Verfahren zur Herstellung von tafelförmigen Silberhalogenid-Körnern

Method of making tabular silver halide grains

Procédé pour la fabrication de grains d'halogénure d'argent tabulaires

Abstract

A photographic material has been coated on at least one side of a support with in at least one photosensitive layer hexagonal and/or circular tabular silver halide emulsion crystals occupying at least 70 % of the total projected area of all grains, having a thickness of 0.15 to 0.30 µm, a coefficient of variation of the tabular grains between 0.15 and 0.45 and an average aspect ratio of at least 2:1, prepared in the absence of ammonia by growing the nuclei, prepared at a pBr value between 1.0 and 2.0 and consuming less than 10 % by weight of silver nitrate, during a first growth step at a pBr value between 1.0 and 2.5 consuming at least 10 % by weight of silver nitrate and during a second growth step at a pBr value higher than 2.7 during the addition of at least 40% of the total amount of silver nitrate used. The loss in sensitivity and gradation after development of said material in a diluted cheap developer after exposing said photographic material containing said emulsion grains is neglectable in comparison with the characteristics obtained after development in stronger high quality developers.

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Patent Citations (2)

    Publication numberPublication dateAssigneeTitle
    US-4755456-AJuly 05, 1988Fuji Photo Film Co., Ltd.Method for preparing silver iodobromide emulsions having high aspect ratio
    WO-9118320-A1November 28, 1991Eastman Kodak CompanySilver halide grains having small twin-plane separations

NO-Patent Citations (1)

    Title
    RESEARCH DISCLOSURE vol. 299, March 1989, HAVANT GB pages 185 - 197 ANONYMOUS : 'Nucleation of Tabular Grain Emulsions at High pBr'

Cited By (4)

    Publication numberPublication dateAssigneeTitle
    EP-0735413-A1October 02, 1996Minnesota Mining And Manufacturing CompanyProcédé de préparation d'une émulsion à grain tabulaire à l'halogénure d'argent monodispersé
    EP-0790526-A1August 20, 1997AGFA-GEVAERT naamloze vennootschapRadiographic image forming film-screen system
    US-5616455-AApril 01, 1997Imation Corp.Method of preparation of a monodispersed tabular silver halide grain emulsion
    US-5702879-ADecember 30, 1997Minnesota Mining And Manufacturing CompanyProcess of preparing monodispersed tabular silver halide emulsion