An information medium according to an embodiment of the present disclosure includes two or more data layers provided on a support base. The two or more data layers have two or more pieces of visible information recorded on the two or more data layers. The two or more pieces of visible information are obtained by decomposing two-dimensional visible information and thereby allowing synthesis of the two or more pieces of visible information to result in the two-dimensional visible information.

An object of the present invention is to provide: a developer that can provide a thermosensitive recording material excellent in color development sensitivity and storage stability; and a thermosensitive recording material obtained using the developer. The object is achieved by a developer including a compound represented by the following Formula (1).

##STR00001##

In Formula (1), a, A, and L are as follows: a is an integer selected from 1 to 5, A is each independently a fluoro group or a perfluoroalkyl group, and L is any of functional groups represented by the following Formula (2):

##STR00002##

wherein in Formula (2), R is a C.sub.1-C.sub.4 alkyl group, and * represents a binding site to a sulfur atom in Formula (1).

An object of the present invention is to provide: a developer that can provide a thermosensitive recording material excellent in color development sensitivity and storage stability; and a thermosensitive recording material obtained using the developer. The object is achieved by a developer including a compound represented by the following Formula (1).

##STR00001##

In Formula (1), a, A, and L are as follows: a is an integer selected from 1 to 5, A is each independently a fluoro group or a perfluoroalkyl group, and L is any of functional groups represented by the following Formula (2):

##STR00002##

wherein in Formula (2), R is a C.sub.1-C.sub.4 alkyl group, and * represents a binding site to a sulfur atom in Formula (1).

An information medium according to an embodiment of the present disclosure includes two or more data layers provided on a support base. The two or more data layers have two or more pieces of visible information recorded on the two or more data layers. The two or more pieces of visible information are obtained by decomposing two-dimensional visible information and thereby allowing synthesis of the two or more pieces of visible information to result in the two-dimensional visible information.

An information medium according to an embodiment of the present disclosure includes two or more data layers provided on a support base. The two or more data layers have two or more pieces of visible information recorded on the two or more data layers. The two or more pieces of visible information are obtained by decomposing two-dimensional visible information and thereby allowing synthesis of the two or more pieces of visible information to result in the two-dimensional visible information.

In one aspect, the present invention relates to a thermosensitive recording medium comprising at least: —a support layer; —a thermosensitive colouring layer over the support layer, the thermosensitive colouring layer containing a leuco dye; and —a protective layer over the thermosensitive colouring layer; wherein the thermosensitive colouring layer comprises a developer having the general formula (I) below: wherein R.sub.1 to R.sub.3 each independently represent a hydrogen atom, a halogen atom, a C1-C6 alkyl group, a C1-C6 alkoxyl group, a C1-C6 fluoroalkyl group; characterized in that the protective layer comprises particles of wax with an average particle size of at least 0.05 μm and at most 2.0 μm. In further aspects, the present invention relates to a label for attachment to a product comprising the thermosensitive recording medium of the invention, and to a consumer product package to which a thermosensitive recording medium or a label of the invention has been attached.

##STR00001##

Disclosed is a heat-sensitive recording material comprising an undercoat layer and a heat-sensitive recording layer in this order on a support, the undercoat layer containing hollow particles, a binder, and an inorganic pigment I, the heat-sensitive recording layer containing a leuco dye, a developer, and an inorganic pigment II, and the heat-sensitive recording layer containing an N,N′-diarylurea-based compound represented by the following formula (1):

##STR00001## wherein R.sub.2s may be the same or different, and each represents C.sub.1-12 alkyl, C.sub.7-12 aralkyl, or C.sub.6-12 aryl, and the aralkyl and the aryl may be each substituted with C.sub.1-12 alkyl, C.sub.1-12 alkoxy, C.sub.6-12 aryl, or halogen; A.sub.1s may be the same or different, and each represents hydrogen or C.sub.1-4 alkyl, as the developer, and a pigment with an oil absorption of 130 ml/100 g or less as the inorganic pigment II.

Disclosed is a heat-sensitive recording material comprising an undercoat layer and a heat-sensitive recording layer in this order on a support, the undercoat layer containing hollow particles, a binder, and an inorganic pigment I, the heat-sensitive recording layer containing a leuco dye, a developer, and an inorganic pigment II, and the heat-sensitive recording layer containing an N,N′-diarylurea-based compound represented by the following formula (1):

##STR00001## wherein R.sub.2s may be the same or different, and each represents C.sub.1-12 alkyl, C.sub.7-12 aralkyl, or C.sub.6-12 aryl, and the aralkyl and the aryl may be each substituted with C.sub.1-12 alkyl, C.sub.1-12 alkoxy, C.sub.6-12 aryl, or halogen; A.sub.1s may be the same or different, and each represents hydrogen or C.sub.1-4 alkyl, as the developer, and a pigment with an oil absorption of 130 ml/100 g or less as the inorganic pigment II.

The invention relates to a color developer of the formula (I), wherein m and n independently of one another are ≥1, Ar.sup.1 is an unsubstinited or substituted (hetero) aromatic radical, Ar.sup.2 is an unsubstituted or substituted phenyl radical, and Y is at least one (m+n)-times substituted benzene or naphthalene group, and to a heat-sensitive recording material, comprising a supporting substrate and a heat-sensitive color-forming layer containing at least one color former and at least one phenol-free color developer, wherein the at least one color developer is the compound of the formula (I). The invention further relates to a method for producing said heat-sensitive recording material.

##STR00001##

The invention relates to a color developer of the formula (I), wherein m and n independently of one another are ≥1, Ar.sup.1 is an unsubstinited or substituted (hetero) aromatic radical, Ar.sup.2 is an unsubstituted or substituted phenyl radical, and Y is at least one (m+n)-times substituted benzene or naphthalene group, and to a heat-sensitive recording material, comprising a supporting substrate and a heat-sensitive color-forming layer containing at least one color former and at least one phenol-free color developer, wherein the at least one color developer is the compound of the formula (I). The invention further relates to a method for producing said heat-sensitive recording material.

##STR00001##