Agfa Gevaert Nv

Piet Kok

Jean-Marie O Dewanckele

Leon L Vermeulen

Eddy A Michiels

Johan August Loccufier

Luc J Vanmaele

Ludovicus H Vervloet

Frank P Michiels

Willy P De Smedt

Richard A Ooms

Serge M Tavernier

Ludo Van Rompuy

Daniel M Timmerman

Robert J Pollet

Jos A Vaes

Hendrik E Kokelenberg

Christian C Van De Sande

Daniel A Claeys

Antoon Leon Vandenberghe

Luc J Wabbes

Robert S Pauwels

Jozef P De Prijcker

Marc B Graindourze

Antonius A Rutges

Fernand I Ketels

Hedwig E De Deyne

Erik V Van Der Eycken

A modified gelatin is disclosed wherein part of the free carboxyl groups is replaced by modifiers having more acid end-standing groups chosen from --SO.sub.3 M, --OSO.sub.3 M, --SSO.sub.3 M, ---OPO(OH).sub.2, --OPO(OH)(OR.sup.2), --PO(OH).sub.2, --PO(OH)(OR.sup.2). In a preferred embodiment such a modified gelatin is incorporated in a DTR photographic material which after processing can serve as a lithographic printing plate. Thanks to the more hydrophilic character of the modified gelatin the differentiation between printing and non-printing areas is improved and toning at printing start-up is reduced.

Type of modified gelatin and its use in a DTR material

A modified gelatin is disclosed wherein part of the free carboxyl groups is replaced by modifiers having more acid end-standing groups chosen from --SO.sub.3 M, --OSO.sub.3 M, --SSO.sub.3 M, --OPO(OH).sub.2, --OPO(OH)(OR.sup.2), --PO(OH).sub.2, --PO(OH)(OR.sup.2). In a preferred embodiment such a modified gelatin is incorporated in a DTR photographic material which after processing can serve as a lithographic printing plate. Thanks to the more hydrophilic character of the modified gelatin the differentiation between printing and non-printing areas is improved and toning at printing start-up is reduced.

New types of modified gelatins are disclosed, modified at part of the free carboxyl groups of the polypeptide chain, by the introduction of a new end-standing amino, sulphinic acid or thiol group. The modified gelatins show an enhanced reactivity towards vinylsulphonyl hardeners. The invention further includes hardened modified gelatin types and hydrophilic elements containing them. In particular, a differentially hardened multilayer element, preferably a photographic element, is disclosed.

Modified gelatin types and hydrophilic elements containing them

A photographic direct positive material is disclosed comprising a support and one or more radiation sensitive emulsion layers containing internal latent image-forming silver halide grains characterized in that at least one of said emulsion layers further contains a masked stabilizer corresponding to general formula (I): ##STR1## wherein Z represents a lower alkyl group, a nitro group or a halogen atom, n=0 to 4, and M represents a positive counterion. Preferred compounds are 1-(2-sulphonatobenzoyl)-5-methyl-benzotriazole, 1-(2-sulphonatobenzoyl)-6-methyl-benzotriazole or a mixture of both. The masked stabilizer is preferably incorporated in the emulsion layer(s). The material preferably further contains a nucleating agent. Improved direct positive sensitometric properties and wider exposure latitude before encountering rereversal are obtained.

Photographic direct positive material containing a masked benzotriazole

A new class of photographic masked stabilizers is disclosed showing following general chemical formula (Ia) or (Ib): ##STR1## wherein X and Y each independently represent N or CR, R being hydrogen or lower alkyl,

Class of masked stabilizers in photographic materials or developing

A method for high contrast development of an image-wise exposed photographic element comprising a support and at least one silver halide emulsion layer, which method comprises contacting said exposed element in the presence of a hydrazine compound with an aqueous alkaline developing solution which has a pH between 10 and 13 and contains a dihydroxybenzene developing agent a 3-pyrazolidinone or an aminophenol developing agent sulphite ions and a contrast promoting amount of an amino compound characterized in that said developing solution further contains an aprotic solvent corresponding to general formula (I) or (II) : ##STR1## wherein R.sub.1 represents alkyl, substituted alkyl, alkylamino or substituted alkylamino, and

High contrast developer containing an aprotic solvent

A new class of photographic stabilizers is prepared and their use in photographic materials is disclosed. These compounds are 1-phenyl-3-pyrazolidinone derivatives corresponding to following general formula: ##STR1## wherein: A represents a group capable of adsorbing at the surface of silver halides;

Photographic stabilizers with 1-phenyl-3-pyrazolidinone moieties

Method for the production of direct-positive images by image-wise exposing a light-sensitive silver halide material comprising a support and an internal latent image-type silver halide emulsion layer and developing said exposed material in the presence of at least one development nucleator and density-increasing amounts of a compound chosen from the class consisting of formic acid, oxalic acid, glyoxylic acid, or salts of these and/or of a compound chosen from the class consisting of polyethylene glycols, with a hydroquinone-type developing solution having a pH not higher than 12.0 and comprising less than 25 g per liter of a hydroquinone and 5 to 100 g per liter of at least one alkanolamine.

Method of developing direct positive silver halide material

A developer liquid suited for use in development of photographic silver halide emulsion layer materials which liquid contains:

Developer liquid for high contrast development

Process for hardening proteinaceous materials by means of a quick acting hardener corresponding to the following formula ##STR1## wherein: Z.sub.1 and Z.sub.2 each independently represent substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, or Z.sub.1 represents substituted or unsubstituted alkylidene or Z.sub.1 and Z.sub.2 together represent the atomic grouping required to complete a 5- or 6-membered substituted or unsubstituted heterocyclic ring, including an aromatic heterocyclic ring and including such a ring with a ring fused-on, which atomic grouping may contain other hetero atoms in addition to the nitrogen atom;

Quick acting hardener for photographic gelatin layers

Process for the production of a laminated article including a sheet support bearing a silver image produced by the silver complex diffusion transfer process in a layer containing developement nuclei, wherein such supported image is heat-laminated with a protective thermoplastic resin layer of sheet that covers it. The heat-lamination of the nuclei-containing layer with the silver image therein takes place in the presence of at least one of certain heterocyclic black-toning agents which are effective to prevent degradation of the neutral black coloration and density loss of the silver image as a result of heat-lamination.

Process for the production of a laminated article

Particulate toner material for use in the development of latent electrostatic images, wherein said particulate toner material is capable of acquiring by triboelectric contact electrification when in admixture with carrier particles a net positive charge and contains at least one thermoplastic resin as binder in combination with a colorant and a colorless compound capable of imparting a positive charge to the particulate toner material when in frictional contact with said carrier particles, characterized in that said colorless compound contains in it molecular structure at least one polyalkyl substituted piperidine group and a sterically hindered phenol group.

Particulate toner material with charge control agent

Particulate toner material for use in the development of latent electrostatic images, wherein said particulate toner material is capable of acquiring by triboelectric contact electrification a net positive charge and contains thermoplastic resin(s) as binder in combination with a colorant and a colorless compound capable of imparting a positive charge to the particulate toner material in contact electrification, wherein said colorless compound contains at least one piperidine nucleus substituted with an --NH-acyl group, N-substituted ureido or N-substituted thioureido group.

Particulate electrophotographic toner material

Image-receiving material for use in diffusion transfer reversal processing comprising a polyvinyl chloride resin support coated with a hydrophilic waterpermeable layer comprising a proteinaceous colloid and a water-dispersible ionogenic polyester-polyurethane wherein isocyanate groups still present in its structure have reacted with an ionogenic compound containing at least one active hydrogen atom and a carboxylate or sulphonate salt group. This material is useful for the production of tamper proof laminates for identification purposes.

Image-receiving material for use in diffusion transfer reversal

An image-receiving material suitable for image production by dye diffusion transfer processing controlled by the development of (an) image-wise exposed silver halide emulsion layer(s), wherein said image-receiving material contains a hydrophobic resin support coated with a subbing layer that is coated with an image-receiving layer containing gelatin in combination with a cationic polymeric mordant containing glycidyl groups that can react with active hydrogen atoms of gelatin, the weight ratio of said polymeric mordant to gelatin being 25:1 to 1:1 and the gelatin being present at a coverage of at least 0.1 g per m2, and wherein said subbing layer has been applied from an aqueous composition comprising a polyester-polyurethane wherein isocyanate groups still present in its structure have reacted with an ionomeric compound containing at least one active hydrogen atom and a carboxylate or sulphonate salt group.

Growing community of inventors

Gent, Belgium

Piet Kok