On the characteristics of water-based varnish

Water-based varnish is mainly composed of three major categories of main agent, solvent auxiliary agent. It has the characteristics of colorless, odorless, strong sense of transparency, non-toxic, no organic volatiles, low cost wide source. It is other solvent-based varnish. Incomparable. So what are its characteristics?

(1) Environmental protection safety

Water-based varnishes use water as a dispersion medium, which can be diluted with water during the printing process, use water to clean the equipment. It will produce harmful gases containing aromatic hydrocarbons. It is easy to burn explode. It is very safe to produce store. Solvent-based varnish can be divided into aromatic hydrocarbons alcohols. Aromatic varnishes contain a large amount of benzene-based harmful substances, which will seriously damage the health of operators pollute the environment during the printing process, are flammable explosive; while alcohol varnishes are relatively low in toxicity, But there are also flammable explosive problems, the safety problems in the production process are more prominent.

(2) Equipment adaptability

The water-based varnish is mainly composed of water-soluble resin water-dispersed resin. Changing the ratio of the two can flexibly adjust the viscosity of the varnish. This feature of it makes waterborne varnish adapt to almost all printing equipment requirements. The water-based glazing oil is a volatile drying type, drying devices such as infrared rays hot air can be used for drying the water-based glazing oil. Solvent-based varnish exists in the form of a resin solution with a small range of viscosity adjustment poor adaptability to equipment. UV varnish needs special UV curing equipment to match it.

(3) Glossiness

When processing high-gloss products, UV varnish has certain advantages, followed by solvent-based varnish, water-based varnish is the worst. The gloss of the water-based varnish coating is low. On the one hand, it is due to the slow evaporation rate of water molecules, which is easy to make the coating film uneven during the evaporation of water; on the other hand, it is due to the presence of emulsion resin particles in the water-based varnish. The surface smoothness of the coating film is affected. In order to improve the gloss of the water-based varnish coating, on the one hand, it is necessary to reduce the particle size of the emulsion as much as possible, so that the flatness of the coating film is correspondingly improved. In recent years, with the development of microemulsion polymerization technology, the gloss of water-based varnishes has been continuously improved. On the other hand, a small amount of high-boiling point solvent can be added to the aqueous glazing oil to swell the emulsion particles promote the formation of a coating film with better flatness. After the above improvements, the gloss of the water-based varnish coating can reach more than 90%, which is close to the gloss level of the UV varnish coating, which can meet the requirements of general high-gloss products.

Water-based varnish is used in the field of matt matt products. To achieve a matt matt effect, one method is to add a matting agent to the varnish; another method is to use two in the same system. An incompatible resin. In a solvent-based varnish, the resin exists in the form of a solution, the two resins that are incompatible with each other cannot exist in the same system. The method of adding a matting agent can only be used to achieve the purpose of gloss control. It increases the product cost. In aqueous varnish, the resin exists in the form of an aqueous dispersion, which creates conditions for the presence of two incompatible resins in the same system. By changing the ratio of the two resins, the product can be flexibly adjusted The gloss, so as to achieve the effect of matt none. It can be said that in the field of matt matt glazing, water-based glazing oil has unique advantages.

(4) Water resistance

In the water-based glaze system, due to the presence of a large number of carboxyl groups in the water-soluble resin the hydrophilic properties of the emulsifier in the emulsion, the water resistance of the water-based glaze was once restricted. In recent years, with the advancement of emulsion-free emulsion polymerization technology the emergence of functional hydrophobic additives, water-based varnishes have been greatly improved in waterproof performance, which can meet the requirements of general printed products for waterproof performance.

(5) Smoothness of glazing products

Due to the large number of water-based coating slip additives, the slip problem of water-based varnishes has been completely resolved, its performance in print smoothness is no less than that of any solvent-based products.