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.

A heat-sensitive recording material having i) a supporting substrate and ii) a heat-sensitive recording layer, where the heat-sensitive recording layer comprises a colour former and a colour developer mixture and the colour developer mixture comprises a) N-[2-(3-phenylureido)phenyl]benzenesulfonamide (compound of the formula (I)), where the compound of the formula (I) is in a crystalline form having an absorption band at 3401 20 cm 1 in the IR spectrum, and b) N-(4-methylphenylsulfonyl)-N-(3-(4-methylphenylsulfonyloxy)phenyl) urea (compound of the formula (II)), where the mass ratio between the compound of the formula (I) and the compound of the formula (II) is 0.5:99.5 to 35:65 or 99.5:0.5 to 65:35.

A heat-sensitive recording material eempri waff-having i) a carrier substrate and ii) a heat-sensitive recording lavcrr-wheKH-fth*. The heat-sensitive recording layer contains a color former and a color developer mixture and the color developer mixture contains a) N-[2 -(3- phenylureido)phenyl]benzole sulfonamide (compound of formula (1)). wherein tlw. The compound of formula (I) is present in a crystalline form, which has an absorption band in the IR spectrum at 3401cm-1. and b) N-(4-methylphenylsulfonyl)-N-(3-(4- methylphenylsulfonyloxy)phenyl)urea (compound of formula (II)).

Dual functionality recording media are disclosed. The recording media or materials can impart information both by direct thermal printing, and by being receptive to a modified inkjet printing technology known in the art as Memjet printing, which combines microelectromechanical systems (MEMS) and inkjet technology. The recording materials include a base substrate to which several coatings are applied. The coatings are selected to provide both direct thermal functionality and receptivity to Memjet-type dye-based inks as applied in Memjet-type printing systems. Heat-sensitive recording capability is provided by a leuco dye/acidic developer combination. Receptivity to Memjet-type dye-based printing is provided by a topcoat of suitable composition. The present inventors recognized that Memjet-type inks printed onto the topcoat suffer from a graying problem, but the problem is solved by appropriate selection of the leuco dye/acidic developer combination.

A recording medium according to an embodiment includes a base material; a first color developing layer that is laminated on the base material, and absorbs light having a given wavelength to develop a color; a photothermal conversion layer that is laminated closer to an incident side of the light than the first color developing layer, transmits visible light, and absorbs the light for photothermal conversion; and a second color developing layer that is laminated closer to the incident side of the light than the first color developing layer, transmits visible light and the light, and develops a color by heat converted by the photothermal conversion layer.

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.

Provided is a thermosensitive recording medium having excellent oil resistance among various performances required for the thermosensitive recording medium. The thermosensitive recording medium has 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 N-[2-(3-phenylureido)phenyl] benzenesulfonamide and an urea-based compound represented by the general formula 1 as the electron accepting color developing agents, ##STR00001##
wherein R.sup.1 represents a substituted or unsubstituted alkyl group, aralkyl group or aryl group, and R.sup.2 represents a hydrogen atom or an alkyl group.

Provided is a thermosensitive recording medium having excellent oil resistance among various performances required for the thermosensitive recording medium. The thermosensitive recording medium has 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 N-[2-(3-phenylureido)phenyl] benzenesulfonamide and an urea-based compound represented by the general formula 1 as the electron accepting color developing agents, ##STR00001##
wherein R.sup.1 represents a substituted or unsubstituted alkyl group, aralkyl group or aryl group, and R.sup.2 represents a hydrogen atom or an alkyl group.