Stationery industry applications

With the rapid advancement of modern science and technology, the continuous improvement of people's living standards, and the rapid development of computer technology, the requirements for various office paper, printer ribbons, ink, and other office supplies are also increasing. The paper should be white and smooth, and the ink and ink should have strong adhesion without penetration, thin without wrinkles, uniform texture, and a smooth surface. In short, it should have satisfactory hardness, coating properties, peel strength, and smoothness. The ink should be fluent in writing, with clear and even lines, and should not settle, fall off, fade, or block the pen. The requirements for printing ink and coating magnetic powder ink are higher, as sometimes it is necessary to print plastic products that need to be maintained for a long time without fading, such as ID card production, film copying, etc. Among all these office supplies, PVP with different molecular weights demonstrated superior performance.

Application of PVP in Ink and Inks：

PVP has good bonding properties and can be used as an adhesive for ink. Ink can firmly adhere written and printed characters to paper without falling off or fading. Furthermore, PVP has a good dispersing and stabilizing effect on inorganic pigments and organic pigment dispersions. It can be used for ink and ink to obtain a uniform dispersion system, which is not suitable for precipitation and does not block pens and various nozzles. The resulting handwriting depth is uniform and consistent. Moreover, PVP is non-volatile and has long-lasting effects and functions, especially when printing or printing equipment stops running for a long time, it will not block the nozzle and has smooth repeated jet writing performance. The PVP used for ink and ink is generally PVP K-12 to PVP K-30 products with lower molecular weight.

Ballpoint pens use ink, and adding PVP K-30 to the ink can protect the colloid, thicken, and increase viscosity, making writing fluent, non overflowing, and non fading. It can also reduce the wear of the ball and extend its service life.

Here are two examples of application formulas and production methods：

The formula for a magnetic recording ink is as follows:

The Application of PVP in Paper and Other Office Supplies：

In the paper industry, PVP is used to improve paper strength, solubilize dyes, and disperse pigments. It is an important additive in waste paper deintercalation, rag decomposition, pulping, and coloring. When used as a coating, it can improve the gloss, printability, and oil resistance of paper. Especially when a transparent coating containing PVP is applied to the surface of the printing paper, it can quickly dry the printing ink on the paper. This transparent layer has good ink absorption, is insoluble in water, has good solidification, and can form images at high speed due to its transparency, making it particularly suitable for multi-color ink printing.

The transparent recording paper used for drawing requires considerable transparency. As drawing is often done with pencils, transparent paper is required to have good adhesion and stability to lead powder. The substrate of this paper is a transparent cellulose film, which forms a transparent sulfuric acid cellulose resin mainly composed of PVP through cross-linking reaction on the cellulose film. The content of PVP in it is 1% to 10%, forming a transparent film of 2-10 microns, which is coated on the substrate cellulose film. On the one hand, the role of PVP in this type of film is to firmly adhere the film and the matrix cellulose film together, while also providing good adhesion stability to the pigments used for drawing. On the other hand, PVP forms a thin film with excellent transparency performance, which can make small pigment particles transparent and extend the storage time of drawings. Even if there is wear, it will not affect the integrity of the drawn pattern.

The commonly used adhesives encounter many inconveniences during use. Only solid paste is solid at room temperature and can be directly wiped and used, overcoming the inconvenience of using liquid adhesives or viscous paste. Solid paste is usually composed of three substances with different functions, namely excipient, solvent, and adhesive resin. The most common adhesive is polyvinylpyrrolidone (PVP), which can be made into rod-shaped solid paste with different hardness by adjusting the ratio between excipient, PVP, and solvent.

Other water-soluble or water dispersible polymers that can be used as paste adhesives include polyvinyl alcohol, polyacrylamides, copolymers of polyacrylamides, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, degraded water-soluble starch, ethoxylated starch, polyvinyl acetate, polyethylene ether, polyvinyl chloride, etc. These polymers, as adhesive components for pastes (especially solid pastes), have inferior performance compared to PVP. With the reduction of PVP production costs, more and more solid glue stick factories are using PVP.