Lithium-based ester is an organic material located at the end of the gel pen and used to seal the neutral ink in the ink tube. Traditional oil-based ballpoint pens may not be filled with lithium-based esters, because oil-based ballpoint pen inks are non-volatile substances, and there is basically no ink thickening or drying due to solvent volatilization. The neutral ink infused into the neutral pen is mostly a water-low carbon alcohol suspension of pigment, which is prone to volatilization of the solvent when exposed to dry air for a long time, resulting in the ink becoming sticky and unable to write normally; in addition, the low viscosity ink Neutral ink will flow back in the ink tube, and the lithium-based ester also acts to prevent the back flow of the ink. Lithium-based ester should be immiscible with neutral ink, the interface should be clear, no turbidity will appear, and the bubbles in the ink tube can be easily removed by centrifugation after the pen is installed. Lithium-based esters are mostly polyorganosiloxane substances, which are immiscible with water, are oily, have good high and low temperature stability, do not freeze at -20℃, do not overflow or evaporate at 80℃, and have excellent thixotropic fluidity. The excellent lithium-based ester enables the gel pen to maintain a good moisturizing seal under the condition of large temperature changes, preventing the ink from evaporating or overflowing; when writing quickly, the sealant can follow up at any time, and the wall hanging is light, until the ink is completely written.
There are many types of gel pens on the market. According to the pen head, there are stainless steel, nickel white copper, lead brass, etc.; according to the material of the ball, it can be divided into tungsten carbide ball, modified ceramic ball, etc.; Different, it can also be a bullet head, a gourd head, a needle tube head, etc. In recent years, the inner diameter of neutral refill ink tubes has changed a lot, and different ink tubes with inner diameters ranging from 2.0mm to 7.0mm have appeared. The amount of ink perfusion in larger inner diameter ink tubes has increased from 0.5g/piece to 2.0g/piece. The writing length of a single pen is increased from 400-500m to nearly 2000m, which puts forward higher requirements for the wear resistance of the pen tip and the storage and follow-up performance of the lithium-based ester.
