Abstract: A method of producing a security document includes the steps of producing a first part of a color image by color laser marking a security document precursor; and producing a second part of the color image by a second imaging technique different from laser marking. The resulting security document is more difficult to falsify.

Abstract: A method of making a lithographic printing plate includes the steps of a) image-wise exposing a lithographic printing plate precursor including a hydrophilic support and a coating containing a colorant precursor to form a lithographic image consisting of printing areas and non-printing areas, b) developing the plate precursor to remove the coating in the non-printing areas from the support, and c) drying the plate precursor, and d) subjecting the plate precursor to heat or radiation to induce a colour change of the coating in the printing areas, wherein before step b) the coating in the non-printing areas and the support are characterised by a CIE 1976 colour difference ?E1 which is 5.0 or less, and after step d) the CIE 1976 colour difference ?E2 between the coating in the printing areas and the non-printing areas is more than 6.8.

Abstract: A set of laminates includes an outer laminate and an inner laminate, wherein the outer laminate includes a transparent polymeric support including on a first side of the support a color laser markable layer containing an infrared dye having an absorption maximum ?max(IR-1) in the infrared region; wherein the inner laminate includes a transparent polymeric support including on, a first side of the transparent polymeric support, a color laser markable layer containing an infrared dye having an absorption maximum ?max(IR-2) in the infrared region and, on a second side of the transparent polymeric support, a color laser markable layer containing an infrared dye having an absorption maximum ?max(IR-3) in the infrared region; and the conditions a) and b) are satisfied: ?max(IR-1)>?max(IR-2)>?max(IR-3); and??a) ?max(IR-1)>1100 nm and ?max(IR-3)<1000 nm.

Abstract: A method for preparing a color laser marked article using three infrared lasers L-1, L-2 and L-3 having respectively a laser emission wavelength of ?(L-1), ?(L-2) and ?(L-3) includes the steps of laser marking with the infrared laser L-1 a first color laser markable layer including an infrared dye IR-1 having an absorption maximum in the infrared region ?max(IR-1); laser marking with the infrared laser L-2 a second color laser markable layer including an infrared dye IR-2 having an absorption maximum in the infrared region ?max(IR-2); laser marking with the infrared laser L-3 a third color laser markable layer including an infrared dye IR-3 having an absorption maximum in the infrared region ?max(IR-3); and at least partially exposing the color laser markable article to light having a wavelength between 520 nm and 700 nm, wherein, the laser emission wavelengths satisfy the condition of: ?(L-1)>?(L-2)>?(L-3); the infrared red dye absorption maxima satisfy the condition of: ?max(IR-1)>?max(IR-2)>?ma

Abstract: A color laser markable laminate includes at least a transparent polymeric support and a color forming layer including a leuco dye; an infrared dye; and a polymeric binder including vinyl acetate and at least 85 wt % of vinyl chloride based on the total weight of the binder; wherein the color laser markable laminate includes a specific phenol stabilizer sterically hindered by a ring containing three nitrogen atoms. A method for preparing a color laser marked document is also disclosed.

Abstract: A method of making a lithographic printing plate includes the steps of a) image-wise exposing a lithographic printing plate precursor including a hydrophilic support and a coating containing a colorant precursor to form a lithographic image consisting of printing areas and non-printing areas, b) developing the plate precursor to remove the coating in the non-printing areas from the support, and c) drying the plate precursor, and d) subjecting the plate precursor to heat or radiation to induce a colour change of the coating in the printing areas, wherein before step b) the coating in the non-printing areas and the support are characterised by a CIE 1976 colour difference ?E1 which is 5.0 or less, and after step d) the CIE 1976 colour difference ?E2 between the coating in the printing areas and the non-printing areas is more than 6.8.

Abstract: A method of producing a security document includes the steps of producing a first part of a colour image by colour laser marking a security document precursor; and producing a second part of the colour image by a second imaging technique different from laser marking. The resulting security document is more difficult to falsify.

Abstract: A colour laser markable laminate includes at least a transparent polymeric support and a colour forming layer including a leuco dye; an infrared dye; and a polymeric binder including vinyl acetate and at least 85 wt % of vinyl chloride based on the total weight of the binder; wherein the colour laser markable laminate includes a specific phenol stabilizer sterically hindered by a ring containing three nitrogen atoms. A method for preparing a colour laser marked document is also disclosed.

Abstract: A method for preparing a surface modified organic pigment includes the steps of a) reacting the organic pigment in an aromatic hydrocarbon solvent with a surface modifying reagent to form a surface modified organic pigment; and b) washing and drying the surface modified organic pigment; wherein the surface modifying reagent is represented by Formula (I): wherein, X is selected from the group consisting of O, S and N—R3; Y is selected from the group consisting of —O—, and NR4; R1 to R4 are each independently selected from the group consisting of hydrogen, an alkyl group, an alkenyl group, an alkynyl group, a -aralkyl group, an alkaryl group, and an aryl group and s heteroaryl group; with the proviso that when Y—R1 is different from OH that at least one of R2 to R4 is substituted by at least one functional group having a pKa between 2.5 and 9.

Abstract: A set of laminates includes an outer laminate and an inner laminate, wherein the outer laminate includes a transparent polymeric support includinq on a first side of the support a colour laser markable layer containing an infrared dye having an absorption maximum ?max(IR-1) in the infrared region; wherein the inner laminate includes a transparent polymeric support including on, a first side of the transparent polymeric support, a colour laser markable layer containing an infrared dye having an absorption maximum ?max(IR-2) in the infrared region and, on a second side of the transparent polymeric support, a colour laser markable layer containing an infrared dye having an absorption maximum ?max(IR-3) in the infrared region; and the conditions a) and b) are satisfied: ?max(IR-1)>?max(IR-2)>?max(IR-3); and??a) ?max(IR-1)>1100 nm and ?max(IR-3)<1000 nm.

Abstract: Infrared dyes soluble in methylene chloride have an infrared absorption maximum above 1100 nm and minor discolouration in the visual spectrum. The infrared dyes are especially useful for producing multicolour laser marked security documents having reduced background discoloration and enhanced colour gamut.

Abstract: A method for preparing a color laser marked article using three infrared lasers L-1, L-2 and L-3 having respectively a laser emission wavelength of ?(L-1), ?(L-2) and ?(L-3) includes the steps of laser marking with the infrared laser L-1 a first color laser markable layer including an infrared dye IR-1 having an absorption maximum in the infrared region ?max(IR-1); laser marking with the infrared laser L-2 a second color laser markable layer including an infrared dye IR-2 having an absorption maximum in the infrared region ?max(IR-2); laser marking with the infrared laser L-3 a third color laser markable layer including an infrared dye IR-3 having an absorption maximum in the infrared region ?max(IR-3); and at least partially exposing the color laser markable article to light having a wavelength between 520 nm and 700 nm, wherein, the laser emission wavelengths satisfy the condition of: ?(L-1)>?(L-2)>?(L-3); the infrared red dye absorption maxima satisfy the condition of: ?max(IR-1)>?max(IR-2)>?ma

Abstract: A method of color laser marking a security document precursor including at least: a transparent biaxially stretched polyethylene terephthalate foil; at least one colorless color forming layer for generating a color different from black containing at least an infrared absorber a color forming compound and a polymeric binder; and a laser markable polymeric support or a laser markable layer for generating a black color; comprising the steps of: laser marking the colorless color forming layer through the transparent polymeric foil with a infrared laser used in continuous wave mode to generate a color different from black; and laser marking the laser markable polymeric support or the laser markable layer through the transparent polymeric foil with the same infrared laser but used in a pulsed mode to generate a black color.

Abstract: A security document precursor including, in order, at least: a) a transparent biaxially stretched polyethylene terephthalate foil; b) a colorless color forming layer containing at least an infrared absorber, a color forming component and a polymeric binder; and c) a polymeric support; wherein the colorless color forming layer contains at least one component forming a compound having a melting temperature of less than 20° C. upon laser marking the colorless color forming layer with an infrared laser. Methods for securing a security document using the security document precursor are also disclosed.

Abstract: A method for preparing a color laser marked article comprising the steps of: a) infrared laser marking a security element including a polymeric support and a color forming layer comprising a color forming compound, an infrared dye and a polymeric binder comprising vinyl acetate and at least 85 wt % of vinyl chloride based on the total weight of the binder; and b) exposing the laser marked security element with light having a wavelength higher than 440 nm. The light exposure of step b) hinders the falsification of an issued security document without significant increase of background density.

Abstract: A security document precursor including, in order: a) at least one transparent biaxially stretched polyester foil; b) one colorless color forming layer containing at least an infrared absorber, a colorless dye-precursor and a polymeric binder; and c) a polymeric support; wherein the polymeric binder is copolymer including at least 90 wt % of a chlorinated ethylene and 1 wt % to 10 wt % of vinyl acetate both based on the total weight of the binder. Methods for making the security document precursor are also disclosed.

Abstract: A method of color laser marking an article having a polymeric foil with at least one colorless layer containing an infrared absorber, a polymeric binder and a color forming compound; including the steps of:—laser marking the colorless layer with an infrared laser using a first laser operation mode to generate a blue or cyan color; and—laser marking the same colorless layer with an infrared laser using a second laser operation mode to generate a black color, wherein the first laser operation mode applies less energy to the colorless layer than the second laser operation mode. Also disclosed is an article, such as a security document, including a polymeric foil and a colorless layer containing laser marked graphical data having a blue or cyan color and laser marked information having a black color.

Abstract: A method for preparing a surface modified organic pigment includes the steps of a) reacting the organic pigment in an aromatic hydrocarbon solvent with a surface modifying reagent to form a surface modified organic pigment; and b) washing and drying the surface modified organic pigment; wherein the surface modifying reagent is represented by Formula (I): wherein, X is selected from the group consisting of O, S and N—R3; Y is selected from the group consisting of —O and NR4; R1 to R4 are each independently selected from the group consisting of hydrogen, an alkyl group, an alkenyl group, an alkynyl group, a -aralkyl group, an alkaryl group, and an aryl group and s heteroaryl group; with the proviso that when Y—R1 is different from OH that at least one of R2 to R4 is substituted by at least one functional group having a pKa between 2.5 and 9.

Abstract: A method of colour laser marking a security document precursor including at least: a transparent biaxially stretched polyethylene terephthalate foil; at least one colourless colour forming layer for generating a colour different from black containing at least an infrared absorber a colour forming compound and a polymeric binder; and a laser markable polymeric support or a laser markable layer for generating a black colour; comprising the steps of: laser marking the colourless colour forming layer through the transparent polymeric foil with a infrared laser used in continuous wave mode to generate a colour different from black; and laser marking the laser markable polymeric support or the laser markable layer through the transparent polymeric foil with the same infrared laser but used in a pulsed mode to generate a black colour.

Abstract: A method of color laser marking a security document precursor including, in order, at least: a) a polymeric foil; b) at least one colorless color forming layer for generating a color different from black containing at least an infrared absorber, a color forming compound and a polymeric binder; and c) either a lasermarkable polymeric support or a lasermarkable layer for generating a black color; comprising the steps of: (1) laser marking a color different from black in the colorless color forming layer with an infrared laser used in continuous wave mode; and (2) laser marking a black color by carbonization in the lasermarkable polymeric support or the lasermarkable layer with the same infrared laser used in a pulsed mode; and wherein at least one of the polymeric foil and the lasermarkable polymeric support is transparent for the infrared light of the infrared laser.