Provided are thermochromic color-memorizing composition and thermochromic color-memorizing microcapsule pigment encapsulating the same, the thermochromic color-memorizing composition including: (a) an electron-donating color-developing organic compound; (b) an electron-accepting compound; and (c) an ester compound represented by the following formula (1) as a reaction medium which controls color reaction between the components (a) and (b): ##STR00001##

A thermal sensitive media for use with labeling or identification methods is disclosed. The thermal sensitive media comprises a media layer and a thermally sensitive record layer formed upon at least one surface of the media layer. The thermally sensitive record layer forms a visually discernable colored image in response to heat. However, the colored image is subject to degradation as a result of exposure to ultraviolet radiation within a known photodegradative wavelength range. An ultraviolet protective coating layer may then disposed over the thermally sensitive record layer. A lamination layer is positioned internal to the media layer and comprises a matrix of micro heating elements driven by radio frequency (RF) power. The matrix of micro heating elements are arranged in a pin array to energize the micro heating elements within the laminated media structure to create a simple numeric image.

A thermal sensitive media for use with labeling or identification methods is disclosed. The thermal sensitive media comprises a media layer and a thermally sensitive record layer formed upon at least one surface of the media layer. The thermally sensitive record layer forms a visually discernable colored image in response to heat. However, the colored image is subject to degradation as a result of exposure to ultraviolet radiation within a known photodegradative wavelength range. An ultraviolet protective coating layer may then disposed over the thermally sensitive record layer. A lamination layer is positioned internal to the media layer and comprises a matrix of micro heating elements driven by radio frequency (RF) power. The matrix of micro heating elements are arranged in a pin array to energize the micro heating elements within the laminated media structure to create a simple numeric image.

Provided by the present invention is a PVA having highly harmonized adequate water solubility, thickening property and coating film strength, and having superior storage stability in terms of the viscosity in an aqueous solution. A vinyl alcohol polymer having a ratio (Mw (A)/Mn (A)) of the weight average molecular weight (Mw (A)) to the number average molecular weight (Mn (A)) of 3 or greater and 8 or less, and being capable of giving a vinyl alcohol polymer having a ratio (Mw/Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 2 or greater and less than 3 when treated at 40 C. for 1 hour in a sodium hydroxide solution.

Provided by the present invention is a PVA having highly harmonized adequate water solubility, thickening property and coating film strength, and having superior storage stability in terms of the viscosity in an aqueous solution. A vinyl alcohol polymer having a ratio (Mw (A)/Mn (A)) of the weight average molecular weight (Mw (A)) to the number average molecular weight (Mn (A)) of 3 or greater and 8 or less, and being capable of giving a vinyl alcohol polymer having a ratio (Mw/Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 2 or greater and less than 3 when treated at 40 C. for 1 hour in a sodium hydroxide solution.

A microencapsulated pigment including a leuco dye system is incorporated as one or more layers in a roll of adhesive tape. The tape is applied and may be rubbed by hand or another object to induce a color change. The change may serve as an indicator that the tape is well adhered for masking purposes in a painting operation, or to present a design where only selected portions of the tape are rubbed to induce the color change. The microencapsulated pigment may be constructed so that the color change is irreversible or reversible.

The invention relates to a heat-sensitive recording material. A heat-sensitive recording material, comprising a carrier substrate and a heat-sensitive, colour-forming layer that contains at least one colour former and at least one phenol-free colour developer, is characterised in that said at least one colour 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 colour developer of formula (I) that is present in said heat-sensitive, colour-forming layer.

##STR00001##

[Problems] An object of the present invention is to provide: thermochromic color-memory composition which effectively expresses a property of being capable of interchangeably memorizing and retaining colors and is thus applicable to various fields; and thermochromic memory microcapsule pigment encapsulating the same. [Means for Solution] Provided are thermochromic color-memory composition and thermochromic color-memory microcapsule pigment encapsulating the same, the thermochromic color-memory composition comprising: (a) a component composed of an electron-donating color-developing organic compound; (b) a component composed of an electron-accepting compound; and (c) a reaction medium which comprises an ester compound represented by the following Formula (1) and controls color reaction between the components (a) and (b): ##STR00001##
(wherein, R represents an alkyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group having 5 to 12 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms or an alkenyl group having 4 to 22 carbon atoms; X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a halogen atom; and n represents 0 or 1).

Provided are thermochromic color-memory composition and thermochromic color-memory microcapsule pigment encapsulating the same, the thermochromic color-memory composition including: (a) a component composed of an electron-donating color-developing organic compound; (b) a component composed of an electron-accepting compound; and (c) a component composed of an ester compound represented by the following Formula (1) as a reaction medium which controls color reaction between the components (a) and (b): ##STR00001##
(wherein, R represents an alkyl group having 3 to 18 carbon atoms or an aliphatic acyl group having 3 to 18 carbon atoms; X represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 or 2 carbon atoms or a halogen atom; Y represents a hydrogen atom or a methyl group; and Z represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 or 2 carbon atoms or a halogen atom).

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.