# US 4,398,753 A · Pressure sensitive recording unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,398,753 A - Document ID: US4398753A - Status: Granted - Kind: A - Application number: 06/330,325 - Filed: 1981-12-14 - Granted: 1983-08-16 - Earliest claimed: 1980-12-26 - Assignees: Mitsui Toatsu Chemicals, Inc. - Inventors: Makoto Asano; Kiyoharu Hasegawa; Hiroyuki Akahori; Michihiro Tsujimoto - Web page: https://patentgrep.com/patent/US4398753A ## CPC - B41M 5/136: Organic colour formers, e.g. leuco dyes - B41M 5/1366: {characterised solely by tri (aryl or hetaryl)methane derivatives (B41M5/1363 takes precedence)} - Y10S 428/914: Transfer or decalcomania - B41M: PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING, (correction of typographical errors B41J; processes for applying transfer pictures or the like B44C1/16; fluid media for correction of typographical errors by coating C09D10/00; printing textiles D06P) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract Disclosed is a pressure sensitive recording unit which comprises a single base web sheet and a methine-type dyestuff and an organic oxidizing compound both supported on the single base web sheet, or a combination of first and second base web sheets and the methine-type dyestuff and organic oxidizing compound supported individually on the first and second base web sheets. Such a recording unit includes for example a pressure sensitive recording unit formed in combination of (a) a back-coated topsheet (CB-sheet) making use of microscopic capsules containing a solution obtained by dissolving a methine-type dyestuff in a solvent having a high boiling point and (b) a front-coated undersheet (CF-sheet) carrying an organic oxidizing compound coated thereon. Also disclosed is a pressure sensitive recording unit which includes a base web sheet carrying thereon such a methine-type dyestuff together with a metal ion sequestering agent and/or alkanol amine. ## Claims ### Claim 1 A pressure sensitive recording unit comprising a single base web sheet and a colorless or light-colored methine-type dyestuff represented by the formula (I): ##STR8## wherein, X, Y and Z represent individually a phenyl, naphthyl, or .beta.-styryl group or a residue of an aromatic heterocyclic ring which group or ring may optionally be substituted, X, Y and Z may be the same or different, and either two of X, Y and Z may be coupled together to form a ring, and an organic oxidizing compound selected from oxidizing quinone derivatives substituted by a multiplicity of electron attractive groups, both the dyestuff and the oxidizing compound being supported on the single base web sheet; or a combination of a first base web sheet on which said methine-type dyestuff is supported and a second base web sheet on which said organic oxidizing compound is supported. ### Claim 2 (depends on 1) The pressure sensitive recording unit according to claim 1, wherein the methine-type dyestuff is supported together with an alkanol amine on its base web sheet. ### Claim 3 (depends on 1) The pressure sensitive recording unit according to claim 1, wherein the methine-type dyestuff is supported together with an alkanol amine and a metal ion sequestering agent on its respective base web sheet. ### Claim 4 A pressure sensitive recording unit comprising, in combination: (A) a first sheet carrying thereon a layer which contains (a) microscopic capsules enclosing a solution of a colorless or light-colored methine-type dyestuff represented by the general formula (I): ##STR9## wherein, X, Y and Z represent individually a phenyl, naphthyl, or .beta.-styryl group or a residue of an aromatic heterocyclic ring which group or ring may optionally be substituted, X, Y and Z may be the same or different, and either two of X, Y and Z may be coupled together to form a ring, and (b) an alkanol amine and/or metal ion sequestering agent; and (B) a second sheet carrying thereon a layer containing an organic oxidizing compound selected from oxidizing quinone derivatives substituted by a multiplicity of electron attractive groups. ### Claim 5 A pressure sensitive recording unit comprising a single base web sheet; and a layer supported on a same surface of the single base web sheet and containing (a) microscopic capsules enclosing a colorless or light-colored solution of a methine-type dyestuff represented by the general formula (I): ##STR10## wherein, X, Y and Z represent individually a phenyl, naphthyl, or .beta.-styryl group or a residue of an aromatic heterocyclic ring which group or ring may optionally be substituted, X, Y and Z may be the same or different, and either two of X, Y and Z may be coupled together to form a ring, (b) an alkanol amine and/or metal ion sequestering agent, and (c) an organic oxidizing agent selected from oxidizing quinone derivatives substituted by a multiplicity of electron attractive groups. ### Claim 6 (depends on 1, 4, 5) The pressure sensitive recording unit according to any one of claims 1, 4 or 5, wherein the methine-type dyestuff has been microencapsulated as a solution of a hydrophobic solvent having a high boiling point. ### Claim 7 (depends on 6) The pressure sensitive recording unit according to claim 6, wherein the methine-type dyestuff is a triphenylmethane-type dyestuff. ### Claim 8 (depends on 1, 4, 5) The pressure sensitive recording unit according to any one of claims 1, 4 or 5, wherein the organic oxidizing compound has its oxidation-reduction potential at 0.4 eV. ### Claim 9 (depends on 1, 4, 5) The pressure sensitive recording unit according to any one of claims 1, 4 or 5, wherein the organic oxidizing compound is a 2,3,5,6-tetra-substituted-1,4-benzoquinone. ### Claim 10 (depends on 4, 5) The pressure sensitive recording unit according to claim 4 or 5, wherein the alkanol amine is a tertiary alkanol amine. ### Claim 11 (depends on 4, 5) The pressure sensitive recording unit according to claim 4 or 5, wherein the metal ion sequestering agent is a water-soluble organic metal ion sequestering agent. ### Claim 12 (depends on 4, 5) The pressure sensitive recording unit according to claim 4 or 5, wherein the metal ion sequestering agent is a polyphosphate.