High solids paint

By depolymerizing PET waste with a polyol and subsequently condensing the oligomeric product with a polycarboxylic acid or anhydride, polyester resins are produced which have wide industrial applications. Depending on the polyol and polycarboxylic acid or anhydride used, saturated resins, alkyd resins, or unsaturated resins are obtained. PET wastes have been used for the production of alkyd resins in water thinnable paints. The materials obtained from the reaction of PET with a mixture of fatty acids high in linoleic acid content and trimethylolethane have been used in the preparation of water-dispersible coatings. Products of the depolymerization of PET with trimethylolpropane and pentaerythritol are used in the manufacture of high-solids paints. In the first step, PET is depolymerized with trimethylopropane and pentaerythritol at temperatures of 230-240°C. The final paint compositions contain 30-50% of PET depolymerization products.12... 

The development of new paint technology has mandated further improvements in the performance of non-chrome rinses. Greater use of a final water rinse in treatment applications has taken place particularly with the advent of anodic and cathodic electropainting which require the use of a deionized rinse to prevent paint contamination. High solids paints which tend to be more... 

In general, paint adhesion and salt spray corrosion inhibition of iron phosphate coatings post-treated with polyvinylphenol derivatives have been equal to or superior to that obtained with chromate based systems. This has been the case particularly with many high solids paints. 

High-Solids Paints. Hitherto, for paints for spraying purposes, the mixed solids contents have been of the order of 5% to 15% by volume. However, with more modern spray equipment and other improvements in plant, the use of paint with solids contents in the range 30% to 40% is possible—which means in turn a diminished need for organic solvents. 

Figure 12. Light stability of a two-coat high-solid paint (silver metallic) with a benzotriazole and a HALS type stabilizer. Exposure Florida, 5 south, black box, unheated.

Cur-Rx. [Mooney Chems] Drier fcx high-solids paint resins. 

Paints may contain all typical coatings components, although the use of organic solvents is being reduced to rely more heavily on water or high-solids paints. 

Thus, numerous low-emission paints have been developed, including high-solids paints, waterborne paints, aqueous dispersions for industrial use, powder coatings, and radiation-curing coatings. At the forefront in adopting these environmentally friendly products is heavy industry, in particular the automobile and household appliance industries. Medium-sized and smaller businesses will profit from this experience, adapting it for their own needs. 

The development of low-solvent (high-solids) paints requires resins with a very low viscosity. The principal viscosity-determining parameters for such binders are the molecular mass and molecular mass distribution [2.45]-[2.47], [2.50]-[2.53]. Oligomers with a molecular mass of ca. 1000 3000 are required for high-solids paints [2.48], [2.54]. An acrylate binder with a molecular mass of 100000 can be processed to form a paint with 12.5% solids content at the application viscosity a molecular mass of ca. 6000 results in a paint with 50% solids content [2.46]. A narrow molecular mass distribution is beneficial in achieving low viscosity [2.45],... 

Solvent emission from paints can be reduced without lowering the molecular mass by using nonaqueous dispersions (NAD) (see Section 3.6). Acrylates have been described as binders for NADs, but apart from a low viscosity they offer few advantages over conventional coatings [2.50] and moreover must compete with high-solids paints and powder coatings [2.56]. 

Solvent-Free and Low-Solvent (High-Solids) Paints... 

Low-solvent paints are commonly referred to as high-solids paints and are defined as systems with a solids content exceeding 85 wt %. In practice, however, paints with a solids content of 60-80 wt% are also termed high-solids paints, particularly if the corresponding conventional (high-solvent) system normally contains <50wt% nonvolatile components [3.28]. 

The advantage of high-solids paints compared with more recent technologies lies in the fact that they can be produced and applied with conventional equipment and by well-known methods. Consequently potential users are primarily small and mediumsized paint shops, the maintenance and architectural sector, as well as the do-it-your-self sector,... 

Given the possibilities for postcombustion of the solvent in industrial coating, the trend towards high-solids paints is, however, not so pronounced in this class of binders as it is, for example, in the case of maintenance paints and architectural coatings. High-quality paints with a solids content > 70 wt% are not widely available. Powder coatings are preferred as an alternative in the industrial sector. 

In general it may be said that solvents of low intrinsic viscosity strongly reduce the viscosity of high-solids paints [14.208]. High-boiling solvents with a high solvency must also be used to obtain good flow properties [14.209],... 

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. 

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