Patent GB-779842-A (GB)
Title: Improvements relating to optical brightening agents and their use
IPC: D06L4/621
Filed: 1955-03-29
Abstract: The invention comprises optical brightening agents of the formula: <FORM:0779842/IV(b)/1> wherein X1 is an organic carboxylic acid radical, a carbamic acid radical, a carbonic acid half ester radical, or a 4.6-diamino-1.3.5-triazinyl radical the amino groups of which can be organically substituted, X2 is a 4.6-diamino-1.3.5-triazinyl radical, the amino groups of which can be organically substituted, an arylcarbamyl radical, or an aryl radical, one Y represents the sulpho group or a salt thereof, the other being hydrogen or a non-ionogenic substituent, and wherein the benzene rings of the stilbene radical may contain further non-ionogenic substituents.  They are made by treating the corresponding stilbene compounds in which one or both X's represent hydrogen with an acid halide or anhydride of carboxylic acids, carbamic acids or carbonic acid half esters or with cyanuric halides, replacing all the halogen substituents in any triazinyl rings by amino or substituted amino.  The starting materials may be prepared according to Specification 668,199 by condensation of 4-nitrotoluene-2-sulpho-aryl esters with 4-nitro- or 4-acylaminobenzaldehydes to give the stilbene-2-sulpho-aryl ester which is saponified.  The 4-1-acylamino-4-nitrostilbene-2-sulphonic acids may be saponified to the 41-amino body, which may be differently acylated before and after reduction of the nitro group if unsymmetrical products are desired, or acylated after such reduction to give symmetrical bodies.  The products may be distributed, in the form of their salts (e.g. lithium, potassium, sodium or ammonium) on white substrata such as cellulose fibres, soaps, synthetic washing agents, and nylon fibres.  In examples: (1) 4.41-diamino-21-ethoxystilbene-2-sulphonic acid is acylated with 2 mols. p-methoxybenzoyl chloride; (2) 4.41-diamino-21-(b  - hydroxyethoxy) - stilbene - 2 - sulphonic acid is reacted with 2 mols. cyanuric chloride and then with aniline and N-methyl monoethanolamine; (3) 4.41-diamino-21-methylstilbene-2-sulphonic acid is reacted with 2 mols. p-methoxybenzoyl chloride; (4) 4.41-diamino-21-methoxy- or ethoxy-stilbene-2-sulphonic acid is reacted two mols. cyanuric, chloride and then with metanilic acid, and N-methyl-monoethanolamine; (5) 4.41-diamino-21-methoxystilbene - 2 - sulphonic acid is reacted with 2 mols. phenyl isocyanate or with 2 mols. cyanuric chloride and then with ethanolamine and ethylamine; (6) 4.41-diamino-21-methylstilbene-2-sulphonic acid is condensed with 2 mols. cyanuric chloride and then with ethanolamine and with N-methyl-ethanolamine, or with diethanolamine only; (7) 4-amino-41-acetamino-21 - benzyloxystilbene - 2 - sulphonic acid is reacted with one mol. cyanuric chloride and then with N - methyl - ethanolamine; (8) 4 - amino-41 - nitro - 2 - methoxystilbene - 21 - sulphonic acid is condensed with one mol. p-methoxy benzoylchloride, the nitro group is reduced, and further condensation effected with cyanuric chloride, followed by diethanolamine; (9) 4.41-diamino - 2 - methylsulphonyl - stilbene - 2-sulphonic acid is condensed with 2 mols. cyanuric chloride followed by ethanolamine.  Alternative reactants are specified.  Examples describe the whitening of cotton poplin and other washing.ALSO:Brightening agents for distribution on more or less white substrata, such as cellulose and nylon fibres, in a content of 0.001-0.1 per cent, comprise the alkali salt (e.g. sodium, potassium, lithium, or ammonium) of stilbene monosulphonic acids of the formula: <FORM:0779842/IV(b)/1> wherein X1 represents an organic carboxylic acid radical, a carbamic acid radical, a carbonic acid half-ester radical. or a 4, 6 - diamino - 1, 3, 5 - triazinyl radical, the amino groups of which may be organically substituted, X2 represents a 4, 6 diamino - 1, 3, 5 - triazinyl radical, the amino groups of which may be organically substituted, an arylcarbamyl radical, or an aroyl radical, one Y is sulpho or a salt thereof, the other Y is hydrogen or a non-ionogenic substituent, and wherein the benzene rings may contain further non-ionogenic substituents (see Group IV(b)).  Examples describe the use of such compounds in whitening cotton poplin and other washing.