A knock type writing tool is provided, in which an appropriate amount of air can be taken in depending on an amount of a thermochromic ink discharged from a pen tip, so that the thermochromic ink can be smoothly discharged from the pen tip, and in which a writing body can rotate surely in conjunction with a rotation of a rotating member. An air hole 63a and a plurality of projection pieces 63b are provided at a rear end portion of a writing body 6. A front surface of a projection and retraction rotating member 7 is provided with a plurality of abutment parts 73, on which respective rear ends of the plurality of projection pieces 63b are to abut, and with a plurality of protrusion parts 72, each of which is formed between the plurality of abutment parts 73 and protruded more forward than the plurality of abutment parts 73. The protrusion parts 72 are respectively inserted in gaps 63c between the projection pieces 63b. An axial length of each projection piece 63b is longer than an axial length of each protrusion part 72, so that a portion of the gap 63c is left more forward than a front end of each protrusion part 72.

Provided are an erasing member which is excellent in erasability for handwritings written by means of a pencil, a mechanical pencil and the like and which does not produce eraser dusts, and an erasing tool in which a part to be erased can be visually recognized in erasing.The erasing member comprises a blend composition containing a liquid-absorbing porous material, and a basic magnesium carbonate porous material and the like can be used as the liquid-absorbing porous material. And in an erasing tool in which an erasing part is formed at one end and in which a transparent or translucent visible part making it possible to visually recognize a writing surface is provided in the vicinity of the erasing part, the erasing member described above is mounted to the erasing part, whereby the erasing tool which does not produce eraser dusts is obtained.

An eraser assembly is provided that includes a housing, a tray, a coupler, and an eraser insert. The housing has a concave shape including an interior portion. The tray has a retaining portion disposed in the interior portion of the housing and a mounting portion disposed opposite the retaining portion. The coupler is configured to releasably hold the tray to the housing. The eraser insert is configured to be mounted to the mounting portion. An eraser insert is also provided that includes a first side and a second side, an eraser pad, and a coupler. The first side includes a mounting surface and an eraser pad is disposed on the second side. The coupler is disposed on or about the mounting surface and is configured to detachably connect the eraser insert to an eraser assembly at the mounting surface.

A holder for a pencil eraser with removable bands. As the eraser wears, connecting bands are removed, revealing more of the eraser. As the connecting bands are removed, they are replaced at the rear end so that the length of the eraser case remains the same. When the eraser is completely worn out, a new eraser is inserted in the eraser case.

A thermochromic ink writing instrument comprising a body extending along an axis, the body having a first end and a second end opposed to the first end along the axis, the first end being provided with a writing tip and with an eraser, wherein the writing tip is fed with thermochromic ink, wherein the writing tip is fixed with regard to the body and the eraser is movable along the axis with regard to the body, and the thermochromic ink writing instrument further comprising a helical-cam propelling mechanism configured to move the eraser along the axis between a retracted position and a protruding position.

An erasable ink writing instrument comprising a body extending along an axis, the body having a first end and a second end opposed to the first end along the axis, the first end being provided with a writing tip and with an eraser, wherein the writing tip is fed with erasable ink, wherein the writing tip is fixed with regard to the body and the eraser is movable along the axis with regard to the body, and the erasable ink writing instrument further comprising a helical-cam propelling mechanism configured to move the eraser along the axis between a retracted position and a protruding position. The erasable ink is a peelable ink and the eraser is a friction body.

There is an erasing tool having a polyetheramine for erasing a thermochromic ink composition capable of undergoing a color change that cannot be reversed by application of a temperature change. There also is a writing instrument having a thermochromic ink composition and an erasing tool. Finally, there is a method for irreversibly erasing a written line made with a thermochromic ink composition and erased with an erasing tool.

A knock type writing tool is provided, in which an appropriate amount of air can be taken in depending on an amount of a thermochromic ink discharged from a pen tip, so that the thermochromic ink can be smoothly discharged from the pen tip, and in which a writing body can rotate surely in conjunction with a rotation of a rotating member. An air hole 63a and a plurality of projection pieces 63b are provided at a rear end portion of a writing body 6. A front surface of a projection and retraction rotating member 7 is provided with a plurality of abutment parts 73, on which respective rear ends of the plurality of projection pieces 63b are to abut, and with a plurality of protrusion parts 72, each of which is formed between the plurality of abutment parts 73 and protruded more forward than the plurality of abutment parts 73. The protrusion parts 72 are respectively inserted in gaps 63c between the projection pieces 63b. An axial length of each projection piece 63b is longer than an axial length of each protrusion part 72, so that a portion of the gap 63c is left more forward than a front end of each protrusion part 72.

There is an erasing tool having a polyetheramine for erasing a thermochromic ink composition capable of undergoing a color change that cannot be reversed by application of a temperature change. There also is a writing instrument having a thermochromic ink composition and an erasing tool. Finally, there is a method for irreversibly erasing a written line made with a thermochromic ink composition and erased with an erasing tool.

Provided is an erasing tool which produces no eraser crumbs and allows a progress for adsorption of even a light color of color pencil leads and the like to be recognized at a glance and which makes it possible to surely erase the color of color pencil lead and has a high light transmittance. The erasing tool is characterized by containing a secondary aggregate having a diameter of 1 to 100 μm with a petaloid particle as a primary particle.