An offset printing process for manufacturing a laser markable packaging uses a laser markable offset ink and a laser markable varnish or a laser markable dispersion-lacquer in the process to provide a laser markable image or area on the packaging. The laser markable offset ink, offset varnish or offset dispersion-lacquer including a leuco dye and a metal free optothermal converting agent may be used in the offset printing process.

This heat-sensitive recording material is configured to contain, as a color-developing compound, at least one compound represented by one of formulas (1)-(3): ##STR00001##

Color change compositions that transition from a first to second color state upon application of an applied stimulus are provided. Also provided are substrates having the compositions on a surface thereof, as well as methods of making and using the compositions.

A thermosensitive recording medium comprising an undercoat layer provided on a substrate, and a thermosensitive recording layer containing a colorless or pale colored electron donating leuco dye and an electron accepting color developing agent provided on the undercoat layer, wherein the thermosensitive recording layer contains as the electron accepting color developing agent a urea compound represented by the following general formula (Formula 1)

##STR00001## (wherein X represents O or NH, R.sup.1 represents a hydrogen atom or SO.sub.2R.sup.3, R.sup.3 represents a substituted or unsubstituted alkyl group, aralkyl group or aryl group, R.sup.2 represents a hydrogen atom or an alkyl group, m represents an integer of 0 to 2, and n represents 0 or 1), and wherein the undercoat layer contains 50 to 95 weight % of a pigment by solid and 50 weight % or more of plastic hollow particles by solid with respect to the pigment.

A thermosensitive recording medium comprising an undercoat layer provided on a substrate, and a thermosensitive recording layer containing a colorless or pale colored electron donating leuco dye and an electron accepting color developing agent provided on the undercoat layer, wherein the thermosensitive recording layer contains as the electron accepting color developing agent a urea compound represented by the following general formula (Formula 1)

##STR00001## (wherein X represents O or NH, R.sup.1 represents a hydrogen atom or SO.sub.2R.sup.3, R.sup.3 represents a substituted or unsubstituted alkyl group, aralkyl group or aryl group, R.sup.2 represents a hydrogen atom or an alkyl group, m represents an integer of 0 to 2, and n represents 0 or 1), and wherein the undercoat layer contains 50 to 95 weight % of a pigment by solid and 50 weight % or more of plastic hollow particles by solid with respect to the pigment.

A label (20) may have a facestock (21). A direct thermal coating layer (21A) may be on the facestock (21), the direct thermal coating configured to selectively darken or change color by heat activation when direct thermal printed. A layer of adhesive (22) may be provided, the direct thermal coating layer (21A) being between the facestock (21) and the layer of adhesive (22).

Use of N-(p-toluenesulfonyl)-N-(3-p-toluenesulfonyl-oxy-phenyl)urea with an X-ray diffraction pattern with Bragg angles (2?/CuK.sub.?) of 10.3, 11.0, 12.9, 13.2, 15.4, 17.1, 18.0, 18.2, 19.4, 20.0, 20.7, 21.2, 23.0, 24.9, 25.3, 26.5, 26.8, 27.5, 30.7, 32.7 as a colour developer in a heat-sensitive recording material comprising a carrier substrate, a heat-sensitive colour-forming layer which is applied to one face of the carrier substrate and which contains at least one non-phenolic colour developer and at least one colour former, and an adhesive layer and/or a coating in order to allow rear-face printing using conventional printing methods on the carrier substrate face facing away from the heat-sensitive colour-forming layer, so as to limit the loss of image density and/or the relative print contrast and/or the reduction of the area-based colour developer quantity, wherein, with a value of ?1.20 optical density units for the heat-sensitive recording material stored in accordance with the migration test defined in the description, the image density equals at least 35% of the value of the image density prior to storage and/or the relative print contrast of the heat-sensitive recording material stored in accordance with the migration test equals at least 70% of the value of the relative print contrast prior to storage and/or the area-based colour developer quantity of the heat-sensitive recording material stored in accordance with the migration test equals at least 30% of the area-based colour developer quantity prior to storage.

The present invention provides a heat-sensitive recording body that is excellent in high-speed recording properties, that makes it possible to perform high-quality image recording with a high sensitivity even at a low thermal energy, and that is excellent in printability and economy. A heat-sensitive recording body containing a support, an intermediate layer, and a heat-sensitive color forming layer comprising as main components a leuco dye and a developer, the intermediate layer and the heat-sensitive color forming layer stacked on the support in the order as mentioned, wherein the intermediate layer contains a hollow particle containing a hollow core portion formed by drying a solvent for an alkali-swellable aqueous gel comprising a (meth)acrylic-based copolymer having an acid value of 200 to 400 mgKOH/g, and a resin portion encapsulating the core portion and having a non-alkali-swellable outermost layer of the particle, the non-alkali-swellable outermost layer formed using a hydrophobic monomer, and the hollow particle has an average particle diameter of 1.5 to 3.5 m and a percentage of hollowness of 60 to 85%.

Provided is a thermosensitive recording medium including a support, and a thermosensitive recording layer provided over at least one surface of the support and containing a leuco dye and a developer, wherein the developer includes 4-hydroxy-4-benzyloxydiphenylsulfone and a diphenylsulfone compound represented by general formula (1), and wherein a content of the diphenylsulfone compound represented by general formula (1) is less than 3.0 parts by mass relative to 1.0 part by mass of the 4-hydroxy-4-benzyloxydiphenylsulfone.

The invention relates to a heat-sensitive recording material, comprising a supporting substrate and a heat-sensitive color-forming layer, which contains at least one color former and at least one phenol-free color developer, characterized in that the at least one color developer is a compound of formula (I), wherein Ar is an aryl residue, a heteroaryl residue, or a benzyl residue and Y is an aryl residue, a heteroaryl residue, a benzyl residue, an aryloxy residue, a heteroaryloxy residue, a benzyloxy residue, an arylamino residue, a heteroarylamino residue, or a benzylamino residue. The invention further relates to a method for producing said heat-sensitive recording material. ##STR00001##