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.

The present disclosure relates to pens comprising a non-aqueous writing ink comprising a solvent, a coloring agent, a resin, a gelling agent, and a homo or copolymer of vinylpyrrolidone, wherein the gelling agent is a mixture of silica particles and of a fatty acid amide wax, and wherein the homo or copolymer of vinylpyrrolidone is present in amounts of between about 0.05 and about 0.6 wt.-%, relative to the total weight of the ink.

The disclosure provides a microcapsule type thermochromic pigment and a preparation method and use thereof, and a thermochromic ink and use thereof. The microcapsule type thermochromic pigment provided by the disclosure includes a core material and a wall material wrapping the core material, wherein the core material includes the following components: a leuco dye, a developer and stearic acid 2-[4-(phenylmethoxy)phenyl]ethyl ester, and the wall material is self-emulsifying polyurethane or self-emulsifying epoxy resin.

An aqueous pigmented ink for use in a capillary reservoir system comprises at least one pigment, at least one water-dispersible, film-forming component, about 0.5 to about 4.5 wt % of at least one suspension substance and about 0.01 to about 0.5 wt % of a gel former combination in an aqueous vehicle, the gel former combination comprising at least one mineral gel former and at least one organic thickener.

The present disclosure relates to writing instruments which are charged or recharged with a water-based ink composition. The water-based ink composition may be prepared from solid ink compositions which may be diluted with water. The solid ink composition comprises a specific combination of polyethylene glycol, at least one coloring agent and a humectant.

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 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.

There is a process for preparing in situ an aqueous gel ink with fixed color having the following steps: (i) preparing a gel-based matrix of aqueous ink comprising 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid as reducing agent, and (ii) adding a solution of metallic salts to the gel-based matrix of aqueous ink prepared in step (i), to obtain an aqueous gel ink with fixed color with metallic nanoparticles dispersed therein.

There is also an aqueous gel ink with fixed color obtained according to the process of the disclosure, comprising 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid and metallic nanoparticles.

There is also a writing instrument comprising an aqueous gel ink with fixed color according to the disclosure.

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.