A color-forming composition is useful to provide a printout image in an imaged lithographic printing plate precursor. This color-forming composition includes (a) an acid generator; (b) a tetraaryl borate; (c) an acid-sensitive dye precursor; and (d) a compound having the following Structure (I):

##STR00001##

wherein n is 1, 2, 3, or 4; R independently represents a monovalent substituent or the atoms necessary to form a fused ring if n is at least 2, and at least one R substituent is an electron-withdrawing group. The color-forming composition is included within a negative-working radiation-sensitive imageable layer along with a free radically polymerizable component and a radiation absorber such as an infrared radiation absorber.

According to one embodiment, a recording medium is a recording medium in a card form. The recording medium includes a substrate, and a color development layer laminated on the substrate, and provided with a line for security that extends along a lamination surface of the substrate from an end face of the recording medium, such that presence or absence of the line for security is optically identifiable at the end face. It is thus provided a recording medium that can easily prevent falsification with a simple structure, and allows authenticity determination to be performed relatively easily.

An object of the present invention is to provide a recording material or a recording sheet using, as a color-developing agent, a non-phenol-based compound good in color developing performance and the like. A compound represented by the following formula (I) is used as the color-developing agent:

##STR00001##

(wherein X represents CH.sub.2 or the like; R.sup.1 to R.sup.3 each independently represent a hydrogen atom, a halogen atom or the like; n1 and n3 each independently represent any integer of 1 to 5; two groups represented by R.sup.3 adjacent to each other on a benzene ring optionally bond to each other to form an optionally substituted 6-membered ring; and n2 represents any integer of 1 to 4).

The invention relates to a compound of the formula (I) Ar(NHSO.sub.2Ar.sup.1)1(SO.sub.2NHAr.sup.1).sub.m(NHC(O)NHAr.sup.2).sub.n (I), wherein 1 and m independently of one another are 0, 1, 2, 3, and/or 4 and the sum of is equal to or more than 1, n is 2, 3, 4, or 5, Ar is a benzol group which is substituted (i+m+n) times, Ar.sup.1 is an unsubstituted or substituted aromatic group, and Ar.sup.2 is an unsubstituted or substituted phenyl group or a benzoyl group. The invention also 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 said color developer.

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 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.

Non-phenolic direct thermal recording media have a thermally responsive layer containing a leuco dye and a plurality of diarylurea acidic developers selected to improve the quality and readability of the image produced in such media, particularly after being contacted with oils such as vegetable oil. The diarylurea developers preferably include, or consist essentially of, or consist of, N,N-diphenylurea (DPU) and a derivative of DPU. An exemplary combination is DPU together with a developer known commercially as TGMD.

The laminate includes: a base material; an intermediate layer provided on the base material and having an accommodation part; a recording medium provided in the accommodation part; and an overlay layer provided on the intermediate layer. The accommodation part is provided in a part of a plane of the intermediate layer, and the accommodation part is a through hole penetrating in the thickness direction of the intermediate layer or a recess recessed in the thickness direction of the intermediate layer. The recording medium includes a color development layer containing: a coloring compound having an electron donating property; a developer having an electron accepting property; and a matrix resin. The base material, the intermediate layer, and the overlay layer contain the same type of resin material. The base material and the intermediate layer are bonded to each other by fusion, and the intermediate layer and the overlay layer are bonded to each other by fusion.