DD205341A1 - METHOD FOR PRODUCING A NEW ADSORPTION AGENT - Google Patents

Abstract

The invention relates to a process for the preparation of a new adsorbent. It is a type 4A synthetic zeolite in which 10 to 20 mol% of the zeolitic cations are exchanged for potassium ions in order to obtain specific application-related properties.

Description

238243 1

VEB CHEMICALS BITTERI ¹ ELD 2246

WP C 10 G / 238 243/1

Process for the preparation of a new adsorbent

Field of application of the invention

The invention relates to a method for producing a new adsorbent for use in insulating glass panes, which are filled with insulating gases.

Characteristic of the known technical solutions

It is known to use adsorbents in insulating glass panes. These adsorbents have the task to remove water vapor or solvent vapors from the space between the panes, but the insulating gases used should not be adsorbed to keep unwanted pressure fluctuations as low as possible.

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WP C 10 G / 238 243/1 Explanation of the essence of the invention

It has been found that a target zeolitic adsorbent is obtained when a zeolite 4A is ion exchanged with KCl, KOH or other solutions containing potassium ions, with a very low supply of K ⁺ ions in a molar ratio

^Ü K ⁺ T = -. fffe ... = 0,1 to 0,2

¹ ^ ⁺

preferably from Tj = 0.12 to 0.15. Tfj means the ratio of the molar concentrations in the ion exchange solution to the molar concentration of sodium ions in the zeolite. The ion exchange is conveniently carried out with stirring and at temperatures between 293 and 363 K. The concentration of potassium exchange solution may be 0.1 to 4 η. The replacement is usually carried out in 1 η solutions, wherein as a starting material washed and filtered or even dried molecular sieve powder can be used. It is also possible that the ion exchange solution is added to the synthesis mixture before or after the crystallization period. The time of ion exchange is 1 to 3 hours, depending on the temperature. The result is a type A zeolite with a share of

* ix ° - o, i bi. o, 2

^K · <* ^Ma Ϊ.Ο1.

238243 1 " ² "

WP C 10 G / 238 243/1

As the adsorbent in the insulating glass panes are known to be silica gels, active alumina (DE-AS 2,538,489), and particularly zeolitic lately molecular sieves of ¹ SJPS 4A or 3A (DE-AS 2,540,997, DE-OS 2,559,720), and mixtures thereof with silica gels or molecular sieves of types X and Y (DD-PS 83 111) used *

While in the application of silica gels or clays only low degrees of drying and adsorption capacities can be achieved, the molecular sieve 4A when used in conjunction with insulating gases undesirable Deflexionserscheinungen, these are pressure fluctuations within the glazing unit, which are caused by adsorption of the insulating gas. Although these are avoided by using the small pore type 3A, it is inevitably necessary to accept the lower water vapor adsorption capacity of this type.

Thus, the disclosed inventions do not represent a real solution, which can achieve a high water vapor absorption capacity, combined with high selectivity in the insulating gas used, for the stated purpose.

Object of the invention

The aim of the invention is the production of a new adsorbent for use in insulating glass panes with insulating gases, which has a high water vapor adsorption capacity and causes the least possible Deflexionserscheinungen.

23 8 2 43] - ⁵ "

WP C 10 G / 238 243/1

Example 2

For the synthesis of Na ⁺ -K ⁺ -A zeolite, 274 ml of sodium waterglass solution (8.9% Wa ₂ O, 27.5% SiO ₃ ) are diluted with 570 ml of water, likewise 476 ml of sodium aluminate solution (20.5 % Na ₂ 0.19.6% Al ₃ O ₃ ) with 657 ml of water. The solutions are mixed with vigorous stirring at 298 K and stirred for a further 15 minutes, and the resulting aluminosilicate gel is crystallized at 353 K for 6 hours. Thereafter, 46 g of KOH are dissolved in 50 ml of water, added to the crystals and stirred for 1 hour. "The thus treated crystallization product can then be filtered off and washed with 1 1 of water. Subsequently, the powder is dried at 393 K.

The product obtained has a KgO content of 12 mol% and a static water vapor adsorption capacity of 22.6 Ma. ~% at 0.6 Torr water vapor partial pressure and 293 K.

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^ ^J Ot ί + Ο I WP G 10 G / 238 243 / f

preferably from ί jy = 0.12 to 0.15, where ί γτ is the molar ratio of the concentration of potassium ions present in the zeolite to the total concentration of cations. (Na + K) in the zeolite. This zeolite powder can then be shaped into spherical granules using the usual binders. It has a higher water vapor adsorption capacity than conventional 3A zeolites and shows no deflexion effects when used in sound insulation panels with corresponding insulating gases, although not yet a complete pore narrowing from 4 to 3 Angstroemeinheiten has been done.

Exemplary embodiments Example 1

375 g zeolite powder of type 4A, calculated anhydrous, are stirred at 303 K with 46 g KOH, which was previously dissolved in 410 ml of water. After 2 hours, the suspension is filtered off and washed with 1.5 1 of water. The zeolite powder is dried at 393K. It has a KgO content of 12.2 mol% and a static water vapor adsorption capacity of 22.9 Ma. % at 0.6 Torr of water vapor partial pressure and 293 K. The output capacity of the 4A powder under the same conditions was 23.15 mass%.

Claims (2)

8 2 43 1 - ⁶ - WP C 10 G / 238 243/1 Inventions Ansprucli A process for the preparation of a new adsorbent for use in insulating glass panes filled with insulating gases which has a high vapor-adsorptive capacity and which does not adsorb the commonly used insulating gases, characterized in that a zeolite of type 4A is stirred for 1 to 4 hours is treated at temperatures between 293 and 363 K with a potassium ion-containing solution whose content of K ions to the cations present in the zeolite has a molar ratio of 0.1 to 0.2 and in a concentration of 0.1 to 2 η is applied. 2. "Process according to item 1, characterized in that the treatment of the zeolite 4A with a solution containing potassium ions with stirring for 1 to 2 hours at 293 to 333 K in a concentration of 1 η and a molar ratio of 0.1 to 0.15 is carried out.