Abstract: A pressure-sensitive recording sheet which comprises a support having thereon a color former-containing microcapsule coating, the microcapsule coating comprising at least two microcapsule layers with the mean particle size of the microcapsules in the microcapsule layer closest to the support being larger than the mean particle size of the microcapsules in the microcapsule layer farther away from the support.

Abstract: A pressure-sensitive recording sheet which comprises a support having thereon a color former-containing microcapsule coating, the microcapsule coating comprising at least two microcapsule layers with the color former concentration in the microcapsules in the microcapsule layer closest to the support being higher than the color former concentration in the microcapsules in the microcapsule layer farther away from the support.

Abstract: A color-forming composition and recording sheets embodying the composition are disclosed, wherein the color-forming composition comprises: (a) a leuco dye, (b) an aromatic secondary amine or derivative thereof and (c) an organic solvent.

Abstract: In a process for producing microcapsules containing hydrophobic oil drops by complex coacervation including a conventional prehardening treatment in which an aldehyde and an alkali material are added to the system, the improvement which comprises adding gelatin having an isoelectric point lower than that of the gelatin employed for forming the walls of the coacervates to the system at a temperature lower than the gelling point of the gelatin employed for forming the walls of the coacervates, but prior to the simultaneous presence in the system of said aldehyde and alkali material, in an amount sufficient to prevent an increase in viscosity due to the reaction of gelatin and aldehyde during said prehardening step.

Abstract: Method of producing microcapsules containing hydrophobic oily liquid, which comprises, in producing microcapsules by complex coacervation, using gelatin, as at least one hydrophilic colloid, adding an aqueous solution of shock preventing agent at a temperature lower than the gelling point of gelatin in order to prevent a rise in viscosity due to reaction of gelatin and aldehyde during hardening pretreatment and rapidly accomplishing hardening pretreatment.