Agfa Gevaert Nv

Agfa-gevaert

Willem Cortens

Guido I Hauquier

Eric Verschueren

Joan T Vermeersch

Paul J Coppens

Erik Mostaert

Dirk Franky Kokkelenberg

Ludovicus H Vervloet

Marcus Jonckheere

Luc J Wabbes

Augustin Meisters

Jean Van Trier

According to the present invention there is provided an imaging element for making a lithographic printing plate, including on a first side of a flexible support a surface capable of being differentiated in oleophilic and oleophobic areas upon imaging and on a second side opposite to the first side a layer or a package of layers, characterized in that the layer or package of layers on the backside has a ratio of the squared value of the gravimetric water absorption (WA) in g/m,over the mean roughness in &mgr;m greater than 20.

Imaging element for making lithographic printing plates with a decreased slippage in the press

An image receiving layer for use in non-impact printing, especially in an electrostatographic printing method, is provided with an image receiving surface having a specified ratio between average and maximum roughness and a specified kinetic coefficient of friction against rubber with shore hardness 70. The receiving layer is especially well suited for producing lithographic printing plates with non-impact printing, especially with electrostatographic means.

Image receiving layer for use in non-impact printing

According to the present invention there is provided a method for making a lithographic printing plate comprising the steps of:

On the press development of a diazo based printing plate

The present invention provides an imaging element comprising on a support in the order given a coated composition of at least two hydrophilic layers being in water permeable contact with each other and each containing a hydrophilic (co)polymer or (co)polymer mixture and having been hardened with a hydrolyzed tetraalkyl orthosilicate and a light sensitive layer containing a diazo resin or a diazonium salt characterized in that the ratio by weight in the top layer of said package of said hydrophilic (co)polymer or (co)polymer mixture versus said hydrolyzed tetraalkyl orthosilicate (expressed as silicon dioxide) is at least 1.1 and the ratio by weight in an underlying layer of said package of said hydrophilic (co)polymer or (co)polymer mixture versus said hydrolyzed tetraalkyl orthosilicate (expressed as silicon dioxide) is not higher than 0.9.

Diazo based imaging element having improved resistance against physical

The present invention provides a lithographic base comprising on a hydrophobic support a packet of subbing layers contiguous to a hydrophilic layer containing a hydrophilic (co)polymer or (co)polymer mixture and being hardened with a hydrolysed tetraalkyl orthosilicate crosslinking agent characterized in that said packet of subbing layers contains as undermost layer a layer comprising, a polymer latex having hydrophilic functionality and as uppermost layer a layer comprising a hydrophilic binder and silica in a weight ratio of the hydrophilic binder to silica of less than 1.

Lithographic base and a lithographic printing plate

The present invention provides an imaging element comprising on a flexible hydrophobic support (i) a hardened hydrophilic layer, containing a hydrophilic synthetic homocopolymer or copolymer and being hardened with a hydrolyzed tetraalkyl orthosilicate crosslinking agent, (ii) a receiving layer containing physical development nuclei contiguous to said hydrophilic layer, (iii) an intermediate layer comprising a non-proteinic hydrophilic film-forming polymer or hydrophobic polymer beads having an average diameter not lower than 0.2 .mu.m and having been prepared by polymerization of a ethylenically unsaturated monomer and (iv) a photosensitive layer containing a silver halide emulsion being in water permeable relationship with said receiving layer. The invention also relates to a method for making lithographic plates with said imaging element.

Imaging element and method for making lithographic printing plates

The present invention provides a lithographic base comprising on a hydrophobic support a subbing layer and a hydrophilic layer containing a hydrophilic (co)polymer or (co)polymer mixture and being hardened with a hydrolyzed tetraalkyl orthosilicate crosslinking agent characterized in that said subbing layer contains a hydrophilic binder and silica, the surface area of the silica being at least 300 m.sup.2 per gram.

Lithographic base and a method for making a lithographic printing plate

The present invention provides a lithographic base comprising on a hydrophobic support a subbing layer contiguous to a hydrophilic layer containing a hydrophilic (co)polymer or (co)polymer mixture and being hardened with a hydrolyzed tetraalkyl orthosilicate crosslinking agent characterized in that said subbing layer contains a hydrophilic binder and silica and is applied at a solids content of more than 200 mg per m.sup.2 but less than 750 mg per m.sup.2.

The present invention provides an imaging element comprising in the order given (i) a hydrophilic grained and anodized aluminum support with an aluminum oxide barrier layer of at least 10 nm thickness, (ii) an image receiving layer containing physical development nuclei in an amount of at least 0.7 mg/m.sup.2 and (iii) a photosensitive layer containing a silver halide emulsion being in water permeable relationship with said image receiving layer. The invention also relates to a method for making lithographic plates with said imaging element.

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Booischot, Belgium

Willem Cortens