WRITING INSTRUMENT

• Main Authors: KAMIYA TOSHIFUMI, SHIINO KENICHI, UEDA SATOSHI
• Format: Patent
• Language: English; Japanese
• Published: 28.02.2024
• Subjects: ADHESIVES; BUREAU ACCESSORIES; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; CORRECTING FLUIDS; DYES; FILLING PASTES; IMPLEMENTS FOR WRITING OR DRAWING; INKS; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; PERFORMING OPERATIONS; POLISHES; TRANSPORTING; USE OF MATERIALS THEREFOR; WOODSTAINS; WRITING OR DRAWING IMPLEMENTS

To provide a writing instrument which has a visible portion on a pen tip that allows a direction of writing to be visually recognized, and can draw a written line without any difference in density without causing uneven supply of ink to a pen core.SOLUTION: Provided is a writing instrument that supplies an ink composition for a writing instrument housed in a writing instrument body to a pen core of a pen tip, the writing instrument including a visible portion that allows the writing direction to be visually recognized on the pen tip. A porosity of the pen core is 30 to 70%. The ink composition for the writing instrument contains colored resin particles with an average particle diameter of 1 to 10 μm, and has an ink viscosity of 8 to 20 mPa.s. The colored resin particles have a particle size distribution (Mv/Mn) of 1 to 3 and contain at least one association agent selected from group X below; Group X: Methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylethylmethylcellulose, hydroxypropylmethylcellulose.SELECTED DRAWING: Figure 1 【課題】 ペン先に筆記方向を視認することができる可視部を有する筆記具において、ペン芯へのインクの供給にムラを生じさせることなく、濃度差もない筆記描線を引くことができる筆記具を提供する。【解決手段】 筆記具本体内に収容される筆記具用インク組成物をペン先のペン芯に供給すると共に、ペン先に筆記方向を視認することができる可視部を有し、前記ペン芯の気孔率が３０～７０％であり、前記筆記具用インク組成物には平均粒子径が１～１０μｍの着色樹脂粒子を含有し、かつ、インク粘度が８～２０ｍＰａ・ｓである筆記具であって、前記着色樹脂粒子の粒度分布（Ｍｖ／Ｍｎ）が１～３であり、下記Ｘ群から選ばれる会合剤を少なくとも１種を含むことを特徴とする筆記具。＜Ｘ群＞メチルセルロース、エチルセルロース、ヒドロキシメチルセルロース、ヒドロキシエチルセルロース、ヒドロキシプロピルセルロース、ヒドロキシエチルエチルメチルセルロース、ヒドロキシプロピルメチルセルロース【選択図】図１