# US 12,759,336 B2 · Pencil lead > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,759,336 B2 - Document ID: US12759336B2 - Status: Granted - Kind: B2 - Application number: 18/248,803 - Filed: 2021-10-05 - Published: 2023-12-14 - Granted: 2026-10-13 - Earliest claimed: 2020-10-14 - Assignees: Mitsubishi Pencil Company, Limited - Applicants: Mitsubishi Pencil Company, Limited - Inventors: Hiroyuki Arai; Ryota Kubo; Masaaki Matsumoto - Web page: https://patentgrep.com/patent/US12759336B2 ## CPC - B43K 19/02: Pencils with graphite; Coloured pencils - C09D 13/00: Pencil-leads; Crayon compositions; Chalk compositions - B43K: IMPLEMENTS FOR WRITING OR DRAWING (containers, casings or accessories for cosmetic substances, e.g. shaving soap, lipstick, make-up A45D34/00, A45D40/00) - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) ## Abstract A pencil lead may achieve high levels of both improved density and improved fixability of a hand-drawn line and also be less likely to stain a hand during writing. Examples of this pencil lead include a pencil lead comprising a black porous fired lead body including at least graphite, wherein at least a compound selected from octyldodecyl erucate, oleyl oleate, octyldodecyl oleate, isopropyl palmitate, 2-ethylhexyl palmitate, and propylene glycol monooleate is impregnated in pores of the porous fired lead body. The pores of the black porous fired lead body are preferably impregnated with at least one selected from a terpene phenolic resin, a rosin ester resin, a ketone resin, and a rosin-modified phenolic resin, in addition to the compound. ## Claims ### Claim 1 A pencil lead, comprising: a black porous fired lead body comprising graphite, wherein, impregnated in pores thereof, the porous fired lead body comprises (i) octyldodecyl erucate, oleyl oleate, octyldodecyl oleate, isopropyl palmitate, 2-ethylhexyl palmitate, and/or propylene glycol monooleate, and (ii) a terpene phenolic resin, a rosin ester resin, a ketone resin, and/or a rosin-modified phenolic resin. ### Claim 2 (depends on 1) The pencil lead of claim 1, wherein jojoba oil, which is a mixture containing the octyldodecyl erucate, is impregnated in the pores of the porous fired lead body. ### Claim 3 (depends on 2) The pencil lead of claim 2, wherein the jojoba oil is present in an amount of 60 mass % or greater in an oil impregnating the pores of the porous fired lead body. ### Claim 4 (depends on 1) The pencil lead of claim 1, wherein, impregnated in pores thereof, the porous fired lead body comprises the octyldodecyl erucate. ### Claim 5 (depends on 1) The pencil lead of claim 1, wherein, impregnated in pores thereof, the porous fired lead body comprises the oleyl oleate. ### Claim 6 (depends on 1) The pencil lead of claim 1, wherein, impregnated in pores thereof, the porous fired lead body comprises the octyldodecyl oleate. ### Claim 7 (depends on 1) The pencil lead of claim 1, wherein, impregnated in pores thereof, the porous fired lead body comprises the isopropyl palmitate. ### Claim 8 (depends on 1) The pencil lead of claim 1, wherein, impregnated in pores thereof, the porous fired lead body comprises the 2-ethylhexyl palmitate. ### Claim 9 (depends on 1) The pencil lead of claim 1, wherein, impregnated in pores thereof, the porous fired lead body comprises the propylene glycol monooleate. ### Claim 10 (depends on 1) The pencil lead of claim 1, wherein, impregnated in pores thereof, the porous fired lead body comprises at least two of octyldodecyl erucate, oleyl oleate, octyldodecyl oleate, isopropyl palmitate, 2-ethylhexyl palmitate, and propylene glycol monooleate. ### Claim 11 (depends on 1) The pencil lead of claim 1, wherein a content of the octyldodecyl erucate, oleyl oleate, octyldodecyl oleate, isopropyl palmitate, 2-ethylhexyl palmitate, and/or propylene glycol monooleate is 60 mass % or greater in an oil impregnating the pores of the porous fired lead body. ### Claim 12 A pencil lead, comprising: a black porous fired lead body comprising graphite, wherein the black porous fired lead body is impregnated with (I) a compound selected from a group consisting of octyldodecyl erucate, oleyl oleate, octyldodecyl oleate, isopropyl palmitate, 2-ethylhexyl palmitate, and propylene glycol monooleate, and (II) a resin selected from a group consisting of a terpene phenolic resin, a rosin ester resin, a ketone resin, and a rosin-modified phenolic resin. ### Claim 13 (depends on 12) The pencil lead of claim 12, wherein a content of the compound of (I) is 60 mass % or greater in an oil impregnating the pores of the porous fired lead body. ### Claim 14 (depends on 12) The pencil lead of claim 12, wherein the resin of (II) is the terpene phenolic resin. ### Claim 15 (depends on 12) The pencil lead of claim 12, wherein the resin of (II) is the rosin ester resin. ### Claim 16 (depends on 12) The pencil lead of claim 12, wherein the resin of (II) is the ketone resin. ### Claim 17 (depends on 12) The pencil lead of claim 12, wherein the resin of (II) is the rosin-modified phenolic resin. ### Claim 18 (depends on 12) The pencil lead of claim 12, wherein the compound of (I) is the octyldodecyl erucate. ### Claim 19 (depends on 12) The pencil lead of claim 12, wherein the compound of (I) is the isopropyl palmitate. ### Claim 20 (depends on 12) The pencil lead of claim 12, wherein the compound of (I) is the octyldodecyl oleate.