JP2010267403A - Discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp having a large integration spectroscopy radiant intensity of ultraviolet rays of a wavelength 300-340 nm. <P>SOLUTION: In the discharge lamp 10 comprising a light emitting tube 11, a pair of electrodes 13, 14 arranged in the light emitting tube 11, and a light emitting material enclosed in the light emitting tune 11, the light emitting material contains zinc and mercury, and a molar ratio of mercury to zinc is 3-35. Further, an enclosed amount of zinc is preferably 0.1μ mol/cm<SP>3</SP>or more. Furthermore, in the light emitting tube 11, there is enclosed iodine or bromine, and a molar number of zinc enclosed in the light emitting tube 11 is preferably larger than the molar number of iodine or bromine converted into two atomic molecules. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a discharge lamp that can be suitably used in a manufacturing process of a liquid crystal display.

  In the manufacturing process of the liquid crystal display, a sealing step in which the peripheral portions of two glass substrates arranged so as to face each other are bonded and sealed with an ultraviolet curable adhesive, followed by the sealing step When the liquid crystal molecules are aligned so as to be inclined with respect to the thickness direction or the plane direction of the glass substrate, for example, the photosensitive monomer encapsulated with the liquid crystal molecules is polymerized when forming the pixels of the liquid crystal display. And a pretilt angle providing step of fixing the alignment direction of the liquid crystal molecules.

In the sealing process, liquid crystal molecules and photosensitive monomers are injected between the two glass substrates, and a mask is placed at the center of the glass substrate to prevent the monomers from being irradiated with ultraviolet rays. In this state, ultraviolet rays are irradiated to the peripheral portion of the glass substrate to which the ultraviolet curable adhesive is applied. Here, the ultraviolet rays to be irradiated are selected according to the ultraviolet curable adhesive, and usually ultraviolet rays having a wavelength of 340 to 390 nm obtained by cutting ultraviolet rays having a wavelength of 340 nm or less by a filter are used (see Patent Document 1). .
On the other hand, the ultraviolet rays used in the pretilt angle providing step are ultraviolet rays having a wavelength of 300 to 380 nm in consideration of small damage to the liquid crystal molecules, high sensitivity of the monomer, and high transparency to the glass substrate. For this reason, as the photosensitive monomer, a monomer that is polymerized by ultraviolet rays having a wavelength of 300 to 380 nm, for example, a monomer having a sensitivity peak in the vicinity of a wavelength of 340 nm is used (see Patent Document 2).

Thus, in the sealing process, in order to reliably prevent the monomer enclosed between the glass substrates from being irradiated with ultraviolet rays, the mask is positioned with high accuracy relative to the glass substrate. It is important to do.
However, even if the mask is aligned with a high accuracy with respect to the glass substrate, ultraviolet rays enter the inside, thereby causing polymerization of the monomer, and particularly when ultraviolet rays having a wavelength of 340 nm enter the inside. There is a problem that monomer polymerization occurs rapidly.
For these reasons, recently, in order to prevent the monomer from being polymerized in the sealing step, there is a tendency to use a monomer having a peak sensitivity in a wavelength region considerably shorter than the wavelength of 340 nm. It is possible to prevent monomer polymerization from occurring in the stopping step.

In the pretilt angle imparting step, it is necessary to match the ultraviolet ray used in the step with the peak sensitivity of the monomer. Therefore, it is desired to use an ultraviolet ray having a wavelength of 300 to 340 nm.
As such a discharge lamp, there is known a discharge lamp in which zinc having an emission spectrum at a wavelength of 333 nm and a wavelength of 338 nm is enclosed as a luminescent substance in an arc tube.
However, the conventional discharge lamp in which zinc is enclosed does not have a large integrated spectral radiant intensity of ultraviolet rays having a wavelength of 300 to 340 nm in the radiated light.

JP2008-269976 JP2008-269977

  The present invention has been made based on the above circumstances, and an object thereof is to provide a discharge lamp having a large integrated spectral radiation intensity of ultraviolet rays having a wavelength of 300 to 340 nm.

The discharge lamp of the present invention is a discharge lamp comprising an arc tube, a pair of electrodes disposed in the arc tube, and a luminescent material enclosed in the arc tube.
The luminescent material contains zinc and mercury, and the molar ratio of the mercury to the zinc is 3 to 35.

In the discharge lamp of the present invention, it is preferred encapsulating amount of said zinc is 0.1 [mu] mol / cm ³ or more.
In addition, iodine or bromine is sealed in the arc tube,
It is preferable that the number of moles of zinc enclosed in the arc tube is larger than the number of moles of iodine or bromine converted to diatomic molecules.

According to the discharge lamp of the present invention, zinc and mercury are enclosed as a luminescent substance in the arc tube, and the molar ratio of the mercury to the zinc is in a specific range, so that the integrated spectral radiation intensity at a wavelength of 300 to 340 nm is large. Is obtained.
In addition, when the amount of zinc enclosed is 0.1 μmol / cm ³ or more, a discharge lamp that emits ultraviolet rays having a large integrated spectral radiation intensity at a wavelength of 300 to 340 nm can be reliably obtained.
In addition, according to the discharge lamp in which iodine or bromine is sealed in the arc tube, a so-called halogen cycle is formed in the arc tube, so that emitted light from zinc can be obtained at a relatively low temperature, and the arc tube Blackening due to reaction with zinc is suppressed, and furthermore, according to a discharge lamp in which the number of moles of enclosed zinc is larger than the number of moles of iodine or bromine converted to diatomic molecules, the lamp is lit for a long time. As a result, even when the zinc used for light emission is exhausted, free halogen is generated and traps electrons to increase the lamp voltage and prevent the lamp from going out beyond the allowable range of the power supply. can do.

It is explanatory drawing which shows the outline of a structure in an example of the discharge lamp of this invention. It is a curve figure which shows the relative output intensity of the light with a wavelength of 250-450 nm in the radiated light of a discharge lamp measured in Experimental example 1. FIG. It is a curve diagram which shows the relationship between the molar ratio of mercury with respect to zinc enclosed in the arc tube, and the integrated spectral radiation intensity (relative intensity ratio) of ultraviolet rays having a wavelength of 300 to 340 nm of the discharge lamp. It is a curve diagram which shows the relationship between the amount of zinc enclosed in the arc tube and the integrated spectral radiation intensity (relative intensity ratio) of ultraviolet rays having a wavelength of 300 to 340 nm of the discharge lamp.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is an explanatory diagram showing an outline of a configuration in an example of a discharge lamp of the present invention.
This discharge lamp 10 has an arc tube 11 made of quartz glass having sealing tube portions 12 formed at both ends, and in the arc tube 11, a pair of electrodes 13 and 14 are arranged in the tube axis direction so as to face each other. Are arranged along. Each of the sealing tube portions 12 in the arc tube 11 is provided with a cylindrical base 15, and a power supply line 16 for supplying power between the electrodes 13 and 14 is provided on each peripheral side surface of the base 15. A power supply terminal 17 connected to the lighting device is provided at the tip of the power supply line 16.

In the arc tube 11, a luminescent material and a rare gas are enclosed, and zinc and mercury are used as the luminescent material.
Thus, mercury is enclosed in addition to zinc as the luminescent material, so that a discharge lamp 10 is obtained that emits ultraviolet rays with wavelengths of 313 nm and 334 nm due to mercury in addition to ultraviolet rays with wavelengths of 333 nm and 338 nm due to zinc. In addition, since the resistance value between the electrodes 13 and 14 is low, the discharge lamp 10 is obtained in which the lamp current is small and the load applied to the electrodes 13 and 14 is small.

  The molar ratio of mercury to zinc enclosed in the arc tube 11 is 3 to 35, preferably 6 to 20. By enclosing zinc and mercury at such a molar ratio, ultraviolet light having a high integrated spectral radiation intensity at a wavelength of 300 to 340 nm can be obtained. When this molar ratio is less than 3, ultraviolet rays having a wavelength of 313 nm and a wavelength of 334 nm due to mercury cannot be sufficiently obtained, and as a result, an ultraviolet ray having a large integrated spectral radiation intensity at a wavelength of 300 to 340 nm cannot be obtained. On the other hand, when this molar ratio exceeds 35, the intensity of ultraviolet rays having wavelengths of 365 nm and 436 nm due to mercury becomes excessive, and the intensity of ultraviolet rays having wavelengths of 313 nm and 334 nm is relatively small. Ultraviolet rays with high integrated spectral radiation intensity cannot be obtained.

Further, the amount of zinc enclosed in the arc tube 11 is preferably 0.1 μmol / cm ³ or more, more preferably 0.2 μmol / cm ³ or more. The upper limit of zinc added amount is not particularly limited, usually, is 5 [mu] mol / cm ³ or less. By enclosing such an amount of zinc, it is possible to obtain ultraviolet rays at a wavelength of 300 to 340 nm with high intensity.

  Further, it is preferable that iodine or bromine is enclosed in the arc tube 11, thereby forming a so-called halogen cycle in the arc tube 11. That is, a halide (iodide or bromide) of zinc is generated in the arc tube 11, and this halide is vaporized at a relatively low temperature because the vapor pressure is higher than that of metallic zinc. In the arc formed at a very high temperature, the halide dissociates and metal vapor is generated, and when the metal vapor approaches the wall of the arc tube 11 having a low temperature, it reacts with the halogen again. As a result, a halide is formed. Therefore, when iodine or bromine is enclosed, emitted light from zinc can be obtained at a relatively low temperature, and blackening due to the reaction between quartz glass and zinc constituting the arc tube 11 may occur in the arc tube 11. It is suppressed.

  When iodine or bromine is enclosed in the arc tube 11, the number of moles of zinc sealed in the arc tube 11 is preferably larger than the number of moles of iodine or bromine converted to diatomic molecules. The number of moles of zinc is preferably 2 to 10 times the number of moles of iodine or bromine converted to a diatomic molecule. By enclosing such an amount of iodine or bromine, when the discharge lamp 10 is turned on for a long time, even when zinc used for light emission is consumed, free halogen is generated and traps electrons. As a result, the lamp voltage can be raised to prevent the lamp from going out beyond the allowable range of the power source.

  When iodine or bromine is sealed in the arc tube 11, it may be sealed as zinc halide (zinc iodide or zinc bromide), but these halides are easy to react with moisture and are handled. However, it is preferable to enclose iodine or bromine alone because the encapsulating operation is complicated.

According to the discharge lamp 10 described above, zinc and mercury are enclosed as the luminescent material in the arc tube 11, and the molar ratio of the mercury to the zinc is in a specific range, so that the integrated spectral radiant intensity at a wavelength of 300 to 340 nm is high. Large ultraviolet rays can be obtained.
Moreover, the discharge lamp 10 which radiates | emits the ultraviolet-ray with a large integral spectral radiation intensity | strength in wavelength 300-340nm is reliably obtained because the enclosure amount of zinc is 0.1 micromol / cm < ³ > or more.
Further, according to the discharge lamp 10 in which iodine or bromine is sealed in the arc tube 11, a so-called halogen cycle is formed in the arc tube 11, so that radiated light from zinc can be obtained at a relatively low temperature, and According to the discharge lamp 10, the occurrence of blackening due to the reaction between the arc tube and zinc is suppressed, and the number of moles of enclosed zinc is larger than the number of moles of iodine or bromine converted to diatomic molecules. Even if the zinc used for light emission is exhausted by lighting for a long time, free halogen is generated and traps electrons to increase the lamp voltage, causing the lamp to go out beyond the allowable range of the power supply. Can be prevented.
Such a discharge lamp 10 is suitable as a discharge lamp used in the pretilt angle providing step in the manufacturing process of the liquid crystal display because the integrated spectral radiation intensity of ultraviolet rays having a wavelength of 300 to 340 nm is large.

<Experimental example 1>
Using an arc tube having an inner diameter of 22 mm and an inner volume of 95 cm ^{3 at} the center, according to the configuration shown in FIG. 1, the amounts of iodine zinc (ZnI ₂ ) or zinc bromide (ZnBr ₂ ) in the amounts shown in Table 1 and Table 2 below are used. ) And mercury, as well as discharge lamps (A1) to (A10) in which xenon gas is sealed so that the sealed pressure at the time of lighting is 5 kPa, and electrodes (13, 14) are arranged at a separation distance of 250 mm; Discharge lamps (B1) to (B8) were produced.
All of these discharge lamps have a rated voltage of 500 V, a rated current of 14 A, and a lamp power of 7000 W.

Each of the discharge lamp (A5) and the discharge lamp (A10) was turned on, and the relative output intensity of light having a wavelength of 250 to 450 nm in the emitted light was measured. The results are shown in FIG. However, in FIG. 2, the solid line relates to the discharge lamp (A5), and the broken line relates to the discharge lamp (A10).
As is apparent from the results of FIG. 2, the discharge lamp (A5) in which zinc iodide is sealed emits ultraviolet rays having wavelengths of 313 nm and 334 nm due to mercury in addition to ultraviolet rays having wavelengths of 333 nm and 338 nm due to zinc. Therefore, it is understood that the integrated spectral radiation intensity of ultraviolet rays having a wavelength of 300 to 340 nm is higher than that of the discharge lamp (A10).

  Further, each of the discharge lamps (A1) to (A10) and the discharge lamps (B1) to (B8) was turned on, and the integrated spectral radiant intensity of ultraviolet rays having a wavelength of 300 to 340 nm in the emitted light was measured. For the discharge lamps (A1) to (A10), the intensity ratio when the integrated spectral radiation intensity of the discharge lamp (A10) is 1.00 is shown in Table 1, and for the discharge lamps (B1) to (B8), Table 2 below shows the relative intensity ratio when the integrated spectral radiation intensity related to the discharge lamp (A10) is 1.00.

FIG. 3 shows the relationship between the molar ratio of mercury to zinc and the integrated spectral radiant intensity (relative intensity ratio) of light having a wavelength of 300 to 340 nm, which was created based on the results of Table 1 and Table 2. However, in FIG. 3, the solid line relates to a discharge lamp enclosing zinc iodide (ZnI ₂ ), and the broken line relates to a discharge lamp enclosing zinc bromide (ZnBr ₂ ).

  As is apparent from the results of FIG. 3, in a discharge lamp having a mercury to zinc molar ratio of 3 to 35 enclosed in the arc tube, the ultraviolet light having a large integrated spectral radiant intensity at a wavelength of 300 to 340 nm, specifically, It was confirmed that ultraviolet rays 1.2 times or more that of a discharge lamp not containing mercury were obtained. In particular, in a discharge lamp having a molar ratio of mercury to zinc enclosed in the arc tube of 6 to 20, the integrated spectral radiant intensity at a wavelength of 300 to 340 nm is extremely large, specifically, a discharge lamp in which mercury is not enclosed. It was confirmed that ultraviolet rays of 1.25 times or more can be obtained.

<Experimental example 2>
Using an arc tube with the same specifications as in Experimental Example 1, according to the configuration shown in FIG. 1, iodine zinc (ZnI ₂ ) or zinc bromide (ZnBr ₂ ) and mercury are enclosed, and the xenon gas is charged at lighting. A plurality of discharge lamps were prepared, in which the electrode (13, 14) was disposed at a separation distance of 250 mm. In these discharge lamps, the amount of zinc enclosed was changed stepwise in the range of 0.01 to 10 μmol / cm ³ , and the amount of mercury enclosed was adjusted so that the molar ratio of mercury to zinc was 12.
All of these discharge lamps have a rated voltage of 500 V, a rated current of 14 A, and a lamp power of 7000 W.
Then, each of the produced discharge lamps is turned on, the integral spectral radiant intensity of ultraviolet rays having a wavelength of 300 to 340 nm in the radiated light is measured, and the discharge in which zinc iodide is enclosed and 1 μmol / cm ³ is enclosed. The intensity ratio was calculated when the integrated spectral radiation intensity of the lamp was 1.00. FIG. 4 shows the relationship between the amount of zinc enclosed based on the result and the integrated spectral radiant intensity (relative intensity ratio) of light having a wavelength of 300 to 340 nm. However, in FIG. 4, the solid line relates to a discharge lamp enclosing zinc iodide (ZnI ₂ ), and the broken line relates to a discharge lamp enclosing zinc bromide (ZnBr ₂ ).

As is clear from the results in FIG. 4, if the discharge amount of zinc is 0.1 μmol / cm ³ or more, the integrated spectroscopy of a discharge lamp having a zinc fill amount of 1 μmol / cm ^{3 at} a wavelength of 300 to 340 nm. It was confirmed that ultraviolet rays having an integrated spectral radiation intensity of 90% or more with respect to the radiation intensity can be obtained.

DESCRIPTION OF SYMBOLS 10 Discharge lamp 11 Light emission tube 12 Sealing tube parts 13 and 14 Electrode 15 Base 16 Feed line 17 Feed terminal

Claims (3)

In a discharge lamp comprising an arc tube, a pair of electrodes disposed in the arc tube, and a luminescent material sealed in the arc tube,
The light-emitting substance contains zinc and mercury, and the molar ratio of the mercury to the zinc is 3 to 35. 2. The discharge lamp according to claim 1, wherein the zinc content is 0.1 μmol / cm ³ or more. In the arc tube, iodine or bromine is sealed,
The discharge lamp according to claim 1 or 2, wherein the number of moles of zinc sealed in the arc tube is larger than the number of moles of iodine or bromine converted to diatomic molecules.

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