Abstract:
According to the present invention there is provided a method for obtaining a high quality printing plate by spraying a spray solution on a receiving surface of grained and anodized aluminum, characterized in that the spray factor (SF) is between 48 and 70 10 mN/m, wherein SF=(P/d×&sgr;) SF: Spray Factor (mN/m) P: Spray Profile (mm) d: distance between spray head and receiving surface (mm) &sgr;: surface tension (mN/m) and wherein the spray solution comprises hydrophobic thermoplastic polymer particles and a compound capable of converting light into heat.
Abstract:
According to the present invention there is provided a heat mode imaging element for making a lithographic printing plate having on a lithographic base with a hydrophilic surface a first layer including a polymer soluble in an aqueous alkaline solution, and a top layer on the same side of the lithographic base as the first layer that is IR-sensitive and unpenetrable for an aqueous alkaline developer wherein said first layer and said top layer may be one and the same layer; characterized in that the surface of said element upon exposure and treatment with an aqueous alkaline developer is such that a) the contact angle between the unexposed areas of the imaging element and the aqueous alkaline developer changes for at most 6° during the first minute of contact with said developer; b) the contact angle between the exposed areas of the imaging element and the aqueous alkaline developer changes more than 15° during the first minute of contact with said developer; c) the difference in contact angle between on the one side the unexposed areas and on the other side the exposed areas of the imaging element with the aqueous alkaline solution at the onset of the measurement is not higher than 10°.
Abstract:
According to the present invention there is provided a heat mode imaging element for making a lithographic printing plate having on a lithographic base with a hydrophilic surface a first layer including a polymer, soluble in an aqueous alkaline solution and a top layer on the same side of the lithographic base as the first layer which top layer is IR-sensitive and unpenetrable for an alkaline developer wherein said first layer and said top layer may be one and the same layer; characterized in that said top layer contains a polymer that lowers the dynamic friction coefficient of the top layer to less than 0.37, and wherein said polymer in the top layer is polytetrafluoroethylene.
Abstract:
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/m2 over the mean roughness in &mgr;m greater than 20.
Abstract translation:根据本发明,提供了一种用于制造平版印刷版的成像元件,该成像元件在柔性载体的第一侧具有在成像时能够在亲油性和疏油性区域中分化的表面,并且在与第一侧相反的第二侧上 一层或多层,其特征在于背面层或层包层的重量吸收光(WA)的平方值(g / m 2)之间的平均粗糙度大于20。
Abstract:
The present invention provides a heat mode recording material comprising on a side of a support having an oleophilic surface (i) a recording layer containing a light-to-heat converting substance capable of converting radiation into heat and (ii) an oleophobic surface layer, wherein said oleophobic surface layer and said recording layer may be the same layer and on another side of the support a backing layer, characterized in that the maximum roughness depth R.sub.t of the surface layer is at least 0.65 .mu.m and/or the maximum roughness depth of the outer back layer is at least 1.20 .mu.m.
Abstract:
According to the present invention there is provided a method for making a lithographic printing plate comprising the steps of: (1) image-wise exposing an imaging element having on a plastic film support in the order given (i) a uniform ink-repellant layer comprising a cross-linked hydrophilic binder and (ii) a photosensitive layer comprising a diazonium salt or a diazo resin; (2) and developing a thus obtained image-wise exposed imaging element by mounting it on a print cylinder of a printing press and supplying an aqueous dampening liquid and/or ink to said photosensitive layer. The present invention also provides a method for making multiple copies of an original comprising the steps of: (1) image-wise exposing an imaging element having on a plastic film support in the order given (i) a uniform ink-repellant layer comprising a cross-linked hydrophilic binder and (ii) a photosensitive layer comprising a diazonium salt or a diazo resin; (2) mounting a thus obtained image-wise exposed imaging element without development, on a print cylinder of a printing press; (3) rotating said print cylinder while supplying an aqueous dampening liquid and/or supplying ink to said photosensitive layer of said imaging element and (4) transfering ink from said imaging element to a receiving element.
Abstract:
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.
Abstract:
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.
Abstract:
An ink-jet recording element is provided comprising a polymeric film substrate or a resin coated paper substrate and at least one ink-receiving layer coated thereon comprising at least one binder and at least one mordanting agent characterized in that said mordanting agent comprises a polymer containing a phosphonium moiety. Preferably said mordanting agent consists of a copolymer of ethylenically unsaturated monomers containing a phosphonium moiety co-polymerized with N-vinyl imidazole or 2-methyl-2-vinyl imidazole and optionally other co-polymerizable monomers or of a mixture of from 5 to 70% by weight, of a polymer containing a phosphonium moiety, and obtained by homo- or co-polymerization of ethylenically unsaturated monomers and from 30 to 95% by weight, of a second polymer, which is free from cationic groups and has been obtained by homo- or co-polymerization of N-vinyl imidazole or 2-methyl-2-vinyl imidazole and optionally other co-polymerizable monomers.
Abstract:
A positive working heat-sensitive lithographic printing plate precursor is disclosed which comprises a support having a hydrophilic surface and a coating, provided on the hydrophilic surface, wherein the coating comprises a spacer particle comprising aluminum hydroxide or aluminum oxide and having an average particle size larger than 0.3 μm, for improving the scuff-mark resistance of the coating. Furthermore, the coating comprises an infrared light absorbing agent, an oleophilic resin soluble in an aqueous alkaline developer and a developer resistant means.