Patent GB-730555-A (GB)
Title: Improvements in or relating to fluorescent compositions
Inventor: GAUNT THOMAS NORMAN
IPC: C09D5/22
Filed: 1950-09-28
Abstract: Fluorescent composition comprises a soluble alkyd resin mixed with a basic dyestuff or mixture of basic dyestuffs present in a concentration of 0.05 to 2 per cent, based upon the weight of solid resin, a white or colourless absorbent material for the dyestuff of low refractive index selected from the group consisting of silica, alumina, complex silicates and complex aluminates, and a solvent consisting of a ketone, an ester, an ether, an alcohol, an aromatic hydrocarbon, a nitroparaffin or a mixture thereof.  The absorbent material can form 5 per cent to 50 per cent, by weight of the total composition.  The dyestuff may be Acronol Yellow TC, Acridine Orange R, Auramine O, Auramine G, Fluorescein, Roseine, Malachite Green, Rhodamine 6G, Rhodamine B or Astraphloxin FF.  The soluble alkyd resins may be derived from polybasic acids such as phthalic, maleic, succinic, adipic and sebacic acids with ethylene glycol, glycerol and pentaerythritol. Paralac 385 (Registered Trade Mark) is preferred. One or more inorganic or organic extenders, for example corn starch or wax, may be added to the composition.  In one example for preparing a printing ink 1 kilo. of Paralac 385 is fused to a temperature of 160 DEG  C., 6 grs. of Rhodamine BN450 added, the mixture is cooled to 120 DEG  C. and 7000 cc. of ethylene glycol monomethyl ether and 700 grs (300 grs. according to the Provisional Specification) of finely divided silica commercially known as Standard Neosyl added. In another example the Rhodamine BN450 is replaced by a mixture of 4.25 grs.  Rhodamine BN450, 4.25 grs. Rhodamine 6G 500 and 10 grs. Acronol Yellow TC. Conc.  Specifications 524,854, [Group XL], and 608,725, [Group XL (a)], are referred to. The Provisional Specification states also that the composition is capable of daylight fluorescence and that Eosine, Brilliant Sulphoflavine FF, Sulpha Rhodamine, Primuline, Duranol Brilliant Yellow 6G, Waxoline Yellow O, Waxoline Orange AS and Durindone Pink FB can also be used as dyestuffs which are added to lacquers formed from ethyl cellulose, cellulose acetate, nitrocellulose, cellulose aceto-butyrate, polyvinyl acetate, polyvinyl butyral, polyvinyl formal, polyvinylidene chloride, polymethyl methacrylate, cyclohexanone formaldehyde, zein, shellac, aqueous urea formaldehyde condensates, spirit soluble urea formaldehyde condensates, melamine formaldehyde condensates, oil modified alkyd resins and alkyd resins. Mixtures of two or more resins can be used and the resins plasticized.  The resins are treated with the dyes in solution, and in some cases are treated in the form of emulsions.  The compositions may be treated with small quantities of copper salts or phosphomolybdotungstic acid to improve the light fastness. Non-fluorescent colouring materials may be added. Instead of being used as an ink the divided powder may be dusted over a suitable printed size.  The alkyd resin may be made harder by addition of a small quantity of ethyl cellulose which makes it possible to grind the resin extremely finely.