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##

The invention relates to a heat-sensitive recording material, comprising a carrier substrate and at least one heat-sensitive thermal reaction layer, which is applied to at least one side of the carrier substrate and contains at least one fluoran color former, at least one color developer, at least one melting aid, and optionally typical additives, such as lubricants, stabilizers (anti-aging agents), and/or pigments, characterized in that the color developer is dodecyl gallate and the melting aid is an ethylene bis fatty acid amide of formula (I), wherein R.sub.1 and R.sub.2 are CH.sub.3(CH.sub.2).sub.mCH.sub.2 with m=13 and/or 15. The invention further relates to a method for producing said recording material.

##STR00001##

The invention relates to a heat-sensitive recording material. A heat-sensitive recording material, comprising a carrier substrate and a heat-sensitive, color-forming layer that contains at least one color former and at least one phenol-free color developer, is characterized in that said at least one color developer is a compound of formula (I) where Ar.sub.1 and Ar.sub.2 are a phenyl group and/or a C.sub.1-C.sub.4-alkyl substituted phenyl group. The invention also relates to a method for producing this heat-sensitive recording material and to the use, in a heat-sensitive recording material, of the color developer of formula (I) that is present in said heat-sensitive, color-forming layer. ##STR00001##

An information recording medium having a front surface and a back surface has a first color developing layer, a second color developing layer and a third color developing layer. The first color developing layer develops yellow at a temperature not less than a first threshold value. The second color developing layer is arranged at the back surface side with respect to the first color developing layer. The second color developing layer develops magenta at a temperature not less than a second threshold value that is lower than the first threshold value. The third color developing layer is arranged at the front surface side with respect to the first color developing layer. The third color develops cyan at a temperature not less than a third threshold value that is higher than the first threshold value.

An information recording medium having a front surface and a back surface has a first color developing layer, a second color developing layer and a third color developing layer. The first color developing layer develops yellow at a temperature not less than a first threshold value. The second color developing layer is arranged at the back surface side with respect to the first color developing layer. The second color developing layer develops magenta at a temperature not less than a second threshold value that is lower than the first threshold value. The third color developing layer is arranged at the front surface side with respect to the first color developing layer. The third color develops cyan at a temperature not less than a third threshold value that is higher than the first threshold value.

A heat-sensitive recording material including a web-shaped substrate having a front side and an opposite reverse side, and at least one heat-sensitive recording layer on either or both of the sides of the web-shaped substrate. The heat-sensitive recording layer contains at least one dye precursor at least one salicylic acid derivative as a (color) developer reactive with this at least one dye precursor, and polyvinylpyrrolidone as auxiliary component augmenting the (color) developer the at least one salicylic acid derivative is 3,5-di(-methylbenzyl)salicylic acid.

A heat-sensitive recording material includes a heat-sensitive recording layer containing a basic dye and a developer and provided on a supporting body, in which the developer is at least one type of an N-substituted amino acid derivative represented by the following General Formula: (RX).sub.mY(Z).sub.m . . . (1) (In Formula (1), R represents an alkyl group or an aryl group which may have a substituent. X is a group bonded to the N-terminus of Y, and represents OCO, SO.sub.2NHCO, NHCO, NHCS, or SO.sub.2. Y represents an amino acid residue or a peptide residue. Z represents a group bonded to the C-terminus of Y and represents an OH group or an OR group. When Y is an amino acid residue other than a cystine residue or when Y is a peptide residue not having a cystine residue, m=1, and when Y is a peptide residue having n cystine residues, m=n+1 and n is 1 or 2.)

A heat-sensitive recording material includes a heat-sensitive recording layer containing a basic dye and a developer and provided on a supporting body, in which the developer is at least one type of an N-substituted amino acid derivative represented by the following General Formula:

(RX).sub.mY(Z).sub.m(1)

(In Formula (1), R represents an alkyl group or an aryl group which may have a substituent. X is a group bonded to the N-terminus of Y, and represents OCO, SO.sub.2NHCO, NHCO, NHCS, or SO.sub.2. Y represents an amino acid residue or a peptide residue. Z represents a group bonded to the C-terminus of Y and represents an OH group or an OR group. When Y is an amino acid residue other than a cystine residue or when Y is a peptide residue not having a cystine residue, m=1, and when Y is a peptide residue having n cystine residues, m=n+1 and n is 1 or 2.)

A thermosensitive recording body has at least a thermosensitive recording layer and a topcoat layer formed on a substrate. The substrate consists of a transparent film. At least the thermosensitive recording layer and the topcoat layer includes a diffuse reflection suppressor component that suppresses diffuse reflection of light from particles constituting the thermosensitive recording layer and the topcoat layer.