Pens that use a ball to roll out a writing medium (ink or ink) are collectively referred to as ballpoint pens. The gel pen is a novel writing tool that is popular in the world at present, and the gel pen is a writing tool belonging to the ballpoint pen. The viscosity of its writing medium is between water-based (viscosity less than 10mPa.s) and oily (viscosity between 10000-20000mPa.s), and the so-called "neutral" is also named after it.
Gel pens originated in Japan. Japan's SAKURA Co., Ltd. successfully developed a product called "Ballsign" in 1984 and put it on the market. In 1988, another Japanese company, Pentel Co., Ltd. developed a product called "Hybrid" on the market. , the gel pen was born.
The biggest difference between a gel pen and a traditional ballpoint pen is that the ballpoint pen is filled with oil-based ink, while the gel pen is filled with water-based gel ink. According to the relevant definition in the Japanese Industrial Standard JIS S 6061:2005 "Gel Ink Ballpoint Pens and Refills", gel ink (neutral ink) is the viscosity of the ink that is reduced by the movement of the ball during writing, and is not static during writing. The ink whose ink viscosity becomes higher in the state is the typical rheological characteristic of neutral ink, that is, the change of the ink state before, during and after writing is gel→sol→gel. Neutral ink uses pigment as the main colorant. Compared with traditional dye-based ink, it has excellent light resistance, water resistance, temperature resistance and chemical resistance (acid, alkali, strong oxidant, bleach, etc.), and also has ink resistance. It has the characteristics of uniform flow and long time to take off the cap, which can be stored permanently. Therefore, gel pens are ideal office supplies, not only for ordinary writing, but also for long-term preservation of important documents.
