JP2001076675A - Lamp sealing body made of functionally gradient material, its manufacture and lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a region of high electric conductivity in spite of low conductive inorganic material component concentration by allowing the average cross sectional area of conductive inorganic material granular bodies on an arbitrary cross section in the region having the conductive inorganic material component concentration of a range to satisfy the prescribed conditions. SOLUTION: An average cross-sectional area S of conductive inorganic material granular bodies on an arbitrary cross section in the region having a conductive inorganic material component concentration of 15-30 vol.% satisfies the equation 1, where S is the average cross sectional area (μm2) of the conductive inorganic material granular bodies, and C is the conductive inorganic component concentration (vol.%). The average cross sectional area (μm2) is the total cross- sectional area (μm2) divided by the number of granular bodies, and the total cross sectional area is obtained by microscope photographing. The conductive inorganic material component is molybdenum, the insulating inorganic material component is silica, and the insulating inorganic material powder having the average grain size twice the average grain size of the conductive inorganic powder or above is preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a functionally graded material sealing body for forming a hermetically sealed structure such as a mercury lamp, a xenon lamp, a metal halide lamp, and a halogen lamp, a method of manufacturing the same, and a lamp.

[0002]

2. Description of the Related Art A functionally graded material is composed of, for example, a mixed sintered body of a conductive inorganic material component composed of a metal and an insulating inorganic material component composed of a metal oxide. When the substance component concentration changes stepwise or continuously, the conductive part having a high conductive inorganic substance component concentration and the insulating part having a conductive inorganic substance component concentration of zero or the low concentration are located at different places. It is a solid material that is positioned and is suitably used as a sealing body that forms a current supply path in a hermetic sealing structure of a lamp bulb, for example.

Conventionally, as a method for producing such a functionally gradient material, a dry method has been advantageously used. In this dry method, for example, by mixing a conductive inorganic material powder made of, for example, molybdenum and an insulating inorganic material powder made of, for example, silica at different ratios, a plurality of mixed powders having different conductive inorganic material powder content ratios Is prepared, usually, in a mold for molding, first, only the insulating inorganic material powder containing no conductive inorganic material powder is filled using gravity to form an insulating inorganic material powder layer, On top of this, the mixed powder having the lowest content ratio of the conductive inorganic material powder is filled in layers in order, and a plurality of powder layers to be mixed are formed under pressure to form a powder laminate. Then, by heating the powder laminate thus obtained to form an integral sintered body, a plurality of mixture layers each having a uniform concentration of the conductive inorganic substance component are formed on the insulating inorganic substance layer. However, a functionally graded material laminated such that the concentration of the conductive inorganic substance component is gradually increased from bottom to top is manufactured.

In each of the mixture layers of the functionally graded material, the insulating inorganic material powder and the conductive inorganic material powder are so arranged that either the insulating inorganic material component or the conductive inorganic material component is not unevenly distributed. Usually, those having the same average particle diameter are used.

[0005] When such a functionally graded material is actually used as a sealing body for a lamp made of a functionally graded material,
It is necessary to connect the lead bar to the functionally graded material in an electrically connected state, and to achieve this,
In the temporary sintered body obtained by temporarily sintering the powder laminated body, a lead rod insertion hole extending from the end face in the laminating direction is formed, the lead rod is inserted therein, and the temporary sintered body is heated in this state Then, the lead rod is integrally fixed to the functionally graded material by sintering, and a method of manufacturing a lamp seal made of a functionally graded material is used.

However, the region where conductivity is obtained in the functionally gradient material is generally a region where the concentration of the conductive inorganic substance is 20% by volume or more. In order to connect the rods while ensuring sufficient conductivity, the tip of the lead rod inserted from the insulating inorganic material layer side has a conductive inorganic material component concentration of 20%.
It is necessary to reach a mixture layer which is at least volume%. However, in such a configuration, there is a problem that the required insertion length of the lead bar becomes large, and a material having a large gradient in the stacking direction is required as the functionally gradient material.

In order to allow a large current to flow in order to increase the amount of light emitted from the lamp, it is necessary that the electrical resistance between the lead rod and the functionally graded material be small. In order to satisfy the above without increasing the length in the stacking direction, for example, the concentration of the conductive inorganic substance in the region where the lead rod is fixed to the functionally gradient material may be increased. It is uneconomical because the total content of the conductive inorganic material component in the above becomes uneconomic, and furthermore, it is necessary to increase the rate of change of the conductive inorganic material component concentration. As a result, the functionally graded material has sufficiently good characteristics. There is a problem that it does not have.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to provide:
An object of the present invention is to provide a functionally graded material sealed body for a lamp having a region having a high electric conductivity despite a low concentration of a conductive inorganic substance component. Another object of the present invention is to provide a method for manufacturing a sealed body for a lamp made of a functionally graded material, which has a region with high electrical conductivity despite a low concentration of a conductive inorganic substance component. Still another object of the present invention is to provide a hermetically sealed structure by a sealing body which can electrically connect the lead bar and the sealing member made of a functionally graded material sufficiently and has good characteristics. It is an object of the present invention to provide a lamp that is configured and has high performance and reliability.

[0009]

According to the present invention, there is provided a seal for a lamp made of a functionally graded material, comprising: a sealing member made of a functionally graded material;
The sealing member includes a lead rod fixed to the sealing member, and the sealing member includes an insulating inorganic material layer and a plurality of mixture layers each including a mixture of a conductive inorganic material component and an insulating inorganic material component. Laminated, each of the mixture layers is made of a functionally graded material consisting of a laminate in which the concentration of the conductive inorganic substance component increases stepwise or continuously in order from the one adjacent to the insulating inorganic substance layer, The functionally graded material has an average cross-sectional area S of the conductive inorganic substance granules in an arbitrary cross section in a region where the conductive inorganic substance component concentration is 15% by volume or more and 30% by volume or less satisfies the condition of the following formula 1. It is characterized by being.

[0010]

Formula 1 S ≧ -0.03C ² + 2.19C-19.1 (S is the average cross-sectional area of the conductive inorganic substance granular material [unit: μm
² ] and C is the concentration of the conductive inorganic substance component [unit: volume%]. )

Preferably, the conductive inorganic substance component is molybdenum, and the insulating inorganic substance component is silica.

[0012] The method for producing a lamp seal made of a functionally graded material according to the present invention is a method for producing the above-mentioned seal for lamps made of a functionally graded material, comprising a conductive inorganic substance powder and an insulating inorganic substance powder. In the step of forming a mixed powder layer in which the content of the conductive inorganic material powder is 15 vol% or more and 30 vol% or less using the mixed powder prepared by mixing It is characterized in that the average particle diameter is at least twice the average particle diameter of the conductive inorganic substance powder.

The lamp of the present invention is characterized in that a hermetic sealing structure is formed by the above-mentioned sealing body for a lamp made of a functionally graded material.

[0014]

According to the functionally graded lamp sealing body of the present invention, the conductive inorganic substance granular material is insulated in a specific region where the concentration of the conductive inorganic substance component in the functionally gradient material constituting the sealing member is low. Exists in the peripheral portion of the inorganic particles,
By forming a continuous tissue state in a state where the adjacent conductive inorganic substance granular bodies have substantially conductivity, the region has high electrical conductivity despite the low conductive inorganic substance component concentration. Will have.

Further, since the specific region has high electric conductivity despite the low concentration of the conductive inorganic substance component, the region of the conductive portion in the sealing member made of the functionally graded material becomes substantially large. As a result, the electric resistance between the connected lead rods can be reduced, and the value of the current flowing under the same conditions can be increased.

According to the method of manufacturing a lamp seal made of a functionally graded material of the present invention, in the step of forming a mixed powder layer having a specific concentration, an average of an insulating inorganic material powder and a conductive inorganic material powder is used. By using one having a particle diameter ratio in a specific range, the effective cross-sectional area of the conductive inorganic substance particles in the obtained functionally graded lamp sealing body is increased, and as a result, the conductive inorganic substance It is possible to obtain a sealed body for a lamp made of a functionally graded material, which has a region with high electric conductivity despite the low concentration of the substance component.

According to the lamp of the present invention, the lead rod and the sealing member made of the functionally graded material can be electrically connected sufficiently, and the above-mentioned sealing for the lamp made of the functionally graded material having good characteristics. A hermetic sealing structure is constituted by the body, and high performance and reliability can be obtained.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory cross-sectional view showing an example of the configuration of a lamp sealing body made of a functionally graded material of the present invention. This lamp sealing body 10 made of a functionally graded material includes a sealing member 11 made of a functionally graded material, and the sealing member 11 is formed of an insulating inorganic material layer located at one end (the left end in the figure). Internal lead rod insertion hole 11A formed to extend from the end face in the direction in which the concentration of the conductive inorganic substance component increases.
And an external lead rod insertion hole 11B located at the other end (right end in the figure) and extending from the end face of the mixed powder layer having the highest concentration of the conductive inorganic substance component. The shape of the internal lead rod insertion hole 11A and the external lead rod hole 11B is such that the outer diameter thereof is adapted to the external diameter of the internal lead rod 13 or the external lead rod 15 to be inserted.

The internal lead rod insertion hole 11 of the sealing member 11
In A, a base end portion of an internal lead rod 13 having a discharge electrode (not shown) formed by winding a metal coil around a front end portion is inserted and fixed. On the other hand, one end portion of the external lead rod 15 is inserted and fixed in the external lead rod insertion hole 11B.
The sealing member 11 and the external lead rod 15 are integrally connected.

The inner lead rod 13 is made of a tungsten wire, and the outer lead rod 15 is made of a metal wire such as a tungsten wire or a molybdenum wire. Then, the inner lead rod 13 and the outer lead rod 15
Is determined in consideration of the current capacity required for each lamp.

The functionally gradient material constituting the sealing member 11 is as follows:
Insulating inorganic material layer, laminated on this insulating inorganic material layer, composed of a plurality of mixture layers consisting of a uniform mixture of insulating inorganic material component and conductive inorganic material component, a specific one direction , The conductive inorganic substance component concentration is gradually increased.

Specific examples of materials suitably used as the insulating inorganic substance component include, for example, silica, quartz, alumina, zirconia, magnesia, silicon carbide, titanium carbide, silicon nitride, aluminum oxynitride and the like. Further, specific examples of the material suitably used as the conductive inorganic substance component include, for example, molybdenum, nickel,
Examples include tungsten, tantalum, chromium, platinum, and zinc. When the bulb of the lamp having the hermetic sealing structure formed by the lamp sealing body 10 is silica glass, it is preferable that the conductive inorganic substance component is molybdenum and the insulating inorganic substance component is silica.

The sealing member 11 has an arbitrary concentration in a region where the conductive inorganic substance component concentration in the functionally graded material is not less than 15% by volume and not more than 30% by volume (hereinafter also referred to as "specific concentration region"). In the cross section, the average cross-sectional area S of the conductive inorganic substance granular material is determined by the conductive inorganic substance component concentration C
Satisfies the condition of Equation 1 below.

[0024]

Equation 1 S ≧ −0.03C ² + 2.19C−19.1 (S is the average cross-sectional area of the conductive inorganic substance granular material [unit: μm
² ] and C is the concentration of the conductive inorganic substance component [unit: volume%]. )

Here, the "average cross-sectional area of the conductive inorganic substance particulate material" means that a part of a polished surface obtained by polishing an arbitrary cross section in a specific concentration region is photographed with a microscope, and the conductive inorganic material in the image is taken. The sum of the number of particles and the cross-sectional area of the conductive inorganic substance particles (hereinafter, also referred to as “total cross-sectional area”) is a value calculated by the following formula 2. In other words, "the average cross-sectional area of the conductive inorganic substance granular material"
Indicates an average size of the conductive inorganic substance granular material substantially in a specific concentration region.

[0026]

## EQU4 ## Equation 2 average cross-sectional area (μm ² ) = total cross-sectional area (μm ² ) / number of granules

In this specific concentration region, the conductive inorganic material component exists as a conductive inorganic material particle having a shape in which a plurality of particles are densely packed, and the adjacent conductive inorganic material particles are substantially separated. Therefore, a large average cross-sectional area S means that the electrical resistance is small and the conductivity is large.

The lamp sealing body 10 made of a functionally graded material having the above structure can be manufactured by the following method. For example, a pin-shaped hole forming molding member is filled with an insulating inorganic material powder in a cylindrical molding die provided vertically on a bottom member, and an insulating inorganic material powder layer is formed. The conductive inorganic material powder and the insulating inorganic material powder are mixed in different ratios under gentle conditions so that the shapes of the powder particles of the insulating inorganic material powder and the conductive inorganic material powder are not broken. A plurality of mixed powders having different contents of the conductive inorganic material powder are filled in a mold in layers in order from the mixed powder having the lowest content of the conductive inorganic material powder to form a powder laminate. Thereafter, pressure is applied by a pressing member having a pin-shaped hole forming member, whereby a laminated molded body that is a pressed molded body is formed. Then, by heating the laminated molded body in a hydrogen atmosphere at a maximum heating temperature of, for example, 1000 to 1200 ° C., a lead rod insertion hole 11A formed by removing the hole forming member and an external lead rod are formed. Insertion hole 11
A temporary sintered body having B is obtained. The lead rod insertion hole 11A and the external lead rod insertion hole 11B can be formed, for example, by subjecting a columnar temporary sintered body to a hole forming process.

In the lead rod insertion hole 11A of the pre-sintered body, an internal lead rod 13 having a discharge electrode formed at the tip is formed.
At the same time, one end of the external lead rod 15 is inserted into the external lead rod insertion hole 11B.
At the maximum temperature, the pre-sintered body is finally made into a functionally graded material made of a sintered body, and at the same time, the internal lead rod 13 and The lamp sealing body 10 made of a functionally graded material, in which the external lead bar 15 is integrally fixed and connected by so-called baking, is manufactured.

In the step of forming all or at least one of the mixed powder layers in which the content ratio of the conductive inorganic substance powder is not less than 15% by volume and not more than 30% by volume, for example, the insulating inorganic substance powder may be used as an average. A mixed powder is prepared using a conductive inorganic substance powder having a particle diameter that is at least twice the average particle diameter of the conductive inorganic material powder, and by using this mixed powder, sealing of the obtained functionally graded lamp sealing body 10 for sealing is performed. In the member 11, the condition of the above equation 1 can be satisfied. This is because the size of the average cross-sectional area of the conductive inorganic substance granular material is affected by the average particle diameter of the conductive inorganic substance powder used for producing the functionally gradient material.

According to the functionally graded lamp sealing body 10 having the above-described structure, as will be apparent from an experimental example described later, the conductive material is formed in a specific concentration region of the functionally graded material constituting the sealing member 11. High electrical conductivity can be obtained despite the low inorganic inorganic component concentration. That is, in the specific concentration region, higher conductivity is obtained at the same concentration of the conductive inorganic substance component. For example, even in a region where the concentration of the conductive inorganic substance component is less than 20% by volume, substantial conductivity is obtained. The region where the concentration of the conductive inorganic substance component is not less than 20% by volume and not more than 30% by volume has higher electric conductivity.

Therefore, if the base end portion of the internal lead rod 13 inserted from the insulating inorganic material layer reaches a mixture layer having a conductive inorganic material component concentration of 15% by volume or more, it is practically sufficient. Conductivity can be ensured. That is, the sealing member 1 made of the functionally gradient material has a configuration in which the base end portion of the internal lead rod 13 reaches, for example, a mixture layer having a conductive inorganic substance component concentration of 15% by volume or more.
The electrical resistance between the lead wire 1 and the inner lead rod 13 can be reduced.

Further, since it has high electric conductivity in the specific concentration region, the region of the conductive portion in the sealing member 11 made of the functionally graded material becomes large, and as a result, for example, the conductive inorganic substance component concentration becomes 15% by volume. Can be reduced, for example, by 10% or more as compared with the conventional one. Therefore, in the lamp using the functionally graded lamp sealing body 10, the value of the current flowing under the same conditions can be increased, and the amount of light emission can be increased.

In the equation (2) relating to the specific concentration region, when the average sectional area of the conductive inorganic substance granular material is too small, substantial conductivity cannot be obtained in the region, and therefore, the above-described operation and effect are obtained. Can not get.

The sealing body 1 for a lamp made of a functionally gradient material according to the present invention.
According to the production method No. 0, in the step of forming a mixed powder layer in which the content ratio of the conductive inorganic substance powder is 15% by volume or more and 30% by volume or less, the average particle diameter of the insulating inorganic substance powder is By using a conductive inorganic substance powder constituting the layer having an average particle diameter of twice or more, the condition of the above-described formula 1 in a specific concentration region is satisfied in the obtained functionally graded material sealing body for lamp 10. Accordingly, it is possible to reliably manufacture a product having a region with high electrical conductivity despite the low concentration of the conductive inorganic substance component.

Further, conventionally, it was necessary to insert until the base end portion of the internal lead rod 13 reached a mixture layer having a conductive inorganic substance component concentration of 20% by volume or more. An equivalent electrical connection state can be realized by inserting the mixture into the mixture layer having a substance component concentration of 15% by volume. Therefore, the entire length of the sealing member 11 may be small, and distortion due to hole processing or molding can be suppressed.

When the average particle size of the insulating inorganic material powder is too small, the conductive material having a specific size in a specific concentration region of the sealing member 11 of the obtained sealing member 10 for a ramp made of a functionally graded material is obtained. Inorganic substance granules are not necessarily formed, and therefore, the above-described effects cannot be reliably obtained.

FIG. 2 is a schematic view showing an example of a configuration of a discharge lamp using the lamp sealing material made of a functionally gradient material according to the present invention. In this discharge lamp, 20 is a bulb made of silica glass, 11 is a lamp seal made of the above-described functionally graded material, 22 is a discharge electrode, 23 is an internal lead rod, 24
Is an external lead rod. The sealing member 10 for a ramp made of a functionally graded material has one end side portion of the sealing tube 2 of the bulb 20.
1 and welded to form a hermetic sealing structure. In this structure, the sealing member 1 constituting the sealing body 10 for a ramp made of a functionally graded material is formed from the external lead rod 24.
1, a path for introducing electricity to the internal lead bar 23 and the discharge electrode 22 is formed.

According to such a configuration, the inner lead rod 2
3 and the sealing member 11 made of the functionally graded material can be electrically connected sufficiently, and the hermetic sealing material made of the functionally graded lamp having good characteristics has a hermetic sealing structure. High performance and reliability can be obtained.

FIG. 3 is an explanatory cross-sectional view showing another example of the structure of the lamp seal made of a functionally gradient material of the present invention. This lamp sealing body 10 made of a functionally graded material is different from the sealing member 11 made of a functionally graded material in that the internal lead rod 13 and the external lead rod 15 are integrally connected to each other. It has the same structure as the functionally graded material sealing body 10 of FIG. 1 except that the lead rod 19 extending in the vertical direction is integrally connected in a penetrating state. In such a sealing member 11, the lead rod 19 extends in the length direction.
In the structure penetrating through, the area of the electrically conductive portion in the sealing member 11 made of the functionally graded material is substantially enlarged by expanding the high electric conductivity area to the area having a lower concentration of the conductive inorganic substance component. And thus the lead rod 1
The electrical resistance between the sealing member 9 and the sealing member 11 made of the functionally graded material can be made sufficiently small.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above examples, and various changes can be made. For example,
The functionally gradient material constituting the sealing member 11 may be one in which the concentration of the conductive inorganic substance component changes continuously. Further, the sealed body for a lamp made of a functionally graded material of the present invention is not limited to a discharge lamp, and can be applied to the formation of a sealed structure in an incandescent lamp. In this case, a lead rod having a filament coil at the tip thereof is integrally connected to a lamp seal made of a functionally graded material.

Hereinafter, an experiment performed to confirm the operation and effect of the present invention will be described. Experimental Example 1 An experimental sample was prepared as follows. <Preparation of Sample A1> A silica powder having an average particle size of 32.6 μm as an insulating inorganic material powder and a molybdenum powder having an average particle size of 3 μm as a conductive inorganic material powder were
The powder particles were mixed under gentle conditions so as not to lose their shapes, to prepare a mixed powder A1 having a molybdenum powder content of 10% by volume. This mixed powder A1 was filled in a molding die, and pressurized to form a columnar laminated molded body, which was heated at 1200 ° C. in a hydrogen atmosphere to obtain a temporarily sintered body. The sintered body is placed in a vacuum at 1720
Sintering at 10 ° C, molybdenum concentration is 10% by volume,
"Sample A1" which was a sintered body having an outer diameter of 3.0 mm and a total length of 14 mm was produced.

<Preparation of Sample A2> A mixed powder A2 was prepared in the same manner as the mixed powder A1 except that silica powder having an average particle diameter of 43.7 μm was used. Similarly, the mixed powder A2 was filled in a molding die, molded, temporarily sintered in a hydrogen atmosphere, and then sintered in a vacuum to produce a sample A2.

<Preparation of Samples B1 to B5> As a silica powder, the average particle diameter shown in Table 1 is 3.9 to 43.7 μm so that the content ratio of the molybdenum powder is 15% by volume.
The mixed powders B1 to B5 were prepared in the same manner as the mixed powder A1 except that
In the same manner as in 1, the mixed powders B1 to B5 are filled in a molding die, molded, and temporarily sintered in a hydrogen atmosphere.
Samples B1 to B5 were produced by sintering in a vacuum. <Preparation of Samples C1 to C5> As a silica powder, the content ratio of molybdenum powder was 20% by volume as shown in Table 1.
The mixed powders C1 to C5 were prepared by the same method as that for the mixed powder A1 except that the powder having an average particle diameter of 3.9 to 43.7 μm was used. C1 to C5 were filled in a molding die, molded, temporarily sintered in a hydrogen atmosphere, and then sintered in a vacuum to produce samples C1 to C5. <Preparation of Samples D1 to D6> As a silica powder, the content of molybdenum powder was 30% by volume.
The mixed powders D1 to D6 were prepared by the same method as that for the mixed powder A1 except that the powder having an average particle diameter of 0.3 to 43.7 μm was used. D1 to D6 were filled in a molding die, molded, temporarily sintered in a hydrogen atmosphere, and then sintered in a vacuum to produce samples D1 to D6. <Preparation of Samples E1 to E6> The silica powder was prepared as shown in Table 1 so that the content ratio of the molybdenum powder was 40% by volume.
The mixed powders E1 to E6 were prepared in the same manner as in the above mixed powder A1, except that the powder having an average particle diameter of 0.3 to 43.7 μm was used. Samples E1 to E6 were prepared by filling E1 to E6 into a molding die, molding, temporarily sintering in a hydrogen atmosphere, and then performing sintering treatment in a vacuum.

[0045]

[Table 1]

In Table 1, the “particle size ratio” is the ratio of the average particle size of the insulating inorganic material powder to the average particle size of the conductive inorganic material powder.

With respect to each sample obtained as described above, one sample was obtained at an arbitrary cross section by the four-terminal method.
By passing the current of A, the resistivity (Ω · cm) was measured. FIG. 4 shows the results. As a result of the above experiment, when the conductive inorganic substance component concentration is not less than 15% by volume and not more than 30% by volume, the sample having a particle size ratio of 2 or more is smaller than the sample having a smaller particle size ratio. It is understood that the resistivity is significantly reduced. In particular, when the concentration of the conductive inorganic substance component is 20% by volume or less, the effect of the particle size ratio on the resistivity is large, and the resistivity is significantly reduced by increasing the particle size ratio. It is understood that it is.

[Experimental Example 2] Using silica powder as an insulating inorganic substance powder and molybdenum powder as a conductive inorganic substance powder, the particle size ratio was determined at the same molybdenum concentration by the same method as in Experimental Example 1. A plurality of different experimental samples or a plurality of experimental samples having the same particle size ratio and different molybdenum concentrations were prepared.

With respect to the experimental samples obtained as described above, the value of the average sectional area of the molybdenum granules in each of the samples was measured. That is, the sample is cut at an arbitrary position and the cross section is polished, and three randomly selected 180 μm and 230 μm regions are selected from the polished surface.
A photograph is taken with a microscope at a magnification of 0 times, and image data obtained from this photograph is analyzed with image analysis software “W
InROOF "(manufactured by Mitani Shoji Co., Ltd.), image processing is performed, binarization is performed to determine the number of molybdenum granules present in the field of view and the total area thereof, and the average cross-section of the molybdenum granules is obtained by the above-described equation 2. The area was calculated. Table 2 shows the results. Here, FIG. 5 is an example of a photograph taken by a microscope of a cross section of a certain experimental sample. In addition, at an arbitrary cross section of each manufactured sample, 1
By passing the current of A, the resistivity (Ω · cm) was measured. The results are shown in Table 2. In Table 2, the maximum value of “particle size ratio 1.
7 "is indicated by the rate of increase or decrease in resistivity with reference to the sample. This ratio indicates that the smaller the sign and the greater the absolute value, the greater the decrease in resistivity.

[0050]

[Table 2]

As a result of the above experiment, when the concentration of the conductive inorganic substance component is, for example, 10% by volume, the resistivity of the reference sample is extremely large, and the measurement cannot be performed. The ratio of increase / decrease in the resistivity of the sample having the ratio of 10.9 cannot be calculated, and even when the average cross-sectional area of the conductive inorganic substance granular material is increased, the resistivity cannot be sufficiently reduced. When the concentration of the conductive inorganic substance component is, for example, 40% by volume, the influence of the average cross-sectional area of the conductive inorganic substance particulate matter on the resistivity is small.
It can be understood that the effect of reducing the resistivity is small even when the average sectional area of the conductive inorganic substance particulate material is increased. In addition, it can be understood that when the conductive inorganic substance component concentration is the same and the particle size ratio is less than 2, the resistivity becomes large. In addition, the particle diameter ratio of the average particle diameter of the insulating inorganic substance powder to the average particle diameter of the conductive inorganic substance powder is 1
When the value exceeds 5, the effect of decreasing the resistivity as described above may not be reliably obtained.
One of the reasons is considered to be that the conductive inorganic material particles are too small in diameter relative to the insulating inorganic material particles, so that formation of a continuous tissue state by the conductive inorganic material particles is insufficient.

Further, when the molybdenum concentration is 15% by volume,
When the relationship between the measured resistivity and the average cross-sectional area of the conductive inorganic substance granular material was determined for each of the cases of volume% and 30 volume%, the curves shown in FIG. 6 were obtained, and each of these curves is represented. The following power curve equations (1) to (3) were determined.
Here, the power curve equation (1) is an equation when the molybdenum concentration is 15% by volume, and the power curve equation (2) is an equation when the molybdenum concentration is 20% by volume. (3) is an equation when the molybdenum concentration is 30% by volume.

[0053]

## EQU5 ## Power curve equation (1) y = 2.9301x ^-3.46 (In this power curve equation, the correlation coefficient is 0.90, y is the resistivity, and x is the average cross-sectional area of the molybdenum granules. is there.)

[0054]

## EQU6 ## Power curve equation (2) y = 0.114x ^-1.34 (In this power curve equation, the correlation coefficient is 0.97, y is resistivity, and x is the average of molybdenum granular bodies. Cross-sectional area.)

[0055]

## EQU7 ## Power curve equation (3) y = 0.012x ^-0.87 (In this power curve equation, the correlation coefficient is 0.91, y is the resistivity, and x is the average cross section of the molybdenum granular material. Area.)

In the power curve equation (1), FIG.
The resistivity of the sample having a particle size ratio of 1.7 indicated by x in the figure is set as a reference value, and the resistivity is 10% with respect to this reference value.
When the value of the average cross-sectional area of the conductive inorganic substance granular material when it became smaller was determined, it was 7.0 μm ² . Similarly to the above, in the power curve equation (2), the value of the average cross-sectional area of the conductive inorganic substance particles when the resistivity is reduced by 10% with respect to the reference value indicated by a mark in FIG. When asked,
12.7 μm ² , and in the power curve equation (3), the resistivity was 10% with respect to the reference value indicated by a black circle in FIG.
%, The value of the average cross-sectional area of the conductive inorganic substance granule was 19.5 μm ² . 15% by volume, 20% by volume and 30% by volume obtained as described above.
Each of the values of the average cross-sectional area of the conductive inorganic substance granule in volume% is plotted on the curve shown in FIG. 7, and the equation of this curve is given by the following equation 1. .

[0057]

Equation 1 S ≧ −0.03C ² + 2.19C−19.1 (S is the average cross-sectional area of the conductive inorganic substance granule [unit: μm
² ] and C is the concentration of the conductive inorganic substance component [unit: volume%]. )

Similarly, in each of the power curve equations (1) to (3), the resistivity of each sample having a particle size ratio of 1.7 shown in FIG. When the value of the average cross-sectional area of the conductive inorganic substance granular material when the resistivity was reduced by 20% with respect to this reference value was determined, it was 7.5 μm ² in the power curve equation (1), and the power curve equation in (2) a 14.0 ^2, in the power curve expression (3) it was 22.5 ^2. When the respective values of the average cross-sectional area of the conductive inorganic substance granules at 15% by volume, 20% by volume and 30% by volume obtained in this way are plotted, they are located on the curve shown in FIG. The equation of this curve is given by Equation 3 below.

[0059]

Equation 3 S ≧ −0.031C ² + 2.39C-21.7 (S is the average cross-sectional area of the conductive inorganic substance granule [unit: μm
² ] and C is the concentration of the conductive inorganic substance component [unit: volume%]. )

Therefore, in the range where the functionally gradient material constituting the sealing member satisfies the condition of the formula 1 in the specific concentration region, high electric conductivity is obtained despite the low concentration of the conductive inorganic substance. It is understood that it can be obtained.
Further, in a range where the functionally gradient material constituting the sealing member satisfies the condition of Expression 3 in the specific concentration region,
High electrical conductivity is reliably obtained despite the low concentration of the conductive inorganic substance.

[0061]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. <Example 1> In all regions where the molybdenum concentration as a conductive inorganic substance component is 15 vol% or more and 30 vol% or less, a mixed powder having a particle diameter ratio of silica powder and molybdenum powder of 10 was used. The produced sealing body for a lamp made of a functionally graded material was obtained, and a discharge lamp using the sealing body for a lamp made of a functionally graded material was produced as follows. The molding member for hole formation has a purity of 9 in a molding die provided on the bottom member.
9.99% silica powder having an average particle size of 30 μm was filled to form an insulating inorganic material powder layer made of silica, and on top of this, molybdenum powder having a purity of 99.99% and an average particle size of 3 μm, and a purity of 99% A plurality of mixed powders each having a different content ratio of molybdenum powder prepared by gently mixing a silica powder having an average particle diameter of 30 μm with 0.99% were prepared, and the mixture was filled in a mold in ascending order of molybdenum concentration to form a total of 9 layers. A powder laminate was obtained, and then pressed by a pressing member having a hole-forming member to obtain a laminate, which was heated at about 1200 ° C. in a hydrogen atmosphere. A temporary sintered body having a rod insertion hole was obtained. Then, an outer diameter of 0.6 m having a discharge electrode with a tungsten wire wound around the tip of the inner lead rod insertion hole.
m, insert a tungsten rod with a length of 15 mm,
External lead rod insertion hole 0.5mm outside diameter, 8mm long tungsten rod inserted state, sintering process in vacuum at about 1720 ℃, outer diameter 3mm, total length 14m
Thus, a sealed body for a ramp made of a functionally graded material was obtained in which an internal lead rod and an external lead rod were integrally fixedly held to a functionally graded material of m. In this lamp seal made of a functionally graded material, one end of the internal lead rod is connected to a conductive inorganic substance component concentration of 1%.
Inserted up to 5% by volume of the mixture layer.

When the average cross-sectional area of the conductive inorganic substance particulate material in the specific concentration region was calculated for the obtained functionally graded material of the sealed body for a functionally graded lamp, it satisfies the condition of Equation 1. When the resistivity was measured, 3.
It was 8 × 10 ⁻⁴ Ω · cm.

Further, the diameter of the light emitting space in the bulb was 11 mm, the distance in the tube axis direction was 11 mm, and the sealed tube portion was used in accordance with the structure of FIG. 10 mercury lamps having an inner diameter of 3.1 mm, a distance between electrodes of 1.5 mm, 40 mg of mercury as a luminescent substance, and 300 Torr of argon as a buffer gas, and having a rated lamp power of 100 W, were manufactured.

When the thus produced mercury lamp was turned on under the rated conditions, stable lighting states were obtained in all mercury lamps.

Comparative Example 1 In all regions where the molybdenum concentration as a conductive inorganic substance component is 15 vol% or more and 30 vol% or less, the particle size ratio between silica powder and molybdenum powder is 0.1. A sealed body for a ramp made of a functionally graded material manufactured using the mixed powder was obtained, and a discharge lamp using the sealed body for a lamp of the functionally graded material made of the functionally graded material was manufactured as follows. Purity 99.99%, average particle size 5
An insulating inorganic material powder layer made of silica is formed by filling silica powder having a thickness of 9 μm, and molybdenum powder having a purity of 99.99% and an average particle diameter of 3 μm, and a purity of 99.99.
%, Mixed with silica powder having an average particle diameter of 0.3 μm,
Except that a plurality of types of mixed powders having different molybdenum powder content ratios were prepared, and one end of the inner lead rod was inserted into the mixture layer having a conductive inorganic substance component concentration of 20% by volume in the functionally graded lamp sealing body. Manufactured 10 mercury lamps having the same configuration as in Example 1. When the average cross-sectional area of the conductive inorganic substance particulate material in the specific concentration region was calculated for the functionally graded material of the sealing body for a functionally graded lamp used in this mercury lamp, a material that satisfies the condition of Equation 1 was not found. Without measuring the resistivity,
It was 2.8 × 10 ⁻³ Ω · cm.

When the thus produced mercury lamp was turned on under the rated conditions, a stable lighting state was not obtained in all the mercury lamps, and the defect occurrence rate was 90%.

<Example 2> A lead rod composed of a tungsten rod having an outer diameter of 0.6 mm and a length of 25 mm having a discharge electrode wound with a tungsten wire at its tip, instead of an inner lead rod and an outer lead rod, has a tilting function. A mercury lamp having the same configuration as that of Example 1 was manufactured except that a sealing body for a functionally gradient material, which was integrally fixed and held in a state penetrating the material, was used. The average cross-sectional area of the conductive inorganic substance particulate material in the specific concentration region was calculated for the functionally graded material of the sealed body for a functionally graded lamp used in this mercury lamp. Yes, when the resistivity was measured, it was 3.8 × 10 ⁻⁴ Ω · c
m. When the manufactured mercury lamps were turned on under the rated conditions, stable lighting states were obtained in all mercury lamps.

<Comparative Example 2> A lead rod composed of a tungsten rod having an outer diameter of 0.6 mm and a length of 25 mm having a discharge electrode wound with a tungsten wire at its tip, instead of the inner lead rod and the outer lead rod, is a functionally graded material. A mercury lamp having the same configuration as that of Comparative Example 1 was manufactured except that a lamp seal made of a functionally graded material, which was integrally fixed and held in a state of penetrating the same, was used. When the average cross-sectional area of the conductive inorganic substance particulate material in the specific concentration region was calculated for the functionally graded material of the sealing body for a functionally graded lamp used in this mercury lamp, a material that satisfies the condition of Equation 1 was not found. And the resistivity was measured to be 2.8 × 10 ⁻³ Ω ·
cm. In addition, when the manufactured mercury lamp was turned on under the rated conditions, a stable lighting state was not obtained in most of the mercury lamps after 100 hours, and the defect occurrence rate was 50%.

[0069]

According to the sealed body for a ramp made of a functionally graded material of the present invention, the conductive inorganic material particulate material is provided in a specific region where the conductive inorganic material component concentration in the functionally graded material constituting the sealing member is low. Is present in the peripheral portion of the insulating inorganic material particles, and the adjacent conductive inorganic material granules form a continuous tissue state in a substantially conductive state. Although having a low component concentration, it has high electrical conductivity. In addition, since the specific region has high electric conductivity despite the low concentration of the conductive inorganic substance component, the region of the conductive portion in the sealing member made of the functionally graded material is substantially increased, and as a result, Since the electrical resistance between the lead rod and the connected lead rod can be reduced, the value of the current flowing under the same conditions can be increased.

According to the method for manufacturing a sealed body for a lamp made of a functionally graded material of the present invention, in the step of forming the mixed powder layer having a specific concentration, the average of the insulating inorganic material powder and the conductive inorganic material powder is used. By using one having a particle diameter ratio in a specific range, the effective cross-sectional area of the conductive inorganic substance particles in the obtained functionally graded lamp sealing body is increased, and as a result, the conductive inorganic substance It is possible to obtain a sealed body for a lamp made of a functionally graded material, which has a region with high electric conductivity despite the low concentration of the substance component.

According to the lamp of the present invention, the lead rod and the sealing member made of the functionally graded material can be electrically connected sufficiently, and the above-mentioned sealing for a lamp made of the functionally graded material having good characteristics. The hermetic sealing structure is formed by the stopper, and high performance and reliability can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing an example of the configuration of a lamp sealing body made of a functionally graded material of the present invention.

FIG. 2 is a schematic diagram showing an example of a configuration of a discharge lamp of the present invention.

FIG. 3 is an explanatory cross-sectional view showing another example of the configuration of the lamp sealing body made of a functionally graded material of the present invention.

FIG. 4 is a grab showing the relationship between molybdenum concentration and resistivity in various experimental samples.

FIG. 5 is a photomicrograph of a cross section of one of the experimental samples.

FIG. 6 is a graph showing the relationship between the average cross-sectional area and the resistivity of molybdenum granules.

FIG. 7 is a graph showing a relationship between molybdenum concentration and average cross-sectional area of molybdenum granules.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Sealing material for functionally graded lamps 10A Insulating part 10B Conductive part 11 Sealing member 11A Lead rod insertion hole 11B External lead rod insertion hole 13 Internal lead rod 15 External lead rod 19 Lead rod 20 Valve 21 Sealing Stop tube part 22 Discharge electrode 23 Internal lead rod 24 External lead rod

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mitsuru Ikeuchi 1194, Sado Bessho-cho, Himeji-shi, Hyogo Ushio Electric Co., Ltd. (72) Koji Tagawa 1194 Sado, Bessho-cho, Himeji-shi, Hyogo F-term (reference) 5C043 AA07 CC01 CD01 DD11 EB18

Claims (4)

[Claims] 1. A sealing member made of a functionally gradient material, and a lead rod fixed to the sealing member, wherein the sealing member insulates an insulating inorganic material layer and a conductive inorganic material component, respectively. A plurality of mixture layers composed of a mixture with a conductive inorganic material component are laminated, and each of the mixture layers has a stepwise or continuous conductive inorganic material component concentration in order from the one adjacent to the insulating inorganic material layer. The functionally gradient material includes a conductive inorganic material particulate material at an arbitrary cross section in a region where the conductive inorganic material component concentration is 15% by volume or more and 30% by volume or less. Wherein the average cross-sectional area S satisfies the condition of the following formula 1. Formula 1 S ≧ −0.03C ² + 2.19C−19.1 (S is the average sectional area of the conductive inorganic substance granular material [unit: μm
² ] and C is the concentration of the conductive inorganic substance component [unit: volume%]. ) 2. The sealed body for a functionally gradient material lamp according to claim 1, wherein the conductive inorganic substance component is molybdenum, and the insulating inorganic substance component is silica. 3. A method for producing a sealing material for a ramp made of a functionally graded material according to claim 1, wherein the method comprises mixing a conductive inorganic substance powder and an insulating inorganic substance powder. Forming a mixed powder layer in which the content ratio of the conductive inorganic material powder is not less than 15 vol% and not more than 30 vol% using the mixed powder thus obtained, as the insulating inorganic material powder, the average particle diameter of which is conductive. A method for producing a seal for lamps made of a functionally graded material, characterized in that an inorganic substance powder having an average particle diameter of twice or more is used. 4. A lamp having a hermetically sealed structure formed by the sealing body for a ramp made of a functionally graded material according to claim 1.