Molecular structures and electronic states of merocyanine dyes adsorbed on AgBr grains have been examined on the basis of their visible and infrared spectra. The conclusion is that the contribution of the ionic form to the resonance structure of a merocyanine dye molecule is greater on the surface of AgBr than in its simple crystal and in organic solvents used in this work. The fact is well explained by the interaction of anionic oxygen and cationic nitrogen atoms in the dye molecule with Ag⁺ and Br^- on the surface of AgBr grains, respectively. No evidence has been obtained for the presence of the strong interaction between C =S in the dye molecule and Ag⁺ on the surface of AgBr crystals.

抄録全体を表示

Effects of about one hundred seven membered ring compounds on photographic silver halide emulsions have been studied. Many of them have been found to show marked desensitization, inhibition of print-out effect and sensitization of the

抄録全体を表示

Gelatin obtained from steer hide collagen pretreated with a solution containing sodium hydroxide, sodium sulfate and an amine, was studied by disc electrophoresis.
The gelatin derived from collagen which had been treated for 2 weeks with 3% sodium hydroxide containing 0.2 M monomethylamine and sodium sulfate consistedmostly of α components which appeared as two bands. Their colour densities, however, were almost identical to each other, unlike the normal collagen pattern which shows a ratio of two al to one α2. When pretreatment conditions were milder, the gelatin exhibited either two less clearly resolved α bands or one diffuse one with a shorter migration distance.
The distribution of molecular species, i. e., α, β, γ and higher-molecular-weight components of the gelatin, can be semi-quantitatively determined by this method.

抄録全体を表示

A part of persulphate, which is added as a initiater of copolymerization of acrylamide, acrylic acid and vinylimidazole, remains in the polymer, and it causes serious fog to the photographic emulsion, especially when the oxidisable substances, such as citric acid, glycine etc., were present in the emulsion. Higher the pH or silver ion concentration of the emulsion, the fog density becomes higher.
The most convenient method of the preparation to remove the fog, is to add N-substituted aniline derivatives into the copolymer solution. This method also improves the reproduceability of the photographic properties of the polymers.
Relation between the composition of the copolymers, prepared by this method, and the restraining power for physical ripening of AgC1 precipitate, were also investigated.

抄録全体を表示

Effect of Rh.., Pb. and Cd. on the photographic properties of AgC1 emulsion, in which the copolymer of acrylamide, acrylic acid and vinylimidazole, was used as a protective colloid, was investigated and compared with that of gelatin emulsion, which was made by the same formula.
Effect of Rh.. appears similarly in any polymer or gelatin emulsion, while the effects of Pb. and Cd. change according to the kind of protective colloid.
Action of Pb.. is affected more strongly by carboxylic groups in polymer, than by imidazole groups. Action of Cd. is affected strongly by imidazole group, and carboxyl group has little influence.
It is considered that Rh.. affects the properties of emulsion, acting directly to AgCl grains, and Pb. and Cd. act in combination with polymers. In this case, Pb. combines strongly with carboxyl group in the polymer molecules, and Cd.. forms coordinate compound with imidazole group.
Photographic properties of AgCI-synthetic polymer emulsion show very sharp change at a certain pH value or Cl^- ion concentration.

抄録全体を表示

Removal of bromide from photographic color developer by means of electrodialysis was examined for the purpose of the recovery of exhausted developer. As diaphragms of dialysis, commercial ion-exchange membranes, Selemion CMV, CSG (cation-exchanger), and Selemion AMT, AST (anion-exchanger), were used in these experiments. Apparatus was composed of several flat cells, divided by cation- and anion-exchange membranes and polypropylene frames, pressed to filter press type. The developer and sodium sulfate solution were flowed through alternate cells. Various D.C. voltages were applied between graphite anode and stainless- steel cathode to get suitable electric current densities (0.5 to 2.0 A/dm²). When Eastmancolor Print Film Developer was used as sample, permeation of bromide across membranes increased with elevation of current densities, without loss of developing agent. Higher selectivity of permeation of bromide could be obtained at lower current densities, at lower flow rates of developer and with narrower cells. More than 30% of bromide, in the developer could be removed without loss of developing agent, under the suitable conditions.

抄録全体を表示