Nitrocellulose-alkyd lacquers

Synonyms nitrocellulose-alkyd lacquers nitrocellulose vinyl resins acrylic resins Lactated Mono-Diglycerides... 

Nitrocellulose based lacquers often contain short or medium oil alkyds to improve flexibiUty and adhesion. The most commonly used are short oil non drying alkyds. Amino resins or urethane resins with residual isocyanate functional groups may be added to cross-link the coating film for improved solvent and chemical resistance. The principal appHcations are furniture coatings, top lacquer for printed paper, and automotive refinishing primers. 

Two of these types are lacquers, giving quick drying to the dust-free state at ambient temperature, but at the expense of lower film build. Nitrocellulose-based lacquers are preferred in some European countries and acrylic lacquers in North America. Nitrocellulose is plasticised with nondrying alkyds, polyester and liquid plasticiser. Acrylics are plasticised internally by use of plasticising monomers with methyl methacrylate and by solvent plasticiser. Acrylics give better durability and nitrocellulose gives easier application. 

Nitrocellulose-based lacquers often contain short or medium oil alkyds to improve flexibility and adhesion. The principal applications are furniture coalings, top lacquer for printed paper, and automotive refinishing primers. 

The use of oil-modified alkyds with nitrocellulose in lacquers is perhaps the first "polymeric merger" that resulted in the remarkable growth in the use of nitrocellulose lacquers. Compatibility of alkyds with nitrocellulose extends up to about 50%... 

An important characteristic of coatings containing water-soluble Cl is washing out of the inhibitors. Coatings of alkyd-nitrocellulose lacquer are preferable in this respect to those of alkyd lacquer. About 70% of the chromate ions are washed out of the alkyd coatings per day, in contrast to the alkyd-nitrocellulose coatings, in which the chromate ions remain practically unwashed during the first five days and then are washed out but very weakly. 

Resins. A large number of synthetic coating resins (e.g., alkyd, ketone, urea, maleate, and acrylic resins) are available for formulating nitrocellulose combination lacquers. Selection criteria include price, color, influence on solvent release, gloss, hardness, sandability, yellowing, and durability of the final coating. 

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. 

Analysis of lacquers containing nitrocellulose, alkyd resins, and phthalate-type plasticizers Melamine (2,4,6-triamino-5-triazine) ... 

Uses Plasticizer, tackifierfornat. and syn. rubber, nitrocellulose, plastics, lacquers, inks, coatings, and pressure-sensitive, emulsion, solv, and hot-melt adhesives fixative for essential oils and aromatics in perfumes chem. intermediate in prod, of oil-modified and oil-free alkyd resins, lubricating oil additives, nonionic surfactants food-contact adhesives, paper/paperboard, rubber articles defoamer in mtg. of food-contact paper/paperboard... 

As solvents, the amyl alcohols are intermediate between hydrocarbon and the more water-miscible lower alcohol and ketone solvents. Eor example, they are good solvents and diluents for lacquers, hydrolytic fluids, dispersing agents in textile printing inks, industrial cleaning compounds, natural oils such as linseed and castor, synthetic resins such as alkyds, phenoHcs, urea —formaldehyde maleics, and adipates, and naturally occurring gums, such as shellac, paraffin waxes, rosin, and manila. In solvent mixtures they dissolve cellulose acetate, nitrocellulose, and ceUulosic ethers. 

Many alternatives to nitrocellulose lacquers for top coats have been investigated and some are used commercially. Especially for lower cost furniture exposed to hard use such as motel and institutional furniture, alkyd—urea top coats are used. Urea—formaldehyde resins, in contrast to... 

With these lacquers, nitrocellulose-based primer-surfacers are used. As well as liquid plasticisers, a wide range of materials are used as plasticising resins short oil alkyds, maleinised oils, ester gum, rosin and bodied castor oils. Pigmentation is usually inert. Thermoplastic acrylics are often preferred under acrylic lacquers these are based on acrylic resins and cellulose acetate butyrate. 

Coating materials may be based on short or medium-oil alkyds (e.g. primers for door and window frames) nitrocellulose or thermoplastic acrylics (e.g. lacquers for paper or furniture finishes) amino resin-alkyd coatings, with or without nitrocellulose inclusions, but with a strong acid catalyst to promote low temperature cure (furniture finishes) two-pack polyurethanes (furniture, flat boards) unsaturated polyester resins in styrene with free-radical cure initiated by peroxides (furniture) or unsaturated acrylic oligomers and monomers cured by u.v. radiation or electron beams (coatings for record sleeves paperback covers, knock-down furniture or flush interior doors). 

Uses. Used in semiconductor industry as a photoresist solvent for nitrocellulose lacquers and alkyd resins in dyeing textiles and leather in cleaners and varnish removers... 

Uses. Intermediate in the manufacture of 2-ethylhexyl acetate, a lacquer solvent solvent for nitrocellulose, urea, resins, enamels, alkyd varnishes, and lacquers used in ceramics, paper coatings, textiles, and latex rubbers... 

Nondrying, short oil alkyds are generally based on castor or coconut oils. They are used with nitrocellulose for exterior lacquers. Coconut oil alkyds give the best exterior durability castor oil lacquers have the best film properties. 

Available forms 203 Replacement for normal butyl alcohol in nitrocellulose lacquers, alkyd resin formulations, and thinners, distillation range 115-120C, flash p 100F (37.7C) (OC). 601 Replacement for methyl ethyl ketone in vinyl and nitrocellulose applications, distillation range 74—84C, flash p 10F (-12.2C) (OC). 

Use Polymer and copolymers used in surgical adhesives, coatings, and lacquers modifier for alkyd and polystyrene resins plasticizer for nitrocellulose and other plastics chemical intermediate. 

The introduction of Rule 66 caused tremendous activity in the reformulation of solvent blends to conform with the regulation. An example of nitrocellulose lacquer solvents for both complying (exempt from control Rule 66) and noncomplying (nonexempt) formulations is shown in Table VII (79). Exempt solvent systems for alkyd resins have been discussed by Fink and Weigel (80). for nitrocellulose and vinyl resins by Crowley (81). for vinyl resins by Park (82) and by Burns and McKenna (83). and for epoxy resins by Somerville and Lopez (84). 

Late in the 1960s, it became apparent that catalyzed lacquers, the hardest, most durable nitrocellulose lacquers commercially available for coating wood, had less resistance to alcohol, cosmetics, and chemicals than did the best quality alkyd-amine compositions or high-pressure melamine overlays. This situation was soon remedied by the development of nitrocellulose-urethane "super lacquers" based on nitrocellulose-isocyanate prepolymers (16). Nitrocellulose as manufactured contains free hydroxyl groups that can provide sites for true cross-linking with an isocyanate-bonded homogeneous coating. Laboratory studies confirmed the theoretical reaction ... 

Water-soluble Cl significantly improve the protective ability of oil, alkyd, alkyd-styrene and alkyd-nitrocellulose coatings (Fig. 3.41), for example, 3wt% of water-soluble potassium chromate guanidine. Cl has been introduced into the lacquer base, after which a 20-pm-thick single-layer coat has been applied on a plate of low-carbon steel (St 2). The time until the appearance of corrosion traces under the coating has been recorded on exposure to atmosphere at 100% humidity and a temperature of T = 18-25°C. The results presented in Fig. 3.38 prove that the introduction of this Cl has perceptibly improved the anticorrosion properties of lacquer coatings [1]. 

Fig. 3.41. Time until formation of corrosion traces on the steel coated by (1) natural drying oil (3, 5) and (7) alkyd, alkyd-styrene and alkyd-nitrocellulose lacquers (2, 4, 6) and (8) the same modified by potassium chromate guanidine...

Short oil alkyd resins can also be combined with nitrocellulose. They are readily soluble in typical nitrocellulose solvents (esters and ketones). Special short oil alkyd resins that are soluble in lower alcohols are often processed into furniture lacquers and acid-curing paints, and are also used in paper (spray) coatings and in flexoprint-... 

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