SU138489A1 - The method of obtaining film filters of copper salts - Google Patents

Description

To obtain light-resistant film filters with a given spectral characteristic, it is necessary that the corresponding dyes or pigments are well matched with the film-forming light filter.

Light-resistant organic dyes and pigments that completely absorb radiation in the long-wave red part of the spectrum are still not sufficiently known. At the same time, inorganic ion-built compounds, such as copper salts, are known to possess these properties. However, these compounds are not soluble in organic solvents and are not compatible, for example, with a film of cellulose ethers.

It has been found that, using the copper salts (soap) of unsaturated fatty acids as a coloring agent, it is possible to obtain preparations that are capable of dissolving in organic solvents and at the same time combined with cellulose ethers.

Based on these observations, a new method of obtaining film filters from copper salts absorbing the red and near infrared spectral regions has been developed, which consists in using cellulose ethers as a binder to increase the mechanical strength and moisture and light resistance of filters for example ethyl cellulose, and unsaturated aliphatic acid copper salts are used as a coloring agent.

When producing filters by the method described, cellulose ethers and copper salts of unsaturated fatty acids are dissolved separately in a nonpolar organic solvent, for example, in benzene; the solutions are mixed and the resulting homogeneous mixture is poured over a smooth surface, for example a plate glass, and then dried to form a film on it.

No. 138489-2 -

Example. The manufacture of a green light filter with a transmission maximum of T is 80% at L 490-500 m / i and full absorption of long-wave radiation in the region A, 620-730 mk.

To a solution of 5 g of oleic acid in 20 ml of alcohol is added 20 ml of an alcoholic 10% solution of copper nitrate. The resulting mixture in a separating vorokke under a layer of benzene is treated with 22 ml of a seminormal alcoholic KOH solution and the copper salt (soap) of oleic acid is extracted with benzene. The benzene layer is washed twice with 10% sodium chloride solution, dried with anhydrous sodium sulfate and the solvent is distilled off. The content of copper salt in the resulting preparation is determined by the Bruns-Koltgoff method.

For the removal of films, ethylcellulose purified by fractionation is used in the form of an 8–8.5% benzene solution mixed with alcohol (97 parts of benzene and 3 parts of alcohol).

A calculated amount of copper soap is added to a measured amount of ethyl cellulose solution; shake the mixture until dissolved and filter. The filtered solution is allowed to settle from the air bubbles and films are obtained from it, which are dried at 20-25 °.

The concentration of copper soap required to obtain a light filter with a given characteristic is calculated from the measurement data of a benzene solution of copper salt according to the Lambert-Beer law.

In a similar way, using a copper salt (soap) of ricinolic acid, a green light filter is obtained with a full absorption of radiation at. 630-670 MMK.

Subject invention

Claims (2)

1. A method for producing film filters of copper salts that absorb the red and the nearest infrared spectral region, characterized in that, in order to increase the mechanical strength and moisture and light resistance of the filters, cellulose ethers, such as ethyl cellulose, are used as a binder, Copper salts of unsaturated aliphatic acids are used as a coloring agent. 2. A method according to claim 1, wherein cellulose ethers and copper salts of unsaturated fatty acids are dissolved separately in a nonpolar organic solvent, for example benzene, the solutions are biased and the smooth surface, for example, glass, then dried to form a film on it.