Water-borne paints

The main reason for loss of dry in water-borne paints is the hydrolysis of the metal soap. In the presence of water the drier is first hydrated. These hydrates are unstable and result in hydrolysis of the metal soap and subsequently the insolubiUty of the basic metal soap. 

Flash Rusting (Bulk Paint and "Wet" Film Studies). The moderate conductivity (50-100 ohm-cm) of the water borne paint formulations allowed both dc potentiodynamic and ac impedance studies of mild steel in the bulk paints to be measured. (Table I). AC impedance measurements at the potentiostatically controlled corrosion potentials indicated depressed semi-circles with a Warburg diffusion low frequency tail in the Nyquist plots (Figure 2). These measurements at 10, 30 and 60 minute exposure times, showed the presence of a reaction involving both charge transfer and mass transfer controlling processes. The charge transfer impedance 0 was readily obtained from extrapolation of the semi-circle to the real axis at low frequencies. The transfer impedance increased with exposure time in all cases. 

The water-soluble EHEC is used in water-borne paints, pastes, polymer dispersions, ceramics and cosmetics, and pharmaceuticals,whereas organic soluble EHEC is used in inks, lacquers, and as coatings. 

Cornwell illustrates many successful cases of water-borne paint use for steel coating, a substrate not traditionally coated with water-based paints because of difficulties with rusting (Cornwell, 1994). 

Hellgren, A.C., Weissenborn, R andHolmberg, K. (1999) Surfactants in water-borne paints. Progr. Org. Coat., 35, 79-87. 

Polymer latices are of extreme technological importance in the development of water-borne paint systems. One method for the production of these latices involves emulsion polymerization, which allows careful control of... 

A general approach to increase adhesion is for polar groups to be introduced to the surface in order to improve the adhesion of water-borne paints. While the polar groups increase the adhesion characteristics, they also increase the surface energy, which makes the adhesion water sensitive and often increases the water permeability. 

There are three major sources that contribute to the increase in viscosity of water-borne paints ... 

If serious problems arise (gel particles or turbidity, or surface demanging surfac-tance, especially in water-borne paints), layered filters such as plate and disk filters with or without adsorptive effects are used. 

Comprehensive information on all paint systems and binders, pigments, fillers, and additives has been given in individual chapters. Modern, low-emission paints such as high-solids paints, water-borne paints, powder paints, and radiation-curing systems are also discussed in detail. 

Uses Surf, additive, slip agent, leveling agent, substrate wetting agent in solv.-based, air drying, baking systems, e.g., alkyd-actylic, polyester-melamine, water-borne paints, inks... 

Uses Preservative for water-borne paints, contact adhesives Features In-can preservation Use Level 0.1-0.5% on finished paint Dehysol [Cognis KGa/VCoatings]... 

Until the mid-1950 s, vinyl acetate was a moderate volume product used to produce specialty polyolefins, such as cling films. However, in the 1950 s, emulsion polymerization ("latex") began to emerge as a major new product line in the chemical industry. (Emulsion polymerization uses surfactants to generate water based emulsions of polyolefin polymers. These products are most familiar to the consumer as water borne paints, but are also found in a wide variety of... 

The additives used in the grinding process are called pigment dispersants. Their primary function is to surround the suspended pigment particles with a barrier envelope that by either ionic repulsion or steric hindrance, or both, prevents random contact with other pigments. In water-borne paints, electrostatic repulsion is usually the most important stabilizing mechanism and the well known DLVO theory that accounts for the balance of... 

In principle, electrostatic stabilization can be achieved by either anionic or cationic pigment dispersants. In order to be compatible with the other components of a paint formulation, in particular the latex which is almost always negatively charged, anionic dispersants are usually employed. A good dispersant for inorganic pigments for water-borne paints should... 

Water is a liquid of high surface tension and is obviously not suitable for wetting of surfaces. Use of water-borne paints would have been very limited had it not been possible to use surfactants in the formulation. A good surfactant reduces the surface tension of water down to 28-30 mN/m, i.e. to the same range as that of the organic solvents used in paints and lacquers. 

A complicating factor is the fact that the humidity of the air influences the evaporation rate of the water in the formulation (Figure 3.6) and hence the solvent balance during evaporation. A certain control of air humidity when applying this type of water-borne paints is therefore in general required [9]. 

It was prophesied in the 1960s that oil-based paints would disappear from the market in about 20 years in favour of petrochemical-based products. This has not happened, and the main protective paints are still based on fatty oils. In fact, following the oil crisis, the trend has been back to raw materials from renewable resources. None of the new technologies such as the use of powder coatings, water-borne paints, or radiation-curing paints, which would not have been based on oils, have proved as versatile as expected. 

Walnut, 52,97 Washing, 191,195 Washingtonia robusta, 79 Water-borne paints, 245 Water solubility of lipids, 353 Water swelling of monogalactosyl-diglycerides, 334 Water phases in soaps, 328 Waxes, 41,42,51-3,133,135,138,142-47, 287, 283, 436, 557... 

This mixing concept has been extended into two large paint markets, to give in one case extended customer choice, and in the other, the only possible means of access to the colour range required. For the decorative paint market, concentrated tinters have been developed, often capable of use in both solvent and water-borne paints, to offer the customer a wider choice of colours than is possible with a standard range, often limited by shelf storage space in the shop. The shop will be equipped with a dispenser for the tinters, and a can-shaker to ensure complete mixing. 

Even if the polymeric salts are capable of anodic or cathodic electrodeposition, water-borne paints made from them do not have to be applied in this way. The solution or emulsion paints produced can be applied by virtually any technique. There is increasing use of this type of paint in all markets as environmental concerns, legislation, economics and lessening of world petroleum stocks encourage the use of decreasing amounts of volatile organic solvents. 

Water-based paints are dispersions based on synthetic polymers. Dispersions of polyacrylates are the most common. Examples of these paints include acrylic latex paint, heavy-bodied latex wall paint, latex enamel, latex primer, latex wall paint and sealing water-borne paint. Water-based paints can also contain water-soluble alkyd resin and a mixture of polyacrylate and polyurethane. Although water is the main solvent in these types of paints, comprising about 30-85% weight-to-weight ratio (w/w) of the raw materials, about 10% organic solvents are added to improve the film forming properties of the paint. (Hansen et al. 1987 van Faassen and Borm 1991 Wieslander et al. 1997). The differences between SBP and WBP can be seen in Table 2. 

Ulfvarson U, Alexandersson R, Dahlqvist M, Ekholm U, Bergstrom B, Scullman J (1992) Temporary effects from exposure to water-borne paints. Scand J Work Environ Health 18 ... 

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