With the rapid development of pigment printing, especially in order to save energy, reduce or avoid the safety and pollution of kerosene and other issues, countries all over the world are conducting active research and exploration, and have successively developed synthetic thickeners to replace pigments in pigment printing. Emulsified paste, and now used more and more. At present, the multi-component polymers of propylene-based and butene-based fusidic acid derivatives are widely used. The main chain of the molecular structure has a large number of shuttle groups, and the main chain has a wide range of cross-links. It is generally composed of two or more of monomers polymerized. The first monomer is the main monomer, mostly olefinic acids, such as acrylic acid, methacrylic acid, itaconic acid, maleic acid or maleic acid and other water-soluble monomers. The presence of this monomer can make the synthesis paste larger. Molecules are ionized in water to form shuttle-based negative ions, and repulsion is generated between macromolecular chains, so that the original curled molecular chains are stretched in water, and the viscosity increases accordingly. At the same time, it can make the synthetic paste have good water solubility and dispersion. The content is 50%-80%. The second monomer can be methyl, acetyl, butylene, etc. of acrylic acid or methacrylic acid, or styrene, ethyl acetate, etc. Its presence can increase the molecular weight of the synthetic paste and reduce its pressure Permeability, in order to increase the amount of color, its content is 15%-40%. The third monomer is a compound with two alkenyl groups, such as succinyl diacrylate, diacryloyl phthalate, and isocyanuric triacrylate, etc. Because it has two double bonds, it is not only related to the first monomer The polymer and the second monomer are copolymerized to form synthetic paste macromolecules, and at the same time, cross-linking can be produced, so that the synthetic paste can form a network structure, which can significantly thicken the synthetic paste and increase the viscosity. Its content accounts for 1%-4 %. The three monomers were copolymerized by emulsion polymerization to synthesize the paste.
When the synthetic paste is used, it should be dissolved in water under rapid stirring, and then ammonia water is added to convert the shuttle group in the synthetic paste into a shuttle acid salt. The paste thickens and the viscosity reaches its best. It has a high paste rate, and the general input amount is only about 2%. It has strong thickening ability and low solid content. It does not affect the hand feel without washing after printing, so it is especially suitable for pigment printing. It is very convenient to make paste and adjust the color paste. It is easy to thicken or dilute the color paste. It is not necessary to cook the paste in advance. It has good washability, bright colors and white ground. It is easy to cause infiltration, so it is best to use the baking fixing process, but it is not suitable for rapid baking and excessive drying during baking to prevent the film from falling off.
Synthetic paste can also be used in disperse dye printing. Due to its low solid content, it is conducive to the fixation of dyes and can increase the color supply, but the viscosity is greatly reduced after encountering electrolytes. For this reason, non-ionic dispersants should be used. The thixotropy of the synthetic paste is excellent. When the shear stress is applied, the viscosity decreases rapidly, and the viscosity recovers immediately after the stress is removed. Therefore, it is an ideal paste for flat screen and rotary screen printing. The printing outline is very clear, the lines are fine, and the color supply high.