Patent GB-310773-A (GB)
Title: Improvements in the production of pattern and like effects upon materials made of orcontaining cellulose esters
IPC: G03C1/76
Filed: 1928-01-30
Abstract: 310,773. British Celanese, Ltd., and Ellis, G. H. Jan. 30, 1928. Diazotype processes.-Photographic or pattern effects are produced upon fabrics, films, or other materials made of or containing cellulose esters by incorporating one or more diazotizable amines in the material, diazotizing, exposing to the action of light of locally varying intensity corresponding to the desired effect, and fixing the effect by development. Amines specified as suitable for use alone or in admixture are pnitraniline, p-nitro-o-anisidine, m-nitro-p-toluidine, m-nitro-o-anisidine, p-chloraniline, a-naphthylamine, benzidine, dianisidine, and p-aminobenzeneazo-a-naphthylamine, and developers specified as suitable for use alone or in admixture are a- or #-naphthylamine, dimethylaniline, mphenylenediamine, a- or #-naphthol, phenol, #- oxynaphthoic acid, p-xylidine, aminonaphthols, and acetoacetic ester. The amines are preferably applied by immersing the material in an aqueous solution of the free base or of a salt thereof or in an aqueous dispersion obtained, e.g. by colloid grinding with or without dispersators or protective colloids, by dissolving in a solvent and pouring into water containing, if desired, dispersators or protective colloids, or by the methods of Specifications 219,349, 224,925. 242,393, 242,711, 269,960, 273,819, or 273,820, [all in Class 15 (ii), ing, Processes &c. for]. Altematively the bases may be applied in solution in an organic solvent such as trichlorethylene or may be incorporated in the solution of the cellulose ester employed in the manufacture of the films, filaments, etc. The diazotization is preferably effected under conditions of subdued, coloured, or excluded light, whereupon the material is preferably dried in the cold. Such dried material may be stored for future exposure and development. The exposure is effected by the use of a camera to produce an image on the material or by the use of a photographic positive or negative or of a stencil. Colouring of the background may be effected by suitable dyeing preceding or following the production of the photographic or pattern effects. The following examples are specified. (1) A bright, scarlet photograph on a pale cream ground is produced on a satin fabric woven from cellulose acetate yarns by treatment for 1¢ hrs. at 80‹ C, in a bath containing dianisidine dispersed with sodium sulphoricinoleate, diazotization, drying, exposure to light passed through a transparent photographic positive, and development .with m-phenylenediamine. (2) A bright bluish red design or photograph on a buff ground is produced on a fabric woven from cellulose acetate yarns by treatment for 1¢ hrs. at 80‹ C. in a bath containing 5-nitro-2-anisidine dispersed with sodium sulphoricinoleate, diazotization, drying, exposure to light passed through a stencil or a transparent photographic positive, and development with 2 : 3-oxynaphthoic acid. (3) A purplebrown design or photograph on a pale buff ground is produced on a fabric woven from cellulose acetate yarns by treatment with a dispersion of dianisidine, diazotization, and drying as in (1), exposure to light passed through a stencil or a transparent photographic positive, and development with a mixture of dimethylaniline and 2 : 3- oxynaphthoic acid.