To provide a heat-sensitive recording material which produces images with excellent resistance to water, while producing background with resistance to heat. A heat-sensitive recording material which is characterized by containing at least one compound represented by general formula (1) as a color-developing compound:

##STR00001##

wherein, R1-R5 each independently represents a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an alkylcarbonylamino group, an arylcarbonylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, a monoalkylamino group, a dialkylamino group or an arylamino group.

To provide a heat-sensitive recording material which produces images with excellent resistance to water, while producing background with resistance to heat. A heat-sensitive recording material which is characterized by containing at least one compound represented by general formula (1) as a color-developing compound:

##STR00001##

wherein, R1-R5 each independently represents a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an alkylcarbonylamino group, an arylcarbonylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, a monoalkylamino group, a dialkylamino group or an arylamino group.

Primer layers having improved reflectivity and thermal insulation properties are provided for use in microencapsulated thermal imaging sheets. Primer layers having a polymeric binder, of about 3% to about 60% by weight, relative to the total weight of the primer layer, of a white particulate, a primer substrate, and hollow particulate particles improve the reflectivity, color development, color density, and thermal insulation of microcapsule imaging sheets including the same. A black back-coat applied to the substrate on a side opposite the primer layer further enhances the Dmax and E.sub.10 of microcapsule imaging sheets and prevents premature exposure of microcapsule imaging sheets in stacked media.

Primer layers having improved reflectivity and thermal insulation properties are provided for use in microencapsulated thermal imaging sheets. Primer layers having a polymeric binder, of about 3% to about 60% by weight, relative to the total weight of the primer layer, of a white particulate, a primer substrate, and hollow particulate particles improve the reflectivity, color development, color density, and thermal insulation of microcapsule imaging sheets including the same. A black back-coat applied to the substrate on a side opposite the primer layer further enhances the Dmax and E.sub.10 of microcapsule imaging sheets and prevents premature exposure of microcapsule imaging sheets in stacked media.

The invention concerns a CF paper comprising a base paper and a coating applied thereto, said coating containing at least one binding agent, at least one ink-absorbing agent, at least one coating pigment and conventional additives, and being characterised in that the at least one binding agent comprises a cross-linked biopolymeric material in the form of nanoparticles.

The present invention relates to devices and apparatus for detecting contact and optionally its duration and/or recording the level of pressure and/or its duration and/or recording the level of shear force and/or its duration. In particular, certain embodiments of the present invention relate to devices which comprise an element comprising a hydrophobic material and a color-forming material dispersed in at least a portion of the hydrophobic material. Certain embodiments of the present invention relates to materials comprising a solid dispersion of a color-forming material in an elastomeric hydrophobic material. The solid dispersion may take the form of a molecular dispersion or a partial molecular dispersion. Also included in the present invention, although not exclusively, are devices which comprise a hydrophobic material, a color-forming material and a color developing material wherein the color forming material and the color developing material are brought into contact when pressure of a predetermined threshold level is applied or removed from the device.

The present invention relates to devices and apparatus for detecting contact and optionally its duration and/or recording the level of pressure and/or its duration and/or recording the level of shear force and/or its duration. In particular, certain embodiments of the present invention relate to devices which comprise an element comprising a hydrophobic material and a color-forming material dispersed in at least a portion of the hydrophobic material. Certain embodiments of the present invention relates to materials comprising a solid dispersion of a color-forming material in an elastomeric hydrophobic material. The solid dispersion may take the form of a molecular dispersion or a partial molecular dispersion. Also included in the present invention, although not exclusively, are devices which comprise a hydrophobic material, a color-forming material and a color developing material wherein the color forming material and the color developing material are brought into contact when pressure of a predetermined threshold level is applied or removed from the device.

Impact indicator compositions, application devices, and methods comprising coating a surface to be impacted, wherein the coating comprises microcapsules having a cross-linked polyurea shell and a core surrounded by the shell, the core comprising at least one color former; and a developer capable of activating the color former when in contact therewith.

Impact indicator compositions, application devices, and methods comprising coating a surface to be impacted, wherein the coating comprises microcapsules having a cross-linked polyurea shell and a core surrounded by the shell, the core comprising at least one color former; and a developer capable of activating the color former when in contact therewith.

A surface treatment composition includes a solution having a pH within a range of above 4 to 8 that includes metal cations produced in situ from a metal-containing substance having a K.sub.sp no greater than 110.sup.6 in a reaction with an acid having a pKa in a range of 3.0 to +3.5. The composition further includes an agent mixed with the solution that is either a surface sizing agent or a coating agent used on a paper substrate. A print media includes the composition applied to a paper substrate. Preparation of the composition includes reacting the metal-containing substance with the acid, adjusting the pH to above 4 to 8, and mixing the metal cation-containing solution with either the surface sizing or coating agents.