Forte Photochemical Industry

Chinoin Gyogyszervegyeszeti Gyar

Forte Fotokemial Idpar

Miklos Szucs

Jozsef Szejtli

Laszlo Toke

Istvanne Palotas

Laszlo Fenichel

Janos Becso

Peter Bako

Judit Csaplaros

Eva Fenyves

The invention relates to a novel process for the chemical sensitization of silver halide photographic emulsions. The process according to the invention comprises adding as additional sensitizing agents a 40-260 .mu. moles/mole of a cyclic polyether containing 1 nitrogen and 5 oxygen atoms, or 2 nitrogen and 4 oxygen atoms, or 3 nitrogen and 3 oxygen atoms, or 4 nitrogen and 2 oxygen atoms as well as 12 carbon atoms and/or their complexes formed with gold and/or palladium and optionally 40-260 .mu. moles/mole of silver halide) of gold (I) or gold (III) sulfide to the sulfur-sensitized emulsion, and employing the cyclic polyether in relation to the noble metal salt in a molar ratio of 0.5:1-5:1 for the complex formation.

Process for the chemical sensitization of silver halide photographic

The invention relates to a process for removing nucleic acids and purine bases from gelatine by (a) adding cyclodextrin bead polymer having a particle size of 20 to 600 .mu., a cyclodextrin content of 30 to 70% and a polyvinyl alcohol content of 0.3 to 0.5% to the gelatin solution in a weight ratio of 1:1 to 10:1 calculated on the amount of the gelatin then filtering off the cyclodextrin polymer or (b) passing the gelatin solution through a cyclodextrin bead polymer column, whereby the amount of the gelatin is 5 to 50% of the weight of the column charge, then eluting the nucleic acids and the purine bases from the cyclodextrin bead polymer.

Process for removing nucleic acids and purine bases from gelatin

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Budapest, Hungary

Miklos Szucs