A thermosensitive recording medium according to an embodiment of the present disclosure includes: a recording layer that includes a coloring compound having electron-donating property, a developer having electron-accepting property, a photothermal conversion agent, and a polymer material; and a protective member that is stacked on the recording layer, and has a convexo-concave shape in a plane.

In the present invention, there is provided a use of 1,1,1-tris(4-hydroxyphenyl)ethane in a composition in the formation of an image on a substrate having said composition applied thereon, wherein the image is formed upon exposure of the composition to NIR or IR radiation, and wherein the image is capable of being retained on the substrate for at least 1 day under conditions of at least 50% relative humidity. The present invention is further directed towards compositions comprising 1,1,1-tris(4-hydroxyphenly)ethane, in addition to substrates, methods of forming an image and printing processes comprising said compositions.

A recording material and a recording sheet having excellent color-developing performance and storage stability and particularly having excellent heat-resistance of background. The recording material contains a color former (A), a compound represented by formula (I) (B), and a compound represented by formula (II) (C).

##STR00001##

An object is to provide a thermosensitive recording material and a laminate which are excellent in color development sensitivity and favorable in storage characteristics such as heat resistance, plasticizer resistance, moisture resistance, oil resistance, and grease resistance. A thermosensitive recording material in which a thermosensitive recording layer is provided on a support, wherein the thermosensitive recording layer contains a specific diphenylsulfone compound and an analog compound thereof at a specific ratio. A laminate in which a thermosensitive recording layer is provided on a support, wherein the thermosensitive recording layer contains a specific diphenylsulfone compound and an analog compound thereof at a specific ratio.

The invention relates to a color developer of formula (I), (Ar.sup.1SO.sub.2NH-)m-Y(NHC(O)NHSO.sub.2Ar.sub.2)n (I), wherein Ar.sup.1 is an unsubstituted or substituted aromatic moiety, Ar.sup.2 is an unsubstituted or substituted phenyl moiety, Y is at least an (m+n)-times substituted benzene group or naphthalene group, and Y is substituted in such a way that at least one Ar.sub.2SO.sub.2NHC(O)NH group is in ortho-position with respect to at least one Ar.sup.1SO.sub.2NH group. The invention further relates to a heat-sensitive recording material, comprising a carrier substrate and a heat-sensitive color-forming layer, which contains at least one color former and at least one phenol-free color developer, the at least one color developer being the compound of formula (I). The invention further relates to a method for producing said heat-sensitive recording material.

An object is to provide a thermosensitive recording material and a laminate which are excellent in color development sensitivity, which cause less color development in a blank area even at a high temperature, which are also favorable in storage stability of a print area, and which are excellent in contrast between a blank area and a print area. A thermosensitive recording material in which a thermosensitive recording layer is provided on a support, wherein the thermosensitive recording layer contains a specific diphenylsulfone compound and an analog compound thereof at a specific ratio. A laminate in which a thermosensitive recording layer is provided on a support, wherein the thermosensitive recording layer contains a specific diphenylsulfone compound and an analog compound thereof at a specific ratio.

Aspects of the invention include color change compositions having a color former and color developer composition that transitions from a first color state to a second color state upon application of an applied stimulus and an amount of a copolymer sufficient to eliminate background color of the color former and color developer composition during transition from the first color state to the second color state. Methods for preparing and devices employing the color change compositions of the invention are also described.

The objective of the present invention is to provide a thermosensitive recording medium excellent in color developing property, especially excellent in bar code readability, under severe environment. Provided is a thermosensitive recording medium having a thermosensitive recording layer comprising a colorless or pale colored electron donating leuco dye and an electron accepting color developing agent on a substrate, wherein the thermosensitive recording layer contains a specific sulfone compound and a specific urea-urethane-based compound in a specific ratio.

A recording material and a recording sheet having better color-developing performance, storage stability, etc. A recording material which contains (A) at least one color former, (B) at least one compound selected from the group including compounds represented by the following formula (I), and (C) at least one compound selected from the group including compounds represented by the following formula (II)

(wherein R.sup.1 to R.sup.3 each represent a halogen atom, a nitro group, a C.sub.1 to C.sub.6 alkyl group, a C.sub.1 to C.sub.6 alkoxy group, a C.sub.2 to C.sub.6 alkenyl group or a C.sub.1 to C.sub.6 haloalkyl group, n1 and n3 each independently represent any integer of 0 to 5, n2 represents any integer of 0 to 4, and X represents SO.sub.2O or OSO.sub.2).

##STR00001##

The invention relates to a color developer of formula (I), (Ar.sup.1SO.sub.2NH)m-Y(NHC(O)NHSO.sub.2Ar.sub.2)n (I), wherein Ar.sup.1 is an unsubstituted or substituted aromatic moiety, Ar.sup.2 is an unsubstituted or substituted phenyl moiety, Y is at least an (m+n)-times substituted benzene group or naphthalene group, and Y is substituted in such a way that at least one Ar.sub.2SO.sub.2NHC(O)NH group is in ortho-position with respect to at least one Ar.sup.1SO.sub.2NH group. The invention further relates to a heat-sensitive recording material, comprising a carrier substrate and a heat-sensitive color-forming layer, which contains at least one color former and at least one phenol-free color developer, the at least one color developer being the compound of formula (I). The invention further relates to a method for producing said heat-sensitive recording material.