GB874236A - Bacteriostatic esters of substituted hydroxybenzoic acids - Google Patents

Abstract

Bacteriostatic esters of formula: <FORM:0874236/IV (a)/1> wherein R is a branched chain alkyl group having eight or more carbon atoms and R1 and R2 are hydrogen (but not both hydrogen), a halogen atom or an alkyl group, and their salts (see Group IV(b)) may be incorporated in thermoplastic resins such as polystyrene, polyvinyl chloride and polyethylene and thermosetting resins, for example, phenol- or melamineformaldehyde resins. Amounts of 0,05%-5,0% by weight may be used, for instance by adding the ester to a granular resin before moulding.ALSO:The invention comprises aliphatic esters of p-hydroxybenzoic acids of formula:- <FORM:0874236/IV (b)/1> wherein R is a branched chain alkyl group having eight or more carbon atoms and R1 and R2 are hydrogen (but not both hydrogen), a halogen atom or an alkyl group, and their salts. They are used as bacteriostats in various compositions (see Groups III, IV(a) and VI). The esters are prepared by halogenation of the corresponding unsubstituted ester or by esterification of a suitable acid with a branched-chain alkanol. A number of suitable acids and esterifying radicals are specified. Sodium and potassium salts of the esters are mentioned. Specified esters are 2-methylheptyl 31-chloro-p-hydroxybenzoate, 2 : 2 - dimethylhexyl 31:51-dichloro-p-hydroxybenzoate, 2:5:5-trimethylhexyl-21-methyl-p-hydroxybenzoate, 2-methyloctyl 21:61-dimethyl-p-hydroxybenzoate and 2:2:4:4-tetramethylbutyl 21 - methyl - 51 - bromo-p-hydroxybenzoate. In examples, 2-ethylhexyl 31-chloro-, -bromo- and -iodo-p-hydroxybenzoates and 3:5:5-trimethylhexyl 31-chloro-p-hydroxybenzoate are prepared by halogenation of the unsubstituted esters.ALSO:Bacteriostatic esters of formula:-<FORM:0874236/III/1> wherein R is a branched chain alkyl group having eight or more carbon atoms and R1 and R2 are hydrogen (but not both hydrogen), a halogen atom or an alkyl group, and their salts (see Group IV(b)) may be incorporated in soaps, such as common and potassium soaps, and waxes, for example beeswax, carnauba wax and paraffin wax. They may be added to the liquid soap or wax in amounts of about 0.05 to 5.0%.ALSO:Bacteriostatic compositions comprise compounds of formula <FORM:0874236/VI/1> wherein R is a branched-chain alkyl group having eight or more carbon atoms and R1 and R2 are hydrogen (but not both hydrogen), a halogen atom or an alkyl group, and their salts (see Group IV(b)). The compositions are liquid (e.g. solutions, dispersions and emulsions) and solid (e.g. using talc as diluent). In an example the bacteriostatic action of aqueous solutions of 2-ethylhexyl 31-chloro-, -bromo- and -iodo-p-hydroxybenzoates and 3 : 5 : 5-trimethylhexyl 31-chloro-p-hydroxybenzoate is described.