An aqueous peelable ink composition comprising at least one film-forming elastomeric polymer, at least one pigment, and water, wherein the film-forming elastomeric polymer is hydrogenated acrylonitrile butadiene rubber, and a method for preparing such an aqueous peelable ink composition.

An aqueous peelable ink composition comprising at least one film-forming elastomeric polymer, at least one pigment, and water, wherein the film-forming elastomeric polymer is hydrogenated acrylonitrile butadiene rubber, and a method for preparing such an aqueous peelable ink composition.

Provided is a thermochromic writing instrument, including thermochromic ink; and a friction unit configured to cause handwriting in the thermochromic ink to undergo a thermochromic change by frictional heat. The thermochromic ink includes a metallic luster pigment added thereto. The thermochromic writing instrument is provided with an attachment hole to attach the friction unit. The friction unit includes an attachment portion to be inserted into the attachment hole and a friction portion in a convex curved surface shape projecting from the attachment hole. The friction portion has a volume Ve and the metallic luster pigment has a volume Vp, the volume Ve and the volume Vp satisfying 5 □ Ve/Vp □ 35, the friction portion 32 has a maximum outer diameter D and a projection length L, the diameter D and the length L satisfying 0.1 □ L/D □ 1.5, and a material for the friction unit 3 has a value of Shore A hardness in accordance with JIS K 7215 of Japan Industrial Standard measured immediately after starting contact with an indenter in a range of 60 or more and 85 or less and has a value (ΔHS) of the Shore A hardness defined by a following equation of 0 or more and less than 5, ΔHS=(Shore A Hardness Value immediately after Starting Contact with Indenter)−(Shore A Hardness Value 15 seconds after Starting Contact with Indenter).

Provided is a thermochromic writing instrument, including thermochromic ink; and a friction unit configured to cause handwriting in the thermochromic ink to undergo a thermochromic change by frictional heat. The thermochromic ink includes a metallic luster pigment added thereto. The thermochromic writing instrument is provided with an attachment hole to attach the friction unit. The friction unit includes an attachment portion to be inserted into the attachment hole and a friction portion in a convex curved surface shape projecting from the attachment hole. The friction portion has a volume Ve and the metallic luster pigment has a volume Vp, the volume Ve and the volume Vp satisfying 5 □ Ve/Vp □ 35, the friction portion 32 has a maximum outer diameter D and a projection length L, the diameter D and the length L satisfying 0.1 □ L/D □ 1.5, and a material for the friction unit 3 has a value of Shore A hardness in accordance with JIS K 7215 of Japan Industrial Standard measured immediately after starting contact with an indenter in a range of 60 or more and 85 or less and has a value (ΔHS) of the Shore A hardness defined by a following equation of 0 or more and less than 5, ΔHS=(Shore A Hardness Value immediately after Starting Contact with Indenter)−(Shore A Hardness Value 15 seconds after Starting Contact with Indenter).

One embodiment is an apparatus for capturing marker stroke locations, including erasures. The marker includes a transmitter of acoustic pulses and an erasure cap detector that detects when a removable erasure cap is attached to the marker. A receiver includes two or more sensors to sense the acoustic pulses, the receiver operable to determine and track marker locations. When the removable erasure cap is attached to the marker, the marker locations are erasures, and when there is no erasure cap attached, the marker locations being tracked capture strokes. Another embodiment is a method of capturing marker stroke locations, including erasures, using the marker, the removable erasure cap for erasures, and the receiver.

One embodiment is an apparatus for capturing marker stroke locations, including erasures. The marker includes a transmitter of acoustic pulses and an erasure cap detector that detects when a removable erasure cap is attached to the marker. A receiver includes two or more sensors to sense the acoustic pulses, the receiver operable to determine and track marker locations. When the removable erasure cap is attached to the marker, the marker locations are erasures, and when there is no erasure cap attached, the marker locations being tracked capture strokes. Another embodiment is a method of capturing marker stroke locations, including erasures, using the marker, the removable erasure cap for erasures, and the receiver.

A thermochromic writing instrument, comprising: a writing body, storing a thermochromic ink therein, stored in a barrel; an operation body provided in the barrel to be operated to longitudinally move the writing body; a nib of the writing body configured to be capable of appearing from a front end of the writing instrument, wherein the writing instrument further includes a friction unit, rubbing handwriting in the thermochromic ink and capable of thermally changing the color of the handwriting by frictional heat generated at that time, and at least one clip body as the operation body, the friction unit is provided at a rear end of the barrel, and the clip body is provided in an area other than the rear end of the barrel.

A thermochromic writing instrument, comprising: a writing body, storing a thermochromic ink therein, stored in a barrel; an operation body provided in the barrel to be operated to longitudinally move the writing body; a nib of the writing body configured to be capable of appearing from a front end of the writing instrument, wherein the writing instrument further includes a friction unit, rubbing handwriting in the thermochromic ink and capable of thermally changing the color of the handwriting by frictional heat generated at that time, and at least one clip body as the operation body, the friction unit is provided at a rear end of the barrel, and the clip body is provided in an area other than the rear end of the barrel.

A mechanical pencil which is configured so that a rotatable cam is rotationally driven with an axis of the rotatable cam relative to a holder member stabled, and smooth operation of a rotational drive mechanism is ensured. The mechanical pencil includes a rotational drive mechanism for driving rotationally a rotatable cam according to writing pressure applied to a writing lead, and transfer rotational motion of the rotatable cam to the writing lead. The rotational drive mechanism includes a holder member supporting the rotatable cam so as to be rotatable, a first fixed cam formed with a funnel-shaped inclined surface Fu and a second fixed cam formed at an obtuse angle α relative to an axial direction. Cam faces of an upper cam and a lower cam alternately meshing with the first and second fixed cams are formed along a conical inclined surface Cs.

A mechanical pencil which is configured so that a rotatable cam is rotationally driven with an axis of the rotatable cam relative to a holder member stabled, and smooth operation of a rotational drive mechanism is ensured. The mechanical pencil includes a rotational drive mechanism for driving rotationally a rotatable cam according to writing pressure applied to a writing lead, and transfer rotational motion of the rotatable cam to the writing lead. The rotational drive mechanism includes a holder member supporting the rotatable cam so as to be rotatable, a first fixed cam formed with a funnel-shaped inclined surface Fu and a second fixed cam formed at an obtuse angle α relative to an axial direction. Cam faces of an upper cam and a lower cam alternately meshing with the first and second fixed cams are formed along a conical inclined surface Cs.