[Printing ink composition]Printing ink composition analysis of the harm of printing ink to human body
Printing ink composition
Printing ink is a paste-like colloid which is uniformly dispersed and mixed by pigments, binders, fillers and other materials. The colorant gives the printed matter a variety of tones; the binder acts as the carrier of the colorant and also acts as a binder to fix the colorant on the surface of the substrate; the filler gives the ink proper properties, so that the ink can meet the printing suitability of various printing processes .
The ink should have certain fluidity, and meet the properties required by various printing processes, and be able to dry quickly on the printed matter. The dried ink film should have various water resistance, acid resistance, and Alkali, light resistance, abrasion resistance, abrasion resistance and other resistance.
1. Connecting material
Connecting material is a kind of adhesive fluid, its function is firstly as a carrier of pigments The solid particles such as pigments are mixed and connected; secondly, as a binder, the pigments can finally be fixed on the surface of the substrate to achieve the purpose of displaying text, images, marks, and decoration. The binder largely determines the viscosity, tack, dryness and fluidity of the ink. In order to obtain high-quality inks, high-quality binders must be used. The main components of the binder are oil (vegetable oil, mineral oil), resin, solvent and auxiliary materials.
2. Auxiliaries
Due to the variability of printing conditions, and in order to enable printers to actively adapt to changing printing conditions, use good Ink, to improve the printing quality, it is inevitable to add several ink additives with specific properties to the ink. Ink additives can improve some properties of inks, such as: plasticizers can increase the plasticity of polymer substances, so that the ink film has better flexibility; diluents can thin the ink, increase the fluidity of the ink, and reduce the The viscosity of the ink; the detackifier, also known as the viscosity reducer, can reduce the viscosity of the ink without affecting the body of the ink; the drier (desiccant) can accelerate the drying speed of the ink; the purpose of the diluent is to dilute the ink The color of the ink is also called the lightening agent; the purpose of the anti-gelling agent is to prevent the gelation, thickening and agglomeration of the ink; the anti-drying agent (antioxidant) can delay the oxidative polymerization process of the drying oil; the anti-fouling agent ( Anti-smudge agent) can prevent the ink on the printed product from smearing to the back of another printed product; surfactant can improve the dispersibility of solid components and prevent it from agglutination and precipitation; preservative can prolong the storage time of water-based ink; defoaming The UV absorber can eliminate the bubbles generated during the use of the ink; the UV absorber can improve the light fastness of the printed matter.
3. Pigments and dyes
The colored materials used in printing inks are usually pigments, and some dyes are also used. Pigments and dyes are colored substances with extremely fine particles. Pigments are generally insoluble in water and in binders, and most of them are called suspensions in solution; dyes are generally soluble in binders. Pigments must have high tinting strength, hiding power, chemical stability, light fastness and other properties, as well as high dispersibility in the binder. Commonly used in printing inks are inorganic pigments, fillers, organic dyes and dyes.
Hazards of printing ink to human body
Ethanol, isopropanol, butanol, propanol, butanone, ethyl acetate, Butyl acetate, toluene, xylene and other organic solvents. Although most of these organic solvents will be eliminated after drying, the residual part will still cause harm to the human body. In particular, the printed matter with a large inking area and a thick ink layer has more residual solvent, and the toxic substances released during the use process pollute the air and endanger people’s health.
A big problem with ink contamination is pigment. These pigment particles are very small and have strong adsorption capacity. They contain heavy metal elements such as lead, chromium, cadmium, and mercury, all of which have certain toxicity. Take lead as an example, a page of color newspapers and magazines contains about 2000 micrograms of lead. Lead is the only trace element that the human body does not need. It is stable, non-degradable and hinders the formation of blood cells. When the lead in the human body accumulates to a certain level, chronic poisoning symptoms such as mental disorders, nightmares, insomnia, headache, etc. will appear. In severe cases, fatigue, loss of appetite, nausea, abdominal distension, abdominal pain, diarrhea, etc. will occur. Lead can also enter brain tissue through the bloodstream and cause brain damage. According to research, children’s absorption of lead is several times higher than that of adults, and lead poisoning has a greater impact on children’s intelligence.
In addition, a large amount of diluent containing benzene is used in printing, which is toxic and has a strong irritating odor. hazard.
