Patent GB-551633-A (GB)
Title: Improvements in and relating to the production of materials containing colloid layers
IPC: G03C1/38
Filed: 1941-08-28
Abstract: 551,633. Wetting agents ; pyridinium compounds. CHILTON, L. V. Aug. 28, 1941. No. 10969. [Classes 2 (iii) and 15 (ii)] [Also in Group XX] In the production of materials containing colloid layers, particularly photographic films, plates, papers, and colour filters, by applying an aqueous dispersion of a colloid, the coating is facilitated by means of a combination of anionactive and kationactive wetting agents, which may be present in substantially chemically equivalent proportions, present during the coating operation at the common surface of the coating composition and the support being coated. A wetting agent in which both the anion and the kation are surface-active mav be produced by reaction between an anionactive and a kationactive wetting agent. The complex wetting agents may be isolated from solutions in which they are formed by centrifuging or by extraction with an organic solvent, e.g. ethyl ether. The combination of wetting agents may be present in the layer to be wetted or in the wetting fluid, or one wetting agent may be in the surface and the other in the fluid. The anionactive wetting agent may be an aliphatic alcohol sulphate, an aliphatic sulphonate, an aromatic sulphonate, a sulphonated taurine derivative, a soap, or a sulphonated castor oil. Specific examples are dodecyl triethanolamine sulphate, dodecyl sodium sulphate. Turkey Red Oil, and the materials known as " Igepon T (Registered Trade Mark), "Aresklene 375," " Lissapol C " (Registered Trade Mark), and " Santomerse D." The kationactive wetting agent may be an alkyl-, aryl-, or aralkylsubstituted ammonium compound or quaternary salt of a heterocyclic nitrogen compound, e.g. dodecyl pyridinium sulphate, hexadecyl pyridinium bromide, and the materials known as " Fixanol " and " Sapamine MS " (Registered Trade Mark). One or more anionactive agents may be used in combination with one or more kationactive agents. The wetting agents may be used in the manufacture and treatment of any materials comprising a support coated with plain, dyed, or pigmented gelatin or other colloid layer or layers, e.g. colour filters. Other colloids may be agar-agar, casein, albumin, alginates, and synthetic colloids. In example 1, a support is coated with a solution of " Fixanol ", dodecyl triethanolamine sulphate, and gelatin in water, and the layer produced, is, after setting, supercoated with gelatin. In example 2, gelatin solutions containing dodecyl pyridinium sulphate and sodium dodecyl sulphate are coated on photographic supports, and the layers produced supercoated with gelatin. In example 3, gelatino silver bromide emulsions containing dodecyl pyridinium sulphate and sodium dodecyl sulphate are coated on glass and supercoated with gelatin. In example 4, a support is coated with a gelatin solution containing dodecyl triethanolamine sulphate, and the resulting layer, when set, .supercoated with gelatin solution containing " Fixanol." The " Fixanol " may be incorporated in the first gelatin solution and the dodecyl triethanolamine sulphate in the supercoating solution. In Example 5, gelatin-coated film is coated with a light-sensitive emulsion containing dodecyl pyridinium dodecyl sulphate or the compound obtained from dodecyl pyridinium sulphate and "Santomerse D " or dodecyl pyridinium oleoylaminoethanesulphonate. In example 6, a solution of hexadecyl pyridinium bromide is mixed with a solution of an alkylated benzenesulphonate, and the coagulated product extracted with ether and used as in Example 5. Dodecylpyridinium dodecylsulphate is prepared by mixing aqueous solutions of dodecyl pyridinium sulphate and sodium dodecylsulphate, and centrifuging the reaction mixture. Dodecylpyridinium oleoylaminoethanesulphonate is similarly prepared. Similar reactions can be effected with dodecylpyridinium sulphate and " Santomerse D" (Registered Trade Mark) and with hexadecylpyridinium bromide and an alkylated benzene sulphonate.