Abstract: The liquid ink writing instrument has a body containing, from its rear end towards its front end, a reservoir for the ink and a front chamber containing a capillary element for transferring ink coming from the reservoir to a writing head. The front chamber communicates with ambient air. The writing head is fed with ink by the capillary element, and projects from the front portion of the body. The reservoir is separated from the front chamber by a flexible wall having shape memory and provided with slots. The flexible wall acts as a valve suitable for opening when the ratio of the pressure inside the reservoir over the pressure inside the volume of the front chamber facing the valve exceeds a first value, and of reclosing instantly as soon as the ratio becomes less than or equal to a second value, the valve releasing the ink in the form of a jet directed towards the rear face of the capillary element. The first value of the ratio of the pressures is preferably about 1.

Abstract: The colored liquid composition of the invention for a highlighter comprises a coloring element and water, the water content by weight lies in the range 10% to 30%. In addition, it comprises at least 40% of a liquid component having surface tension greater than 40 mN/m. In a variant, the coloring element is a tracer solvent having a fluorescent appearance under basic pH, in particular hydroxypyrenetrisulfonic acid, the pH of the composition lying in the range 8 to 9, and the component having surface tension greater than 40 mN/m is triethanolamine. Under such circumstances, the composition contains an acid to neutralize the triethanolamine in part in order to obtain the basic pH, for example hydrochloric acid.

Abstract: The invention concerns a writing implement (1) comprising ink (5) in a fibrous or non-fibrous reservoir, a retarding agent soluble or dispersible in the ink and a nib (7) for transferring ink (5) from the reservoir to the writing medium and a method for making such a nib (7). The invention is characterised in that a retarding agent is included in the writing nib (7) and is adapted to be carried by the ink (5) when it is transferred into said nib (7). The inventive method consists in impregnating an already machined writing nib with a solution containing a specific amount of a retarding agent, drying the impregnated writing nib, without stirring, by heating at a temperature less than 60° C.

Abstract: A method for increasing homogeneously the wettability of a porous body vis a vis a fluid includes a step in which the porous body is exposed in a treatment chamber to a nitrogen plasma generated by an electromagnetic wave discharge in nitrogen gas. Applications include increasing the wettability of a marker tip.

Abstract: A liquid ink writing implement comprises a body whose rear portion constitutes a reservoir for containing an ink, a transfer rod whose rear end opens out into the reservoir and whose front end projects out from the body and forms a writing tip, and a buffer reservoir in contact with the transfer rod. The ink has a surface tension lying in the range 21 of mN/m to 25 mN/m, and is intended for use on a non-absorbent media made of metal or of plastic. The surface tension of the material constituting the buffer reservoir is less than that of the ink by a predetermined difference which is preferably equal to or less than 4 mN/m, thereby enabling the buffer reservoir to absorb and give back any excess ink coming from the transfer rod by capillarity in the event of variation in the pressure inside the reservoir. The surface tension of the material of the buffer reservoir has been lowered by depositing an agent, whose surface tension is less than that of the ink but within the predetermined difference, e.g.

Abstract: A buffer reservoir suitable for absorbing surplus ink and a writing instrument including the buffer reservoir are provided. The buffer reservoir includes a mixture of microbeads that are hydrophobic relative to the ink and microbeads that are hydrophilic relative to the ink. The mixture of microbeads may either be uniform throughout the entire volume of the buffer reservoir, or non-uniform throughout the entire volume of the buffer reservoir, with the proportion of hydrophilic microbeads to hydrophobic microbeads being smaller in the zone immediately in contact with the feed tip and larger in the zone farthest away from the feed tip. Preferably, the proportion of hydrophilic microbeads is in the range of about 2% to about 10%, by weight, relative to the total weight of the buffer reservoir. The writing instrument includes a reservoir for liquid ink, a feed tip opening out into the reservoir, and a buffer reservoir.

Abstract: A writing instrument is provided, including a writing tip, a reservoir containing a liquid ink, and a capillary transfer rod extending from a first end to a second end of the reservoir. The capillary transfer rod transfers the liquid ink from the reservoir to the writing tip. A capillary element having an orifice is slidably mounted around the capillary transfer rod so as to move freely in the reservoir. An outside edge of the capillary element comes into the immediate vicinity of an inside wall of the reservoir in such a manner that the capillary element comes substantially flush with an inside wall of the reservoir as it slides along the transfer rod.

Abstract: According to the invention, the writing or coloring pencil is obtained by tri-extrusion of three thermoplastic materials forming the lead material, the expanded wood material and an intermediate protective layer, containing no expanding agent, which is compatible with the lead material and the wood material and has a melting point which is equal to or higher than the melting points of the lead material and the wood material. The three co-extruded materials all contain in particular the same basic component, such as for example a polystyrene-methacrylate copolymer. The protective layer can be of a different color from the other two layers. The writing or coloring pencil with protective casing between the lead and the expanded wood, all three being in thermoplastic material, is, in particular a pencil with soft or extra-soft lead.