PAINT VARNISH FORMULATIONS

The final distillation stage is extremely important in order to ensure removal of any low molecular weight volatile monomeric isocyanates. 

An aliphatic based polyisocyanate, such as hexamethylene diisocyanate (HMDI), although slower to cure than its aromatic counterpart, displays superb stability to UV light and as such is found in the widest range of applications. However, HMDI is volatile and extremely toxic. Its use as HMDI is very limited to closed handling systems. The use of dimers or trimers as adducts of HMDI is much safer due to their lower volatility and as such these are often used in place of the HMDI monomer. 

Although tetramethylxylene diisocyanate (TMXDI) also bears an aromatic structure like the TDI based products, it shows greater durability as the isocyanate group is not directly attached to the aromatic ring. 

Isophorone diisocyanate (IPDI) based isocyanate curing agents confer very high durabihty to 2 component polyurethane systems, but this is offset by poor flexibility and low reaetivity. Hence IPDI adducts are usually combined with flexible hydroxy prepolymers in low bake applications. They are also used as partial replacements for the aromatic or aliphatic polyisocyanates. Compared to other diisocyanates, IPDI has the advantage that it has relatively low volatility, whilst still being a liquid. 

The major suppliers of isocyanate curing agents and their respective trade names can be seen in the following table. 

---

Branched-chain acids have a wide variety of industrial uses as paint driers (7), vinyl stabilizers (8), and cosmetic products (9). Cobalt and manganese salts of 2-ethyIhexanoic acid and neodecanoic acid are used as driers for paint, varnishes, and enamels litbium, magnesium, calcium, and aluminum salts of 2-ethyIhexanoic acid are used in the formation of greases and lubricants (see Driers and metallic soaps). Derivatives of isostearic acid have been used as pour point depressants in two-cycle engine oils, as textile lubricants, and in cosmetic formulations. Further industrial appHcations can be found (10). 

The ether is also used in paint, varnish and lacquer formulations. A recent development is the use of ethyl cellulose gel lacquers. These are permanent coatings applied in a similar way to the strippable coatings. They have been used in the United States for coating tool handles, door knobs and bowling pins. 

Wastes from the manufacture, formulation, supply and use (MFSU) of coatings (paints, varnishes and vitreous enamels), adhesive, sealants and printing inks Wastes from the photographic industry Inorganic wastes from thermal processes... 

American Society for Testing and Materials. 1970 Annual Book of ASTM Standards. Part 21. Paint, Varnish, Lacquer and Related Products— Tests for Formulated Products and Applied Coatings. Philadelphia American Society for Testing and Materials, 1970. 744 pp. 

Formulation chemistry is the branch of manufacturing that addresses substances that do not react with each other, but have desirable properties as a mixture. These products include paints, varnishes, cosmetics, petroleum products, inks, adhesives, detergents, pesticides, and a broad range of household products. 

Some of the other industrial uses for corn oil include insecticide formulations, paints, varnishes, mbber substitutes, mst preventatives, soaps, leather tanning, and textiles (87). 

Dowanol" DPM has a mild, pleasant odor. Becouse of its structure it is completely miscible with water and a wide variety of organic substances, and has the combined solubiiity characteristics of an alcohoi, an ether and a hydrocarbon, it is used in formulations of brake fluids, lacquers, paints, varnishes, dye and ink solvents, wood stains, textile processes, dry cleaning soaps and cleaning compounds. 

It has not been feasible to identify the compositions of individual Soviet paint and varnish formulations. The following tabulation, however, shows the general types of coating materials identified by code letters in this chapter. 

Trichloroethylene Vapor degreasing of metal parts solvent for greases, oils, fats, waxes, and tars fabric cleaner waterless dying ingredient of formulations of adhesives, lubricants, paints, varnishes, and paint strippers 90... 

Among the additives which may be used as substitutes for these systems, intumescent additives seems to be particularly attractive. Fire protection of flammable materials (in particular, paints, varnishes and cellulose-based materials) by an intumescence process has been known for several years [1]. Intumescent technology has more recently found a place in polymer science as a method of providing flame retardancy to polymer formulations, especially polypropylene (PP) formulations [2]. These systems interrupt the self-sustained combustion of the polymer at its earliest stage, i.e. the thermal degradation with evolution of the gaseous fuels. 

There are three broad classes of polymeric coatings lacquers, varnishes, and paints. Varnishes are materials that are solutions of either a resin alone in a solvent (spirit varnishes), or an oil and resin together in a solvent (oleo-resinous varnishes). A lacquer is generally considered to be a material whose basic film former is nitrocellulose, cellulose acetate-butyrate, ethyl cellulose, acrylic resin, or another resin that dries by solvent evaporation. The term paint is applied to more complex formulations of a liquid mixture that dries or hardens to form a protective coating. 

Other miscellaneous uses for the isoparaffin solvents, dearomatized paraffinic solvents, normal paraffinic fluids, and aromatic blends include pesticide formulation applications, wood preservatives, fat and oil extractions, cosmetic and notion formulations, paper coatings, and textile coatings and printing. Inks, paints varnishes, and lacquers are among the largest uses of the hydrocarbon solvents. 

Tables 15.6 and 15.7 lists the various hydrocarbon solvent blends marketed by Shell Chemical. The blends with boiling points ranging from 61 to 204°C find use as solvents in adhesives, agricultural formulations, automotive undercoating, cleaning and polishing formulations, cosmetics, drugs and pharmaceuticals, inks, paints, varnish, lacquers, paper coatings, resin and plastic applications, textile coatings, printing, and other miscellaneous uses.

As noted previously, the major use of turpentine at one time was as a solvent, particularly in varnish formulations, and as a thinner for linseed-oil-base paints. Petroleum-based solvents have now replaced turpentine for these purposes. However, turpentine or turpentine fractions are packaged in small containers (up to 1 gallon) for the retail market for home use as paint thinners (including use with artist s oil paints) and as a general-purpose solvent. Turpentine fractionation products may recover some of the historical solvent use by replacing chlorofluoro-carbons in the specialized circuit board cleaning market (1). 

During the 19th and 20th Century, drying oils, mainly linseed and tung oils, became the principal components in paints, varnishes and enamel formulations, but since World VJar II have been displaced in many of their traditional uses by petroleum-derived products. 

Washall [566] has reviewed analytical pyrolysis of cationic alkylammonium halide surfactants and has shown that analytical pyrolysis is a technique that works well even with trace quantities (low ppm level). For applications which require protection of sample integrity, as in forensic science and in art conservation, analytical pyrolysis is an obvious analytical tool. Bart [563] has reviewed polymer/additive analysis by flash pyrolysis techniques and Challinor [567] the applications of analytical pyrolysis in forensic science. Paints, varnishes, glues, pigments, waxes, organic binder formulations have been studied from the aspects of both conservancy and authentication. 

Nearly all surface finishes and coatings, with the exception of ceramic types for high-temperature applications, are based on a polymer film of some sort. They account for the use of a lot of polymer, but determining just how much and which polymers is not easy because most formulations are proprietary, and production figures do not always separate polymer and nonpolymer components. Five traditional types of surfaces finishes, lacquers, oil paints, varnishes, enamels, and latex paints, will be discussed, along with the role the polymers play in the finish. 

These products are solvents or intermediates for syntheses. They are part of the formulation of paints, varnishes, resins, etc. 

---