Improvements relating to ª¤-hydroxyphenyl-s-triazines and their use

New o-hydroxyphenyl-s-triazines of formula <FORM:1011575/C3/1> in which X and Y are hydrogen, alkyl, alkenyl, cycloalkyl or aralkyl groups which may be substituted, R1 represents hydrogen, or an alkyl, alkenyl or aralkyl group which may be substituted and the benzene nucleus A may be further substituted in the 31 and 51 positions by C1-C10 alkyl or alkenyl groups, are used for improving the stability of light-sensitive organic materials. They may be incorporated, for example, in thermoplastic or thermosetting addition or condensation polymers, e.g. (a) homopolymers and copolymers of vinyl and vinylidine compounds, epoxides, particularly bis-epoxides, lactams and lactones, and aldehydes; (b) reaction products of isocyanates with hydroxyl and/or amino compounds or with polyesters and/or polyethers; (c) linear condensation products derived from dicarboxylic acids and dihydroxy compounds; (d) crosslinked polycondensates obtained by the condensation of aldehydes with compounds such as phenols, ureas and melamines; (e) condensation polymers subsequently cross-linked by addition polymerization, e.g. copolymers of polyesters of unsaturated carboxylic acids with polyhydric alcohols modified by dicarboxylic acids or vinyl or vinylidine monomers. They may also be incorporated in natural polysaccharides which may be modified such as cellulose and cellulose esters. Examples are given of the use of the new compounds in stabilizing the following compositions:-(a) cellulose acetate films; (b) a polyester resin produced by adding a mixture of maleic anhydride and tetrachlorophthalic acid anhydride (or phthalic anhydride) to a mixture of ethylene glycol and diethylene glycol and treating the polyester so produced with styrene or methyl methacrylate; (c) methylmethacrylate polymerized in the presence of lauroyl peroxide; (d) a copolymer of polyvinyl chloride and dioctyl phthalate; (e) polyethylene or polypropylene; (f) polycaprolactam and polyhexamethylene adipamide; and (g) a lacquer comprising cellulose acetobutyrate, dimethyl glycol phthalate, methyl alcohol and acetone.ALSO:The invention comprises compounds of the general formula IV <FORM:1011575/C2/1> in which X and Y are the same or different and represent hydrogen or an alkyl, alkenyl, cycloalkyl or aralkyl group which may be substituted, R1 represents hydrogen or an alkyl, alkenyl or aralkyl group which may be substituted and the benzene ring A may be further substituted in the positions 31 and 51 by C1-C10 alkyl or alkenyl groups. X and Y may be, for example, alkyl substituted by hydroxy, alkoxy, alkyl mercapto, amino, alkylamino or halogen radicals; alkenyl groups which may be substituted by phenyl groups such as syrtyl and 2 - phenyl - propen - (1) - yl - (1)-; cycloalkyl groups having 5-10 carbon atoms; or an aralkyl group which may be substituted on the aryl nucleus by alkyl, chloro or methoxy radicals. R1 is preferably an alkyl group having 1-12 carbon atoms and may be substituted, for example, by halogens, free or etherified hydroxy groups, free or modified carboxylic groups such as an amide group, or a cyano group. The new compounds may be prepared by heating together equimolar amounts of an amidine of formula <FORM:1011575/C2/2> an amidine of formula <FORM:1011575/C2/3> and an o-hydroxybenzene carboxylic ester of Formula III. <FORM:1011575/C2/4> The reaction is preferably carried out in a boiling organic solvent, e.g. an alcohol, ethylene glycol monomethyl or monoethyl ether, or dioxan. If desired, reactive substituents present in the new o-hydroxyphenyl-s-triazines may subsequently be altered. If X or Y is an alkoxyalkyl group it may be converted with hydrobromic acid into a bromoalkyl group; halogen may be replaced by a hydroxy group, an ether group or an amino group by reaction with aqueous sodium hydroxide, an alkali alcoholate or phenolate, or ammonia or a primary or secondary amine respectively; or an alcoholic or phenolic hydroxy group may be esterified or etherified. Examples are given of the preparation of 2-(21,41-dihydroxyphenyl)-4,6-dimethyl-s-triazine and the corresponding 4,6-dinonyl, dicyclohexyl, dibenzyl, didecyl, diheptadecyl, di - 31 - methylcyclohexyl, di - 41 - chlorobenzyl, di - (D - methoxyethyl), di - (D - dimethylaminoethyl), di - (b - carboxyethyl), di - (carboxymethyl), di(methoxycarbonylmethyl) and di-(octonycarbonylmethyl) - s - triazines; 2 - (21,41-dihydroxyphenyl) -s-triazine; 2-(21-hydroxy-41-ethoxyphenyl) - 4,6 - dipropyl - s - triazine; 2-(21 - hydroxy - 41 - allyloxyphenyl) - 4,6 - dimethyl-s-triazine of the corresponding compounds in which the 41-alkyloxy group is replaced by 41-benzyloxy, 41-methoxy, 41-decyloxy, 41 - b - methoxyethoxy, carboxymethoxy and carbethoxymethoxy groups; 2-(21-hydroxy - 41 - methoxyphenyl) - 4,6 - bis - b -phenylvinyl - s - triazine; 2 - (21 - hydroxy - 41 - ethoxyphenyl - 4,6 - dibutyl - s - triazine; 2 - (21,41-dihydroxy - 31 - methylphenyl) - 4,6 - dibutyl-s-triazine; 2 - (21,41 - dihydroxy - 51 - tert - butylphenyl) - 4,6 - dibutyl - s - triazine; and 2-(21,41 - dihydroxy - 51 - allylphenyl) - 4,6 - dibutyl-s-triazine.