Polaroid Corporation

Presstek, Inc.

Covestro LLC

Frederick R Kearney

Rong-Chang Liang

Maurice J Fitzgerald

William C Schwarzel

Ernest W Ellis

John M Hardin

Thomas E Lewis

John Charles Warner

Daoshen Bi

Tung-Feng Yeh

John C Warner

Kevin Ray

Carmen M Baldino

Justin Whitfield

Eugene L Langlais

Steven J Frank

Donna J Guarrera

Donald Sundberg

John Tsavalas

The present invention provides compositions comprising the reaction product of an aliphatic diisocyanate, and a reactive intermediate made from one selected from the group consisting of oxazolidinones, benzoic sulfimides (saccharins), 1H-indole-2,3-diones (isatins), succinamides, N-hydroxysuccinamides, 4-hydroxy-3-methoxybenzaldehydes (vanillins), &#x3b1;-ketoamides, piperazines, benzofuranones, 3,4-dihydroxycyclobut-3-ene-1,2-diones (squaric acids), squaric acid esters, &#x3b1;-ketoamides, anilines, and &#x3b1;-ketoamide, phenols. The aliphatic diisocyanate comprises one selected from the group consisting of isocyanurates, biurets, iminooxadiazine diones, urethanes, uretdiones, carbodiimides, and allophanates. The resulting compositions may be useful in producing coatings, adhesives, sealants, castings, composites and films having durability, color stability, high gloss, and chemical resistance properties similar to those made from polyurethane.

Alternative crosslinking mechanisms for polyurethane-based systems

Embodiments of the present invention involve printing members that utilize a particle-fusion imaging mechanism but avoid susceptibility to handling damage. In particular, printing plates in accordance with the invention may utilize two phases, and these may originate, during manufacture, as two particle systems. Both systems are initially dispersed in a single coating applied as a layer, or in multiple coatings applied as adjacent layers, on a substrate. The second particle system exhibits a glass-transition or thermal coalescing temperature well above room temperature and also above the temperature at which the coating is dried. The coalescing temperature of the first particle system is below the drying temperature. As a result, when the coating is dried, the first particle system coalesces and forms a binder that entrains the second particle system, which has not coalesced. The binder formed by the first particle system is preferably insoluble in aqueous liquids, but is swellable or softened by such liquids, whereas the binder formed by the second particle system is preferably insoluble in and not swellable by aqueous liquids. Aqueous insolubility allows the dried (and ready-to-image) coating to resist handling damage, while swellability facilitates development.

Lithographic imaging and printing with printing members having fusible polymeric particles

Lithographic imaging using non-ablative printing members combines the benefits of simple construction, the ability to utilize traditional metal base supports, and amenability to imaging with low-power lasers that need not impart ablation-inducing energy levels. A representative printing member has a topmost layer that is ink-receptive and does not significantly absorb imaging radiation, a second layer thereunder that is hydrophilic and does absorb imaging radiation, and a metal substrate under the second layer. The printing member is selectively exposed to laser radiation in an imagewise pattern, and laser energy passes substantially unabsorbed through the first layer and is absorbed by the second layer. Heat builds up in the second layer sufficiently to detach the first layer, which is formulated to resist reattachment. But the first layer and, more significantly, the third layer act to dissipate heat from the second layer to prevent its ablation. Where the printing member has received laser exposure&mdash;that is, where the first and second layers have been detached&mdash;remnants of the first layer are readily removed to produce a finished printing plate.

Lithographic imaging with non-ablative wet printing members

Lithographic printing is accomplished using wet lithographic printing plates that include a protective layer providing protection against handling and environmental damage, extension of plate shelf life, and entrainment of debris generated by ablation. The layer washes away during the printing make-ready process, effectively cleaning the plate and disappearing without the need for a separate removal process.

Printing with self-cleaning, abrasion-resistant, laser-imageable

Wet lithographic printing plates include a protective layer that provides protection against handling and environmental damage, extends plate shelf life, and entrains debris generated by ablation. The layer washes away during the printing make-ready process, effectively cleaning the plate and disappearing without the need for a separate removal process.

Self-cleaning, abrasion-resistant, laser-imageable lithographic printing

Described is the use of a plasticizing-permeation enhancing additive in negative-working, on-press developable lithographic printing plates. Briefly, a plasticizer, which is dispersible or soluble in press fountain and ink solutions and soluble in acrylic monomers and oligomers, are incorporated into a plate's photoresist at concentrations sufficient to enhance said resist's permeability to or diffusion by press solutions. Such additives make the photoresist more permeable to fountain solution prior to crosslinking, while being easily extracted with ink and fountain solution after crosslinking. In certain embodiments, a surfactant is added to facilitate the dispersion of hydrophobic remnants of removed resist material in the fountain solution, and thereby reduce scumming. Lithium salts may also be incorporated into the photoresist to disrupt hydrogen bonding of, for example, urethane acrylate polymers which tend to associate by hydrogen bonding.

On-press developable lithographic printing plates with high plasticizer

The present invention provides a lithographic printing plate comprising a substrate and a photocurable polymeric photoresist, such as those based on free-radical initiated photocuring mechanisms. To constrain detrimental and undesired activity of excess free radicals, an embodiment of the printing plate is further provided with a free-radical regulating system. In a particular embodiment, the free-radical regulating system is provided as an overcoat, the overcoat being a light-transmissive overcoat and comprising a polymer having a pendant free-radical trapping group. A particular polymer for the overcoat has the formula ##STR1## wherein, m is from approximately 20% by weight to approximately 95% by weight, and n is from approximately 0% by weight to approximately 75% by weight. Capable of deactivating free-radicals actinically generated in the photoresist subsequent to exposure, the polymer is soluble in fountain or ink solution and incompatible with the photoresist.

Photoreaction quenchers in on-press developable lithographic printing

The present invention sets forth the incorporation of a substituted 2-phenyl-4,6-bis (trichloromethyl)-1,3,5-triazine in photoresists of lithographic printing plates for the purpose of promoting their shelf-life, room light stability, and developability. The present invention provides a photocurable composition comprising at least a photopolymerizable ethylenically unsaturated monomer having at least one terminal ethylenic group and capable of forming a polymer upon exposure to actinic radiation; and an s-triazine capable of initiating free radical polymerization of the photopolymerizable ethylenically unsaturated monomer and being represented by the following general formula [I]: ##STR1## wherein R.sub.1 is either OR.sub.4 or NR.sub.5 R.sub.6, wherein R.sub.5 and R.sub.6 may or may not be identical with each other, either R.sub.5 or R.sub.6 may represent hydrogen, and wherein R.sub.4 and at least one of R.sub.5 and R.sub.6 represent a ballast group capable of preventing the substantial volatilization of the s-triazine from the photoresist composition, the ballast group being a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, the substituted or unsubstituted alkyl group having at least 4 carbon atoms, the substituted or unsubstituted aryl group having at least 6 carbon atoms; R.sub.2 and R.sub.3 may or may not be identical with each other and each represent hydrogen, halogen, phenyl, a substituted or unsubstituted alkyl group, or an alkoxyl group; X and Y may or may not be identical with each other and each represent chlorine or bromine; and m and n may or may not be identical with each other and are each an integer of 0, 1, or 2. Desirable compositions will further comprise at least one photooxidizable leuco triarylmethane dye.

Low-volatility, substituted 2-phenyl-4,6-bis (halomethyl)-1,3,5-triazine

A photoreactive binder that may be used to enhance photospeed in either conventional plates or on-press developable lithographic printing plates. Briefly, a polymer of m-isopropenyl-.alpha.,.alpha.-dimethylbenzyl isocyanate is derivatized for vinyl group reactivity by reacting the isocyanate groups thereof with hydroxyalkyl acrylate. The resulting photopolymeric binder provides significantly higher photospeed than the non-reactive binder currently utilized in the production of conventional printing plates. The resulting lithographic printing plate also shows better durability (as manifested by longer run-length) and is more easily developed by the microencapsulated developers utilized in the present invention. As to the preparation of the photoreactive binders, the application discloses a method of copolymerizing m-isopropenyl-.alpha.,.alpha.-dimethylbenzyl isocyanate (m-TMI) through complexation with an electron-deficient monomer such as maleic anhydride to accelerate free radical copolymerization with other monomers, and thus, provides greater monomer-to-polymer conversion. Use of the resulting product in the photoresist of a lithographic printing plate improves its adhesion to an underlying substrate.

Growing community of inventors

Walpole, MA, United States of America

Frederick R Kearney