Experiments on the suitability of different dispersants in water-like alicic acid paint.

The applicability of different dispersants in water-based alcoholic acid paint experiments
Yi Shiming, Zheng Qi, Liu Zhanchuan, Liu Yanfei
(Hebei Chenyang Industry and Trade Group Co., Ltd., Hebei Baoding 072550) 0 Introduction
In the past 30 years, China's coating industry in the reform and opening up, environmentally friendly water-based paint gradually into the household. Traditional solvent-based coatings gradually reduce their share of the market because they contain a large number of organic volatile substances. Environmental pollution, air pollution, toluene and other additives to the degree of personal harm has also begun to be well known, environmental protection has become a growing trend, water-based paint research and development more and more attention. Water-based coatings instead of solvent-based coatings is a market trend, health and environmental protection concepts are gradually the main factors in people's choice of water-based coatings.
Traditional coatings, inks need a large number of organic solvents, with the depletion of petroleum resources, organic solvent products prices are getting higher and higher, and people's environmental awareness is further enhanced, so that domestic and foreign researchers began to pay more attention to water instead of organic solvents to prepare water-based coatings, inks (such as water suspension agents, water dispersants) and so on. As an important raw material of water-based coating, the quality of dispersant determines the yield value of the coating and the gloss and cover force of the coating film., also known as a wetting dispersant, can be adsorbed at one end of its active group on the surface of the pigment crushed into fine particles, in addition to having the same wetting effect as the wetting agent. Solventization at the other end into the paint base to form an adsorption layer (the more adsorption base, the longer the chain, the thicker the adsorption layer), the generation of charge rebuke force (water-based paint) or entropy rebuke force (solvent-based paint), so that pigment particles long-term dispersion suspended in the paint base, to avoid flocculation again, thus ensuring the storage stability of the color paint system. Most of the wetting dispersants that are anionized and non-ionized are now on the market. Their principle is low surface pressure, quickly wet pigment particles, and then through high shear force, such as dispersion machines, grinding machines, so that pigment particles form a semi-flocculation (or controlled flocculation) dispersion. There are many types of dispersants, and preliminary estimates suggest that there are more than 1,000 substances in the world that are dispersed. According to its structure, can be divided into: (1) anion type, (2) cation type, (3) non-ion type, (4) sex type, (5) electro-neutral type, (6) polymer type (including high and low relative molecular mass) ultra-dispersant.study used water-based alicic acid resin as a membrane carrier, with different dispersants to paint, and then verify its properties, and develop an experimental scheme. The resin with water and a small amount of solvent-assisted preparation of the coating system VOC content is low, in line with modern green industrial coating and environmental protection requirements. Water-based alicic acid paint is a water-based alicic acid resin as the main film-forming substance, pigments, fillers have a better wetting and dispersion, paint film gloss is high, good plumpness. Since aliclicic acid resins are a combination of alcohols and acids, solids contain ester bonds that are prone to hydrolysing, degradation causes relative molecular mass to decrease and acid values to rise, leading to a decrease in dispersion stability and even stratification. Therefore, it is very important to choose the right dispersant in the water-like alicic acid paint system. In particular, polymer dispersants have a significant effect on pigment dispersion, especially in wetting, stability and other aspects of a considerable role in the pigment application performance has also been greatly improved, has become a new generation of high-efficiency dispersants.1 Experimental part
According to the performance characteristics of different dispersants, the same amount is added to the hydroolic acid decorative paint, a single variable experiment is carried out, its chemical properties are tested, and suitable dispersants are selected.1.1 Experimental raw material
TEGO Dispers 760W (active content about 35%): Dicko; BYK-194: Bick, Germany; Water-based alkalic acid resin (solid content of 70%): homemade; ethylene glycol butyl ether (BCS): commercially available; rust-proof fillers (composite zinc phosphate, aluminum tripolyphosphate), titanium dioxide, precipitated sulphate (1,500 eyes), neutralizer 1, neutralizer 2, de-foaming agent, anti-sink agent, detoxifier, substrate moisturizer: market.1.2 Experimental instruments
shown in Table 1.2 Experimental process
2.1 raw material screening
resin selection: Chenyang Industry and Trade Group independent research and development team developed water-based alcoholic acid resin as a carrier, its solid content of 70%, the resin has a high gloss, good plumpness, pigments, fillers have better wetting and dispersion, and excellent water resistance.
solvent selection: the international common code-named BCS (ethylene glycol butyl ether) as a solvent, mainly to dissolve resin and improve the surface leveling of the paint film, its volatile properties are also one of the factors that dictate the drying speed of the paint film.
Powder selection: Rust-proof fillers (composite zinc phosphate, aluminum tripolyphosphate) is an important part of water-based coatings to obtain good rust prevention effect, can improve the denseness of the paint film, enhance the mechanical properties of the coating, improve water resistance at the same time its salt spray resistance is also greatly improved. Aluminum tripophosphate in the coating can be dissophed out of the tripophosphate root ions, tripophosphate ions have a very strong ability to capture metal ions, can effectively close the metal ions to form inorganic polymer disintegration, passivation metal surface, play a chemical anti-rust role. Then it slowly decomposes into dense orthophosphate skin film, insulated moisture, oxygen and other contact with metals, resulting in isolated rust-proof effect. Therefore, it has the dual effect of chemical corrosion prevention and isolation of rust prevention.
composite zinc phosphate is mainly composed of zinc phosphate, iron phosphate, alumina, silica, which contains free phosphate root ions to form a passivation film, and other pigment ions interlink to form a complex, play a protective role.additive selection:
1. TEGO Dispers 760W: Suitable for water-based formulations, especially for carbon black and organic pigments. Free of solvents and acetylphenols.
2. BYK-194: This is mainly the function of reducing surface stress between molecules and thus physically accelerating the crosslinking of membranes. Excellent storage performance and excellent viscous effect. Dispersant addition: 0.3% (added in stirring).2.2 Experimental Formulas
Basic Recipes can be found in Table 1.3.3 Performance Detection Control
performance as compared to Table 2.2.4 results and samples
results and samples are found in Table 3.3 Conclusion
Water-based alkalic acid resin as a membrane substance, with additives, powder paint test, change a single variable (dispersant) detection of various properties, including drying speed, water resistance, salt spray resistance, thermal storage performance, physical performance and a series of indicators. Experiments show that TEGO (Dico) 760 w in water-based alicic acid paint performance indicators in addition to water resistance test slightly inferior, are superior to BYK194. Therefore, according to a large number of experiments measured TEGO760 w is more suitable for water-based alicic acid decorative paint.
Water-based alicic acid paint contains water-based alicylated steel paint, decorative paint, protective paint and other types, low price, high gloss satiety, suitable for different fields and coating surfaces, the future health and environmental protection, low VOC, high anti-corrosion will be the development direction of water-based alicic acid paint, water-based paint will be the future development trend, environmentally friendly paint is the new pattern of the future..