JP2005213129A - Lighting glass composition, fluorescent lamp and lighting fittings - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optimal glass composition satisfying various characteristics required for lighting application. <P>SOLUTION: The lighting glass composition contains 60-75% SiO<SB>2</SB>, 1-5% Al<SB>2</SB>O<SB>3</SB>, 0-13% Na<SB>2</SB>O, 1-12% K<SB>2</SB>O, 1-5% Li<SB>2</SB>O, 13.5-18% Li<SB>2</SB>O+Na<SB>2</SB>O+K<SB>2</SB>O, 1-5% CaO, 0-5% MgO, 0-7% BaO, 0-2.5% SrO, 5-16% MgO+CaO+BaO+SrO, 0-3% Fe<SB>2</SB>O<SB>3</SB>, 0-3% B<SB>2</SB>O<SB>3</SB>, 0-1% CeO<SB>2</SB>and 0-1% Ti<SB>2</SB>O by mass percentage. The optimal glass composition satisfying various characteristics required for the lighting application is obtained by suppressing the content of SrO to ≤2.5mass% and controlling the other composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a glass composition for lighting having a glass composition suitable for an illumination light source, and particularly suitable for use in a fluorescent lamp.

  Fluorescent lamps generally used as illumination light sources are widely used for light sources for OA equipment, pixel light sources for large screens, and the like recently, including those for general illumination. In addition, the three-wavelength fluorescent lamp has been spreading remarkably in recent years because it satisfies both high efficiency and high color rendering properties for general illumination. In such a fluorescent lamp, a mixed gas containing mercury and a rare gas is enclosed as a discharge gas in a glass bulb having an inner wall provided with a phosphor layer, and a positive column discharge is generated in the mixed gas. It is configured.

Conventionally, lead glass containing about 20 to 30% by mass of lead oxide (PbO) has been mainly used for glass bulbs. However, harmful lead (Pb) components are substantially eliminated in consideration of environmental problems. Soda lime glass which does not contain has come to be used. Soda lime glass usually has a composition containing about 15 to 17% by mass of sodium oxide (Na ₂ O).

The softening temperature of the conventional soda-lime glass described above is around 690 ° C. Since such a soda-lime glass contains a relatively large amount of sodium oxide (Na ₂ O) of about 15 to 17% by mass, the sodium component in the glass penetrates into the glass bulb and functions as a light source. May be affected. In particular, ring fluorescent lamps using soda-lime glass as a glass bulb are heated to a temperature higher than the softening temperature when the glass bulb formed with the phosphor layer is bent. This causes the sodium component to react with mercury entering the glass bulb, causing the fluorescent lamp to be colored blackish brown. Further, it has been found that the coloring of the fluorescent lamp by the sodium component appears more prominently as the number of heating steps in processing the glass bulb increases. This is presumably because a large amount of sodium component is deposited on the inner surface of the bulb by the heating process of the glass bulb and enters the phosphor layer.

Under these circumstances, recently, a glass composition for lighting has been developed that does not substantially contain a lead component and has a sodium oxide content of 13% or less by mass (see, for example, Patent Documents 1 and 2). ).
Japanese Patent Laid-Open No. 11-224649 Japanese Patent No. 3204626

  The present inventor investigated the conventional lighting glass composition having a sodium component content of 13% or less by mass percentage, and found that the melting property, electrical characteristics, softening temperature, thermal expansion characteristics, transmittance, Sufficiently satisfactory results were not obtained with respect to mechanical strength and chemical stability.

  In particular, it has been necessary to further improve various characteristics such as the initial luminous flux, luminous flux rise characteristic and luminous flux maintenance factor of the fluorescent lamp when the above conventional glass composition for illumination is used in a glass bulb for a fluorescent lamp.

  This invention is made | formed in view of the said subject, and it aims at providing the optimal glass composition which satisfies the various characteristics requested | required for illumination use, and a fluorescent lamp using the same.

Lighting glass composition of claim 1, substantially without containing lead, mass _{percentage, SiO 2 60~75%, Al 2} O 3 1~5%, Na 2 O 0~13%, K 2 O 1-12%, Li ₂ O 1-5%, Li ₂ O + Na ₂ O + K ₂ O 13.5-18%, CaO 1-5%, MgO 0-5%, BaO 0-7%, SrO 0-2 5%, MgO + CaO + BaO + SrO 5 to 16%, Fe ₂ O ₃ 0 to 3%, B ₂ O ₃ 0 to 3%, CeO ₂ 0 to 1%, Ti ₂ O 0 to 1%.

In the present invention, the content ratio of SrO is suppressed in consideration of the influence of SrO on the glass composition for lighting, and other compositions are adjusted. SrO is mainly used for the purpose of stabilizing the electrical resistance of the glass, but when the content exceeds 2.5%, a devitrified material is generated upon melting. Therefore, as a result of performing the test while changing the content of SrO to 2.5% or less and changing the content of other alkaline earth metal oxides and alkali metal oxides, 13% by mass of Na ₂ O was obtained. % Or less (preferably 11% or less), the total content of alkali metal oxide (Li ₂ O + Na ₂ O + K ₂ O) is 13.5-18%, and the total content of alkaline earth metal oxide (MgO + CaO + BaO + SrO) ) Of 5 to 16%, it was possible to obtain a highly reliable lighting glass composition that satisfactorily satisfies various characteristics required for lighting applications without excessively reducing electrical resistance. .

  The lighting glass composition of the present invention is mainly used for glass bulbs, but also satisfies the requirements of electrical characteristics required for the glass constituting the stem part, so that the electrode support such as the stem part or inner wells is supported. It can also be used for bead glass welded to a member.

A second aspect of the present invention is the glass composition for lighting according to the first aspect, wherein the mass percentage of K ₂ O is 5 to 12%.

K ₂ O is mainly used as a flux, and improves the meltability of the glass, but it is used in an amount of 5% or more because the content ratio of Na ₂ O which is the same alkali metal oxide is suppressed. There is a need.

  A third aspect of the present invention is the glass composition for lighting according to the first aspect, wherein the mass percentage of MgO + CaO + BaO + SrO is 5 to 13%.

  Although the amount of MgO, CaO and BaO, which are other alkaline earth metal oxides, is taken into account by setting the SrO content to 2.5% or less, the total content of alkaline earth metal oxides is 13 If it exceeds 50%, the glass becomes more devitrified, so the total content of the alkaline earth metal oxide is preferably 13% or less.

  A fluorescent lamp according to claim 4 is a glass bulb formed from the glass composition for lighting according to any one of claims 1 to 3 and filled with a discharge gas; and a phosphor layer formed on the inner surface of the glass bulb And electrode means provided on the glass bulb.

  Examples of the electrode means include a hot cathode made of at least one filament sealed in a glass bulb and a cold cathode made of nickel sleeve. However, the electrode means is not limited to these due to the nature of the present invention, and may be, for example, an induction coil used in an electrodeless fluorescent lamp or an electric field application type external electrode.

The fluorescent lamp of the present invention is easy to manufacture because the glass composition used for the glass bulb satisfies various characteristics such as electric resistance and transmittance, and the initial luminous flux of the lamp is improved, and the luminous flux maintenance factor is large. There is no decline. Further, since mercury (Hg) is enclosed in the glass bulb, the sodium component in the glass reacts with mercury to produce amalgam. In the present invention, Na ₂ O is 13% or less. Therefore, this can be suppressed, and the influence of the sodium component on the phosphor can be suppressed.

  According to a fifth aspect of the present invention, there is provided a lighting apparatus comprising: the fluorescent lamp according to the fourth aspect; an apparatus main body that supports the fluorescent lamp; and a lighting device that is accommodated in the apparatus main body and that lights the fluorescent lamp. It is characterized by.

  According to the invention of claim 1, by controlling the other composition while suppressing the content ratio of SrO to 2.5% by mass or less, the reliability sufficiently satisfies various characteristics required for lighting applications. A high lighting glass composition can be obtained.

According to the invention of claim 2, since the K ₂ O is an alkali metal oxide is 5% or more, it can also reduce the content ratio of Na ₂ O improve the meltability of glass.

  According to the invention of claim 3, the SrO content is set to 2.5% or less and the total content of the alkaline earth metal oxide is set to 5 to 13%, so that the electrical insulation of the glass is maintained. Glass devitrification can be further suppressed.

  According to invention of Claim 4, the fluorescent lamp which improved the initial light beam and the light beam maintenance factor can be provided.

  According to invention of Claim 5, the lighting fixture provided with the fluorescent lamp of Claim 4 can be provided.

  Hereinafter, an embodiment of the present invention will be described.

The lighting glass composition of the present embodiment is a low-softening point alkali glass containing substantially no lead and using K ₂ O and Li ₂ O as a flux together with Na ₂ O, compared to conventional soda-lime glass. Thus, the softening temperature can be lowered to 685 ° C. or lower. By using such a glass bulb made of glass with a low softening point for a fluorescent lamp that requires a heating process at the time of manufacture, the heating temperature at the time of bulb processing can be lowered. It becomes possible to suppress the thermal deterioration of the layer, and hence the reduction of the total luminous flux. Furthermore, in order to be possible to make the Na ₂ O content 13 wt% or less, coloring caused by the Na component in the glass, it is possible to suppress the reduction of the thus luminous flux maintenance factor.

The lighting glass composition is substantially free of lead, and the content ratio SiO ₂ is 60 to 75% by mass, Al ₂ O ₃ is 1 to 5% by mass, and Na ₂ O is 0 to 13% by mass. K ₂ O is 5 to 12% by mass, Li ₂ O is 1 to 5% by mass, Na ₂ O + K ₂ O + Li ₂ O is 13.5 to 18% by mass, CaO is 1 to 5% by mass, and MgO is 0 to 5%. Mass%, BaO is 0-7 mass%, SrO is 0-2.5 mass%, CaO + MgO + BaO + SrO is 5-13 mass%, B ₂ O ₃ is 0-3 mass%, CeO ₂ is 0-1 mass%, Ti A glass composition having a composition in which ₂ O is 0 to 1% by mass, ZnO is 0 to 1% by mass, Sb ₂ O ₃ is 0.1 to 0.5% by mass, and a softening point is 650 to 680 ° C. is used. It is preferable.

In the low softening point alkali glass having the glass composition described above, SiO ₂ is a glass network forming component, and the content thereof is in the range of 60 to 75% by mass. When the amount of SiO ₂ is less than 60% by mass, the chemical durability of the glass is lowered. On the other hand, when it exceeds 75% by mass, the meltability and workability of the glass are deteriorated.

Further, Al ₂ O ₃ is to contribute to the improvement of the homogenization and chemical durability of the glass, the content thereof is in the range of 1 to 5 mass%. If the amount of Al ₂ O ₃ is less than 1% by mass, phase separation occurs in the glass, making it difficult to form, while if it exceeds 5% by mass, striae occurs and it becomes difficult to obtain a homogeneous glass, Moreover, there exists a possibility that devitrification may become strong.

Na ₂ O, K ₂ O and Li ₂ O act as fluxes, and contribute to improving the melting property of the glass and further lowering the softening temperature. In particular, in the present invention, the amount of Na ₂ O at which the softening temperature is increased is reduced to 13% by mass or less, preferably 11% by mass or less, and the K ₂ O content is increased to 5% by mass or more accordingly. This makes it possible to lower the softening temperature of the lighting glass composition to 680 ° C. or lower.

In order to obtain the effects as described above, K ₂ O and Li ₂ O are preferably contained in a total amount of 6% by mass or more. The amount of K ₂ O is 5% by mass or more, and the amount of Li ₂ O is set in consideration of the amount of K ₂ O. Further, the total amount including the _{Na 2 O (Na 2 O +} K 2 O + Li 2 O) is set to 13.5 mass% or more. When the total amount of the flux is less than 13.5% by mass, there is a problem that the viscosity becomes high and the meltability cannot be maintained when the lighting glass is manufactured.

Further, Na ₂ O as described above, K ₂ O and Li ₂ O is, the effect of adjusting the thermal expansion coefficient of the glass is also shown, their total amount in order to obtain a proper thermal expansion coefficient is 18 mass% or less. When the total amount of Na ₂ O, K ₂ O and Li ₂ O exceeds 18% by mass, the thermal expansion coefficient becomes too high and the chemical durability is lowered. Individually, the amount of Na ₂ O is 13% by mass or less, the amount of K ₂ O is 12% by mass or less, and the amount of Li ₂ O is 5% by mass or less. When the amount of Na ₂ O exceeds 11% by mass, the softening point increases and the thermal expansion coefficient becomes too high. Similarly, when the amounts of K ₂ O and Li ₂ O exceed the above upper limit values, the thermal expansion coefficient becomes too high.

  BaO is a component that imparts high electrical insulation to the glass, and its content is in the range of 0 to 7 mass%. When BaO exceeds 7% by mass, the erosion of the melting furnace material becomes remarkable, and the defect is increased. Like BaO, SrO contributes to the improvement of electrical insulation, and its content is in the range of 0 to 2.5 mass%, preferably 0.1 to 2 mass%. When the amount of SrO is less than 0.1% by mass, sufficient electric insulation cannot be obtained, while the tendency to devitrify exceeding 2.5% by mass is increased and the raw material cost is increased. The amount of SrO is more preferably 2% by mass or less.

  CaO and MgO contribute to improving the durability of the glass. However, if their content exceeds 5% by mass, devitrification of the glass tends to occur. Accordingly, these contents are set to the upper limit values or less.

  BaO, SrO, CaO and MgO mentioned above have the effect of enhancing the electrical insulation of the glass as a whole, and the total amount (BaO + SrO + CaO + MgO) is 5 to 16% by mass, preferably 8.5 to 13% by mass. To do. When the total amount is less than 5% by mass, the electrical insulation required for the glass composition for lighting cannot be obtained, while when it exceeds 16% by mass, the crystallization tendency of the glass increases.

B ₂ O ₃ has the effect of improving the meltability in a small amount, but if its content exceeds 3% by mass, the chemical durability of the glass is lowered, and there is a possibility that weathering will occur on the surface during long-time use. ZnO has an effect of suppressing volatilization when B ₂ O ₃ or an alkali component is melted, but when its content exceeds 3% by mass, devitrification becomes strong.

Sb ₂ O ₃ is an essential component for applying the oxidation melting method when producing a glass tube used for the annular glass bulb 1, and its content is in the range of 0.1 to 0.5 mass%. And When the amount of Sb ₂ O ₃ is less than 0.1% by mass, the clarification action is insufficient, while when it exceeds 0.5% by mass, the luminous flux maintenance factor decreases.

It is also possible to contain Fe ₂ O ₃ in the glass composition. In this case, Fe ₂ O ₃

Is a component that is slightly contained in the glass raw material from the beginning, but is a component that may be mixed for the purpose of adjusting the transmittance of the glass, and its content is 0.01 to 0.05 mass%. Range. If the amount of Fe ₂ O ₃ is less than 0.01% by mass, a glass material with high purity is required and the cost is increased. On the other hand, if it exceeds 0.05% by mass, the visible light transmittance of the glass is decreased.

Next, the specific composition ratio of the glass composition for illumination of this embodiment is shown. Table 1 shows the composition ratios of Embodiments 1 to 4 and Conventional Examples 1 to 5 in which the content ratios of SrO and other oxides were changed.

In Table 1, RO represents the total content of alkaline earth metal oxides, and R ₂ O represents the total content of alkali metal oxides.

  In Table 1, the electric resistance is an electric resistance value (log δ [Ω · cm]) at 250 ° C., α is a thermal expansion coefficient, and Ts is a softening point temperature of the glass.

  Thus, in the glass compositions for lighting of Embodiments 1 to 4, the SrO content ratio is 2.5% by mass or less, the electrical resistance is stable to 8.7 or less, and the glass softening point ( It can be seen that Ts) is in the range of 650-680 ° C. This sufficiently satisfies the glass characteristics necessary for a lighting glass composition.

  On the other hand, the glass compositions of Conventional Examples 1 and 3 are not preferable because the SrO content ratio exceeds 5% by mass and the electrical resistance value is 8.9 or more.

  The glass composition of Conventional Example 2 has an electrical resistance value of 8.7, but tends to be devitrified because the total content (RO) of alkaline earth metal oxide is as high as 15.7% by mass, It was not suitable for industrial glass.

The glass composition of Conventional Example 4 has a SrO content ratio of 1.0% by mass, but has a high viscosity because the total content of alkali metal oxide (R ₂ O) is only 13% by mass. Not suitable for glass.

  The glass composition of Conventional Example 5 has a SrO content ratio of 2.5% by mass, but the total content (RO) of the alkaline earth metal oxide exceeds 16% by mass, so that the glass is not crystallized. It tends to increase and is unsuitable for lighting glass.

  FIG. 1 is a front view showing an embodiment of a light bulb shaped fluorescent lamp using the lighting glass composition of the above embodiment. FIG. 2 is a development view showing the same fluorescent lamp.

  In each figure, 1 is a fluorescent lamp, 2 is a lighting circuit, 3 is an envelope, and 4 is a base. The fluorescent lamp 1 includes a translucent discharge vessel 1a, a phosphor layer 1b, an electrode assembly 1c, a main amalgam 1d, and an auxiliary amalgam 1e. The translucent discharge vessel 1a connects three U-shaped glass tubes 1a1 having an outer diameter of 10 mm by two connecting tubes 1a2, and each U-shaped glass tube 1a1 is equally arranged on the circumference. Is formed. Each U-shaped glass tube 1a1 has pinch seal portions 1a3 formed at both ends thereof, and one thin tube 1a4 protrudes from one pinch seal portion 1a3 to the outside. The thin tube 1a4 communicates with the inside of the translucent discharge vessel 1a and includes a constricted portion 1a41 at a joint portion with the pinch seal portion 1a3. The narrow tube 1a4 is used for exhausting the inside of the translucent discharge vessel 1, storing main amalgam 1d described later, and sealing rare gas. The connecting pipe 1a2 is formed by a blow-through method.

  The phosphor layer 1b is mainly composed of a three-wavelength light emitting phosphor, and is formed on the inner surface side of the translucent discharge vessel 1a via a protective film mainly composed of alumina fine particles (not shown). Yes. The electrode assembly 1c includes a filament electrode 1c1, a pair of lead-in wires 1c2, and a glass bead 1c3, and the pair is used. The filament electrode 1c1 is formed by applying an oxide of an electron emitting material made of an alkaline earth metal to a double coil made of a tungsten wire. The pair of lead wires 11 are held at predetermined intervals by the glass beads 1c2, and both ends of the filament electrode 1c1 are connected and supported between the tips.

  Further, the electrode assembly 1c is sealed at both ends of the translucent discharge vessel 1 by hermetically sealing the lead wire 1c2 at a position where the pair of pin assemblies 1a3 at both ends of the translucent discharge vessel 1 avoids the narrow tube 1a4. It is sealed.

  The main amalgam 1 d is accommodated in a thin tube 1 a 4 on one end side of the translucent discharge vessel 1. And the main amalgam 1d consists of Bi-In-Hg, and consists of two particles with a particle size of about 2.5 mm. The auxiliary amalgam 1e is formed by plating indium In on a stainless steel thin plate, and is welded to the lead-in wire 1c2 so as to be positioned in the vicinity of the main amalgam 1d.

  The lighting circuit 2 is mainly composed of a high-frequency inverter and energizes the fluorescent lamp 1 to light it. The lighting circuit 2 is housed in a light-shielding base 3b of an envelope 3 to be described later. The high-frequency output end is connected to the fluorescent lamp 1 as necessary.

  The envelope 3 includes a translucent globe 3a and a light-shielding base 3b. The translucent glove 3a is made of glass with light diffusibility by applying light diffusing fine particles on the inner surface thereof, and has a bottomed cylindrical shape. Then, the fluorescent lamp 1 is housed inside to be mechanically protected, and the visible light emitted from the fluorescent lamp 1 is led to the outside with the brightness lowered.

The light-shielding substrate 3b is formed in a cup shape by molding a synthetic resin, and covers the opening end with the opening end of the translucent glove 3a. And the lighting circuit 2 is accommodated in the inside.

  The base 4 is made of an E26 type screw base, is attached to the base end of the light-shielding base 3 b of the envelope 3, and is connected to the input end of the lighting circuit 2.

  In addition, you may use the glass composition for illumination of this invention for a ring-shaped fluorescent lamp other than a lightbulb-shaped fluorescent lamp.

The front view which shows embodiment of the lightbulb-type fluorescent lamp using the glass composition for illumination of this invention. The expanded view which expands and shows the lightbulb-type fluorescent lamp of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fluorescent lamp, 1b ... Phosphor layer, 1c ... Electrode means.

Claims (5)

Contains substantially no lead and has a mass percentage
SiO ₂ 60~75%,
Al ₂ O ₃ 1-5%,
Na ₂ O 0-13%,
K ₂ O 1-12%,
Li ₂ O 1-5%,
Li ₂ O + Na ₂ O + K ₂ O 13.5-18%,
CaO 1-5%,
MgO 0-5%,
BaO 0-7%,
SrO 0-2.5%,
MgO + CaO + BaO + SrO 5-16%,
Fe ₂ O ₃ 0 to 3%,
B ₂ O ₃ 0-3%,
CeO ₂ 0 to 1%,
Ti ₂ O 0-1%
The glass composition for illumination characterized by comprising. The lighting glass composition according to claim 1, wherein a mass percentage of K ₂ O is 5 to 12%.   The lighting glass composition according to claim 1, wherein a mass percentage of MgO + CaO + BaO + SrO is 5 to 13%. A glass bulb formed from the lighting glass composition according to any one of claims 1 to 3 and filled with a discharge gas;
A phosphor layer formed on the inner surface of the glass bulb;
Electrode means provided on the glass bulb;
A fluorescent lamp characterized by comprising: A fluorescent lamp according to claim 4;
An instrument body supporting the fluorescent lamp;
A lighting device housed in the instrument body and for lighting the fluorescent lamp;
The lighting fixture characterized by comprising.

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