JP2010251196A - Fluorescent lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent lamp retaining a scatter prevention function for a long period of time. <P>SOLUTION: A first fluorescent lamp includes a fluorescent tube and a resin film covering the fluorescent tube, and the resin film is formed of a resin containing an ultraviolet absorbent, a light stabilizer, and an antioxidant. A second fluorescent lamp includes the fluorescent tube and an ultraviolet absorbing layer formed on an inner surface of the fluorescent tube, the ultraviolet absorbing layer includes an ultraviolet absorbing material formed of inorganic particles, and the thickness of the ultraviolet absorbing layer is 2 μm or more. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fluorescent lamp having a scattering prevention function, and is intended to reduce changes with time of a scattering prevention film by absorbing ultraviolet rays emitted from the fluorescent lamp.

  As fluorescent lamps with anti-scattering functions, various fluorescent lamps such as straight tube fluorescent lamps are used to prevent breakage when dropped, to prevent glass fragments from scattering when broken, or to clean box lighting for semiconductor processing. The thing which coat | covered the outer surface with the heat-shrinkable resin film is proposed (for example, refer patent document 1). A fluorescent lamp having a scattering prevention function using this heat-shrinkable resin film has been confirmed to have a certain effect in preventing breakage of the lamp by adjusting the tensile strength in the tube axis direction.

JP-A-1-159959

  In recent years, due to demands for improving environmental performance and efficiency, fluorescent lamps have been increased in power and rated life, and it has become necessary for fluorescent lamps having a scattering prevention function to maintain the scattering prevention function over a long period of time. . However, if a conventional fluorescent lamp with a heat-shrinkable resin film and having a scattering prevention function is used for a long time, heat shrinkability is caused by ultraviolet rays from sunlight or ultraviolet rays emitted from the fluorescent lamp itself or other fluorescent lamps. There has been a problem that mechanical strength is reduced due to hydrolysis of the resin film. For this reason, it has been difficult to maintain the anti-scattering function over a long period until the end of the life of the fluorescent lamp.

  The present invention solves the above-described problems and provides a fluorescent lamp capable of maintaining a scattering prevention function over a long period of time.

  The first fluorescent lamp of the present invention is a fluorescent lamp having a scattering prevention function including a fluorescent tube and a resin film covering the fluorescent tube, the resin film comprising an ultraviolet absorber, a light stabilizer, It is formed from resin containing antioxidant.

  The second fluorescent lamp of the present invention is a fluorescent lamp including a fluorescent tube and an ultraviolet absorbing layer formed on the inner surface of the fluorescent tube, and the ultraviolet absorbing layer is an ultraviolet absorbing material made of inorganic particles. The thickness of the ultraviolet absorbing layer is 2 μm or more.

  ADVANTAGE OF THE INVENTION According to this invention, the fluorescent lamp which can maintain a scattering prevention function over a long period can be provided.

FIG. 1 is a diagram showing the results of a scattering prevention test of a fluorescent lamp using a conventional heat shrinkable tube. FIG. 2 is a partial cross-sectional view showing an example of the fluorescent lamp of the present invention. FIG. 3 is a diagram showing the measurement results of the light transmission characteristics of the heat-shrinkable tube used in Example 1. FIG. 4 is a diagram showing measurement results of light transmission characteristics of the heat-shrinkable tube used in Comparative Example 1.

  The present inventors conducted a non-scattering prevention test of the Japan Light Bulb Industry Association standard described later at certain time intervals after lighting for various fluorescent lamps with different tube wall loads using a heat shrinkable tube having a scattering prevention function. It was. Specifically, the following three (1) to (4) fluorescent lamps are prepared as fluorescent lamps (correlated color temperature: 5000K) of the same three-wavelength type having different tube wall loads and having the same length. Each fluorescent lamp was coated with a 100 μm-thick heat-shrinkable tube made of polyethylene terephthalate resin, and then an anti-scattering test was conducted. The result is shown in FIG.

(1) FLR40S / EX-N / M / 36 (tube diameter: 3.25 cm, length 119.8 cm, input power 36 W, tube wall load: 29.4 mW / cm ² )
(2) FL40SS / EX-N / 37 (tube diameter: 2.8 cm, length 119.8 cm, input power 37 W, tube wall load: 35.1 mW / cm ² )
(3) FHF32EX-N (tube diameter: 2.55 cm, length 119.8 cm, input power 45 W, tube wall load: 46.9 mW / cm ² )
(4) FHF63EXN-G (tube diameter: 2.55 cm, length 117.8 cm, input power 63 W, tube wall load: 66.8 mW / cm ² )

  In FIG. 1, the pass of the anti-scattering test is indicated by a black circle, and the failure is indicated by an x mark. From FIG. 1, it can be seen that there is a difference in the results of the anti-scattering test depending on the tube wall load. By the way, it is well known that a polyester resin such as a polyethylene terephthalate resin used as a material resin for a heat shrinkable tube having a scattering prevention function is decomposed when irradiated with ultraviolet rays. As is clear from FIG. 1, the fluorescent lamps in a certain range (the tube wall load and the lighting time are in inverse proportion) between the tube wall load and the lighting time pass the anti-scattering test. That is, it is considered that the degradation of the polyester resin by ultraviolet rays occurs when the total amount of ultraviolet rays per unit area determined by the product of the ultraviolet ray density and time exceeds a certain value. In addition, the film thickness of the heat-shrinkable tube and the lighting time for passing the anti-scattering test were proportional, and the lighting time for passing the anti-scattering test was extended as the film thickness was increased. Therefore, the film thickness of the heat shrinkable tube needs to be increased according to the rated lighting time or the tube wall load.

  The present invention has been made from the above viewpoint, and the present invention will be described in detail below.

  A first fluorescent lamp of the present invention includes a fluorescent tube and a resin film that covers the fluorescent tube, and the resin film is formed of a resin including an ultraviolet absorber, a light stabilizer, and an antioxidant. ing.

  By forming the resin film with a resin containing an ultraviolet absorber, a light stabilizer, and an antioxidant, it is possible to provide a fluorescent lamp that can suppress deterioration of the resin film and maintain a scattering prevention function for a long period of time. .

  The resin film is preferably a heat-shrinkable resin film, and the resin is preferably a polyester resin. Thereby, the mechanical strength of the resin film can be improved.

Moreover, it is preferable to set the film thickness of the said resin film in the range of the following lower limit and the following upper limit. That is, the lower limit value of the resin film thickness is D1 (μm), the upper limit value of the resin film thickness is D2 (μm), the rated life of the fluorescent lamp is A (hours), and the tube wall of the fluorescent lamp When the load is B (mW / cm ² ), D1 = C × A × B, C = 6.4 × 10 ^{−5 to} 1.2 × 10 ⁻⁴ , D2 = 150 μm, D1 Is less than 50 μm, the lower limit of the thickness of the resin film is preferably 50 μm. The reason why the lower limit value is set to 50 μm is that if the lower limit value is smaller than this, the uniformity of the resin is lost during heat shrinkage and the film may be cut. The reason why the upper limit value is set to 150 μm is that workability is significantly deteriorated if the upper limit value is larger than this. The basis for determining the coefficient C will be described later.

  It is preferable that an ultraviolet absorbing layer is further formed on the inner surface of the fluorescent tube. By forming the ultraviolet absorbing layer on the inner surface of the phosphor, it is possible to provide a fluorescent lamp that can further absorb ultraviolet rays, can further suppress deterioration of the resin film, and can maintain the scattering prevention effect for a longer period.

  The ultraviolet absorbing layer contains an ultraviolet absorbing material made of inorganic particles, and the thickness of the ultraviolet absorbing layer is preferably 2 μm or more. Thereby, a sufficient ultraviolet absorption effect can be exhibited. The upper limit of the thickness of the ultraviolet absorbing layer is not particularly limited, but is usually 5 μm or less.

  The second fluorescent lamp of the present invention includes a fluorescent tube and an ultraviolet absorbing layer formed on the inner surface of the fluorescent tube, and the ultraviolet absorbing layer includes an ultraviolet absorbing material made of inorganic particles, The thickness of the absorption layer is 2 μm or more.

  Only by forming the ultraviolet absorbing layer on the inner surface of the fluorescent tube, it is possible to provide a fluorescent lamp capable of suppressing deterioration of the resin film and maintaining the scattering prevention function for a long period of time. The upper limit of the thickness of the ultraviolet absorbing layer is not particularly limited, but is usually 5 μm or less as described above.

  Next, the fluorescent lamp of the present invention will be described with reference to the drawings. FIG. 2 is a partial cross-sectional view showing an example of the fluorescent lamp of the present invention. In FIG. 2, in order to avoid complication of the drawing, a part of the cross section is not hatched. In FIG. 2, the fluorescent lamp 10 of the present invention includes a fluorescent tube 11 formed of a glass tube or the like, and a resin film 12 that covers the outer surface of the fluorescent tube 11. Also. An ultraviolet absorption layer 13 and a phosphor layer 14 are provided on the inner surface of the fluorescent tube 11. A filament electrode 15 is provided inside both ends of the fluorescent tube 11, and a base 16 is provided outside the both ends of the fluorescent tube 11. Further, an inert gas such as argon and mercury are enclosed in the fluorescent tube 11.

  The resin film 12 is formed of a heat-shrinkable resin film. Examples of the resin forming the resin film 12 include polypropylene terephthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene terephthalate / isophthalate. Polyester resins such as copolymers and polyethylene / neopentyl terephthalate copolymers can be used. These may be used alone or in combination of two or more.

  The resin that forms the resin film 12 contains an ultraviolet absorber, a light stabilizer, and an antioxidant.

  As the ultraviolet absorber, an organic material having high compatibility with the resin is preferably used. As an organic material that can be used as an ultraviolet absorber, for example, a benzotriazole compound, a benzophenone compound, a triazine compound, or the like can be used. In particular, a benzotriazole compound is most preferable because of its high ultraviolet absorption ability. These organic materials can be used alone or in combination.

  Examples of the benzotriazole compounds include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, and 2- [2-hydroxy-3. , 5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (2 ′ -Hydroxy-5'-t-octylphenyl) benzotriazole and the like can be used. Examples of the benzophenone compounds include (2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, etc. Examples of the triazine compounds include 2- (4,6 -Diphenyl-1,3,5-triazin-2-yl) -5 [(hexyl) oxy] -phenol and the like can be used.

  Examples of the light stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and bis (1,2,2,6,6-pentamethyl-4) which are hindered amine light stabilizers. -Piperidinyl) sebacate, 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), etc. Can be used.

  Examples of the antioxidant include 3,9-Bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyl] -1,1-dimethylethyl] -2,4,8,10. -Tetraoxaspiro [5/5] undecane, Pentaerythritol tetrakis (3-laurothiopropionate), etc. can be used.

The film thickness of the resin film 12 is set within the range of the following lower limit value and the following upper limit value. That is, the lower limit of the film thickness of the resin film 12 is D1 (μm), the upper limit of the film thickness of the resin film 12 is D2 (μm), the rated life of the fluorescent lamp 10 is A (hour), and the tube wall of the fluorescent lamp 10 When the load is B (mW / cm ² ), D1 = C × A × B, C = 6.4 × 10 ^{−5 to} 1.2 × 10 ⁻⁴ , D2 = 150 μm, D1 Is less than 50 μm, the lower limit of the film thickness of the resin film 12 is set to 50 μm.

The ultraviolet absorbing layer 13 includes an ultraviolet absorbing material made of inorganic particles, and the thickness of the ultraviolet absorbing layer 13 is set to 2 to 5 μm. Examples of the inorganic particles that can be used as the ultraviolet absorbing material include zinc oxide (ZnO), titanium oxide (TiO ₂ ), cerium oxide (CeO ₂ ), and the like. In particular, ZnO is most preferable because of its high ultraviolet absorbing ability. . As the ultraviolet absorbing material, these inorganic particles can be used alone or in combination. The particle size of these inorganic particles is preferably 10 to 100 nm. This is because even within this range, it is possible to absorb even near ultraviolet rays typified by a wavelength of 375 nm.

Further, the ultraviolet absorption layer 13 can include inorganic particles that do not absorb ultraviolet rays. Examples of inorganic particles that do not absorb ultraviolet rays include aluminum oxide (Al ₂ O ₃ ) and silicon dioxide (SiO ₂ ). When the ultraviolet absorption layer 13 contains these inorganic particles, the ultraviolet absorption layer 13 can be provided with a function as a protective film for the phosphor. When the ultraviolet absorption layer 13 includes inorganic particles that do not absorb ultraviolet rays, it is preferable to increase the thickness of the ultraviolet absorption layer 13 as compared with a case where only the inorganic particles that absorb ultraviolet rays are included. In addition to the ultraviolet absorbing layer 13, a protective film made of only inorganic particles that do not absorb ultraviolet rays may be formed separately.

  2 has been described using a straight tube fluorescent lamp, but the fluorescent tube has a round shape or a square shape, and an annular fluorescent lamp in which ends provided with electrodes are connected with a base between them; a straight tube bulb A so-called straight tube-type twin fluorescent lamp connected in a bridge shape and held at the end; a so-called twin-shaped ring-shaped fluorescent lamp formed by connecting a plurality of round or square bulbs in a bridge shape The present invention is also applicable to lamps and the like.

  Hereinafter, the present invention will be described based on examples. However, the present invention is not limited to the following examples.

Example 1
First, as described below, a straight fluorescent lamp having a tube diameter of 25.5 mm and a length of 1178 mm and a rating of 63 W (hereinafter referred to as FHF63 straight pipe type) was produced.

<Preparation of protective film solution>
A protective film solution was prepared by adding 260 g of an aqueous acetic acid solution having a pH of 5 to 60 g of aluminum oxide fine particles having an average particle diameter of 50 nm and stirring the mixture using a stirrer.

<Preparation of phosphor coating solution>
The following were prepared as materials for the phosphor coating solution.
(1) Solvent: 1700 g of distilled water
(2) Phosphor: 350 g of europium activated yttrium oxide phosphor (Y ₂ O ₃ : Eu ³⁺ , hereinafter referred to as “YOX”) as a red phosphor, and cerium terbium activated strontium phosphate phosphor (LaPO) as a green phosphor. ₄ : Ce ³⁺ , Tb ³⁺ , hereinafter referred to as “LAP”) 350 g, and europium-activated barium / magnesium aluminate phosphor as a blue phosphor (BaMgAl ₁₀ O ₁₇ : Eu ²⁺⁾ , hereinafter referred to as “BAM”. ) 300g
(3) Thickener: 15 g of polyethylene oxide having a weight average molecular weight of about 1 million
(4) Binder: 15 g of alumina having an average particle size of 50 nm

  Next, after dissolving polyethylene oxide in distilled water using a stirrer, a phosphor and an alumina were added in this order and stirred to prepare a phosphor coating solution.

<Production of straight tube fluorescent lamp>
Using the protective film solution and the phosphor coating solution, an FHF63 straight tube type fluorescent lamp was produced as follows. First, the protective film liquid is poured from the top into a soda glass straight tubular glass tube installed so that the vertical direction is the longitudinal direction, and is allowed to flow naturally to adhere the protective film liquid to the inside of the glass tube. It was. Thereafter, the attached protective film solution was dried with warm air of about 60 ° C. for 4 minutes to form a protective film on the inner surface of the glass tube. The thickness of the protective film at this time was 2 μm.

  Next, the phosphor coating solution was poured from above into the glass tube on which the protective film was formed, and allowed to flow down naturally to adhere the phosphor coating solution on the protective film. Thereafter, the adhered phosphor coating solution was dried with hot air at about 60 ° C. for about 10 minutes to laminate a phosphor layer on the protective film. Thereafter, the entire glass tube was put in a gas furnace and heated in air at a temperature of about 550 ° C. for about 3 minutes, and the protective film and the phosphor layer were baked and fixed to the glass tube. The design thickness of the protective film was 2 μm, and the design thickness of the phosphor layer was 20 μm. Subsequently, glass with an exhaust pipe equipped with a filament electrode was fused to both ends of the glass pipe, and the air inside the glass pipe was evacuated from the exhaust pipe with a rotary pump. Finally, mercury and argon gas were sealed, and a base was attached to produce a fluorescent lamp.

  Subsequently, the above-mentioned fluorescent lamp is covered with a heat shrinkable tube having a scattering prevention function, and is shrunk by passing through a heating furnace having a temperature of 150 to 170 ° C. for about 2 minutes, and the portion protruding from the base is cut off. I got a lamp. The heat-shrinkable tube with anti-scattering function is a heat-shrinkable tube manufactured by Gunze Polymer Industries Co., Ltd. (trade name) formed from polyethylene terephthalate (PET) resin to which an ultraviolet absorber, light stabilizer, and antioxidant are added. : Copalon PET tube PTNA, film thickness: 100 μm).

(Example 2)
Instead of the protective film solution used in Example 1, the following ultraviolet absorbing layer forming coating solution was used, and instead of the heat shrinkable tube used in Example 1, an ultraviolet absorber, a light stabilizer, and an antioxidant were used. The fluorescence of this example was the same as that of Example 1 except that a heat-shrinkable tube (trade name: teletube, film thickness: 100 μm) manufactured by Teijin Chemicals Co., Ltd., which was formed from an unadded PET resin. A lamp was produced.

<Preparation of UV absorbing layer forming coating solution>
An ultraviolet absorbing layer forming coating solution was prepared by adding 250 g of deionized water to 30 g of zinc oxide fine particles having an average particle diameter of 30 nm, which is an ultraviolet absorbing material, and stirring the mixture using a stirrer.

(Example 3)
A fluorescent lamp of this example was produced in the same manner as in Example 1 except that the UV absorbing layer forming coating solution used in Example 2 was used instead of the protective film solution used in Example 1. .

(Comparative Example 1)
Instead of the heat-shrinkable tube used in Example 1, a heat-shrinkable tube manufactured by Teijin Kasei Co., Ltd. (trade name: Teletube, formed from a PET resin to which no UV absorber, light stabilizer, and antioxidant are added. A fluorescent lamp of this comparative example was produced in the same manner as in Example 1 except that the film thickness was 100 μm.

Example 4
A fluorescent lamp of this example was produced in the same manner as in Example 1 except that the following phosphor coating solution was used. The fluorescent lamp of this example is an ultraviolet radiation fluorescent lamp for an accelerated test of ultraviolet irradiation.

(1) Solvent: 1200 g of distilled water
(2) Phosphor: 400 g of europium activated strontium borate phosphor (SrB ₄ O ₃ : Eu ²⁺ , hereinafter referred to as “BLK”) as an ultraviolet radiation phosphor.
(3) Thickener: 15 g of polyethylene oxide having a weight average molecular weight of about 1 million
(4) Binder: 15 g of alumina having an average particle size of 50 nm

  Next, after dissolving polyethylene oxide in distilled water using a stirrer, a phosphor and alumina were added in this order and stirred to prepare a BLK phosphor coating solution.

(Comparative Example 2)
Instead of the heat-shrinkable tube used in Example 4, a heat-shrinkable tube (trade name: teletube, film thickness: 100 μm) manufactured by Teijin Chemicals Ltd. to which no ultraviolet absorber, light stabilizer, or antioxidant is added. A fluorescent lamp of this comparative example was produced in the same manner as in Example 4 except that it was used.

  Next, the anti-scattering test method using the fluorescent lamps of the above examples and comparative examples, the measuring method of each characteristic, and the accelerated test method of anti-scattering will be described.

<Spattering prevention test method>
For the evaluation of the scattering prevention function of each fluorescent lamp, the following two evaluation tests were conducted, and those that passed both evaluation tests were regarded as passing the anti-scattering test.

  The first evaluation test was carried out in accordance with the scattering resistance test of the JEL 218 anti-scattering fluorescent lamp standard of the Japan Light Bulb Industry Association. The acceptance criteria for the scattering resistance test is that a fluorescent lamp held horizontally at a height of 3 m from the floor is naturally dropped on the floor, and the length of the fluorescent lamp is +1 m from the approximate center of the dropped fluorescent lamp (this embodiment) In this fluorescent lamp, glass pieces are not scattered outside a circle having a radius of about 220 cm).

  The second evaluation test was performed in accordance with the scattering prevention film strength test of the Japan Light Bulb Industry Association standard. The standard for passing the anti-scattering film strength test is that a steel ball with a mass of 200 g suspended from a 1 m long thread is stopped in a state where the thread is stretched in the direction of 30 ° and the vertical of the thread fulcrum. The lamp held at a position of about 1 m below is released from the stationary state of the steel ball and caused to collide with the center of the circumference of the fluorescent lamp by the action of gravity, so that the scattering prevention film of the fluorescent lamp does not break.

<Measurement method of emission spectrum and light intensity>
The emission spectrum and light intensity from the ultraviolet region to the visible light region of each fluorescent lamp were measured using an instantaneous multi-photometry system “MCPD-3000” (manufactured by Otsuka Electronics Co., Ltd.). The light intensity was calibrated using an ultraviolet intensity meter “UM-10” (Minolta).

<Measurement method of light transmission characteristics of anti-scattering film>
The light transmission characteristics of the scattering prevention film from the ultraviolet region to the visible light region of each fluorescent lamp were measured using a spectrophotometer “U-4100” (manufactured by Hitachi High-Technologies Corporation).

<Measurement method of correlated color temperature>
The correlated color temperature was measured in accordance with a Japanese Industrial Standard light source distribution temperature and a color temperature / correlated color temperature measurement method (JIS Z 8725).

<Acceleration test method for scattering resistance using ultraviolet radiation fluorescent lamp>
The heat shrinkable tube having the scattering prevention function is subject to light degradation due to the ultraviolet region, and therefore the ultraviolet region per unit area on the surface of the lamp tube at the input power of 63 W of EX-N color in a normal FHF63 type straight tube type fluorescent lamp. The radiation intensity (200 to 380 nm region) is 0.31 (μW / cm ² ), while the ultraviolet radiation intensity per unit area of the ultraviolet radiation fluorescent lamp (input power 63 W) is 13.8 μW / cm. ^2, so it is possible to perform an accelerated test of ultraviolet radiation by using ultraviolet radiation fluorescent lamp, a 45.4 times as its acceleration factor. The results of the anti-scattering test at 0 hours, 2000 hours, and 3000 hours as lighting times in the fluorescent lamp of Comparative Example 1, and 0 hours, 2000 hours, and 3000 as lighting times in the accelerated test using the ultraviolet radiation fluorescent lamp. The results were consistent with the results of the anti-scattering test corresponding to the time. Using this accelerated test method, the anti-scattering test corresponding to the lighting time of 18000 hours was evaluated for the fluorescent lamps of Example 4 and Comparative Example 2.

(Comparative Example 3)
The correlated color temperature is 3000 K in the same manner as in Example 1 except that the composition ratio of the red phosphor (YOX), the green phosphor (LAP), and the blue phosphor (BAM) is changed without using the heat shrinkable tube. Each fluorescent lamp of 3500K, 4200K, 5000K, and 6700K was produced.

[Comparison between the fluorescent lamp of the present invention and a conventional fluorescent lamp]
3 and 4, each lighting time of the fluorescent lamps of Example 1 and Comparative Example 1 (input power: 63 W constant, tube wall load: 66.8 mW / cm ² , heat shrinkable tube thickness: 100 μm) (0, 2300, 6000, and 9000 hours) show the measurement results of the light transmission characteristics of the respective heat-shrinkable tubes. The heat shrinkable tube to be measured was peeled off from the fluorescent lamp at the time of measurement, and the light transmission characteristics were measured.

As can be seen from FIG. 3, in Example 1, a heat-shrinkable tube in which an ultraviolet absorber, a light stabilizer, and an antioxidant are added to PET resin is used, so that the absorption coefficient of ultraviolet rays up to 380 nm is 200 cm for 9000 hours. ^Since it showed a high value of ⁻¹ and ultraviolet rays up to 380 nm were sufficiently absorbed, the heat shrinkable tube hardly deteriorated. This trend was the same up to 18000 hours. Therefore, the decomposition of the PET resin did not occur, and the result of the anti-scattering test was acceptable up to 10,000 hours.

On the other hand, as can be seen from FIG. 4, in Comparative Example 1, a heat-shrinkable tube having no UV absorber, light stabilizer, or antioxidant added to the PET resin is used, so that light in the near UV region is transmitted. Furthermore, the PET resin bond was broken with time, and the absorption coefficient decreased. Further, in Comparative Example 1, the fluorescent lamp itself that was actually transparent was faded. In addition, as shown in FIG. 1, if this 63W lighting (tube wall load: 66.8 mW / cm ² ), a 100 μm heat-shrinkable tube made of PET resin can maintain the scattering prevention function only for 2000 hours, The rated life of the FHF63 straight tube type fluorescent lamp did not reach 18000 hours.

[Relationship between correlated color temperature of fluorescent lamp and ultraviolet radiation]
The amount of ultraviolet rays of fluorescent lamps having various correlated color temperatures prepared in Comparative Example 3 was measured, and the results are shown in Table 1.

  From Table 1, it can be seen that the ultraviolet irradiance decreases as the correlated color temperature increases. This is considered to be because the amount of the blue phosphor needs to be increased in order to increase the relative color temperature, and the blue phosphor absorbs light in the near ultraviolet region of the fluorescent lamp and emits light. Moreover, even if the tube wall load is the same, the amount of ultraviolet radiation differs due to the difference in the correlated color temperature. For this reason, it is thought that a difference arises in the lighting time which can pass the anti-scattering test of the heat shrinkable tube which has an anti-scattering function.

  Next, the fluorescent lamps of Examples 1 to 3 and Comparative Example 1 were lit at a constant input power of 63 W, and the anti-scattering test was performed at 9000 hours and 10,000 hours. Moreover, the anti-scattering test corresponding to 18000 hours was done using the ultraviolet radiation fluorescent lamp of Example 4 and Comparative Example 2 for the acceleration test. Moreover, the presence or absence of the fading at the time of 10,000 hours of the fluorescent lamps of Examples 1 to 3 and Comparative Example 1 and the presence or absence of the fading of the fluorescent lamps of Example 4 and Comparative Example 2 corresponding to 18000 hours were observed. The results are shown in Table 2. In Table 2, the pass of the anti-scattering test is indicated as A, and the failure is indicated as B.

  As is clear from Table 2, in the fluorescent lamp in which an ultraviolet absorber, a light stabilizer, and an antioxidant are added to the PET resin of the heat shrinkable tube, the scattering prevention function can be maintained up to 18000 hours. Even in the fluorescent lamp of Example 2 in which an ultraviolet absorbing layer that absorbs ultraviolet rays was formed, the scattering prevention function could be maintained up to 9000 hours. On the other hand, no fading of the heat-shrinkable tube was observed in fluorescent lamps with an ultraviolet absorbing layer.

  From the above results, it is understood that the scattering prevention function can be maintained in a fluorescent lamp using a resin to which an ultraviolet absorber, a light stabilizer, and an antioxidant are added. In the fluorescent lamp in which the ultraviolet absorbing layer is formed, when the thickness of the ultraviolet absorbing layer is 2 μm or more, the ultraviolet ray from the fluorescent lamp is blocked and the scattering prevention function can be maintained. In order to produce a scattering prevention effect over a long period of time, it is necessary to increase the thickness of the ultraviolet absorbing layer. Furthermore, when ultraviolet rays from the fluorescent lamp are blocked, the heat-shrinkable tube has an anti-fading effect.

  From the above results, the film thickness of the anti-scattering film for effectively acting the anti-scattering effect is considered in consideration of the light deterioration caused by the ultraviolet rays emitted from the fluorescent lamp in the PET resin and the saturated ester resin, particularly the anti-scattering test result. Is considered to be proportional to the amount of ultraviolet rays (proportional to the tube wall load) and the total amount of ultraviolet radiation exposed (proportional to the lighting time).

From these results, in the case of a PET resin obtained by adding a UV absorber, a light stabilizer, an antioxidant, etc. to a heat shrinkable tube having a scattering prevention function, the film thickness is 100 μm, the rated life is 18000 hours, the tube wall load is 66.8 mW / From cm ² , the film thickness (D) is considered to be proportional to the product of the rated life (A) (18000 hours) and the tube wall load (B) (67 mW / cm ² ). Considering the difference between
Film thickness (D) = proportionality constant (C) x rated life (A) x tube wall load (B)
Since it was EX-N color and the film thickness was 100 μm,
100 μm = C × 18000 hours × 67 mW / cm ²
Therefore, C = 8.3 × 10 ⁻⁵ (μm / hour / mW / cm ² ),
Considering the light color, the EX-D color has a relative ratio of 77 to the EX-N color, and the EX-L color has 143.
The proportionality constant C is 6.4 × 10 ^{−5 to} 1.2 × 10 ⁻⁴ .

From the above, the lower limit value of the resin film thickness is D1 (μm), the upper limit value of the resin film thickness is D2 (μm), the rated life of the fluorescent lamp is A (hours), and the tube wall load of the fluorescent lamp is B. (MW / cm ² )
When D1 = C × A × B, C = 6.4 × 10 ^{−5 to} 1.2 × 10 ⁻⁴ , D2 = 150 μm, and D1 is less than 50 μm, the thickness of the resin film It can be seen that the lower limit is preferably 50 μm.

  In this example, zinc oxide fine particles having an average particle diameter of 30 nm were used as the ultraviolet absorbing material. However, if the average particle diameter was about 10 to 100 nm, the ultraviolet absorbing effect was similarly obtained in the case of the same film thickness. Moreover, although zinc oxide was used as the ultraviolet absorbing material, titanium oxide and cerium oxide also had the same ultraviolet absorbing effect.

  ADVANTAGE OF THE INVENTION According to this invention, the fluorescent lamp which can maintain a scattering prevention function over a long period of time can be provided, The industrial value is great.

DESCRIPTION OF SYMBOLS 10 Fluorescent lamp 11 Fluorescent tube 12 Resin film 13 Ultraviolet absorption layer 14 Phosphor layer 15 Filament electrode 16 Base

Claims (7)

A fluorescent lamp having a scattering prevention function including a fluorescent tube and a resin film covering the fluorescent tube,
The fluorescent lamp, wherein the resin film is formed of a resin containing an ultraviolet absorber, a light stabilizer, and an antioxidant.   The fluorescent lamp according to claim 1, wherein the resin film is a heat-shrinkable resin film.   The fluorescent lamp according to claim 1, wherein the resin is a polyester resin. The lower limit value of the resin film thickness is D1 (μm), the upper limit value of the resin film thickness is D2 (μm), the rated life of the fluorescent lamp is A (hour), and the tube wall load of the fluorescent lamp is When B (mW / cm ² )
D1 = C × A × B, C = 6.4 × 10 ^{−5 to} 1.2 × 10 ⁻⁴ , D2 = 150 μm,
The fluorescent lamp according to claim 1, wherein when D1 is less than 50 µm, a lower limit value of the film thickness of the resin film is set to 50 µm.   The fluorescent lamp according to any one of claims 1 to 4, wherein an ultraviolet absorbing layer is further formed on an inner surface of the fluorescent tube.   The fluorescent lamp according to claim 5, wherein the ultraviolet absorbing layer includes an ultraviolet absorbing material made of inorganic particles, and the thickness of the ultraviolet absorbing layer is 2 μm or more. A fluorescent lamp comprising a fluorescent tube and an ultraviolet absorbing layer formed on the inner surface of the fluorescent tube,
The ultraviolet absorbing layer includes an ultraviolet absorbing material made of inorganic particles,
The fluorescent lamp, wherein the ultraviolet absorbing layer has a thickness of 2 μm or more.

Images