A thermochromic writing instrument including 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 1 further includes a friction unit, for 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 10 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 dry erase ink for a writing instrument. The dry erase ink includes, as the main organic solvent, a solvent selected from the group consisting of n-propyl acetate, isopropyl acetate, or mixtures thereof.

An alcohol-based dry-erasable ink for a writing instrument including, as separation agent, a mixture of glycerol, glycol and pentaerythritol ester.

An ink and method of conducting an examination suitable for reducing the likelihood that the students' answers on paper-based examinations may be changed at a later time prior to being graded. The ink includes a solution of marking particles, a suspension material, and a preserving material. A mark made with the ink is initially erasable for a predetermined period of time after the mark is formed and after the expiration of the predetermined period of time the mark is not erasable. The method of conducting an examination includes providing an ink to an individual, and then providing questions to an individual wherein the individual indicates answers to the questions by producing marks with the ink.

An ink and method of conducting an examination suitable for reducing the likelihood that the students' answers on paper-based examinations may be changed at a later time prior to being graded. The ink includes a solution of marking particles, a suspension material, and a preserving material. A mark made with the ink is initially erasable for a predetermined period of time after the mark is formed and after the expiration of the predetermined period of time the mark is not erasable. The method of conducting an examination includes providing an ink to an individual, and then providing questions to an individual wherein the individual indicates answers to the questions by producing marks with the ink.

Provided is an aqueous ink composition for writing instruments which is excellent in an antibacterial property and an antifungal property without damaging storage stability and writing performances. The aqueous ink composition for writing instruments according to the present invention is characterized in that at least particles comprising principally a polymer represented by the following Formula (I) are contained as an active ingredient and that a content thereof is 0.1 to 30 mass %: ##STR00001##
wherein R is an alkyl group having 2 to 8 carbon atoms.

Provided is an aqueous ink composition for writing instruments which is excellent in an antibacterial property and an antifungal property without damaging storage stability and writing performances. The aqueous ink composition for writing instruments according to the present invention is characterized in that at least particles comprising principally a polymer represented by the following Formula (I) are contained as an active ingredient and that a content thereof is 0.1 to 30 mass %: ##STR00001##
wherein R is an alkyl group having 2 to 8 carbon atoms.

A method for preparing a thermochromic water-based gel ink composition, as well as a thermochromic water-based gel ink composition thereof comprising a specific monocarboxylic or polycarboxylic acid. A writing instrument, such as a ballpoint pen, a brush pen, a marker, a highlighter, and a felt pen, comprising a thermochromic water-based gel ink composition according to the disclosure.

The present disclosure concerns non-aqueous gel writing ink including a solvent, a coloring agent and a gelling agent, in which the gelling agent is a mixture of silica particles and of a fatty acid amide wax. It also concerns the process of preparation of the non-aqueous gel writing ink and the use of a mixture of silica particles and of a fatty acid amide wax, as a gelling agent in a non-aqueous gel writing ink. It finally concerns a writing instrument containing the ink according to the present disclosure.

Provided is an aqueous ink composition for a writing instrument which is excellent in a drying property of drawn lines and a low temperature stability of the ink while inhibiting the pen tip from drying and which prevents the drawn lines from causing feathering and strike-through. The aqueous ink composition for a writing instrument described above contains at least a colorant, trimethylglycine, pentaerythritol, 10% by mass or less of a water-soluble organic solvent and water.