Abstract: A photosensitive composition can be used to prepare negative-working photosensitive elements such as lithographic printing plates. The composition includes a first photocrosslinkable aromatic resin having photocrosslinkable groups and a number average molecular weight of at least about 1500. Also included is a polymerizable monomer, a photocrosslinkable polyester and a photoinitiator. The photosensitive resins are present at a total weight ratio to the monomer of at least 1.5:1.

Abstract: A holder for preventing the incidental rotation of film material on a roll, comprising at least two parts which fit together, with a roll of film material on a roll core therein, having a lip of which extends outside the holder, and a flange having a support plate and a protruding part, which protruding part engages with the roll core, and the anti-incidental rotation mechanism undetachably mounted on the flange.

Abstract: An assemblage for forming a lithographic printing plate is disclosed. The assemblage contains a receiver support with a rough hydrophilic surface; a layer containing a poly(cyanoacrylate) binder; and a donor support. When the assemblage is exposed with a high intensity laser beam, the binder is transferred to the hydrophilic surface of the receiver support to produce a lithographic printing plate. The transfer requires relatively low exposure and no post processing is necessary.

Abstract: An infrared imaging composition contains two essential components, namely an infrared absorbing compound, and a phenolic resin that is either mixed or reacted with an o-diazonaphthoquinone derivative. These compositions are useful in positive-working elements such as lithographic printing plates that can be adapted to direct-to-plate imaging procedures. The weight ratio of infrared radiation absorbing compound to diazonaphthoquinone moiety is less than 1:14.

Abstract: An alkaline developing composition for processing a lithographic printing plate includes an alkali metal silicate and at least 6 weight % of a thickener such as glycerine. The lithographic printing plate can be either positive- or negative-working, and includes negative-working thermal plates.

Abstract: Binders useful in photosensitive compositions contain units A, B, C and D, wherein A is present in an amount of 0.5 to 15 wt. % and is of the formula ##STR1## B is present in an amount of 10 to 35 wt. % and is of the formula ##STR2## C is present in an amount of 10 to 50 wt. % and is of the formula ##STR3## wherein R.sup.1 is methyl, ethyl, propyl, and D is present in an amount of 25 to 70 wt. % and is of the formula ##STR4## wherein n is an integer of from 1 to 3 and R.sup.2, R.sup.3 are hydrogen or methyl and R.sup.4 is alkyl, aralkyl or aryl.

Abstract: A radiation sensitive composition containing an adduct of a diazonium resin having pendant diazonium groups, with a sulfonated acrylic copolymer having pendant sulfonate groups. The sulfonated acrylic copolymer contains an acrylic moiety and a sulfonated styryl or acrylic moiety. The copolymer may optionally contain styryl moieties. The composition is useful as a radiation sensitive layer in imaging elements for graphic arts applications and is particularly useful in preparing durable, long-wear, printing plates.

Abstract: Provided are 4-(alkoxyhydroxy)styryl triazine photoinitiator compounds having the formula: ##STR1## wherein n is 3 or 4, as well as photopolymerizable compositions and photographic elements containing such photoinitiator compounds. These photoinitiator compounds improve the reproduction quality of photographic elements such as lithographic printing plates since the photosensitive compositions in which they are incorporated are resistant to surface blooming.

Abstract: Improved lithographic printing plates adapted to be imagewise-exposed with ultraviolet- or visible-light-emitting lasers such as argon-ion lasers and frequency doubled Nd:YAG lasers, are comprised of a radiation-sensitive layer and an oxygen barrier layer. The radiation-sensitive layer includes one or more addition-polymerizable ethylenically-unsaturated compounds and a photopolymerization initiator system comprised of a spectral sensitizer that sensitizes in the ultraviolet or visible regions of the spectrum and an N-aryl, O-aryl or S-aryl polycarboxylic acid co-initiator; the oxygen barrier layer comprises fully hydrolyzed polyvinyl alcohol; and a basic compound is incorporated in the oxygen barrier layer or the radiation-sensitive layer or both in an amount sufficient to control thermal fog susceptibility of the lithographic printing plate.

Abstract: A photosensitive composition can be used to prepare negative-working photosensitive elements such as lithographic printing plates. The composition includes a first photocrosslinkable aromatic resin having photocrosslinkable groups and a number average molecular weight of at least about 1500. Also included is a polymerizable monomer, a photocrosslinkable polyester, a photocrosslinkable copolymer of styrene and maleic anhydride, and a photoinitiator. The photocrosslinkable resins are present at a total weight ratio to the polymerizable monomer of at least 1.5:1.

Abstract: An alkaline developing composition for processing a lithographic printing plate includes an alkali metal silicate, at least 6 weight % of a thickener such as glycerine, and a nonionic fluorosurfactant or a phosphate ester hydrotrope. Lithographic printing plates that can be developed using this composition are either positive- or negative-working, and include both positive- and negative-working thermal plates.