Patent GB-991205-A (GB)
Title: Improvements relating to the stabilisation of organic materials which are sensitive to light and oxidation
IPC: C07D249/20
Filed: 1962-06-15
Abstract: Substituted 2 - (21 - hydroxyphenyl) - benztriazoles of the general formula <FORM:0991205/C2/1> wherein X represents a divalent aliphatic, cycloaliphatic, araliphatic or aromatic radical, possibly including the carboxylic acid ester or amide group; R1 represents hydrogen or a carboxylic acid alky ester or, if Y is a secondary or tertiary amino group, a carbonyl group bound to the latter; R2 and R3 independently represent hydrogen or a C1 to C6 alkyl group; Y represents oxygen or a secondary or tertiary amino group both having two separate bonds, the latter possibly substituted by alkyl, cycloalkyl or aralkyl; Z represents an alkyl, cycloalkyl aralkyl or aryl group possibly substituted by hydroxyl or free or esterified carboxyl groups; and n is 1 or 2 and wherein the nucleus can be substituted at the 4, 5 and 6 positions by alkyl, alkoxy, carboxyl, carboxylic acid ester or amide, sulphonic acid amide, alkylsulphonyl groups or halogens and at the 31, 41 and 51 positions by alkyl, cycloalkyl, aralkyl, aryl and alkoxy groups or halogen, and wherein the grouping <FORM:0991205/C2/2> is bound to the 4, 5, 6, 31, 41 or 51 positions, are incorporated into light and oxidation sensitive organic materials to stabilize them. These compounds may be produced by (1) reduction, e.g. with zinc dust in an alkaline medium, of a 2-nitro-21-hydroxy-1,11-azobenzene compound containing at least one b -thioalkylcarbonyl group; (2) oxidation, e.g. with cupric salts in a neutral or alkaline medium, of a 2-amino-21-hydroxy-1,11-azobenzene compound containing at least one b -thioalkylcarbonyl group; and (3) introduction of the b -thioalkylcarbonyl group into a 2-(21-hydroxyphenyl)-benztriazole compound by, for example (a) adding an a -b  unsaturated carbonyl compound to a reactive mercapto group which is a substituent of the benztriazole; (b) adding a mercaptan to an a -b  unsaturated carbonyl group in the benztriazole; (c) reaction of a reactive halide with a b -carbonyl-mercapto group in the benztriazole; (d) acylation of a hydroxy or amino-2-(21-hydroxyphenyl)-benztriazole with a reactive derivative of b -thiopropionic acid, e.g. b -alkylmercaptopropionic acid chlorides; or (e) direct substitution of the aromatic ring of the benztriazole by compounds containing b -thioalkylcarbonyl groups, e.g. the methylol compound of b -alkylmercaptopropionic acid amide. Specification 991,204 is referred to.  Reference has been directed by the Comptroller to Specification 878,362.ALSO:Synthetic and natural polymers are stabilized against light by the incorporation, usually as 0.001 to 5% by weight, therein of 2-(21- hydroxy phenyl) benztriazoles of the general formula <FORM:0991205/C3/1> wherein X represents a divalent aliphatic, cycloaliphatic, araliphatic or aromatic radical, possibly including the carboxylic acid ester or amide group; R1 represents hydrogen or a carboxylic acid alkyl ester or, if Y is a secondary or tertiary amino group, a carbonyl group bound to the latter; R2 and R3 independently represent hydrogen or a C1 to C6 alkyl group; Y represents oxygen or a secondary or tertiary amino group, both having two separate bonds, the latter possibly substituted by alkyl, cycloalkyl or aralkyl; Z represents an alkyl, cycloalkyl, aralkyl or aryl group possibly substituted by hydroxyl or free or esterified carboxyl groups; and n is 1 or 2, and wherein the nucleus can be substituted at the 4, 5 and 6 positions by alkyl, alkoxy, carboxyl, carboxylic acid ester or amide, sulphonic acid amide, alkylsulphonyl groups or halogens and at the 31, 41 and 51 positions by alkyl, cycloalkyl, aralkyl, aryl and alkoxy groups or halogen, and wherein the grouping <FORM:0991205/C3/2> is bound to the 4, 5, 6, 31, 41 or 51 positions. Specified polymers are the polymers and copolymers of ethylenically unsaturated monomers, polyacrylic compounds, polyesters, polyamides, polyester resins, cellulose and cellulose esters and ethers.  Specification 991,204 is referred to. Reference has been directed by the Comptroller to Specification 878,362.ALSO:Lacquers used to protect light-sensitive materials from light contain at least one 2(-21-hydroxy phenyl) benztriazoles of the general formula <FORM:0991205/C4-C5/1> wherein X represents a divalent aliphatic, cycloaliphatic, araliphatic or aromatic radical, possibly including the carboxylic acid ester or amide group; R1 represents hydrogen or a carboxylic acid alkyl ester or, if Y is a secondary or tertiary amino group, a carbonyl group bound to the latter; R2 and R3 independently represent hydrogen or a C1 to C6 alkyl group; Y represents oxygen or a secondary or tertiary amino group both having two separate bonds, the latter possibly substituted by alkyl, cycloalkyl or aralkyl; Z represents an alkyl, cycloalkyl, aralkyl or aryl group possibly substituted by hydroxyl or free or esterified carboxyl groups; and n is 1 or 2 and wherein the nucleus can be substituted at the 4, 5 and 6 positions by alkyl, alkoxy, carboxyl, carboxylic acid ester or amide, sulphonic acid amide, alkylsulphonyl groups or halogens and at the 31, 41 and 51 positions by alkyl, cycloalkyl, aralkyl, aryl and alkoxy groups or halogen, and wherein the grouping <FORM:0991205/C4-C5/2> is bound to the 4, 5, 6, 31, 41 or 51 positions. The actinic agent is advantageously present as 10-30% by weight of the protective coating material for coatings of less than 0.01 mm. thickness and 1-10% for coatings of 0.01 mm. thickness. Specification 991,204 is referred to.  Reference has been directed by the Comptroller to Specification 878,362.