JPS59108295A - Arc carbon for ageing discolor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to arc carbon used as a light source in tests for resistance to discoloration and fading, weather resistance tests, and the like.

Generally a weather meter or dual cycle weather meter
Meters are used to perform weather resistance tests and fading resistance tests on paints, plastics, rubbers, fibers, etc. by exposing them to light for 100 to 500 hours. As these light sources, arc carbon for aging and fading is used, which has a carbon core in the hollow part of a carbon tube to which a rare earth element compound is added as a luminescent agent.

However, when arc carbon is generated between carbons, the core is rapidly oxidized and the core quickly wears out.The lifespan of arc carbon depends on the rate at which the core wears out. It took 22 to 24 hours at most.

For these reasons, the above-mentioned arc carbon is
When used as a light source for a weather meter or the like, which requires a light irradiation time of 0.00 hours, it has to be replaced frequently, which takes time and effort.

In order to improve the short lifespan of arc carbon, it is possible to increase the diameters of the carbon tube and the core, but with this method, the position of the arc generated between the arc carbon becomes unstable. However, there was a drawback that the light emitting performance was impaired due to the arc flickering.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an arc car for aging and fading that can be used for a long time without impairing the luminous performance of the arc.

As a result of various studies, the present inventors have found that by specifying the cross-sectional area ratio of the carbon tube to the core and the content of additives in the core, it is possible to stabilize the light emission performance of the arc and significantly extend the life. I discovered that it can be done.

That is, the arc carbon for aging fading of the present invention has a cross-sectional area ratio of the carbon tube to the core of 15 to 6o:1, a content of rare earth element compound in the core of 30 to 70% by weight,
It is characterized in that the content of the alkali metal compound is 1 to 10% by weight.

In the present invention, the cross-sectional area ratio between the carbon tube and the core body is set to 15 to 60:1.
This is because the arc becomes unstable due to long-life combustion of 00 hours or more.

In normal upper arc carbon, the outer diameter is 23
mm or 36++++n is used.

In the present invention, examples of the rare earth element compound contained in the core include cerium fluoride, lanthanum fluoride, and cerium oxide. The content of these rare earth element compounds in the core is 30 to 70% by weight.
If it is less than 700% by weight, it will not be possible to obtain the spectral energy necessary for weather resistance tests, etc., and if it exceeds 700% by weight, the oxidative wear and tear of the core will be severe and the life of the arc carbon will be shortened.

In the present invention, potassium sulfate, potassium chloride, potassium borofluoride and the like can be mentioned as the plucarium metal compound to be contained in the core. The content rate of these alkali metal compounds in the core is 1 to 10.
If it deviates from the range of 0% by weight, the arc becomes unstable and it becomes impossible to stably obtain spectral energy σ.

In addition, in order to sustain the arc for a long time in the present invention, it is necessary to reduce the difference in the wear rate between the carbon tube and the core, and for this purpose, the true specific gravity of the core is set to 2.7 to 3.3. This is desirable.

As a method for producing arc carbon for aging fading as described above, 2. A method may be used in which a mixture of a rare earth element compound, an alkali metal compound, graphite, etc. is injected into the hollow part of a carbon tube, and then the mixture is fired. A method may also be used in which the mixture is fired and then fitted into the hollow part of the carbon tube. Further, the cross-sectional shape of the core may be any shape such as a circle or the shape of a gear having 6 to 12 pieces of i1'1.

The present invention will be explained in detail below.

Example 1 Cerium fluoride was used as a rare earth element compound, potassium sulfate was used as an alkali metal compound, and a core material consisting of these and fine carbon black and graphite powder was mixed with tar,
A pitch mixture was added and kneaded. Subsequently, this mixed material was filled into the hollow part of the carbon tube and fired to obtain an arc carbon having an outer diameter of 36 mm, a core diameter of 9 mm, and a length of 350 m.

The content of cerium fluoride in the core was 422% by weight, the content of potassium sulfate was 5% by weight, and the true density of the core was 2.9%.

Example 2 Using lanthanum fluoride as the rare earth element compound and potassium chloride as the alkali metal compound, an outer diameter of 36 mm, a core diameter of 5 mm, and a length of 35 mm were prepared in the same manner as in Example 1 above.
A 0 mm arc carbon was obtained. The content of lanthanum fluoride in the core was 566% by weight, the content of potassium chloride was 3% by weight, and the true specific gravity of the core was 3.0.

Example 3 Cerium oxide was used as a rare earth element compound, potassium borofluoride was used as an alkali metal compound, and a core material consisting of these and fine carbon black and graphite powder was mixed with tar,
The pitch blend was added and kneaded. Subsequently, the kneaded product was molded into a round bar using a press molding machine, and then fired to produce a core. The content of cerium oxide in the core is 63% by weight, and the content of potassium borofluoride is 6% by weight.
The true specific gravity of the core was 3.0. Subsequently, this core was coated with an adhesive such as phenol resin or tar, and then inserted into the hollow part of the carbon tube. Next, the adhesive is heated to harden, and the core body and carbon tube are bonded to each other with an outer diameter of 36 mm.
An arc carbon having a core diameter of 5 nm and a length of 350 nm was obtained.

Comparative Example 1 An arc carbon having an outer diameter of 36 m, a core diameter of 10 mm, and a length of 350 arcs was obtained in the same manner as in Example 1 using potassium fluoride as the rare earth element compound and potassium sulfate as the alkali metal compound.

The content of potassium fluoride in the core was 855% by weight, the content of potassium sulfate was 5% by weight, and the true specific gravity of the core was 2.8.

Comparative Example 2 Arc carbon having an outer diameter of 36 mm, a core diameter of 7 columns, and a length of 350 mm was obtained in the same manner as in Example 1 using potassium fluoride as the rare earth element compound and potassium sulfate as the alkali metal compound.

The content of potassium fluoride in the core was 200% by weight, the content of potassium sulfate was 200% by weight, and the true specific gravity of the core was 2.4.

Comparative Example 3 Arc carbon having an outer diameter of 36 mm, a core diameter of 4 mm, and a length of 350 mm was obtained in the same manner as in the above Example, using potassium fluoride as the rare earth element compound and potassium sulfate as the alkali metal compound.

The content of potassium fluoride in the core was 188% by weight, the content of potassium sulfate was 255% by weight, and the true specific gravity of the core was 3.6.

Carbon tube cross-sectional area a, core cross-sectional area b, cross-sectional area ratio a/b of the arc carbons of Examples 1 to 3 and Comparative Examples 1 to 3 described above,
The contents of rare earth element compounds and alkali metal compounds in the core and the true specific gravity of the core are shown in the table below.

In addition, the outer surface of these arc carbons was plated with copper and used as the upper carbon of a due cycle weather meter, and the lower carbon had an outer diameter of 23 wn and a core diameter of 8.
Using arc carbon with a length of 350mm and copper plating on the outer surface, an arc was generated under AC60A and 50V conditions and the arc characteristics were measured.The results are the arc life, degree of consumption of the arc carbon, and number of arc flashes. and arc stability are also listed in the table below.

As is clear from the table above, in the arc carbon of Comparative Example 1, the cross-sectional area ratio between the carbon tube and the core and the content of the rare earth element compound in the core are outside the range of the present invention, so the arc stability is almost stable. However, the wear rate is large and the arc life is short. In addition, the content of rare earth element compounds and alkali metal compounds in the core of the arc carbon of Comparative Example 2 is outside the scope of the present invention, and the content of the rare earth element compound and alkali metal compound in the core of the arc carbon of Comparative Example 3 is Since the content of rare earth element compounds and alkali metal compounds in the body are both outside the scope of the present invention, the arc life is short and the arc is unstable.

On the other hand, the arc carbons of Examples 1 to 3 can all generate a stable arc for a long time of 60 hours or more.

In the above embodiment, only the outer surface of the carbon tube was plated with copper, but the core may also be plated with copper. Further, the arc carbon of the present invention may have a carbon tube having a double tube structure, and steel plating may be applied to the outer surfaces of the outer carbon tube and the inner carbon tube.

As described in detail above, according to the present invention, it is possible to provide an arc carbon for aging fading that can maintain a stable arc having the spectral energy necessary for a weather resistance test for a long period of time.

Applicant's agent: Patent attorney Suzue Takehiko-46 ( )

Claims (2)

[Claims] (1) An arc carbon for aging fading consisting of a carbon tube and a carbonaceous core body provided in the hollow part of the carbon tube and containing a rare earth element compound and an alkali metal compound as a luminescent agent, wherein the carbon tube and the core body The cross-sectional area ratio is 15 to 60
:1, the content of the rare earth element compound in the core is 30 to 70%, and the content of the alkali metal compound is 1 to 70%.
An arc carbon for aging fading characterized by an amount of 1ON. (2) The arc carbon for aging fading according to claim 1, characterized in that the core has a true specific gravity Ω of 2.7 to 33.