Drying alkyd resins

All members of this pigment family share good lightfastness, combined with poor solvent and migration resistance. These properties define and limit their application. Monoazo yellow pigments are used extensively in air-dried alkyd resin and in emulsion paints, and certain inks used in flexo and screen printing. Other applications are in letterpress and offset inks, as well as in office articles. 

Fig. 54 Influence of the pigment concentration on the rheological behavior. P.Y.73 in air drying alkyd resin paint.

Fig. 80 Influence of the gloss of air-dried alkyd resin systems containing Pigment Red 3 of different particle sizes with the drying time. Pigment content of the systems 8%.

P.R.68 is used in paints for applications where it performs well, especially in terms of lightfastness. Incorporated in an air drying alkyd resin vehicle, full shades equal step 5 on the Blue Scale for lightfastness. 1 5 Ti02 reductions, however, only score as high as step 2. P.R.68 exhibits excellent resistance to a large number of organic solvents, while it is quite sensitive to alkali and acid, as well as to water. 

On account of these disadvantages and the relatively long drying time, oil paints have almost completely lost their former importance over the last 30 years in favor of oxidatively drying alkyd resins. Being naturally-based paints , renewed interest has, however, recently been shown in oil paints owing to ecological reasons. 

Long oil drying alkyd resins are used as binders for architectural and do-it-yourself paints, and are mainly modified with soybean oil. In the absence of direct light, they do not yellow as much as linseed oil alkyd resins and are less expensive than safflower oil types. Long oil linseed oil alkyd resins are principally used in corrosion protection coatings and colored architectural coatings. 

Thixotropic air-drying and oven-drying alkyd resins with low oil contents are used as binders for one-coat industrial paints with a high dry-film thickness of 50-75 pm. In special-effect paints (e.g., hammer finishes, soft-feel coatings, textured finishes) they facilitate fixation of the desired effect and prevent smudging. 

Solvent-Containing, Air-Drying Epoxy Esters. In order to produce epoxy resin esters that can be cured at room temperature, solid epoxy resins (M, 1500-2000 e.g., Araldite GT 6084, Ciba-Geigy Epikote 1004, Shell) are reacted with air-drying fatty acids (e.g., linseed oil or soybean oil fatty acid). The area of application of these resins is very similar to that of air-drying alkyd resins, but they have a higher chemical resistance and improved flexibility. Normal driers (e.g., cobalt octoate) are used to accelerate drying. 

Solvents used for paint removal are able to dissolve or considerably swell physically drying binders (e.g., vinyl chloride copolymers, cellulose nitrate, polyacrylates) and chemically cross-linked coatings (e.g., oil-based paints, dried alkyd resins, cross-linked polyester-melamine resins, cross-linked epoxy and isocyanate coatings) [14.237]. A combination of dichloromethane with low-boiling ketones or esters is particularly suitable. Small amounts of high-boiling solvents with a low volatility (e.g., tetrahydronaphthalene, solvent naphtha, methyl benzyl alcohol, or benzyl alcohol) are added to these mixtures to retard evaporation and increase the solvency. Modern paint removers do not contain chlorinated hydrocarbons, they are formulated on the basis of high boilers (e.g., dimethylformamide, dimethyl sulfoxide, propylene carbonate, and yV-methylpyrrolidone) in combination with alcohols and aromatics, or consist of aqueous, frequently alkaline or acidic systems. 

Uses Drier for waterborne oxidatively drying alkyd resin paints, esp. externally emulsified alkyd resin emulsions Features Lead-free, barium-free nonylphenol ethoxylate-ffee Properties Violet liq. water-emulsifiable dens. -1.09 g/cm (20 C) dynamic vise. 150-1000 mPa s flash pt. = 66 C 5% Co, 0.22% Li, 7.5% Zr Use Level 1-3% (on solid resin)... 

Uses Wetting agent, dispersant, antisedimentation aid, antitlooding agent for pigmenfs, extenders, and binder systems in air-dried alkyd resins, chlorinated polymers, alkyd/amino resin combinations and epoxies Features Reduced disp. time stabilization of the pigment disp. reduced... 

Fast drying alkyd resin obtained from soya oil is used as a core material and mixed xylene is used as a solverrt (to reduce the viscosity of the resin). Urea, formaldehyde, resorcinol and arttmonium chloride were the waU forming materials. Polyvinyl alcohol as a surfactant and n-octanol as an anti-foarrring agerrt supports to achieve high yield of rrricrocapsules without arty air ftUed capsrrles. 

Rapid drying is one of the most important characteristics of nitrocellulose-based coatings. Nitrocellulose alone produces hard and brittle films, and therefore, nitrocellulose-based coatings generally are formulated with plasticizers to improve flexibility and adhesion as well as compatibility with other resins. They are also blended with other polymers such as hard resins and non-drying alkyd resins, to name a couple. On the limiting side, nitrocellulose-based lacquers have generally poor resistance to chemicals and poor durability. 

Uses Defoamer for solv.-based paints, esp. long-oil and med.-oil air-drying alkyd resins systems, wood preservatives, vinyl resin paints, acrylic resin paints, nitrocellulose paints, chlorinated rubber paints Features Highly effective... 

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