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).

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).

A marking system comprises a substrate having a surface coated with a color-triggering developer and a deactivating ink composition; and a marking composition comprising at least one color precursor. At least one “non-color developing portion” of the surface is coated with both the color-triggering developer and the deactivating ink composition, and at least one “color-developing portion” of the surface is coated with the color-triggering developer and is not coated with the deactivating ink composition. Color development occurs at the color-developing portion(s) and does not occur at the non-color developing portion(s) upon application of the marking composition to the surface of the substrate.

A marking system comprises a substrate having a surface coated with a color-triggering developer and a deactivating ink composition; and a marking composition comprising at least one color precursor. At least one “non-color developing portion” of the surface is coated with both the color-triggering developer and the deactivating ink composition, and at least one “color-developing portion” of the surface is coated with the color-triggering developer and is not coated with the deactivating ink composition. Color development occurs at the color-developing portion(s) and does not occur at the non-color developing portion(s) upon application of the marking composition to the surface of the substrate.

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.2—O— or —O—SO.sub.2—). ##STR00001##

Provided are a material for pressure measurement, including a color forming layer that contains microcapsules A encapsulating an electron-donating colorless dye precursor and microcapsules B not encapsulating an electron-donating colorless dye precursor, in which a volume standard median diameter D50A of the microcapsules A and a volume standard median diameter D50B of the microcapsules B satisfy Equation 1; a material composition for pressure measurement; and a material set for pressure measurement:
D50A<D50B  Equation 1.

Provided are a material for pressure measurement, including a color forming layer that contains microcapsules A encapsulating an electron-donating colorless dye precursor and microcapsules B not encapsulating an electron-donating colorless dye precursor, in which a volume standard median diameter D50A of the microcapsules A and a volume standard median diameter D50B of the microcapsules B satisfy Equation 1; a material composition for pressure measurement; and a material set for pressure measurement:
D50A<D50B  Equation 1.

Provided are a material for pressure measurement, including a color forming layer that contains microcapsules A encapsulating an electron-donating colorless dye precursor and microcapsules B not encapsulating an electron-donating colorless dye precursor, in which a volume standard median diameter D50A of the microcapsules A and a volume standard median diameter D50B of the microcapsules B satisfy Equation 1; a material composition for pressure measurement; and a material set for pressure measurement:

D50A<D50B  Equation 1.

Provided are a material for pressure measurement, including a color forming layer that contains microcapsules A encapsulating an electron-donating colorless dye precursor and microcapsules B not encapsulating an electron-donating colorless dye precursor, in which a volume standard median diameter D50A of the microcapsules A and a volume standard median diameter D50B of the microcapsules B satisfy Equation 1; a material composition for pressure measurement; and a material set for pressure measurement:

D50A<D50B  Equation 1.

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.