactam using the photoreaction method. Regarding

The photoreaction is also called a photochemical reaction, and by irradiation with light, that is, by causing the radical reactant to absorb energy from the irradiation light, the molecule is brought into a high energy level state, a so-called excited state, and the reaction is caused by the excited molecule. Refers to all chemical reactions that occur. There are various types of photoreactions, such as oxidation/reduction reaction by light, substitution/addition reaction by light, etc., and they are used in the photo industry, copy technology, induction of photoelectromotive force, and synthesis of organic compounds. It is known. Further, as an unintentional photochemical reaction, photochemical smog belongs to the photochemical reaction.

For example, it is known that cyclohexanone oxime can be synthesized by a photochemical reaction, and the photonitrosation of cycloalkane is now a widely known technique.

As the light source for the photoreaction that has been used so far, all of them contain mercury, thallium, sodium, and other metals in a vacuum or an environment close to a vacuum to apply a voltage, and the emitted electron beam is sealed in a metal. In most cases, a lamp that utilizes light emission due to discharge in a gas or vapor, for example, a discharge lamp or a fluorescent lamp, is used as a light source by irradiating the light.

For example, when a high pressure mercury lamp is used as a light source, the effective wavelength is 365 nm to 600 nm. However, in a discharge lamp using this kind of mercury, peculiar emission energy due to mercury also exists in a wavelength range including ultraviolet rays of less than 365 nm. Therefore, for example, when the emission energy is in a short wavelength region including ultraviolet rays of less than 350 nm, it is comparable to the dissociation energy of many chemical bonds, so that a reaction other than the purpose proceeds and promotes a side reaction, and is tar-like. A brown film is formed on the light-irradiated surface of the discharge lamp, which reduces the yield. Therefore, in order to block the ultraviolet rays, the use of a water-soluble fluorescent agent and the ultraviolet ray cutting glass are used.

In order to reduce the above problems in the mercury lamp and to increase the luminous efficiency, it is known that a thallium lamp that exhibits effective emission energy at a wavelength of 535 nm and a sodium lamp that exhibits effective emission energy at a wavelength of 589 nm are effective. There is. By using a sodium lamp as the light source, the yield is dramatically increased and a stable reaction is possible. Further, by using the high-pressure sodium discharge lamp, the industrial effective wavelength is 400 to 700 nm, and the efficiency can be improved in the wavelength range of 600 nm to 700 nm. The peak wavelength in this range can be estimated to be about 580 to 610 nm. However, coexistence of mercury is unavoidable in order to improve the electric characteristics and starting of the discharge lamp, and a filter that blocks ultraviolet rays due to mercury is necessary. In particular, a short wavelength of less than 400 nm generated by mercury is an unnecessary wavelength because the energy is too strong to cause an unnecessary side reaction.

Further, the sodium lamp has a peculiar luminescence energy peak in a wavelength range including infrared rays having a wavelength of 780 to 840 nm, and its energy intensity is often at a level comparable to the maximum luminescence energy of the sodium lamp. The dissociation energy of nitrosyl chloride is about 156 kJ/mol, which is comparable to the emission energy near the wavelength of 760 nm according to Einstein's law, so the light energy is small in the longer wavelength region beyond that, and nitrosyl chloride does not dissociate in the reaction. It does not contribute to the energy loss.

The light emitting diode, which is also abbreviated as LED, has an advantage that electric energy can be directly converted into light by using a semiconductor, and has been attracting attention in terms of suppression of heat generation, energy saving, long life, and the like. The history of its development is still short, and red LEDs were commercialized in 1962, and blue, green, and white LEDs were developed around 2000, and were commercialized for display and lighting applications. On the other hand, the discharge lamp used for photoreaction has a very high output and a high luminous efficiency, but if an LED is required to obtain the luminescence energy required for a photoreaction equivalent to that of the discharge lamp, it is necessary to use the LED. It has been thought that it is difficult to apply LEDs as a light source of photoreaction, because the number of them becomes enormous and the problems of circuit design, heat countermeasures for LEDs and cost aspects remain. Further, the photoreaction requires irradiation of the reaction material with uniform light, but the LED has a strong directivity, and it is difficult to obtain the wavelength required for the reaction with high efficiency. The application of LEDs to reaction light sources has been considered difficult. However, in recent years, as described in Patent Document 1 and Patent Document 2, there have been seen examples in which a photoreaction by an LED is carried out using a small reaction device, and as described in Patent Document 2, the illuminant is enlarged. There is also a prospect for a solution to the problem.

However, in the inventions disclosed in Patent Documents 1 and 2, it cannot be said that a structure of a light irradiation device or a photoreaction device that can effectively use the light linearly emitted from the light emitting diode can be proposed. Further, in the case of aiming at a photoreaction, the target substance is almost always a flammable liquid, and it is essential to physically separate the light irradiation device serving as an ignition source and the target substance. In the invention disclosed in 2, there is a problem that the light is blocked by reflection by the obstacle in the light irradiation path for separation, that is, the light transmissive container, and the ratio of light transmission is reduced.

In order to solve such a problem, according to Patent Document 3, high light transmission is achieved by suppressing reflection of light between a light emitting diode light source isolated by a light transmissive container and a target substance (target liquid). There have been proposed a light irradiation device aiming at achieving a more desirable light irradiation with a ratio, a photoreaction method using the light irradiation device, and a lactam production method using the light reaction method. More specifically, it is a light irradiation device that uses a light emitting diode as a light source, which is usable for photoreaction, and includes a first light transmissive container that covers a light emitting body including the light emitting diode, A liquid phase part formed of a liquid having a refractive index closer to that of the first light transmissive container than a gas forming the gas phase part inside the first light transmissive container, and a second light covering the liquid phase part. A light irradiation device including a transparent container has been proposed.

In addition, "Fluorinert" (registered trademark, manufactured by 3M Company) as a fluorine-based inert liquid used as an insulating liquid having a light-transmitting property in Examples of the present invention described later is described in, for example, Patent Document 4. However, Patent Document 4 does not particularly mention the use of "Fluorinert" in the light irradiation path of a photoreaction device in which a light source composed of a light emitting diode is covered with a double light transmissive container. ..

JP, 2010-006776, A JP, 2013-200944, A International Publication 2016/056370 JP, 2008-016545, A

With the technique proposed by the above-mentioned Patent Document 3, it is possible to irradiate the target liquid with the light from the light emitting diode light source with a higher transmittance than before, thereby obtaining a higher reaction yield and a higher reaction yield in the photoreaction. Became. However, as a result of further study by the present inventors, in the light irradiation device described in Patent Document 3, since the gas phase portion is formed inside the first light transmissive container, the first light transmissive property is obtained. Refraction at the interface between the container and the gas that forms the gas phase portion may not sufficiently suppress the reflection of light from the light emitting diode light source, and therefore, the light emitting device as a whole may not emit light from the light emitting diode light source. It was found that the light transmission of the above may not be sufficient, and there is room for further improvement.

Therefore, an object of the present invention is to advance the technique proposed by Patent Document 3 to a much improved technique based on the above-described examination results and to establish a practically more useful technique. By further suppressing the reflection of light in the light irradiation path between the light emitting diode light source isolated by the light transmissive container and the target photoreactive substance, thereby achieving more desirable light irradiation with higher light transmittance. (EN) Provided are a photoreaction device using a light irradiation device, a photoreaction method using the photoreaction device, and a lactam production method using the photoreaction method.

In order to solve the above problems, the present invention adopts the following configurations. That is,
(1) Light from a light irradiation device having a light source including a light emitting diode, a first light transmissive container that covers the light source, and a second light transmissive container that covers the first light transmissive container A photoreactive device for irradiating a photoreactive substance introduced around the irradiation device, wherein the photoreactive substance is provided inside the first light transmissive container (to the light source side inside the first light transmissive container). A photoreaction device comprising: an insulating liquid having a light-transmitting liquid filled between the first light-transmitting container and the second light-transmitting container.
(2) The photoreaction device according to (1), wherein the insulating liquid has a refractive index of 1.25 or more.
(3) The photoreaction device according to (1) or (2), wherein the refractive index of the insulating liquid is equal to or higher than the refractive index of the light transmissive fluid.
(4) The refractive index of the insulating liquid is closer to the refractive index of the material forming the first light transmissive container than the refractive index of the light transmissive fluid. (1) to (3) The photoreactor according to.
(5) The photoreactor according to any one of (1) to (4), wherein the insulating liquid is one of a fluorine-based inert liquid, silicone oil, and water.
(6) The photoreaction device according to any one of (1) to (5), wherein the light-transmitting fluid is any one of water, silicone oil, and a fluorine-based inert liquid.
(7) The photoreaction device according to any one of (1) to (6), wherein at least the first light transmissive container of the first light transmissive container and the second light transmissive container is made of glass.
(8) The photoreaction device according to any one of (1) to (7), wherein the light emitting diode sealant is a silicone lens.
(9) The photoreaction device according to any one of (1) to (8), wherein the photoreactive substance is a photoreactive liquid.
(10) A photoreaction method using the photoreaction device according to any one of (1) to (9).
(11) The photoreaction method according to (10), wherein the composition of the photoreactant contains at least carbon atoms.
(12) The photoreaction method according to (11), wherein the photoreaction liquid as the photoreaction substance contains cycloalkane.
(13) The photoreaction method according to (12), wherein a cycloalkanone oxime is produced by irradiating the cycloalkane and the photonitrosating agent with light from a light irradiation device.
(14) The photoreaction method according to (13), wherein the cycloalkanone oxime is cyclohexanone oxime or cyclododecanone oxime.
(15) The photoreaction method according to (13) or (14), wherein the photo-nitrosating agent is nitrosyl chloride or trichloronitrosomethane.
(16) A method for producing a lactam, which comprises using the cycloalkanone oxime produced by the photoreaction method according to any one of (13) to (15).

According to the present invention, in a light irradiation device including a light source including an LED and first and second light transmissive containers provided in a light irradiation path from the light source to a target photoreactive substance, Since the insulating liquid having a light-transmitting property is filled inside the transparent container and the light-transmitting liquid is filled between the first light-transmitting container and the second light-transmitting container, the reflection of the light in the light irradiation path is reflected. Can be greatly suppressed, and in particular, the reflection of light in the light irradiation path from the light source to the inside of the substance forming the first light transmissive container can be largely suppressed, and as a result, the target photoreactive substance can be obtained. It is possible to significantly increase the light transmittance in the entire light irradiation path up to and to realize a photoreaction with extremely high energy efficiency. Therefore, it becomes possible to obtain an extremely high reaction yield and reaction yield in the photoreaction. In particular, the present invention is extremely useful for photoreaction for producing cycloalkanone oxime, and for producing lactam using the cycloalkanone oxime.

It is a schematic longitudinal cross-sectional view of a photoreaction device according to an embodiment of the present invention. It is a schematic diagram which shows an example of refraction of the light in the boundary surface between media. It is a schematic diagram which shows another example of refraction|bending of the light in the boundary surface between media.

Embodiments of the present invention will be described below with reference to the drawings.
In the present invention, the light irradiation device in the photoreaction device is a device that includes a light source that emits light and can irradiate the photoreactive substance as the target object with light. The photoreactive substance is, for example, a photoreactive liquid that is a raw material for the photoreaction. FIG. 1 shows a photoreaction device 100 according to an embodiment of the present invention. In particular, a photoreaction substance as a target object of the photoreaction, particularly a photoreaction substance introduced into a reaction vessel 11 (particularly, , Photo-reactive liquid) is irradiated with light from the light irradiation device 1. The light irradiation device 1 is inserted in the reaction container 11 in order to irradiate the photo-reactive substance 10 in the reaction container 11 with light from the light source 3 and provide the light reaction. In the mounting position shown in FIG. 1, the light irradiation device 1 includes a light source 3 that includes a power supply unit 4 at an upper portion and a large number of light emitting diodes (hereinafter also referred to as LEDs) 2 at a lower portion thereof. The upper side of the power supply unit 4 is sealed by the lid 5.

The light source 3 is covered with a first light transmissive container 6, and the first light transmissive container 6 is covered with a second light transmissive container 7 at intervals. The inside of the first light transmissive container 6, that is, the space between the light source 3 and the first light transmissive container 6 is filled with an insulating liquid 8 having light transmissivity, and this part is a liquid phase part. Has been formed. A light-transmitting liquid 9 is filled between the first light-transmitting container 6 and the second light-transmitting container 7, and this portion is also formed in the liquid phase portion.

The light emitting diode is a light emitting diode that emits ultraviolet light, visible light, and infrared light, and as the light emitting diode 2 to be used, a type in which the wavelength required for the application of the light irradiation device 1 is selected can be appropriately selected. The shape and size of the light emitting diode 2 are not particularly limited, and a shape and size suitable for the purpose can be used. It may be a general shell type, a mounting type, a chip type, or the like, but a type that can radiate heat from the back surface side of the light emitting diode 2 is preferable because heat removal is easy. Further, it is desirable that the heat radiation substrate is provided on the back surface of the light emitting diode 2 because the heat transfer area can be increased and the cooling performance can be improved. Further, although some kind of encapsulant is generally used for the light emitting diode, a silicone lens is preferable as the encapsulant from the viewpoint of improving the encapsulation performance and the light transmittance.

In the present invention, the shape of the light source 3 is not particularly limited, but since the irradiation light from the light source 3 is used for a photoreaction requiring a large reaction energy, it is preferable that the light source 3 is composed of an extremely large number of light emitting diodes 2.

The first light transmissive container 6 is a container that covers the light source 3 and is installed to protect the light source 3 from the outside. The first light transmissive container 6 may be made of a material that transmits light. When a material having a transmission wavelength selectivity is used for the light transmissive container, it is possible to suppress the transmission of light having an unnecessary wavelength. The overall shape of the first light transmissive container 6 may be, for example, a test tube type as shown in FIG. 1, but the shape is not particularly limited, and may be a cylindrical type, a box type, a spherical type, or the like depending on the purpose. The shape can be appropriately selected.

The second light transmissive container 7 is a container arranged outside the first light transmissive container 6, and may be made of a material that transmits light as with the first light transmissive container 6. The material of the second light transmissive container 7 may be the same as or different from that of the first light transmissive container 6. The shape may be, for example, a test tube type as shown in FIG. 1, but the shape is not particularly limited, and a shape such as a cylindrical shape, a box shape, or a spherical shape can be selected according to the purpose. The shape may be similar to or different from that of the permeable container 6.

In the present invention, in order to largely suppress the reflection of light in the light irradiation path by the light irradiation device 1 and to significantly increase the light transmittance in the entire light irradiation path up to the target photoreactive substance, The refractive index of the light-transmitting insulating liquid 8 filled in the light-transmitting container 6 is preferably 1.25 or more. The refractive index of the insulating liquid 8 is preferably 9 or more as the light transmissive liquid. Further, it is also preferable that the refractive index of the insulating liquid 8 is closer to the refractive index of the material forming the first light transmissive container 6 than the refractive index of the light transmissive fluid 9.

As the insulating liquid 8, for example, any one of fluorine-based inert liquid, silicone oil, and water can be used. As the light transmissive fluid 9, for example, water, silicone oil, or a fluorine-based inert liquid (such as Fluorinert (registered trademark, manufactured by 3M) or Galden (registered trademark, manufactured by Solvay)) can be used. From the viewpoint of easy availability, easy handling, and the like, industrially preferable combinations include, for example, a fluorine-based inert liquid or silicone oil as the insulating liquid 8 and water or silicone oil as the light-transmitting fluid 9. Can be mentioned.

The material forming the first light transmissive container 6 and the second light transmissive container 7 is not particularly limited, but at least the first light transmissive container 6 is made of glass in terms of light transmittance and strength. preferable.

In the present invention, the light transmissive liquid 9 is filled between the first light transmissive container 6 and the second light transmissive container 7, and the first light transmissive container 6 has a light transmissive property. By being filled with the insulating liquid 8, the reflection of the light from the light source 3 in the irradiation path is suppressed, the energy loss due to the reflection of the light is suppressed, and the transmittance of the light to the photoreactive substance 10 is increased, and The energy used for the photoreaction is effectively increased, and an extremely high reaction yield and reaction yield in the photoreaction can be obtained.

In order to suppress the reflection in the light irradiation path, it is required to reduce the reflectance at each boundary surface in the light irradiation path. Refraction and reflection of light at the boundary surface between the medium 1 and the medium 2 having different refractive indices n1 and n2 will be described with reference to the schematic diagrams shown in FIGS. Light causes reflection loss at the interface between media having different refractive indices. When the incident angle θ1 is other than 0 degree, the surface reflectance of light is expressed by the following equation (1), and it is known that the larger the difference in refractive index between the media forming the boundary surface, the larger the reflection loss. Here, the incident angle and θ2 indicate the refraction angle. More specifically, when the incident angle θ1 is other than 0 degrees, the incident angle θ1, the refraction angle θ2, and the refractive indices n1 and n2 have a relationship of sin θ1/sin θ2=n2/n1. When the refractive indices n1 and n2 are determined, the refraction angle θ2 is determined. Since θ1 and θ2 are determined, the surface reflectance R is calculated by the following equation (1).
Surface reflectance R=0.5×{tan(θ1−θ2)/tan(θ1+θ2)} ² +{sin(θ1−θ2)/sin(θ1+θ2)} ²・・・(1)

That is, when there is a medium boundary surface with a large difference in refractive index on the optical path, the loss due to light reflection increases. In the present invention, the space between the light source 3 and the first light transmissive container 6 is filled with the insulating liquid 8 having light transmissivity, and the space between the first light transmissive container 6 and the second light transmissive container 7 is filled. By filling the space with the light transmissive liquid 9, the reflectance of each boundary surface in the light irradiation path from the light source 3 is suppressed to be small, and the transmittance of the entire light irradiation path is increased.

When the incident angle θ1 is 0 degree, the surface reflectance R on the boundary surface is expressed by the following equation (2).
Surface reflectance R＝(n1-n2) ² /(n1+n2) ²・・・(2)

However, the light emitted from each light-emitting diode 2 has a strong straight-line property along the optical axis, but the light emitted from each light-emitting diode 2 is actually emitted at various angles, and thus is actually incident. When the angle θ1 is 0 degree, there is a combined form of reflection and refraction at various incident angles θ1. Therefore, as shown in the examples described later, in addition to the evaluation of the reflectance when the incident angle θ1 is 0 degree, at each boundary surface, for example, a certain typical incident angle θ1 (for example, the incident angle 60 degrees). In the case of, it is necessary to evaluate the reflectance and mutually consider these evaluation results. Overall, it can be said that the lower the reflectance on the boundary surface, the higher the light transmittance as a whole is.

The incident angle of light on the container surface is determined by the positional relationship between the light emitting surface on which the light emitting diode 2 is arranged and the container surface, specifically, the angle formed by the light emitting surface and the container surface. Since the angle formed by the light emitting surface and the container surface is determined by the shape of the structure in which the light emitting diode 2 is arranged and the shape of the container, the incident angle can be adjusted by adjusting the shapes of the structure and the container. ..

It is known that, when light is incident on the medium side having a high refractive index to the medium side having a low refractive index, at a certain incident angle or more, total reflection occurs in which all of the incident light is not transmitted. The minimum incident angle that causes total internal reflection is called a critical angle, and the critical angle is expressed by the following equation (3) using the incident-side medium refractive index n1 and the transmitting-side medium refractive index n2. Light incident at an incident angle equal to or greater than the critical angle does not pass through, but is entirely reflected at the boundary surface. Therefore, it is important for suppressing the reflection loss that the incident angle does not exceed the critical angle. Where critical angle θc = arcsin(n2/n1)・・・(3)

Further, the liquid forming each liquid phase portion may be, for example, one in which sugar or the like is dissolved in water, or one in which a soluble substance is dissolved in water to adjust the refractive index, such as an aqueous glycerin solution. Further, the liquid forming each liquid phase portion has a refractive index that varies depending on the temperature, and thus the refractive index may be adjusted by adjusting the temperature.

It is also possible to remove light of a specific wavelength unnecessary for the reaction by adding a substance that absorbs light of a specific wavelength to the liquid forming each liquid phase portion.

In the present invention, at least one of the first and second light transmissive containers (preferably, at least the second light transmissive container) is preferably made of a material having a refractive index of 1.4 or more. Examples of such a material include glass, but organic materials such as resin may be used. More specifically, examples of the glass include borosilicate glass, soda-lime glass, lead glass, and the like, and examples of the resin include acrylic resin, methacrylic resin, polycarbonate, polystyrene, polyvinyl chloride, polyester, and the like.

A material that absorbs light of a specific wavelength may be used for the first and second light transmissive containers. By absorbing wavelengths unnecessary for photoreaction in the container, only wavelengths required for photoreaction can be transmitted to the photoreactive substance.

In the present invention, the photoreactive substance, particularly the photoreactive liquid, may contain carbon atoms. The liquid as the raw material is not particularly limited as long as it is a liquid containing carbon atoms, and examples thereof include hydrocarbons such as alkanes and cycloalkanes.

In the present invention, the number of carbon atoms of the cycloalkane is not particularly limited, but for example, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, and cyclododecane are preferable. In particular, cyclohexane which is a raw material of ε-caprolactam and cyclododecane which is a raw material of ω-lauryllactam are preferable.

Using the above cycloalkane and photonitrosating agent, cycloalkanone oxime can be obtained by a photochemical reaction by light irradiation of a light emitting diode. The photonitrosating agent is preferably, for example, nitrosyl chloride or a mixed gas of nitrosyl chloride and hydrogen chloride. In addition, since a mixed gas of nitric oxide and chlorine, a mixed gas of nitric oxide, chlorine and hydrogen chloride, a mixed gas of nitrogen gas and chlorine, etc. all act as nitrosyl chloride in the photoreaction system, The supply form of the nitrosating agent is not limited. Also, trichloronitrosomethane obtained by photochemically reacting nitrosyl chloride and chloroform may be used as a nitrosating agent. When the photochemical reaction is carried out in the presence of hydrogen chloride, the cycloalkanone oxime becomes its hydrochloride, but it may be in the form of its hydrochloride as it is.

By the above photoreaction, a cycloalkanone oxime corresponding to the carbon number of the cycloalkane can be obtained. For example, cyclohexanone oxime can be obtained by a photonitrosation reaction with nitrosyl chloride using cyclohexane. In addition, cyclododecanone oxime can be obtained by the photonitrosation reaction with nitrosyl chloride using cyclododecan.

<Lactam production method>
A lactam can be obtained by carrying out a photochemical reaction using the light irradiation device according to the present invention and subjecting the obtained cycloalkanone oxime to Beckmann rearrangement. For example, in the reaction of Beckmann rearrangement of cyclohexanone oxime, ε-caprolactam is obtained as shown in the following reaction formula [Formula 1]. In addition, ω-laurolactam is obtained by the Beckmann rearrangement reaction of cyclododecanone oxime.

Hereinafter, the present invention will be described more specifically with reference to Examples.
Example 1
As shown in Table 1, a light source using a large number of light emitting diodes having a silicone lens as a sealant, borosilicate glass having a refractive index of 1.47 for both the first light transmissive container and the second light transmissive container, Refraction to both the liquid phase portion inside and outside the transparent container (in the table, the liquid phase portion due to the insulating liquid 8 is referred to as the liquid phase portion 8 and the liquid phase portion due to the light transmissive liquid 9 is referred to as the liquid phase portion 9) When a silicone oil with a rate of 1.425 (KF-50-100cs (Shin-Etsu Chemical Co., Ltd.): specific gravity 1.00) is filled and the incident angle at the interface between the liquid phase part and the light-transmissive solid is all 0 degrees. The light transmittance of was calculated. The table shows that the total reflectance from the silicone lens of the light emitting diode to the incidence of the second light transmissive container is low.

Example 2
A light source using a large number of light emitting diodes having a silicone lens as a sealant, and borosilicate glass having a refractive index of 1.47 for both the first light transmissive container and the second light transmissive container are used inside the first light transmissive container. Silicone oil having a refractive index of 1.425 (KF-50-100cs (Shin-Etsu Chemical Co., Ltd.): specific gravity of 1.00) was filled on the outside with water having a refractive index of 1.33 to form a liquid phase portion and a light-transmissive solid. The light transmittance was calculated when all the incident angles on the interface were 0 degree. Table 1 shows that the total reflectance from the silicone lens of the light emitting diode to the incidence of the second light transmissive container is low.

Example 3
A light source using a large number of light emitting diodes having a silicone lens as a sealant, borosilicate glass having a refractive index of 1.47 for both the first light transmissive container and the second light transmissive container, and the inside of the first transmissive container, Water having a refractive index of 1.33 was placed in both outer liquid phase portions, and the light transmittance was calculated when all incident angles at the interface between the liquid phase portion and the light transmissive solid were 0 degrees. The table shows that the total reflectance from the silicone lens of the light emitting diode to the incidence of the second light transmissive container is low.

Example 4
A light source using a large number of light emitting diodes having a silicone lens as a sealant, and borosilicate glass having a refractive index of 1.47 for both the first light transmissive container and the second light transmissive container are used inside the first light transmissive container. "Fluorinert" (registered trademark, manufactured by 3M Co.) 6-308-06 having a refractive index of 1.28, water having a refractive index of 1.33 is filled on the outside, and the incident angle at the interface between the liquid phase portion and the light-transmissive solid. The light transmittance was calculated in the case where all were 0 degrees. The table shows that the total reflectance from the silicone lens of the light emitting diode to the incidence of the second light transmissive container is low.

Comparative Example 1
A light source using a large number of light emitting diodes having a silicone lens as a sealant, and borosilicate glass having a refractive index of 1.47 for both the first light transmissive container and the second light transmissive container are used inside the first light transmissive container. Gas phase nitrogen (N ₂ ) having a refractive index of 1.00 was filled outside with water having a refractive index of 1.33, and the incident angle at the interface between the liquid phase part or the gas phase part and the light transmissive solid was all 0. The transmittance of light was calculated for each degree. From the table, the total reflectance from the silicone lens of the light emitting diode to the incidence of the second light transmissive container was higher than those of Examples 1 to 4.

Example 5
A light source using a large number of light emitting diodes having a silicone lens as a sealant, borosilicate glass having a refractive index of 1.47 for both the first light transmissive container and the second light transmissive container, and the inside of the first transmissive container, Silicone oil (KF-50-100cs (Shin-Etsu Chemical Co., Ltd.): specific gravity 1.00) having a refractive index of 1.425 is arranged on both outer liquid phase parts, and the liquid phase part and the light transmissive solid are incident on the interface. The light transmittance was calculated when all the angles were 60 degrees. As shown in Table 2, the total reflectance from the silicone lens of the light emitting diode to the incidence of the second light transmissive container was 0.0079.

Example 6
A light source using a large number of light emitting diodes having a silicone lens as a sealant, and borosilicate glass having a refractive index of 1.47 for both the first light transmissive container and the second light transmissive container are used inside the first light transmissive container. A silicone oil having a refractive index of 1.425 (KF-50-100cs (Shin-Etsu Chemical Co., Ltd.): specific gravity of 1.00) was placed on the outside with water having a refractive index of 1.33 to form a liquid phase portion and a light-transmissive solid. The light transmittance was calculated when the incident angles at the interfaces of all were 60 degrees. As shown in Table 2, the total reflectance from the silicone lens of the light emitting diode to the incidence of the second light transmissive container was 0.0886.

Example 7
A light source using a large number of light emitting diodes having a silicone lens as a sealant, borosilicate glass having a refractive index of 1.47 for both the first light transmissive container and the second light transmissive container, and the inside of the first transmissive container, Water having a refractive index of 1.33 was placed in both outer liquid phase portions, and the light transmittance was calculated when the incident angle at the interface between the liquid phase portion and the light transmissive solid was all 60 degrees. As shown in Table 2, the total reflectance from the silicone lens of the light emitting diode to the incidence of the second light transmissive container was 0.1325.

Example 8
A light source using a large number of light emitting diodes having a silicone lens as a sealant, and borosilicate glass having a refractive index of 1.47 for both the first light transmissive container and the second light transmissive container are used inside the first light transmissive container. "Fluorinert" (registered trademark, manufactured by 3M) 6-308-06 having a refractive index of 1.28 and silicone oil having a refractive index of 1.425 on the outside (KF-50-100cs (Shin-Etsu Chemical Co., Ltd.): specific gravity 1. 00) was placed, and the light transmittance was calculated when the incident angles at the interface between the liquid phase portion and the light-transmissive solid were all 60 degrees. As shown in Table 2, the total reflectance from the silicone lens of the light emitting diode to the incidence of the second light transmissive container was 0.2184.

Example 9
A light source using a large number of light emitting diodes having a silicone lens as a sealant, and borosilicate glass having a refractive index of 1.47 for both the first light transmissive container and the second light transmissive container are used inside the first light transmissive container. "Fluorinert" (registered trademark, manufactured by 3M Co.) 6-308-06 having a refractive index of 1.28 and water having a refractive index of 1.33 are arranged on the outside, and the light enters the interface between the liquid phase and the light transmissive solid. The light transmittance was calculated when all the angles were 60 degrees. As shown in Table 2, the total reflectance from the silicone lens of the light emitting diode to the incidence of the second light transmissive container was 0.2771.

Comparative example 2
A light source using a large number of light emitting diodes having a silicone lens as a sealant, and borosilicate glass having a refractive index of 1.47 for both the first light transmissive container and the second light transmissive container are used inside the first light transmissive container. When gas phase nitrogen with a refractive index of 1.00 and water with a refractive index of 1.33 are placed outside and the incident angles at the interface between the liquid phase part or the gas phase part and the light-transmissive solid are all 60 degrees. The light transmittance of was calculated. As shown in Table 2, the overall reflectance from the silicone lens of the light emitting diode to the incidence of the second light transmissive container is higher than that of Examples 5 to 9. The reflectance of 1.0000 represents total reflection.

INDUSTRIAL APPLICABILITY The photoreactor according to the present invention is applicable to all fields in which efficient photoirradiation of a photoreactant is desired, and in particular, a photoreaction method using the photoreactor and a lactam production using the photoreaction method. It is suitable for the method.

DESCRIPTION OF SYMBOLS 1 Light irradiation device 2 Light emitting diode 3 Light source 4 Power supply unit 5 Lid 6 First light transmissive container 7 Second light transmissive container 8 Insulating liquid 9 Light transmissive liquid 10 Photoreactive substance 11 Reaction container 100 Photoreactive device

Claims (16)

Light from a light irradiation device having a light source including a light emitting diode, a first light transmissive container that covers the light source, and a second light transmissive container that covers the first light transmissive container is supplied to the light irradiation device. A photoreactor for irradiating a photoreactive substance introduced into the surroundings, wherein an insulating liquid having a light transmissive property is provided inside the first light transmissive container and the first light transmissive container and the second light transmissive container. A photoreaction device, characterized in that a light-transmitting liquid is filled between the light-transmitting containers. The photoreaction device according to claim 1, wherein the refractive index of the insulating liquid is 1.25 or more. The photoreaction device according to claim 1, wherein the refractive index of the insulating liquid is equal to or higher than the refractive index of the light transmissive fluid. The photoreaction according to claim 1, wherein the refractive index of the insulating liquid is closer to the refractive index of the material forming the first light transmissive container than the refractive index of the light transmissive fluid. apparatus. The photoreactor according to claim 1, wherein the insulating liquid is one of a fluorine-based inert liquid, silicone oil, and water. The photoreactor according to claim 1, wherein the light-transmitting fluid is water, silicone oil, or a fluorine-based inert liquid. 7. The photoreaction device according to claim 1, wherein at least the first light transmissive container of the first light transmissive container and the second light transmissive container is made of glass. The photoreaction device according to claim 1, wherein the encapsulant for the light emitting diode is a silicone lens. The photoreaction device according to claim 1, wherein the photoreactive substance is a photoreactive liquid. A photoreaction method comprising using the photoreaction device according to claim 1. The photoreaction method according to claim 10, wherein the composition of the photoreactant contains at least carbon atoms. The photoreaction method according to claim 11, wherein the photoreaction liquid as the photoreaction substance contains cycloalkane. The photoreaction method according to claim 12, wherein a cycloalkanone oxime is produced by irradiating the cycloalkane and the photonitrosating agent with light from a light irradiation device. The photoreaction method according to claim 13, wherein the cycloalkanone oxime is cyclohexanone oxime or cyclododecanone oxime. The photoreaction method according to claim 13 or 14, wherein the photo-nitrosating agent is nitrosyl chloride or trichloronitrosomethane. A method for producing a lactam, which comprises using the cycloalkanone oxime produced by the photoreaction method according to any one of claims 13 to 15.

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