A light to heat conversion layer which has visible light permeability, excellent near infrared absorption characteristics, and which can improve the transfer accuracy of an organic electroluminescent element using laser irradiation; and a donor sheet using the light to heat conversion layer. The light to heat conversion layer contains near infrared absorption particles and a binder component. The near infrared absorption particles are composite tungsten oxide microparticles wherein if the value for the XRD peak intensity of the face of a silicon powder standard sample (manufactured by NIST, 640c) is defined as 1, the value for the ratio of XRD peak top intensity is at least 0.13, and the light transmissivity is at least 45%.

An object of the present invention is to provide a print product which has a printed region where printing with ultraviolet laser is applied and which is excellent in viewability, a method for producing a print product by irradiation with ultraviolet laser, and a printing medium for laser printing, for use in the print product and the method for producing a print product. The print product of the present invention has a printed region comprising discolored titanium oxide in at least one portion of a sheet medium selected from the group consisting of paper or a film having a printable region comprising titanium oxide; titanium oxide is filled in the sheet medium; a titanium oxide content in the printable region in the sheet medium is 1.0% by mass or more, pulp constituting the paper has a length-weighted average fiber length and an average fiber width in specified ranges, and the paper has a basis weight of 20 g/m.sup.2 or more, when the sheet medium is the paper; a titanium oxide content in the printable region in the sheet medium is 0.3% by mass or more, the film has a thickness of 15 μm or more, and a resin constituting the film comprises a specified resin, when the sheet medium is the film; and a ratio between a Raman intensity assigned to titanium oxide in the printed region and a Raman intensity assigned to titanium oxide in a non-printed region is 0.70 or less.

The invention is directed towards a composition comprising: a near-infrared radiation absorbing compound; a colour-forming compound; and a heat transfer agent operable to facilitate heat transfer from the near-infrared radiation absorbing compound to the colour-forming compound; wherein the near-infrared radiation absorbing compound is present in an amount of 0.1-3.5 wt % of the total composition, and the heat transfer agent is present in an amount of 1-15 wt % of the total composition, and the heat transfer agent is present in the composition as solid particles. The invention further relates to substrates comprising the composition applied thereto, as well as methods of forming colour or an image on said substrates.

The present invention relates to a new photo-initiating composition for red and near infrared-induced photopolymerization, method of using same in photopolymerization reactions and polymers obtained by such method.

A recording medium includes a recording layer configured to be able to change a color-developed state by an external stimulus and a plurality of structures provided on the recording layer. The recording layer has a plurality of color-developing portions, and a pitch Δd′ between the color-developing portions and a width W of each of the color-developing portions satisfy a relationship of Δd′>W.

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 λ.sub.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 λ.sub.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 λ.sub.max(IR-3) in the infrared region; and the conditions a) and b) are satisfied:
λ.sub.max(IR-1)>λ.sub.max(IR-2)>λ.sub.max(IR-3); and  a)
λ.sub.max(IR-1)>1100 nm and λ.sub.max(IR-3)<1000 nm.  b)

A reversible recording medium according to an embodiment of the present disclosure includes a first recording layer to be colored in a first color, a second recording layer to be colored in a second color, the second color being different from the first color, and a first intermediate layer provided between the first recording layer and the second recording layer, the first intermediate layer including a plurality of layers respectively containing materials different from each other.

A drawing method according to an embodiment of the present disclosure to be performed on a heat-sensitive recording medium including a recording layer, the recording layer containing a leuco dye and a photothermal conversion agent that absorbs infrared wavelength light, includes: performing drawing in a plurality of first regions, the plurality of first regions each extending in one direction and having gaps therebetween; and thereafter detecting recorded states of the plurality of first regions, calculating differences from the input image information, and performing drawing in a plurality of second regions at recording intensities determined on a basis of the differences, the plurality of second regions each extending in the one direction and being provided at the gaps between the plurality of first regions.

A drawing method according to an embodiment of the present disclosure to be performed on a heat-sensitive recording medium including a recording layer, the recording layer containing a leuco dye and a photothermal conversion agent that absorbs infrared wavelength light, includes: performing drawing in a plurality of first regions, the plurality of first regions each extending in one direction and having gaps therebetween; and thereafter detecting recorded states of the plurality of first regions, calculating differences from the input image information, and performing drawing in a plurality of second regions at recording intensities determined on a basis of the differences, the plurality of second regions each extending in the one direction and being provided at the gaps between the plurality of first regions.

A color laser markable article includes a color laser markable layer provided on a support, the laser markable layer including an infrared absorbing compound; a leuco-dye; and an acid generating compound, wherein the acid generating compound has a structure according to Formulae (I) or (II): ##STR00001##
wherein R1 and R3 independently represent an optionally substituted alkyl group, an optionally substituted (hetero)cyclic alkyl group, an optionally substituted (hetero)aryl group, an optionally substituted aralkyl group, an optionally substituted alkoxy group, an optionally substituted (hetero)cyclic alkoxy group, or an optionally substituted (hetero)aryl group; R2, R4 and R5 independently represent an optionally substituted alkyl, an optionally substituted (hetero)cyclic alkyl group or an optionally substituted aralkyl group; and R1 and R2, R4 and R5, R3 and R4, and R3 and R5 may represent the necessary atoms to form a ring.