Abstract: The present invention discloses a decolorizable toner wherein a cationic dye having absorbance from the visible region to the near infrared region is contained in a binder resin together with a decolorant and anti-discoloration agent. In addition, the present invention also discloses a production process of a decolorizable toner that contains a step wherein cationic dye having absorbance from the visible region to the near infrared region, decolorant, binder resin and anti-discoloration agent are uniformly dissolved or dispersed in an organic solvent to prepare a mixed solution; a step wherein the solvent is removed from this mixed solution followed by drying; and, a step wherein the resulting dried mixture is pulverized to produce a toner.

Abstract: A sheet of paper, plastic or the like on which an image has been formed using a toner that is photochemically decolorizable by absorption of near infrared rays is illuminated with near infrared rays under the state wherein the image is heated to a temperature equal to or higher than the glass-transition temperature of a binding resin of the toner. The color of the toner can thereby be easily and rapidly eliminated. This enables the reuse of the sheet to be realized easily and at a low cost.

Abstract: A decolorizable toner including a resin binder, a near infrared ray-absorbing dye, a decolorizing agent and a light fastness stabilizer, and a process for preparing the decolorizable toner, which includes the steps of mixing the near infrared ray-absorbing dye and the light fastness stabilizer with the resin binder, and then mixing the decolorizing agent therewith. The decolorizable toner has excellent light stability during its production or storage and excellent decolorizing property.

Abstract: A sheet of paper, plastic or the like on which an image has been formed using a toner that is photochemically decolorizable by absorption of near infrared rays is illuminated with near infrared rays under the state wherein the image is heated to a temperature equal to or higher than the glass-transition temperature of a binding resin of the toner. The color of the toner can thereby be easily and rapidly eliminated. This enables the reuse of the sheet to be realized easily and at a low cost.

Abstract: A decolorizable toner including a resin binder, a near infrared ray-absorbing dye, a decolorizing agent and a light fastness stabilizer, and a process for preparing the decolorizable toner, which includes the steps of mixing the near infrared ray-absorbing dye and the light fastness stabilizer with the resin binder, and then mixing the decolorizing agent therewith. The decolorizable toner has excellent light stability during its production or storage and excellent decolorizing property.

Abstract: The present invention relates to a near infrared ray-decolorizable recording material comprising a near infrared ray-absorbing cationic dye-borate anion complex having the formula (I): ##STR1## wherein D.sup.+ represents a cationic dye having absorptions in the near infrared region; R.sub.1, R.sub.2, R.sub.3, and R.sub.4 independently represent an alkyl, aryl, alkaryl, allyl, aralkyl, alkenyl, alkynyl, silyl, alicyclic, or saturated or unsaturated heterocyclic group, substituted alkyl, substituted aryl, substituted alkaryl, substituted allyl, substituted aralkyl, substituted alkenyl, substituted alkynyl, or substituted silyl, with the proviso that at least one of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 represents an alkyl group having 1 to 8 carbon atoms.

Abstract: A fluoran derivative useful for a heat-sensitive recording material, having the following general formula I; ##STR1## wherein R.sub.1 and R.sub.2, which may be the same or different, stand for an alkyl group having 1 to 9 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a phenyl group or a phenyl group substituted by an alkyl group having 1 to 4 carbon atoms, and R.sub.3 and R.sub.4, which may be the same or different, stand for an alkyl group having 1 to 6 carbon atoms or a phenyl group or R.sub.3 and R.sub.4 may form a 5- to 8-membered cycloalkane together with the carbon atom to which they are bonded.