NO153699B - SEALING DEVICE FOR THERMAL DOOR. - Google Patents

Abstract

1. Sealing arrangement on a door with no still, with a guide profile (1) which is inserted in a longitudinal groove in the door-leaf bottom edge and in which is mounted a sealing body (3) which is vertically displaceable under the effect of a one-part connecting rod (17) between a lower position resting resiliently on the ground and an upper position raised from the ground, one end of the connecting rod projecting beyond one side of the door leaf and being displaceable inwards when it comes up against a stop fastened to the door frame, in order to bring about the downward movement of the sealing body counter to the force of the spring (15), characterised in that the connecting rod (17) is mounted in such a way that it forms, together with a pivoting arm (7) articulated to it and to the guide profile (1), a toggle lever, the toggle joint (21, 22) of which moves resiliently inwards and downwards when the connecting rod (17) is displaced, in that the sealing body (3) is fastened to the toggle joint (21, 22) in a way known per se, and in that one end of the spring (10) acts on the pivoting arm (7).

Description

Method of manufacturing an anode for an electrolytic capacitor.

The invention relates to a method

for the production of an anode for an electrolytic capacitor by sintering pressed powder of

a film-forming metal.

To get a capacitor that has a largest

possible capacity per one strives for unit volume

to produce an anode with the largest possible surface. With many film-forming metals such as

Ta, Nb, Ti and Zr have achieved this so far

essentially in that it pulverized metal

is pressed into an anode body and then sintered.

For aluminum anodes, this is usually assumed

metal foils that are equipped with the help of etching

with an enlarged surface, the pressing of aluminum with subsequent sintering is however also known. It is also already known

that by adding a volatile compound to the metal powder at the sintering temperature

to be pressed, a further can be achieved

increase of the anode surface, because the porosity

is thereby increased.

However, it has been shown that in general

by adding such a compound as e.g.

an adhesive based on acrylate or also camphor,

as is known from German patent no. 708 895,

an optimal surface increase is not obtained. Moreover, it turned out that by adding such

connection, the anode after sintering usually has a lower capacity or a higher leakage current. Possibly the latter is caused

by the formation of metal carbides at the carbon of the splitting compounds.

According to the invention, one anode is obtained for one

electrolytic capacitor with a lower value for

the leakage current and/or a higher capacity.

For this purpose, the metal powder is compressed with naphthalene. After the mixture has been compressed into an anode body, this compound can be removed from an anode body by a small increase in temperature or by arranging a body in a ventilated room, thereby giving the anode body a large porosity. When the sintering temperature is reached during subsequent sintering, even traces of the added compounds are no longer present.

The anode bodies thus formed can now be assembled in a known manner into an electrolytic capacitor after the anode body is equipped with an oxide layer serving as a dielectric by means of anodic oxidation (multiplication). A liquid or pasty electrolyte solution can be used as operating electrolyte. A solid, semi-conducting compound such as Mn02 can also be used for this purpose, which, during pyrolysis of manganese nitrate, is again moistened with a solution of manganese nitrate and then heated, as MnO, is formed during pyrolysis. As the dielectric layer is damaged during the pyrolysis, it must be reformed each time after such processing of the anode body. The semi-conductive layer is then covered with an electrically conductive layer, e.g. with a graphite suspension, this layer being covered with a metal layer, after which the construction is finally built into a house.

According to a further design of the method according to the invention, it is sintered

pressed the anode body in vacuum at a temperature just below the metal's melting point, i.e. for aluminum at a temperature between 650

and 659 °C. Preferably, the lozenges which are to be sintered within a very short time are held at the melting point, so that the lozenges retain their porous structure. The advantage is that with a vacuum, the volatilization of the compound added to the metal powder is carried out together with the sintering in one work process.

In the following, the invention will be explained in more detail with the help of some design examples.

Example 1.

High purity tantalum powder (> 99.85% Ta) with an average particle size of 50 n was mixed with

a) 2 percent by weight naphthalene

b) 3.9% by weight acrylate varnish

c) 1% by weight acrylate varnish

and from this mixture lozenges with a diameter of 2.9 mm and a length of 4.85 mm were pressed around tantalum wires with a diameter of 0.5 mm. The powder weight per anode amounted to 260 mg. The pellets were sintered for 30 minutes at a temperature of 1900 °C and a pressure of

< 20 x 10-5 mm Hg.

Then they were cultured for 20 hours in 0.01% HN0 3 until a voltage of 140 volts, then rinsed for 5 minutes in distilled water and air dried.

The leakage current was measured at 140 volts in 0.01% HNO 2 after 1 minute. The capacity measurement took place in 5% HN03 against a blackened Pt cathode.

The following values were measured:

Table.

Capacity Series- Leakage- CV Ca(»F) resistance current (/iFV/g)

Rs(£>) 1(hA)

a 5.4 7 4.2 2990

b 4.4 8 3.4 2390

c 4.4 8 3.4 2390

Naphthalene thus shows an increase in capacity and therefore an increase in surface area of 25% compared to acrylate resins.

The resistance and the leakage current were roughly the same here.

Example 2.

Aluminum powder with a purity of 99.99% Al and an average particle size of 20 µm was mixed with 12% by weight of naphthalene and from this mixture, per lozenge pressed 40 g around an aluminum wire with a length of 30 mm and a diameter of 0.5 mm over a length of 4.4 mm and up to a diameter of 2.8 mm. There was therefore 0.88 x 40 mg = 36 mg Al present per lozenge.

The pellets were sintered for one hour at a temperature of 650-655°C at a pressure of less than 10 x 15-5 mm Hg. The lozenges were then formed in a solution of 2.5% by weight potassium biphthalate in distilled water at 21 volts and then thoroughly rinsed in distilled water. The pastilles were impregnated in vacuum with a solution of Mn (NO:J,) 2 in their own crystal water during 3/4 of a minute, heated at 450 °C, then dissolved in K-biphthalate solution and rinsed in water. This processing was carried out a total of 4 times, after which the lozenges were dipped three times in a graphite suspension and each time dried. Finally, the lozenges were equipped with a metal layer and built into a housing.

The capacitors thus formed have a leakage current of 7.9 /XA at 6.4 V, a capacity of 11.4 fJP, a loss factor tg 8 of 8.4% and an impedance at 100 kHz of 6.7 ohms. The product CV per g Al amounted to 6650 ^F V/g.

Pellets were produced in an essentially identical manner, starting from Al powder of the same purity. This powder was mixed with 6% by weight acrylate varnish and from this mixture 28 mg was pressed around an aluminum wire to a diameter of 2.8 mm over a length of 3.2 mm. There was therefore 28x0.94 = 26.5 mm Al present per lozenge. The otherwise identically produced capacitors have a leakage current of no less than 92.5 juA, a capacity of 8.7 i±F, a loss angle

(tgS) of 3.5% and an impedance of 100 kHz

of 1.2 Ohms. The product CV per g Al amounted to 6,900 fj. F W/ g.

Example 3.

Aluminum with a purity of 99.99% Al and an average particle size of 20 jx was mixed with 12% by weight of naphthalene

and from this mixture it was pressed per lozenge

40 g around a length of aluminum wire

of 30 mm and a diameter of 0.5 mm over a length of 4.4 mm and up to a diameter of 2.8 mm. The degree of compression, i.e. the percentage of visible density of the pressed body compared to the dense compact aluminum amounted to 49%. The pellets were sintered for one hour at a pressure of less than 10 x 10-5 mm Hg at the following temperatures: 655, 650, 625, 600 and 500°C. At each temperature, 20 pellets were sintered. The lozenges were then propagated in a solution of 2.5% by weight potassium biphthalate in distilled water at 21 volts for such a long time that the lowest propagation current was achieved and then rinsed thoroughly in de-

ionized water. The lozenges were impregnated in vacuum with a solution of Mn(N03)2 in separate crystal water and then in the same solution capacity and loss factor (tg8) were measured.

For the pellets sintered at 655 °C, a capacity of 16.3 ± 0.6 ^F and a loss factor of 26.7 ± 1.3% were measured; for the pellets sintered at 650 °C, these values were 16.2 ± 0.7 fiF resp. 25.4 ± 1.3%. For the pellets sintered at 625°C, the values were 17.8 ± 1.2 p.F and 27.6 ± 1.2%.

Of the 20 pellets sintered at 600 °C, 11 had a capacitance less than 0.2 fiF and a loss factor tg 8, which was so high that it could not be measured. The remaining 9 lozenges had a capacity of 17.5 ± 1.3 ^F and a loss factor tg 8 of 25.9 1.4%. The thieves know

500 °C sintered pellets all subsequently fell after being taken out of the sintering furnace from the wire as free powder.

Claims (1)

Method for the production of an anode for an electrolytic capacitor by sintering pressed powder of a film-forming metal, to which auxiliary substances have been added, which volatilize during processing and thereby increase the porosity and anodic oxidation of the sintered body, characterized in that naphthalene is used as auxiliary substance. '