Views: 4 Author: Site Editor Publish Time: 2022-01-20 Origin: Site
Water based paint , including waterborne wood coatings, are coatings with water as dispersing medium and diluent.
Not commonly used solvent based paint is different, its formulation system is a more complex system. In the formulation design, not only the type of polymer, the performance of emulsion and dispersion should be paid attention to, but also the reasonable selection of various auxiliaries and the interaction between the components should be taken into account.
Sometimes for special requirements to select some special additives, and eventually form a suitable formula.
1 The basic composition of the recipe
1.1. Water-based resin: this is the base material for film formation, which determines the main function of the paint film.
1.2, film forming auxiliaries: after the water volatilizes, the emulsion or dispersion particles form uniform and dense film, and improve the film forming property under low temperature conditions.
1.3, foam suppressor and antifoaming agent: inhibit the production process of the paint produced in the bubble and can make the bubble has been produced to escape the liquid surface and bubble.
1.4, leveling agent: improve the construction performance of the paint, the formation of smooth, smooth coating.
1.5, wetting agent: improve the wettability of the paint liquid on the substrate, improve the leveling, increase the adhesion of the paint film on the substrate.
1.6, dispersant: promote the dispersion of pigment filler in the paint.
1.7, rheological additives: to provide good fluidity and leveling of paint, reduce the defects in the coating process.
1.8, Hydroxyethyl cellulose HEC: increase the viscosity of paint, improve the wet film thickness of a painting, and the putty and solid color paint has the effect of precipitation and stratification.
1.9, preservative: prevent paint from mildew in the storage process.
1.10, essence: make the paint has a pleasant smell.
1.11, colorant: mainly for color paint, so that the water-based paint has the required color. Colorants include pigments and dyes. Pigments are used for solid paints (which do not reveal wood grain) and dyes are used for transparent paints (which reveal wood grain).
1.12, filler: mainly used in putty and solid paint, increase solid points and reduce costs.
1.13, pH regulator: adjust the pH value of the paint to make the paint stable.
1.14, wax emulsion or powder: improve the scratch resistance of the paint film and improve its feel.
1.15. Special additives: For the special requirements of water-based paint additives, such as anti-rust agent (tin packaging to prevent premature rust), hardening agent (improve the film hardness), dimming agent (reduce the film gloss), anti-scratch agent, slippery agent (improve the film feel), anti-adhesion agent (prevent the coating stacking adhesion), cross-linking agent (made of two-component paint, Improve comprehensive performance), detest agent (make coating has lotus leaf effect), wear-resisting agent (increase the wear resistance of coating), ultraviolet absorption agent (outdoor paint is anti-aging, prevent yellowing), etc.
1.16, ionized water: formula design often add a small amount of deionized water to make paint.
2 Waterborne colorful coating formula design skills
▲ Base paint
2.1, hydroxyethyl cellulose HEC is the key to the formation of gel system, must be added;
2.2, protective glue helps to make the coarse in the formation of internal "house" structure, improve the toughness of colorful particles;
2.3. Viscosity of base paint affects rough shape, VS affects flatness of paint film;
2.4, surface active wattle can effectively moisten the "stuck house" structure, TSPP viscosity reduction (can be considered as structural wetting);
2.5. The emulsion with poor compatibility with the protective glue is easy to expand and has poor water resistance.
▲ Bring about granulation
2.1. Proper amount of protective adhesive helps particles form "stuck house" shell and avoid secondary aggregation;
2.2, over the whole TSPP into the protection of rubber precipitation, after the thick, particles reaggregation.
▲ Match color and paint
2.1, and the protection of poor compatibility emulsion, multi-color paint gelatinization, false plastic thick;
2.2. Thickener containing strong polar cationic groups is easy to cause the thickening of multi-color paint;
2.3, emulsion is conducive to improve the effect of opening cans, conducive to secondary repair;
2.4, multi-color paint KU at about 90, large particles can also be adjusted to 100-120.
3 Key points of production and preparation of water based paint
Water-based paint with water as solvent, a kind of coating, it as a substitute for containing solvent coating system, has gradually been recognized, in recent years, due to the ideal of human ecological environment pollution-free water-based coating and have a certain advantage in transportation and use of performance, its products quickly accepted by the market, and call it a high-tech products.
4. Water-based paint production process:
4.1, the formula material should be selected as far as possible with good dispersion pigment and ultrafine filling material, so as to cancel the grinding operation, simplify the production process and improve the production efficiency on the premise of stable improvement of product quality;
4.2. In the early stage of dispersion, appropriate amount of hydroxyethyl cellulose HEC can be invested in advance, which not only helps to disperse, but also prevents or reduces slurry sticking to the wall and improves the dispersion effect;
4.3, in the liquid thickener before adding, should try to use 3~5 times the water dilute, in the full stirring slowly added, from the local thickener concentration is too high to make the emulsion clumping or micelle, thickener can be put in the slurry dispersed into the slurry fully stirring to avoid the above problems;
4.4, the way of adding half of the antifoaming agent is added to the slurry, and the other half is added to the paint process, so that the antifoaming effect is better; Paint mixing process, stirring speed should be controlled in 200~ 400R /min to prevent the introduction of a large number of bubbles in the production process, affecting the quality of paint.