Patent GB-942935-A (GB)
Title: Photographic silver halide emulsions of increased sensitivity
IPC: C08G63/688
Filed: 1959-12-11
Abstract: The Specification describes linear thiopolyesters of molecular weight at least 350 being free from disulphide linkages or mercapto substituents and having recurring units of the general formula: <FORM:0942935/C2/1> wherein R, R1, R2 and R3 are alkylene groups of 1 to 10 carbon atoms, s is 0 and m is 1, 2 or 3, or s is 1 and d and m are 0 to 3 (provided that d and m are not both 0). They may be prepared by condensing a glycol with a dicarboxylic acid or an anhydride or ester thereof, at least one of which contains a thioether group. Glycols used are 3-thiapentane -1;5-diol, 3;6- dithia-octane-1;8-diol, 4;10-dithia-tridecane -1;13-diol, 4;15-dithia-octadecane-1;18-diol 7:13-dithianonadecane -1;19-diol, 7;18-dithiatetracosane -1;24-diol-4;8 - dithia - undecane - 2;10 - diol, 3-thiahexane-1;6-diol, 4-thiaheptane-1;7-diol, 3-thianonane-1;9-diol or ethylene glycol. Dicarboxylic acids or anhydrides used are succinic, glutaric, adipic, azelaic, sebacic, pimelic, suberic, 3-thiapentane -1;6-dicarboxylic, 2;5-dithiahexane, -1;6-dicarboxylic, 2;6-dithiaheptane -1;7-dicarboxylic, 2;7-dithia-octane-1;8-dicarboxylic, 2 - thiabutane - 1;4-dicarboxylic, methylene-bismercapto-acetic or 2;2-dimethyl-glutaric acid. Examples also are given of the condensation of 3-thiapentane-1;5-diol with diethyl oxalate, diethyl malonate, diethyl succinate or dimethyl adipate in the presence of titanium butoxide. The thiopolyesters also may be obtained by reacting a compound of the formula: HS(-R2-S)x with a compound of the formula: CH2=CH (-CH2)q-Z-(CH2)q-CH=CH2 where R2 is as defined above, q ir 0 or 1, x is 1 or 2 and z is a diacyloxy residue of an aliphatic dicarboxylic acid. Thus ethane -1;2-diol may be reacted with divinyl succinate, diallyl adipate, diallyl sebacate or diallyl succinate under the unfluence of U.V. light. The thiopolyesters may have some or all of their thioether groups converted to ternary sulphonium salt groups by reaction with dimethyl sulphate, diethyl sulphate, methyl benzene sulphonate or methyl p-toluene sulphonate. Specifications 235,211, 541,589, 636,140, 719,920, 791,219, 942,931, 942,932, 942,934, U.S.A. Specifications 2,347,182 and 2,948,614 are referred to.ALSO:The Specification describes linear thiopolyesters of molecular weight at least 350 being free from disulphide or linkages mercapto substituents and having recurring units of the general formula: <FORM:0942935/C3/1> wherein R, R1, R2 and R3 are alkylene groups of 1 to 10 carbon atoms, s is 0 and m is 1, 2 or 3, or s is 1 and d and m are 0 to 3 (provided that d and m are not both 0).  They may be prepared by condensing a glycol with a dicarboxylic acid or an anhydride or ester thereof, at least one of which contains a thioether group.  Glycols used are 3-thiapentane -1;5-diol, 3;6-dithia-octane -1;8- diol, 4;10- dithia-tridecane -1;13- diol, 4;15- dithia-octadecane -1;18-diol, 7;13-dithianonadecane -1;19-diol, 7;18-dithiatetracosane -1;24-diol, 4;8- dithia-undecane- 2;10-diol, 3thiahexane -1;6-diol, 4-thiaheptane -1;7-diol, 3-thianonane -1;9-diol or ethylene glycol.  Dicarboxylic acids or anhydrides used are succinic, glutaric, adipic, azelaic, sebacic, pimelic, suberic, 3-thiapentane -1;6-dicarboxylic, 2;5-dithiahexane-1;6-dicarboxylic, 2;6-dithiaheptane -1;7dicarboxylic, 2;7-dithia-octane -1;8-dicarboxylic, 2-thiabutane -1;4-dicarboxylic, methylene-bismercapto-acetic or 2;2-dimethyl-glutaric acid. Examples also are given of the condensation of 3-thiapentane -1;5-diol with diethyl oxalate, diethyl malonate, diethyl succinate or dimethyl adipate in the presence of titanium butoxide. The thiopolyesters also may be obtained by reacting a compound of the formula: HS(R2-S)xH with a compound of the formula: CH2=CH (-CH2)q-Z(-CH2)q-CH=CH2 where R2 is as defined above, q is 0 or 1, x is 1 or 2 and Z is a diacyloxy residue of an aliphatic dicarboxylic acid.  Thus ethane -1;2-diol may be reacted with divinyl succinate, diallyl adipate, diallyl sebacate or diallyl succinate under the influence of U.V. light. The thiopolyesters may have some or all of their thioether groups converted to ternary sulphonium salt groups by reaction with dimethyl sulphate, diethyl sulphate, methyl benzene sulphonate a methyl p-toluene sulphonate. Specifications 235,211, 541,589, 636,140, 719,920, 791,219, 942,931, 942,932, 942,934, and U.S.A. Specifications 2,347,182 and 2,948,614 are referred to.