Formaldehyde metalworking fluids

Other Nitrogen Compounds. The basis of the sophisticated nitrogen compounds Hsted in Table 10 is the reaction of formaldehyde with amino compounds. A significant amount of Hterature details investigation of the mechanism of action, particularly whether or not the antimicrobial activity depends on decomposition to formaldehyde (40—42). These compounds tend to have substantial water solubiUty and are more effective against bacteria than fungi and yeasts. Key markets for these compounds are metalworking fluids, cosmetics, and in-can preservation of paints (see Alkanolamines Amines, fatty amines). 

Formaldehyde release biocides are perhaps the most commonly used biocides in metalworking fluids. One of die best know examples of this chemistry is hexahedron -l,3,5-tris(2-hydroxyethyl)-s-triazine, (see Figure 2). 

This is a monoethanolamine formaldehyde condensate. It is cheap, compatible with most metalworking fluid concentrates and provides a valuable source of reserve alkalinity. It is bactericidal and is typically incorporated into metalworking fluid concentrates at between 2.5 to 3% by weight. Good antibacterial performance is seen at between 1200-1500 parts per million (ppm) in-use. 

It does have a number of draw backs. It has poor thermal stability (a property common to most formaldehyde release biocides) and, in some instances, may cause blackening of metalworking fluid concentrates if heated above 50°C for a period of time. Recently, this active ingredient was placed on Annex 1 of the Dangerous Substances Directive having been identified as a potential skin sensitiser. This means that formulations containing efficacious levels of this class of triazine in them would have to be labelled with R43 - may cause sensitisation by skin contact. This is unacceptable to many UK customers. As this material is only bactericidal, it needs to be co-formulated with a fungicide to provide complete protection for a product. 

Formaldehyde, released from certain antimicrobials in metalworking fluids, activates amines toward nitrosation by nitrite (21). This reaction enhances nitrosation in neutral and basic medium. Since metalworking fluids are typically of pH 9-11, formaldehyde released from... 

Biocides that function as formaldehyde-releasers comprise about 60 % of total sales of antimicrobials (29). Thus, such antimicrobials are expected to be common additions to metalworking fluids. Examples of formaldehyde-releasing antimicrobials are tris(hydroxy methyl) nitromethane, trivially called tris nitro, 4,4 -(2-ethyl-2-... 

The pH of a metalworking fluid must be kept above neutrality in order to prevent acid corrosion of the metal In vitro, acid catalyzed nitrosation is optimized at pH 3.5 (4 0) however, it has been shown that In the presence of other catalysts, aqueous solutions of amines and nitrite leads to significant yields of nitrosamines at room temperature over the pH range of 6.4 to 11.0 (41). Furthermore, C-nitro-containing, formaldehyde-releasing biocides, such as bronopol or tris nitro, exert their potential catalytic effect in alkaline solution. It would thus be desirable to determine the optimum pH for a metalworking fluid that would lead to the lowest concentration of nitrosamine possible. 

Nitromethylidynetrimethanol Nitr-otris(hydroxymethyl)methane NSC 17675 S.S.T Sump Saver Tablets Trihydroxymethylnitromethane Trimethyl-olnitromethane Tris-Nitro Tris(hydroxy-methyl)nitro-methane. Antibacterial agent, preservative for water treatment, metalworking fluids, oil production, de-odorizing formaldehyde releaser. Used as a bactericide in pesticide products and consumer products, building materials or furnishings. Registered by EPA as an antimicrobial and disinfectant. Crystals mp = 165° bp dec very soluble in H2O (220 g/100 ml), EtOH, EtsO. Dow Chew. U.S.A. Hess Clark Inc. Whittaker Clark Daniels. 

Chem. Descrip. Benzylhemiformal CAS 14548-60-8 EINECS/ELINCS 238-588-8 Uses Formaldehyde releaser, preservative, bactericide, fungicide, yeast inhibitor in aq. coatings, polymer disps., filler suspensions, slurries, sol ns. and disps. of adhesives and thickeners, concrete additives, metalworking fluids, cleaners... 

Uses Emulsifier for creams/lotions, oils, fats, waxes, cosmetics, min. oil and paraffin wax emulsions, leather dressings, textile specialties, polishes, cleaners absorbent for acidic gases medicine buffer in cosmetics solubilizer, stabilizer, buffer in pharmaceuticals formaldehyde scavenger in curing U-F resins, phenolics amine soaps (metalworking fluids) synthesis of surfactants, vulcanization accelerators, pharmaceuticals chemical intermediate for paints, etc. 

Precaution May release formaldehyde Hazardous Decomp. Prods. Heated to decomp., emits toxic vapors of NOx Uses Biocide for household, industrial, institutional prods., latex paints, adhesives, aq. inks, polishes, waxes, pulp and paper, metalworking fluids antimicrobial, preservative for cosmetics, toiletries, topical pharmaceuticals keratin softener in dry skin prods. antiseptic Features Broad-spectrum Regulatory USA CIR approved Europe listed Japan not approved Manuf./Distrib. ISP Sutton Labs ISP http //www.ispcorp.com, Int l. Sourcing Sigma Universal Preserv-A-Chem http //www. upichem. com Trade Name Synonyms German II [ISP Sutton Labs] Integra 22 t[ISP Sutton Labs] ... 

Uses Catalyst for formaldehyde polymerization vulcanization accelerator corrosion inhibitor for textile lubricants, metalworking fluids solvent mfg. of pesticides, polymers, rubber, dyes intermediate for emulsifiers, dyes, insecticides, flotation agents inhibitor for butadiene... 

Diethanolamine, 2% pet (corrosion inhibitor) 2-Hydroxymethyl-2-nitro-i,3-propandiol (Tris Nitro), 1% pet [biocide, formaldehyde releaser use in metalworking fluids forbidden in Germany (Geier et al. 1996)]... 

The microbicide is recommended for use as an industrial preservative for the protection of water-based functional fluids with pH values > 7 such as latex paints, resin emulsions, adhesives, pigment slurries, concrete additives, metalworking fluids. Its compatibility with protein containing formulations is very limited. Normal use levels range between 0.1 and 0.3%. The spectrum of efficacy (see Table 31) covers above all bacteria as is characteristic for a formaldehyde releasing compound. 

Aeeordingly N-(2-hydroxypropyl)-aminomethanol can be used for the in-ean preservation of a great variety of aqueous produets such as adhesives, bitumen emulsions, metalworking fluids. However, one has to keep in mind that formaldehyde releasing eompounds are not in any case compatible with protein-based (e.g. easein-eontaining) produets. Addition rates move between 0.05A).3%. 

Uses Corrosion inhibitor for steam-condensate lines component of metalworking fluids with extended fluid longevity co-dispersant for particulate systems formaldehyde scavenger... 

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