Wetting agent
Wetting agents supplied in the market, such as JFC, jfcs, pingpingjia series, El series and AEO series, and penetrant T, are all surfactants and wetting agents for textiles. Wetting agents for textiles are all aliphatic carbon chains as hydrophobic groups, which have no similarity to the chemical structure of aromatic hydrocarbons in dyes (pigments), low affinity and weak binding. Therefore, the application of hydrophobic group of wetting agent for dye (pigment) is aromatic hydrocarbon, which combines with dye (pigment) particles in a strong anchoring manner, so as not to fall off from the particle surface during long-term storage. The hydrophilic group extends in water to provide steric repulsion or electric repulsion.
The wetting agent whose hydrophobic group is aromatic hydrocarbon has different binding degree with dye (pigment) particles. Take TX-10 and solsperse27000 as examples for comparison. TX-10, s-27000 and emulsifier 600 were sulfated to obtain a molecule with two hydrophilic groups. In addition to sulfuric acid esterification, there are also carboxylic acid esterification, which has good compatibility with many common organic pigments and carboxylic acid polymer dispersants.
In order to improve the affinity with the hydrophobic part of organic pigments, Xu Yanli of Beijing University of chemical technology and others studied the surface modification of phthalocyanine blue with tmeen20 carboxylate as an aqueous decomposition agent.
Add 0.5% ~ 3.0% of the above additives to phthalocyanine blue to increase the critical surface tension σ C( σ SC) increased by 351% from 23mn / m to 34.8mn/m; The contact angle with water was reduced from 82.4 to 47, a decrease of 347%. Therefore, the wettability of phthalocyanine blue in water was greatly improved, the fluidity was improved by 2.5 times after treatment, and the dispersion stability in water was improved by 29%.
The above non-ionic surfactants are carboxylated to obtain corresponding products, which can be used as surfactants with both wetting and dispersing effects on dyes (pigments).
dispersant
Lignosulfonic acid is the most effective dispersant. Lignosulfonate is an anionic surfactant composed of a plurality of hydroxyl groups and sulfonic acid groups of 4-carboxy-3-methoxypropane. Its average molecular weight is 8000 ~ 13000. The sulfonate is generally sodium salt, calcium salt, and also ammonium salt. It is a polymer electrolyte.
Ammonium lignosulfonate is more effective than other sulfonates in improving the solubility of dyes. However, ammonium lignosulfonate has not been mass produced in China. It is suggested to use borresperseam-320 of borregard company; Reed's ligosoltsf, ligosoltsd, ligosoltsf-65 and ligosolsfx-65.
Water based inks: use additives, water-soluble resins and pigments of water-based inks to produce environmentally friendly water-based inks
Water soluble resin: rosin modified maleic acid resin, urethane resin, styrene modified maleic acid resin, water-soluble amino resin, polyvinyl alcohol, carboxymethyl cellulose and other water-soluble acrylic modified resins are often used in China.
Surfactant for water-based ink additives
There are several kinds of water-based ink additives: ① defoamer, used to eliminate foam in water-based ink, is generally 1% ~ 2%. ② Ink stabilizer is mainly used to prevent the aggregation and mildew of ink during storage and transportation. It can reduce the viscosity of ink and adjust the pH value of ink. Generally, ammonia water or ethanolamine are used. ③ Others include dispersants, preservatives, leveling agents, slip enhancers and cross-linking agents. Through the scientific use of these additives, the weaknesses of water-based inks can be improved, so as to improve the stability of water-based inks.
Solvent for water-based ink
The optimized basic formula of water-based ink is: water-soluble acrylic acid 25% ~ 35%, water 15% ~ 25%, ethanol 5% ~ 15%, triethylamine 5% ~ 10%, pigment 10% ~ 30%, and auxiliary 1% ~ 3%.
Application of environmental friendly water-based ink: at present, the most important application fields of environmental friendly water-based ink are flexographic printing and gravure printing. 95% of flexographic printing uses water ink and 80% of gravure printing uses water ink. In 2001, there were 200 narrow width flexographic printing production lines in China, with an annual demand of 100000 tons of water-based ink.
