Paint removal

The nature, condition, and quality of the paintand substrate are important in paint removal. The paint binder plays a decisive role in paint dissolution the substrate influences the choice of paint removal method. Various chemical and physical methods exist for removing paint from different substrates (metals, wood, and mineral substrates) [6.1], [6.2]. 

Ingredients % bv Weight Aerosol C-61 Surfactant 20.0 Sodium Carbonate 40.0 Sodium Metasilicate 30.0 Sodium Hydroxide 10.0 

Grind the powders together and add the Aerosol C-61 slowly while mixing. 

Ingredients % bv Weight Aerosol OS Surfactant 10.0 Sodium Bifluoride 75.0 Sodium Tetraphosphate 10.0 Sodium Bisulfite 15.0 

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C, b.p. 81"C. Manufactured by the reduction of benzene with hydrogen in the presence of a nickel catalyst and recovered from natural gase.s. It is inflammable. Used as an intermediate in the preparation of nylon [6] and [66] via caprolactam and as a solvent for oils, fats and waxes, and also as a paint remover. For stereochemistry of cyclohexane see conformation. U.S. production 1980 1 megatonne. 

CH2CI2. A colourless liquid with a chloroform-like odour b.p. 4I°C. Prepared by heating chloroform with zinc, alcohol and hydrochloric acid manufactured by the direct chlorination of methane. Decomposed by water at 200°C to give methanoic and hydrochloric acids. Largely used as a solvent for polar and non-polar substances, particularly for paint removal (30%), dissolving cellulose acetate and degreasing (10%). It is more stable than carbon tetrachloride or chloroform especially towards moisture or alkali. It is somewhat toxic. U.S. production 1981 280000 tonnes. 

Most of the trichloroethylene produced is used for metal degreasing. Other important uses are in the scouring of wool and as an extractive solvent, e.g. for olive and soya bean oils. Minor uses are as a heat transfer medium, anaesthetic, insecticide and fumigant, paint remover and fire extinguisher. 

Paint driers Paint formulations Painting Paint removers... 

Furfuryl alcohol is used alone or in combination with other solvents for various cleaning and paint removing operations. The ethylene oxide adduct of furfuryl alcohol is especially useful in this type of appHcation (80—83). 

S. ColHs, The Development and Evaluation of Paint Remover Used bj the US. AirTorce Air Force Technical Report 5714, Suppl. 1, Jan. 1955. 

Other. 2-Nitro-1-butanol is an excellent solvent for many polyamide resins, cellulose acetate butyrate, and ethylceUulose. It can be utilized in paint removers for epoxy-based coatings. 2-Hydroxymethyl-2-nitro-l,3-propanediol is usebil for control of odors in chemical toilets. Its slow release of formaldehyde ensures prolonged action to control odor, and there is no reodorant problem which sometimes is associated with the use of free formaldehyde. 2-Hydroxymethyl-2-nitro-l,3-propanediol solutions are effective preservative and embalming fluids. The slow Uberation of formaldehyde permits thorough penetration of the tissues before hardening. 

The physical properties of finish removers vary considerably due to the diverse uses and requirements of the removers. Finish removers can be grouped by the principal ingredient of the formula, method of appHcation, method of removal, chemical base, viscosity, or hazardous classification. Except for method of apphcation, a paint remover formulation usually has one aspect of each group, by which it can be used for one or more appHcations. A Hst of the most common organic solvents used in finish removers has been compiled (3). Many are mentioned throughout this article others include ethyl lactate [97-64-3] propylene carbonate [108-32-7] furfural alcohol [98-01-1/, dimethyl formamide [68-12-2] tetrahydrofuran [109-99-9] methyl amyl ketone [110-43-0] dipropylene glycol methyl ether [34590-94-8] and Exxate 600, a trade name of Exxon Chemicals. 

Evaporation Retardants. Small molecule solvents that make up the most effective paint removers also have high vapor pressure and evaporate easily, sometimes before the remover has time to penetrate the finish. Low vapor pressure cosolvents are added to help reduce evaporation. The best approach has been to add a low melting point paraffin wax (mp = 46-57° C) to the paint remover formulation. When evaporation occurs the solvent is chilled and the wax is shocked-out forming a film on the surface of the remover that acts as a barrier to evaporation (5,6). The addition of certain esters enhances the effectiveness of the wax film. It is important not to break the wax film with excessive bmshing or scraping until the remover has penetrated and lifted the finish from the substrate. Likewise, it is important that the remover be used at warm temperatures, since at cool temperatures the wax film may not form, or if it does it will be brittle and fracture. Rapid evaporation occurs when the wax film is absent or broken. 

There are approximately 114 paint remover manufacturers in the United States. Among them are companies that speciali2e in the manufacture of paint removers only, paint and coating manufacturers that produce a line of paint removers, specialty products manufacturers, and other manufacturers of finish removers for unique or special appHcations. Each group of paint remover manufacturer can be divided into retail or industrial products. A Hst of U.S. paint remover manufacturers is given in Table 2. 

Industrial Users of Paint and Finish Kemovers, Paint Remover Manufacturer s Association, 1992. 

Trisodium phosphate is strongly alkaline many of its appHcations depend on this property. For example, many heavy-duty cleaning compositions contain trisodium phosphate as a primary alkalinity source. The crystalline dodecahydrate itself is marketed as a cleaning compound and paint remover. Traditionally, trisodium phosphate has been used in water softening to remove polyvalent metal ions by precipitation as insoluble phosphates. Because the hypochlorite complex of trisodium phosphate provides solutions that are strongly alkaline and contain active chlorine, it is used in disinfectant cleaners, scouring powders, and automatic dishwashing formulations. 

To reduce the amount of dust produced, water can be added to the abrasive from a circular water sprayer around the no22le. Chemical corrosion inhibitors must be dissolved in the water to prevent flash msting of the steel. Newer methods to reduce dust include the use of ice, soHd carbon dioxide (dry ice), or plastic beads as abrasives. Blasting with dry ice is inexpensive and effective, but the accumulation of carbon dioxide must be avoided in enclosures. Plastic beads are inexpensive, but the cutting efficiency is low and paint removal is slow the beads can be cleaned of paint particles and reused. 

N-Methyl pyrrolidone, dibasic ethers, and organic esters, substituting for more hazardous paint removers (Paint Removers, 1991 Davis et al., 1994)... 

Paint Removers New Products Eliminate Qld Hazards (1991). Consumer Reports (May), 340-343. 

Methylene chloride has a wide variety of markets. One major use is a paint remover. It is also used as a degreasing solvent, a blowing agent for polyurethane foams, and a solvent for cellulose acetate. 

The major use of sec-butanol is to produce MEK by dehydrogenation, as mentioned earlier. 2-Butanol is also used as a solvent, a paint remover, and an intermediate in organic synthesis. 

Hot steam and severe condensation acting on a film surface exert a very destructive effect, comparable with that of a paint remover they are particularly liable to cause swelling. Dry steam, in contrast to condensed steam, does not cause corrosionLess severe attack by water vapour can cause blistering, which can be of two types intercoat blisters between paint films, and blisters through the complete film system. Only the latter leads to corrosion of the underlying material. 

Trichloroethylene is also known as Triclene and Vitran and by other trade names in industry. It is a nonflammable, colorless liquid at room temperature with a somewhat sweet odor and a sweet, burning taste. Trichloroethylene is now mainly used as a solvent to remove grease from metal parts. It is also used as a solvent in other ways and is used to make other chemicals. Trichloroethylene can also be found in some household products, including typewriter correction fluid, paint removers, adhesives, and spot removers. Most people can begin to smell trichloroethylene in air when there are around 100 parts of trichloroethylene per million parts of air (ppm). Further information on the physical and chemical properties of trichloroethylene can be found in Chapter 3, and further information on its production and use can be found in Chapter 4. 

Various consumer products found to contain trichloroethylene include typewriter correction fluids, paint removers/strippers, adhesives, spot removers, and rug-cleaning fluids (Frankenberry et al. 1987 LARC 1979). 

Various consumer products have been found to contain trichloroethylene. These include wood stains, varnishes, and finishes lubricants adhesives typewriter correction fluids paint removers and cleaners (Frankenberry et al. 1987). Trichloroethylene use as an inhalation anesthetic, fumigant, and extractant for decaffeinating coffee has been discontinued in the United States (EPA 1985c). 

A survey of 20 brands of typographical correction fluids found that several contained 10% or less trichloroethylene, although other volatile organic compounds present at higher levels probably posed a greater hazard to people using these products (Ong et al. 1993). Various other consumer products have been found to contain trichloroethylene, such as paint removers, strippers, adhesives, and lubricants (Frankenberry et al. 1987). 

Pollock CA, lbels LS. 1986. Lead intoxication in paint removal workers on the Sidney Harbour Bridge. Med JAust 145 635-639. 

In addition to tobacco smokers, individuals who have had previous exposure to materials containing methylene chloride, such as degreasers, solvents, paint removers, and furniture strippers, are at greater risk because of an existing body burden of carbon monoxide. Approximately one-fourth to one-third of inhaled methylene chloride vapor is metabolized in the liver to carbon monoxide. In addition, methylene chloride is readily stored in body tissue. This stored material is released over time and results in elevated levels of carbon monoxide for extended periods, in some cases more than twice as long as compared with direct carbon monoxide inhalation. 

Used industrially as a chemical intermediate in the production of rayon, carbon tetrachloride, xanthogenates, flotation agents, and pesticides used in the cold vulcanization of vulcanized rubber, in adhesive compositions for food packaging as a solvent for phosphorus, sulfur, selenium, bromine, iodine, fats, resins, rubbers, waxes, lacquers, camphor, resins and in the production of optical glass, paints, enamels, varnishes, paint removers, tallow, putty preservatives, rubber cement, soil disinfectants, explosives, rocket fuel, and electronic vacuum tubes. 

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