JPH06176737A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To maintain the excellent color rendering property, and to reduce the cost by providing an organic group material layer for reducing the light emission at wavelength 430nm or less on the outer surface of a lamp bulb. CONSTITUTION:In a fluorescent lamp, in which the double-layer coating of fluorescent film is performed, the outer surface of a lamp bulb is provided with an organic group material layer 4 for reducing the light emission at 430nm or less of wavelength. As a result, the light emission at 430nm or less among the blue light emitting area strengthened by the increase of halocalcium phosphate of a first fluorescent film layer 2 of the double-layer coating and the light emission of blue mercury emission line at 405nm of a second layer, which is strengthened by the reduction of active alkaline earth group metal borophosphate with europium, are weakened. The ratio of a halocalcium phosphate phosphor of the second layer at a low cost is increased to improve the color rendering property in the double-layer coated fluorescent lamp, of which color rendering property is lowered. Namely, the weight ratio of halocalcium phosphate phosphor, of which cost is low, of the layer 2 of the double-coated fluorescent films can be increased to reduce the cost of the fluorescent lamp.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a fluorescent lamp used for color evaluation.

[0002]

2. Description of the Related Art Fluorescent lamps having a color rendering AAA with excellent color rendering properties have been commercialized as fluorescent lamps for color evaluation as standard illumination for color plate making, printing and painting. Generally, it is necessary to suppress light emission in the blue region, which is detrimental to color rendering properties, as a means of enhancing the color rendering properties of fluorescent lamps.
2, a divalent europium-activated alkaline earth that absorbs blue mercury emission lines with wavelengths of 405 nm and 436 nm generated by fluorescent lamp mercury vapor discharge without emission in the blue region having an emission peak in the wavelength range of 480 to 490 nm. An excellent color rendering property of Ra98 is realized by using borophosphoric acid having a metal group.

Further, in the fluorescent lamp for color evaluation, a layer of titanium oxide or zinc oxide, which is an inorganic material, is provided between the glass bulb and the fluorescent film to block ultraviolet rays generated by mercury vapor discharge, As an anti-fading fluorescent lamp with reduced fading of the irradiated object, it is also used for lighting in museums and museums.

By the way, the layer for blocking ultraviolet rays, which is applied between the glass bulb and the fluorescent film, absorbs the impure gas,
Since the discoloration of the layer adversely affects the lamp characteristics, a method of providing it on the outer surface of the lamp bulb was studied. As an example, there is Japanese Patent Application Laid-Open No. 4-104453 in which a fading-preventing type fluorescent lamp is manufactured by mixing titanium oxide and zinc oxide in a water-repellent silicone resin and coating the mixture on the outer surface of the lamp. Recently, organic materials have also been applied as UV-cutting materials for fluorescent lamps. This material is mixed with heat-shrinkable polyethylene terephthalate resin and made into a tube so that it can be coated on the outer surface of the lamp. "Copalon (registered trademark)" UV-400 manufactured by Kogyo Co., Ltd. is commercially available.

To be precise, the above-mentioned organic material for cutting off the ultraviolet rays completely cuts off the ultraviolet rays of 400 nm or less, and exhibits an absorbing effect even for the light emission of 400 nm to 430 nm. It is possible to absorb and attenuate the light emission of 405 nm in the blue mercury emission line which is harmful to.

Next, the relationship between the cost reduction effect and the color rendering properties of a fluorescent lamp having two layers of fluorescent films coated thereon will be described.

Since fluorescent lamps using a phosphor containing a rare earth such as europium are expensive, it has been conventionally devised to reduce the deposition amount of the phosphor containing the rare earth. As shown in Japanese Examined Patent Publication No. 53-867, two layers of fluorescent film are applied, the first layer is an inexpensive calcium halophosphate phosphor, and the second layer is a rare earth phosphor, so that the deposition amount of the rare earth phosphor is reduced. Although there is a method to reduce the cost of fluorescent lamps, the color rendering of fluorescent lamps using rare earth phosphors is superior to that of fluorescent lamps using calcium halophosphate phosphor, and the ratio of phosphors in the first layer is the highest. If it is larger than that of the second layer, the color rendering property is deteriorated.

[0008]

By the way, the inventor of the present invention has found that even in the fluorescent lamp for color evaluation, in order to reduce the cost,
Similar to fluorescent lamps using other rare earth phosphors such as three-wavelength emission type fluorescent lamps, as shown in FIG. 2, two-layer coating using a calcium halophosphate phosphor as the first layer fluorescent film has been studied. When the ratio of the calcium halophosphate in the first layer to the whole phosphor is increased and the ratio of the phosphor in the second layer is decreased, the emission of calcium halophosphate in the blue region becomes stronger, and in addition, the second layer Of europium-activated alkaline earth metal borophosphate contained in
There is a problem that the effect of absorbing the emission of the 36-nm blue mercury emission line is weakened, and the color rendering is deteriorated. As a means for solving such a problem, as shown in FIG. 2, when an inorganic substance such as titanium oxide or zinc oxide that absorbs blue light is provided on the inner or outer surface of the lamp, the spectral transmittance curve of FIG. As shown in b and c, the transmittance for light emission of 400 nm or less is as high as 70% or more, and a large effect cannot be expected. Further, when an organic material that attenuates light emission of wavelength 430 nm or less as shown by the spectral transmittance curve a in FIG. 4 is provided on the inner surface of the lamp, the material is It decomposes and evaporates.

The present invention has been made in view of the above circumstances, and maintains the excellent color rendering properties of a fluorescent lamp for color evaluation, while the first layer of the fluorescent film contains calcium halophosphate. The purpose is to reduce the cost by applying a two-layer coating.

[0010]

The present invention has been solved by providing a fluorescent lamp having a two-layer coating of a fluorescent film with an organic material layer on the outer surface of a lamp bulb for attenuating light emission of a wavelength of 430 nm or less.

[0011]

In the present invention, the wavelength 43 is provided on the outer surface of the lamp bulb.
Since the organic material layer for attenuating the emission of 0 nm or less was provided, the emission of 430 nm or less and the emission of the second layer of the blue emission region strengthened by the increase of calcium halophosphate in the two-layer coating first-layer emission film. The emission of the blue mercury emission line having a wavelength of 405 nm, which was intensified by the decrease in the europium-activated alkaline earth metal borophosphate, was weakened, the ratio of the inexpensive calcium halophosphate phosphor in the first layer was increased, and the color rendering property was decreased.
It is possible to improve the color rendering of a fluorescent lamp that has been coated with two layers.

[0012]

EXAMPLES Examples of the present invention will be described below.

Example 1 First, a fluorescent lamp in which an organic substance that attenuates light having a wavelength of 430 nm or less is mixed with a heat-shrinkable resin and a film of this resin is coated on the outer surface of the lamp bulb will be described. The inner surface of the bulb 1 of the straight tube fluorescent lamp shown in FIG.
A first layer fluorescent film 2 made of calcium halophosphate activated with antimony and manganese and a second layer fluorescent film 3 made of strontium orthophosphate containing divalent europium activated strontium borophosphate and tin activated magnesium were coated. ing. On the outer surface of the lamp, a heat-shrinkable film 4 of polyethylene terephthalate resin mixed with 2,4-dihydroxybenzophenone that absorbs light having a wavelength of 430 nm or less by having the spectral transmittance curve a of FIG. 4 as an organic material, This is made into a tube, and the lamp bulb is covered with an inner diameter larger than the outer diameter of the bulb in advance.
It is coated by heating to 0 ° C.

The organic substance 2,4-dihydroxybenzophenone mixed in the polyethylene terephthalate resin has a deposition amount of 0.3 per 1 cm ^{2 of the} outer surface of the lamp.
It is adjusted to be mg.

Next, with respect to the color rendering properties of the thus obtained fluorescent lamp, the results of an experiment in which the weight ratio of the fluorescent films of the first layer and the second layer is changed will be described.

[0016]

[Table 1]

Table 1 shows FLR40S / N-EDL / M.
(Correlation color temperature 5000k, deviation from black body 0.003d
uv), after 100 hours of lighting, Ra is the same as that of the example and the comparative example 1 shown in FIG. 2 not using the blue emission decay method, and as shown in FIG. 3, a titanium oxide film is formed on the inner surface or the outer surface of the bulb. 3 shows Comparative Example 2 and Comparative Example 3 provided with. From the above table, in the comparative example 1, when the phosphor layer of the first layer exceeds 30 wt%, the color rendering property is deteriorated, and in order to improve the color rendering property, the titanium oxide film is provided on the inner surface or the outer surface of the bulb. Has almost no effect of improving Ra, while in the example in which the resin film mixed with the organic material for attenuating the light emission of wavelength 430 nm or less is coated on the outer surface of the bulb, the ratio of the first layer of the fluorescent film is 70 wt%.
It can be seen that the effect of improving the color rendering property is maintained even when the amount is increased up to.

5 and 6 show the spectral energy characteristics of the fluorescent lamps of Example 1 and Comparative Example 2, respectively. In the examples, it can be seen that the light emission having a wavelength of 430 nm or less in the blue light emission region harmful to the color rendering property is significantly attenuated.

Example 2 An organic material layer made of 2,4-dihydroxybenzophenone for attenuating light having a wavelength of 430 nm or less was dissolved on acetone on the outer surface of the lamp. The organic material was immersed in acetone, and the fluorescent lamp was immersed in the organic solvent. Example 1 is the same as Example 1 except that it was formed by a method of drying.

The acetone-dissolved 2,4-dihydroxybenzophenone is adjusted to 0.3 mg per 1 cm ^{2 of the} outer surface of the lamp when the coating is formed on the fluorescent lamp. The drying of the organic solvent was carried out at a temperature of 50 ± 5 ° C. so as to prevent uneven adhesion of the coating film and to prevent foaming due to boiling of the solvent.

The color rendering of the thus obtained fluorescent lamp is FLR40S.N-, as shown in Table 1 Example 2.
The lighting result after 100 hours at EDL / M (correlation color temperature 5000 k, deviation from black body 0.003 duv) was 70 wt% of the first layer fluorescent film and 30 w of the second layer fluorescent film.
It was 98 at t% as in Example 1.

In this embodiment, an organic substance that attenuates light having a wavelength of 430 nm or less is mixed with a heat-shrinkable film to coat the outer surface of the lamp, or dissolved in an organic solvent to immerse the fluorescent lamp in it. Although it is provided on the outer surface of the lamp by a method of drying after the application, any method may be applied as long as the substance is uniformly applied to the outer surface of the lamp.

In the present embodiment, 2,4-dihydroxybenzophenone was used as the organic substance for attenuating the emission of light having a wavelength of 430 nm or less. Other organic materials, such as 2-hydroxy-4-methoxybenzophenone, as long as they are organic and thermally stable materials.
2-hydroxy-4-octoxybenzophenone, 2,
Benzophenone derivatives such as 2'-dihydroxy-4,4'-dimethoxybenzophenone and 2,2'-dihydroxy-4-methoxybenzophenone, and 2- (2'-
Hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5-di-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5) ′ -Methylphenyl) -5
Benzotriazole derivatives such as -chlorobenzotriazole, 2-ethylhexyl-2-cyano-3,
3'-diphenyl acrylate, ethyl-2-cyano-
Cyanoacrylate derivatives such as 3,3′-diphenyl acrylate, phenyl salicylate, and salicylate P
It can be applied even when a salicylic acid derivative such as -t-butylphenyl is used.

In the present embodiment, the first phosphor of the second layer is a divalent europium-activated strontium borophosphate,
The second phosphor was performed as tin-activated magnesium-containing strontium orthophosphate, and other europium-activated alkaline earth metal borophosphates and europium-activated alkaline earth metal aluminates were used as the first phosphor. Divalent europium-activated alkaline earth metal halosilicate, divalent europium-activated alkaline earth metal chlorophosphate, other tin-activated magnesium-containing alkaline earth metal orthophosphate, with tin as the second phosphor It is also applicable when at least one of the active zinc-containing alkaline earth metal orthophosphates is used.

Further, in the present embodiment, the same effect is obtained when a phosphor having a higher color rendering property than the phosphor of the first layer is selected as the phosphor of the second layer, such as a phosphor for a three-wavelength band emission type fluorescent lamp. Can be obtained.

[0026]

As described above, according to the present invention,
Since the organic material layer for attenuating the light emission with a wavelength of 430 nm or less is provided on the outer surface of the fluorescent lamp bulb, the weight ratio of the inexpensive first layer calcium halophosphate phosphor in the two-layer coating of the fluorescent film can be increased. Therefore, the cost of the fluorescent lamp can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a lamp according to an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional lamp.

FIG. 3 is a sectional view of a conventional lamp.

FIG. 4 is a spectral transmittance curve of a material that absorbs blue light used in the present invention and a conventional example.

FIG. 5 is a diagram showing spectral energy distribution characteristics of a lamp in one example of the present invention and a conventional example.

FIG. 6 is a diagram showing spectral energy distribution characteristics of a lamp in one example of the present invention and a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 bulb 2 1st layer fluorescent film 3 2nd layer fluorescent film 4 organic material-containing heat-shrinkable tube 11 valve 12 1st layer fluorescent film 13 2nd layer fluorescent film 21 valve 22 1st layer fluorescent film 23 2nd layer fluorescent film 24 Inorganic substance film 25 Inorganic substance film a Organic substance that attenuates light emission of wavelength 430 nm or less b Titanium oxide c Zinc oxide

Claims (1)

[Claims] 1. A two-layer fluorescent film is coated on the inner surface of the lamp, the first layer containing calcium halophosphate activated with antimony and manganese, and the second layer containing divalent europium-activated alkaline earth metal. At least one of borophosphate, divalent europium-activated alkaline earth metal aluminate, divalent europium-activated alkaline earth metal chlorosilicate, divalent europium-activated alkaline earth metal chlorophosphate
A fluorescent lamp containing at least one of a tin-activated magnesium-containing alkaline earth metal orthophosphate and a tin-activated zinc-containing alkaline earth metal orthophosphate as a second phosphor, A fluorescent lamp comprising an organic material layer that attenuates light emission of 430 nm or less.