Basf Lacke+farben Ag

Basf Aktiengesellschaft

Basf Lacke + Farber Aktiengesellschaft

Friedrich Goffing

Thomas Loerzer

Hartmut Sandig

Markus T&ouml;nnessen

Markus Tonnessen

Jan Holoch

Alfred Leinenbach

Heino Thiele

Rainer Nachtrab

Joerg Kroker

Helmut Heel

Gerd Esswein

Hans-Jurgen Nisslmuller

Stefan Wegener

Preparation of photopolymeric letterpress printing plates

Preparation of photopolymeric gravure printing plates

A multilayer recording element is suitable for the production of flexographic printing plates by digital information transfer and has, arranged one on top of the other on a dimensionally stable substrate, a layer (A) crosslinkable by actinic radiation, a layer (B) sensitive to IR radiation and, if required, a peelable cover sheet, the layer (A) crosslinkable by actinic radiation being capable of being washed out by means of a developer after imagewise exposure and consisting essentially of a mixture of at least one elastomeric binder, ethylenically unsaturated copolymerizable organic compounds, a photoinitiator and, if required, further assistants, and the layer (B) sensitive to IR radiation being a layer which is soluble or dispersible in the developer and contains, in a film-forming binder having elastomeric character, at least one finely divided substance which has a high absorbance in the wavelength range from 750 to 20,000 nm.

Multilayer recording element suitable for the production of flexographic

Photopolymeric letterpress printing plates which are to be developed with water or water/alcohol mixtures after imagewise exposure and have, arranged one on top of the other on a dimensionally stable substrate, a layer (A) which may be bonded to the dimensionally stable substrate by an adhesion-promoting layer and is crosslinkable by actinic radiation, a layer (B) which is sensitive to IR radiation and, if required, a parting layer arranged between layer (A) and layer (B), and a peelable protective film applied to the layer (B), are produced by a process in which the layer (A) contains a mixture of at least one polymeric binder which is soluble or dispersible in water or water/alcohol mixtures, copolymerizable ethylenically unsaturated organic compounds which are compatible with the polymeric binder and a photoinitiator, the layer (B) sensitive to IR radiation has an optical density.gtoreq.2.5 in the actinic range and contains a film-forming polymeric binder which is soluble or dispersible in water or water/alcohol mixtures and a substance which is finely distributed in this binder and absorbs IR radiation, and the layer (B) sensitive to IR radiation is structured by laser ablation and is then exposed uniformly to actinic radiation, developed and dried in a conventional manner. The novel process is suitable for the production of letterpress printing plates.

Photopolymeric gravure printing plates which are to be developed with water or water/alcohol mixtures after imagewise exposure and have, arranged one on top of the other on a dimensionally stable substrate, a layer (A) which may be bonded to the dimensionally stable substrate by an adhesion-promoting layer and is crosslinkable by actinic radiation, a layer (B) which is sensitive to IR radiation and, if required, a parting layer arranged between layer (A) and layer (B), and a peelable protective film applied to the layer (B), are produced by a process in which the layer (A) consists of a mixture of at least one polymeric binder which is soluble or dispersible in water or water/alcohol mixtures, copolymerizable ethylenically unsaturated organic compounds which are compatible with this polymeric binder, a photoinitiator or photoinitiator system and, if required, further assistants, the parting layer which may be arranged between layer (A) and layer (B) is oxygen-permeable and the layer (B) sensitive to IR radiation has an optical density .gtoreq.2.5 in the actinic range and contains a film-forming polymeric binder which is soluble or dispersible in water or water/alcohol mixtures and at least one substance which is finely distributed in this binder, absorbs IR radiation and has a high absorbence in the wavelength range from 750 to 20,000 nm, the layer (B) sensitive to IR radiation is structured by laser ablation after the protective film has been peeled off and is then exposed uniformly to actinic radiation, developed with water or water/alcohol mixtures and dried in a conventional manner. The novel process is suitable for the production of gravure printing plates.

(A) being a photosensitive relief-forming layer in which imagewise exposure to actinic light results in different solubilities of the exposed and unexposed parts, and this layer consists of a mixture of:

Multilayer, sheet-like, photosensitive recording material for the

Aqueous non-self-emulsifying polymer dispersions having small particles and a long shelf life and based on highly viscous reaction resins are prepared without the addition of solvents, by means of an intensively dispersing screw apparatus, by a continuous process in which the preparation of the polymer dispersion is carried out in an intensive shear zone of the screw apparatus, the water/reaction resin ratio in this intensive shear zone corresponding to the phase inversion point or being close to it, and the specific energy supply is 0.01-0.15 kWh/kg, the residence time is 0.1-60 sec and the shear gradient is 2,000-20,000 sec.sup.-1.

Continuous preparation of aqueous non-self-emulsifying polymer

Pigmented curable polyester molding compounds which cure to give homogeneously colored moldings contain an unsaturated polyester, copolymerizable monomers, a thermoplastic polymer and a color pigment and are prepared by dispersing the pigment in the molten thermoplastic in an extruder.

Growing community of inventors

Limburgerhof, Germany

Friedrich Goffing