Agfa-gevaert

Agfa-gevaert Ag

Agfa Gevaert Nv

Raschig Gmbh

Agfa Graphics Nv

Harréus, Frank

Denzinger, Steffen

Schmitt, Alexander

Steffen Denzinger

Andreas Elsaesser

Michael D&ouml;rr

Andreas Els&auml;sser

Michael Doerr

Paul J Coppens

Engelbert Pliefke

Peter Lehmann

Allen Peter Gates

Klaus-Peter Konrad

Roland Robinson

Alexander Schmitt

Michael Dörr

G&uuml;nther Hultzsch

Günther Hultzsch

Klaus Peter Konrad

Frank Harréus

Guenther Hultzsch

Paul Eckler

The present invention provides a method for the production of free-flowing additive compounds that comprises the steps of preparation of a particulate additive compound and storage of a mass of the particulate additive compound at a surface pressure of at least 30 g/cmuntil the mass of additive compound is baked together. Then follows the crushing of the baked-together mass of the additive compound into a crushed particulate additive compound and the sieving of the crushed particulate additive compound, whereby particles of a size in excess of 4.0 mm and particles of a size of less than 0.1 mm are separated from the crushed particulate additive compound such that a fraction containing a free-flowing additive compound with long-term stability of particle sizes is obtained.

Method for the production of free-flowing additives

The invention relates to a recording material for the production of offset printing plates, having a web- or plate-form support, a radiation-sensitive layer on the front of the support and a continuous, pigment particle-free layer on the back of the support. The back layer essentially consists of an organic polymeric material having a glass transition temperature Tg of at least 45&#xb0; C., and its surface has a Bekk smoothness of from 5 to 800 s. It also relates to a process for the production of this recording material.

Radiation-sensitive recording material having a structured back

The invention relates to a radiation-sensitive recording material for the production of offset printing plates having a dimensionally stable support, a radiation-sensitive layer located on the front of the support, and a layer which comprises an organic polymeric material having a glass transition temperature of 35&deg; C. or above and in which pigment particles are embedded and which is resistant to processing chemicals and is located on the back of the support. The pigment particles are preferably silica gel particles having a mean diameter of from 0.1 to 50 &mgr;m or organic particles having a mean diameter of from 3 to 10 &mgr;m. The image layer on the front may be matted or pigmented. The back coating enables the recording material to be stacked without separating paper. The image layer located on the front is not scratched by the pigmented back coating during storage and transport and during removal from the stack.

Presensitized printing plate with pigmented back coating

The invention relates to a recording material for the production of offset printing plates having a web- or plate-form support, a radiation-sensitive layer on the front of the support and a continuous layer on its back. The back layer has a glass transition temperature Tg of at least 55&deg; C. and a surface resistance of 10 &OHgr; or less.

Radiation-sensitive recording material having an electrically conductive back coating

The invention relates to a process for the production of a photosensitive recording material for the production of offset printing plates which comprises a dimensionally stable, two-dimensional support of a metal or metal alloy and a silver halide-containing, photosensitive layer on the front of the support and a layer which essentially consists of an organic polymeric material and is resistant to processing chemicals on the back of the support. The layer on the back of the support is applied before the photosensitive coating on the front. The invention furthermore relates to a corresponding recording material in which the layer on the back comprises at least one organic polymer having a glass transition temperature T of 50&deg; C. or above. Due to the back coating, the formation of local elements between the metallic support and the silver-containing layer is reliably prevented when the recording materials are stacked. Coating flaws during application of the photosensitive coating have been virtually eliminated.

Process for the production of back-coating recording material for the production of offset printing plates

The invention relates to a recording material for the production of an offset printing plate, having a substrate on whose front a photosensitive image layer is present and on whose back a layer of an organic polymeric material having a glass transition temperature T,of 45&deg; C. or more is present. The photosensitive image layer, or any top layer present thereon, has a pigment layer formed thereon.

Pigmented recording material having a backing coating for the production of offset printing plates

The invention relates to polymers containing N-substituted maleimide units, to a positive- or negative-working radiation-sensitive mixture comprising a) a polymeric binder which is insoluble in water, but soluble in aqueous-alkaline solutions, and b) at least one radiation-sensitive compound, where the binder comprises a polymer containing N-substituted maleimide units of the formula (I)

Polymers containing N-substituted maleimide units and their use in radiation-sensitive mixtures

The invention relates to a developer for irradiated, radiation-sensitive recording materials, in particular for the production of offset printing plates, which contains water, a compound which is alkaline in aqueous solution and a copolymer which acts as an emulsifier and has units of (I) a hydrophobic vinyl compound which has at least one optionally substituted mono- or bicyclic (C.sub.6 -C.sub.14)aryl radical and (II) a hydrophilic, ethylenically unsaturated carboxylic acid. Some of the carboxyl groups of the copolymer are esterified with reaction products of (A) (C.sub.1 -C.sub.30)alkanols, (C.sub.8 -C.sub.25)alkanoic acids, (C.sub.1 -C.sub.12)-alkylphenols or di(C.sub.1 -C.sub.20)alkylamines with (B) (C.sub.2 -C.sub.4)-alkylene oxides or tetrahydrofuran, the molar ratio (A):(B) being in the range from 1:2 to 1:50. If it is intended to develop recording materials having a negative-working layer, the developer additionally contains a water-miscible organic solvent and a surface-active compound. The developer has a low initial viscosity, which increases only slowly with increasing contamination with layer components. Furthermore it shows only a particularly low tendency to foam.

Developer for irradiated, radiation-sensitive recording materials

A developer for irradiated, radiation-sensitive recording materials, in particular for the production of offset printing plates, which contains water, a compound which is alkaline in aqueous solution and a copolymer which acts as an emulsifier and has units of (I) a hydrophobic vinyl compound which has alkyl radicals having up to 30 carbon atoms and (II) a hydrophilic, ethylenically unsaturated carboxylic acid. Some of the carboxyl groups of the copolymer are esterified with reaction products of (A) (C.sub.1 -C.sub.30)alkanols, (C.sub.8 -C.sub.25)alkanoic acids, (C.sub.1 -C.sub.12)alkylphenols or di(C.sub.1 -C.sub.20)alkylamines with (B) (C.sub.2 -C.sub.4)alkylene oxides or tetrahydrofuran.

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Mainz, Germany

Steffen Denzinger