JP2016207566A - Fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp including a luminous tube made of silica glass, and internally enclosing discharge gas of excimer emission containing rare gas, and a phosphor layer formed on the luminous tube and radiating ultraviolet light, and radiating ultraviolet light having a wavelength of 250-280 nm efficiently.SOLUTION: The phosphor layer includes a phosphor represented by general formula (Y, Pr)MgBO, especially the ratio x of Pr in the general formula is in a range of 0.03≤x≤0.15.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fluorescent lamp that emits light in the ultraviolet region, and particularly relates to a fluorescent lamp having an emission peak in the vicinity of a wavelength of 250 to 280 nm.

Ultraviolet rays are used in the production of substances by modification of various objects to be treated or treatments using photochemical reactions.
For example, ultraviolet rays having a wavelength of about 200 nm are mainly used in a sterilization treatment process such as water treatment using ultraviolet rays, a hardening treatment of a resin such as an adhesive, or an exposure treatment of a printed circuit board.
Recently, in the process of improving the mechanical strength of a low dielectric constant film (low-k film) in a semiconductor manufacturing process, ultraviolet rays in the above-mentioned wavelength band are used, and the range of use of such ultraviolet rays in the wavelength range of 200 nm. Is expanding.

As a light source that emits ultraviolet light in the 200 nm range, instead of conventional high-pressure mercury lamps, development of fluorescent lamps with phosphors that emit light efficiently in the 200 nm range and have little deterioration due to long-time lighting is being promoted. ing.
For example, in Japanese Patent Application Laid-Open No. 2011-175823 (Patent Document 1), vacuum ultraviolet light having a wavelength of 200 nm or less emitted by light emission of a discharge gas sealed in an arc tube is used as excitation light, and an emission peak is generated at a wavelength of 220 to 230 nm. A lamp having a phosphor that efficiently emits ultraviolet rays having a wavelength of 200 to 260 nm is described.

  By the way, development of a phosphor having a light emission peak on a longer wavelength side is desired from the viewpoints of light source use, light emission efficiency, ease of handling of ozone generation, and the like. For example, JP2013-25968A (Patent Document 2) describes a phosphor having an emission peak in the vicinity of 240 nm.

Further, depending on the use of another type of light source, there is one that exhibits effectiveness with ultraviolet light having a wavelength longer than 240 nm.
For example, when considering a light source for sterilization use, the relationship curve between the sterilization effect of E. coli phage MS2 generally used for confirming the sterilization effect and the wavelength of ultraviolet rays shown in FIG. It is being considered.
Referring to the figure, it can be seen that the sensitivity is extremely high in the wavelength range of about 230 nm or less, and at the same time, the sensitivity is constant in the wavelength range of 250 to 280 nm.

  By the way, the shorter wavelength region of 230 nm or less, which is a higher sensitivity region, is not necessarily suitable particularly for sterilization use due to the reason described in the paragraph 0004, and from this point of view, the longer wavelength region, more specifically, Therefore, a light source that efficiently emits ultraviolet rays of 250 to 280 nm is desired.

JP 2011-175823 A JP 2013-25968 A

  In view of the above circumstances, the present invention is to provide a novel fluorescent lamp capable of efficiently radiating ultraviolet rays having a wavelength of 250 to 280 nm.

In order to solve the above-described problems, a fluorescent lamp according to the present invention includes an arc tube in which a discharge gas that emits excimer including a rare gas is sealed, and a phosphor layer that emits ultraviolet rays formed in the arc tube. The phosphor layer includes a phosphor represented by a general formula (Y _1-x , Pr _x ) MgB ₅ O ₁₀ .
The phosphor is characterized in that the ratio of Pr (praseodymium) is in the range of 0.03 ≦ x ≦ 0.15.

  The fluorescent lamp according to the present invention has an effect of efficiently emitting a light emission spectrum having a wavelength of 250 to 280 nm.

It is sectional drawing of the fluorescent lamp which concerns on this invention, (A) is a sectional side view, (B) is AA sectional drawing. The emission spectrum graph of the fluorescent lamp of this invention. The graph which shows the relationship between Pr density | concentration and integral intensity | strength of the fluorescent lamp of this invention. The graph which shows the bactericidal effect of Escherichia coli phage MS2, and the relationship between the wavelength of an ultraviolet-ray.

FIG. 1 is a cross-sectional view of a fluorescent lamp according to an embodiment of the present invention, in which (A) is an axial cross-sectional view and (B) is a radial cross-sectional view.
As shown in FIG. 1, in the fluorescent lamp 1 of the present invention, a pair of external electrodes 3, 4 are arranged opposite to each other along the length direction of the arc tube 2 on the outer peripheral surface of the arc tube 2 made of quartz glass. Has been. The electrodes 3 and 4 are disposed with a discharge gas sealed in the arc tube 2 interposed therebetween. That is, in this example, both the electrodes 3 and 4 are respectively disposed between the electrode and the discharge gas. 2 is disposed in a state where a dielectric material composed of 2 is interposed.
These external electrodes 3 and 4 have a substantially strip shape extending in the tube axis direction. For example, a conductive paste such as a silver paste mixed with silver (Ag) and frit glass or a gold paste mixed with gold (Au) and frit glass. It is formed from a film. Of course, the configuration is not limited to such an external electrode alone, and if at least one of the electrodes has a dielectric layer interposed between the electrode and the discharge gas, one or both electrodes are inside the arc tube. It does not matter even if it is arranged in.
The external electrodes 3 and 4 are connected to lead wires W1 and W2 at their respective ends, and are connected to a power source 9 that generates a high-frequency voltage via the lead wires W1 and W2.

The arc tube 2 is made of quartz glass that is highly transmissive to ultraviolet rays having a wavelength of 200 nm. As the quartz glass, either fused silica glass or synthetic quartz glass can be used.
The arc tube 2 is filled with a discharge gas that emits excimer light, and this discharge gas contains at least xenon. For example, xenon alone or a mixed gas of xenon and other rare gases. Become.

As shown in FIG. 1B, a glass layer 5 is formed on the inner surface of the arc tube 2 so as to spread almost all over. A phosphor layer 6 is formed so as to be laminated on the inner surface of the glass layer 5.
This glass layer 5 is for adhering the phosphor layer 6 to the quartz glass constituting the arc tube 2, and as a characteristic of the glass, the softening point is preferably an appropriate firing temperature (400 ˜900 ° C.), specifically, soft glass or hard glass. Particularly preferred is a hard glass with good thermal shock resistance.

The phosphor constituting the phosphor layer 6 is irradiated with vacuum ultraviolet light such as 146 nm or 172 nm emitted by excimer emission of xenon gas as excitation light, and is excited thereby to emit ultraviolet light in a predetermined wavelength region. Is.
The phosphor in the present invention strongly emits fluorescence having a wavelength range of 200 nm, particularly 250 to 280 nm, and is represented by the following general formula.
(Y _1-x , Pr _x ) MgB ₅ O ₁₀
The ratio x of Pr (praseodymium) is in the range of 0.03 ≦ x ≦ 0.15.

  By using the above phosphor, it is possible to provide a fluorescent lamp that maximizes the light emission characteristics of ultraviolet rays in the wavelength range of 250 to 280 nm and has extremely good efficiency.

In the present invention, various changes can be made with respect to the structure of the lamp, and although not shown here, for example, a circular part of the phosphor layer may be removed to serve as an aperture for light extraction. Alternatively, an ultraviolet reflecting film may be formed on the inner surface of the arc tube, and a part of the circumference thereof may be cut out to form an aperture, and a phosphor layer may be laminated on the ultraviolet reflecting film.
Furthermore, although the phosphor layer is formed on the inner surface of the arc tube, it may be formed on the outer surface of the arc tube.

<Experimental example>
Subsequently, a fluorescent lamp was constructed by changing the composition of the phosphor in the same manner as in the above example, and the emission spectrum was measured with a spectral distribution meter.
Further, the integrated intensity was determined in the range of the wavelength of 250 to 300 nm in the emission spectrum by changing the composition of the phosphor.
The phosphor is (Y _1-x , Pr _x ) MgB ₅ O ₁₀ and the value of x is changed to 0.01, 0.03, 0.07, 0.15, 0.25, 0.4. It was produced.
For example, when x = 0.15, the ratio of Y (yttrium) is 0.85, which is a composition ratio of (Y _0.85 , Pr _0.5 ) MgB ₅ O ₁₀ .

An example of the emission spectrum of the phosphor is shown in FIG. 2, and the integrated intensity in the wavelength region of 250 to 300 nm obtained from the emission spectrum is shown in FIG.
In FIG. 2, in order to avoid complexity, all of the experimental examples are not described, and only four examples are described, and in FIG. 3, all of the six examples are described.
Further, in FIG. 2, in order to eliminate the overlapping of the emission spectrum graphs of the fluorescent lamps, the vertical axis is sequentially increased as the value of x increases with reference to the emission spectrum of the fluorescent lamp when x = 0.01. The value of the emission intensity is added by “500”, and the emission spectrum is shifted to express the overlap.

As is clear from FIG. 2, all the phosphors can obtain a good light emission state between 250 and 300 nm, but the emission intensity and the peak wavelength are different depending on the phosphor composition (ratio of Y and Pr). ing.
When looking at the integrated intensity in the wavelength range of 250 to 300 nm shown in FIG. 3, the maximum value is obtained when the Pr (praseodymium) ratio x is x = 0.03, and the integrated intensity at that time Is 100%, and a region where 80% or more is considered as one criterion, the value of Pr ratio x is 0.03 ≦ x ≦ 0.15, and particularly good light emission characteristics are obtained in this region. It is obtained.

As described above, in the fluorescent lamp of the present invention, the phosphor layer including the phosphor represented by the general formula (Y _1-x , Pr _x ) MgB ₅ O ₁₀ is formed on the arc tube made of quartz glass. Therefore, a fluorescent lamp having excellent light emission characteristics in the wavelength range of 250 to 280 nm can be obtained, and particularly good light emission characteristics can be obtained when the Pr ratio x = 0.03 to 0.15.

1 fluorescent lamp 2 arc tube (quartz glass)
3, 4 External electrode 5 Glass layer 6 Phosphor layer

Claims (2)

In a fluorescent lamp comprising a light emitting tube made of quartz glass and filled with a discharge gas that emits excimer light containing a rare gas, and a phosphor layer that emits ultraviolet rays formed in the light emitting tube,
The phosphor layer is generally formula _{(Y 1-x, Pr x} ) fluorescent lamp, characterized in that it comprises a phosphor represented by MgB _{5 O 10.} The fluorescent lamp according to claim 1, wherein the phosphor has a Pr ratio in a range of 0.03 ≦ x ≦ 0.15.

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