Abstract: A sheet coated with a reduced charge montmorillonite pigment for use in record material, especially pressure-sensitive carbonless copying systems. The pigment is produced by replacing exchangeable cations of a substantially dioctahedral montmorillonite (exemplified by certain bentonite clays) with lithium ions, mildly heating the lithium-exchanged montmorillonite to collapse irreversibly the montmorillonite structure, and grinding the heat-treated material to pigment-size particles. The sheets produce stabilized intense images when printed with a solution of crystal violet lactone (CVL) dye precursor and thus may be used with CVL without employing secondary slow acting dyes such as benzoyl leuco methylene blue. The sheets are also useful with other colorless or substantially colorless dye precursors.

Abstract: A sheet coated with a reduced charge montmorillonite pigment for use in record material, especially pressure-sensitive carbonless copying systems. The pigment is produced by replacing exchangeable cations of a dioctahedral montmorillonite (exemplified by certain bentonite clays) with lithium ions, mildly heating the lithium-exchanged montmorillonite to collapse irreversibly the montmorillonite structure, and grinding the heat-treated material to pigment-size particles. The sheets produce stabilized intense images when printed with a solution of crystal violet lactone (CVL) dye precursor and thus may be used with CVL without employing secondary slow acting dyes such as benzoyl leuco methylene blue. The sheets are also useful with other colorless or substantially colorless dye precursors.

Abstract: A reduced charge montmorillonite pigment useful as a color-former in record material, especially pressure-sensitive carbonless copying record systems. The pigment is produced by replacing exchangeable cations of a selected dioctahedral montmorillonite crude clay (exemplified by certain bentonite clays) with a predetermined amount of lithium ions, mildly heating the lithium-exchanged montmorillonite to collapse irreversibly the montmorillonite structure, and grinding the heat-treated material to pigment-size particles, the grinding preferably being carried out in a fluid energy mill. When the pigment particles are coated on paper, the coated sheets produce stabilized intense images when printed with a solution of crystal violet lactone (CVL) dye precursor and thus may be used in record material with CVL without employing secondary slow acting dyes such as benzoyl leuco methylene blue. The sheets are also useful with other colorless or substantially colorless dye precursors.

Abstract: A reduced charge montmorillonite pigment useful as a colorformer in record material, especially pressure-sensitive carbonless copying record systems. The pigment is produced by replacing exchangeable cations of a selected dioctahedral montmorillonite crude clay (exemplified by certain bentonite clays) with a predetermined amount of lithium ions, mildly heating the lithium-exchanged montmorillonite to collapse irreversibly the montmorillonite structure, and grinding the heat-treated material to pigment-size particles, the grinding preferably being carried out in a fluid energy mill. When the pigment particles are coated on paper, the coated sheets produce stabilized intense images when printed with a solution of crystal violet lactone (CVL) dye precursor and thus may be used in record material with CVL without employing secondary slow acting dyes such as benzoyl leuco methylene blue. The sheets are also useful with other colorless or substantially colorless dye precursors.