Antifreeze inhibitor

About 98% of EDC is used to manufacture VC. Relatively small amounts are used in the manufacture of perchloroethylene (an industrial degreaser and dry cleaning agent), in the manufacture of methyl chloroform (an anesthesia), and ethylenediamine (a fungicide and antifreeze inhibitor). About 99% of VC is used to manufacture polyvinyl chloride in a polymer-... 

Use Fungicide, manufacture of chelating agents (EDTA), dimethylolethylene-urea resins, chemical intermediate, solvent, emulsifying agent, textile lubricants, antifreeze inhibitor. 

H-Benzotriazole Glycerin Isopropyl alcohol Meroxapol 311 Methoxydiglycol Methoxyethanol Methyl alcohol Propylene glycol SD alcohol 40 SD alcohol 40-B Trimethylene glycol antifreeze ingredient Diethylene glycol antifreeze inhibitor Ethylenediamine Ethylenediamine dihydrochloride antifreeze mfg. 

Ethylenediamine is used to synthesize EDTA chelating agent as well as certain fungicides. It is also an antifreeze inhibitor and is used to produce certain lubricants for textile applications. EDTA is widely used as a chelating agent to sequester transition metal ions and reduce their negative effect (that is, catalysis of oxidative degradation) in many applications. 

Methanol has been used in a variety of applications, which can be divided into three cate ries feedstock for other chemicals, fuel use, and other direct uses as a solvent, antifreeze, inhibitor, or substrate. Primary and secondary derivatives or applications of methanol are summarized in Table 3. Chemical feedstock accounted for 62% of the total U.S. methanol consumption of 5.16 million t in 1990 fuel use for 27%, and other direct uses for 11% [1]. Growth in methanol consumption in the next few years will come lar ly from fuel use, especial MTBE [22, 23]. The demand pattern will chan. SRI (Stanford Research Institute) International forecasted that the fuel industry will become the lar st sector for U.S. methanol consumption in 1995. It will account for 54% of about 8.6 million ton methanol demand, followed by 39% as a chemical feedstock and 7% in other uses [1]. 

Methanol as a chemical feedstock, a fuel, or a fuel additive covers most present methanol consumption. Other uses of methanol, although small for each, are broad. New uses of methanol are being explored and have potential for substantial growth. These other uses can be classified into four areas solvent, antifreeze, inhibitor, and substrate. 

Antifog agents Antifoggants Antifolate TS inhibitor Antifouling agents Antifreeze... 

Chemical Specialties Manufacturers Association 1001 Connecticut Avenue, NW Washington, D.C. 20036 Standard Reference TestingMaterials for insecticides (see Insect control technology), cleaning products, sanitizers, brake fluids, corrosion inhibitors (see Corrosion and corrosion control), antifreezes, poHshes, and floor waxes. 

Corrosion Inhibitors. Steel-reinforcing wire and rods embedded in concrete containing quinoline or quinoline chromate are less susceptible to corrosion (72) (see Corrosion and corrosion control). Treating the surface of metals with 8-hydroxyquinoline [148-24-3] makes them resistant to tarnishing and corrosion (73). Ethylene glycol-type antifreeze may contain quinoline, 2-chloro-, 4-amino-, 8-nitro-, or 8-hydroxyquinoline to prevent corrosion (74). 

Corrosion Inhibition. Another important property of antifreeze solutions is the corrosion protection they provide. Most cooling systems contain varied materials of constmction including multiple metals, elastomeric materials, and rigid polymeric materials. The antifreeze chosen must contain corrosion inhibitors that are compatible with all the materials in a system. Additionally, the fluid and its corrosion inhibitor package must be suitable for the operating temperatures and conditions of the system. 

Despite all these safeguards to extend the service life of the antifreeze, fluid replacement is requited periodically. Typically, fluids are replaced because of irreversible damage caused by one of four conditions contamination, gel formation because of glycol/siUcate reaction, extensive glycol degradation caused by overheating or excessive oxygen exposure, or inhibitor depletion. 

When antifreeze becomes unsuitable for use, either because of depletion of inhibitors, presence of corrosion products or corrosive ions, or degradation of the fluid, recycling and reuse of the antifreeze, rather than disposal, may be considered. Although ethylene glycol is readily biodegraded in typical municipal waste treatment faciHties, antifreeze disposal becomes problematic because the coolant may contain hazardous quantities of heavy metals picked up from the cooling system. Recycling may be economically preferred over coolant disposal and reduces the concern for environmental impact. 

Ideally, a system for recycling spent antifreeze consists first of the removal of the deleterious contaminants such as the corrosion products, corrosive ions, degradation products, and remaining inhibitors. Then the clean fluid could be reinhibited to a known concentration of both inhibitors and glycol. 

See also Antioxidants Antifreezes and deicing fluids Antistatic agents Corrosion and corrosion inhibitors Industrial antimicrobial agents. 

Approximately 5% of the U.S. consumption of is in agriculture. Boron is a necessary trace nutrient for plants and is added in small quantities to a number of fertilizers. Borates are also used in crop sprays for fast rehef of boron deficiency. Borates, when apphed at relatively high concentration, act as nonselective herbicides. Small quantities of borates are used in the manufacture of alloys and refractories (qv). Molten borates readily dissolve other metal oxides usage as a flux in metallurgy is an important apphcation. Other important small volume apphcations for borates are in fire retardants for both plastics and ceUulosic materials, in hydrocarbon fuels for fungus control, and in automotive antifreeze for corrosion control (see Corrosion and corrosion inhibitors). Borates are used as neutron absorbers in nuclear reactors. Several borates, which are registered with the Environmental Protection Agency (EPA) can be used for insecticidal purposes, eg, TIM-BOR. 

Metal- Working and Hydraulic Fluids. In the preparation of fluids for metal-working and hydrauflcs, the trend has been to replace organic-based materials with aqueous-based materials. Neodecanoic acid has found apphcation in these newer fluids as a corrosion inhibitor and a viscosity improver. For example, neodecanoic acid is used in an aqueous hydrauflc fluid concentrate for corrosion inhibition and improved antiwear properties (101), in the preparation of a thickened aqueous hydrauflc fluid to reduce viscosity loss (102), and in a water-soluble metal working oil to reduce corrosion (103). In a similar vein, neodecanoic acid has been used in antifreeze concentrates for corrosion inhibition (104). 

Miscellaneous Derivatives. Fimehc acid is used as an intermediate in some pharmaceuticals and in aroma chemicals ethylene brassylate is a synthetic musk (114). Salts of the diacids have shown utUity as surfactants and as corrosion inhibitors. The alkaline, ammonium, or organoamine salts of glutaric acid (115) or C-5—C-16 diacids (116) are useflil as noncorrosive components for antifreeze formulations, as are methylene azelaic acid and its alkah metal salt (117). Salts derived from C-21 diacids are used primarily as surfactants and find apphcation in detergents, fabric softeners, metal working fluids, and lubricants (118). The salts of the unsaturated C-20 diacid also exhibit anticorrosion properties, and the sodium salts of the branched C-20 diacids have the abUity to complex heavy metals from dilute aqueous solutions (88). 

Soldered brass seldom gives trouble. In radiators, antifreeze solutions have been alleged to cause corrosion, possibly because materials such as ethylene glycol sometimes detach protective deposits. Sodium nitrite, valuable as a corrosion inhibitor for other metals in a radiator, tends to attack solders, but sodium benzoate is safe and, in addition, protects the soldered joint against the action of nitrites. In an investigation of other inhibitors in ethylene glycol solutions, 1% borax, either alone or in combination with 0-1% mercaptobenzothiazole, appeared to be satisfactory. 

In all circumstances it is important to ensure that the inhibitor is chemically compatible with the liquid to which it is added. Chromates, for example, cannot be used in glycol antifreeze solutions since oxidation of glycol by chromate will reduce this to the trivalent state which has no inhibitive properties. 

Locomotive diesels As larger volumes of coolant are required in railway locomotives than in road vehicles, the cost of inhibition is proportionally greater. An additional factor is the possibility of cavitation attack of cylinder liners. These considerations place a restriction on the choice of inhibitors. In the past, chromates have been used at concentrations of up to 0-4%, but their use presents handling and disposal problems. Chromates cannot be used with ethanediol antifreeze solutions. A IS I borate-metasilicate at a concentration of 1 % has been used in the UK. Nitrate is added to this to improve inhibition of aluminium alloy corrosion. Tannins and soluble oils are also used, but probably to a lesser extent than in the past. The benzoate-nitrite formulation (formerly BS 3151) is effective and has been used by continental railways . ... 

It is also used as a corrosion inhibitor in automotive antifreeze products. 

Dibasic salts of dicyclopentadiene dicarboxylic acid are claimed to be active as corrosion inhibitors [444], Certain salts of fatty acids (metal soaps), together with benzotriazole, are claimed to give synergistic effects for corrosion in antifreeze-agent formulations [446]. 

The choice of a corrosion inhibitor as an additive in antifreezing agents is also dependent on the mode of operation. For instance, cars are operated intermittently. Here the corrosion inhibitors must also protect the system when it is idle. Film-forming silicates can protect the system while idle. This is especially true of aluminum parts, which are introduced in cars for the sake of weight reduction. But silicones can react with ethylene glycol to form crosslinked polymers. These gels may clog lines. 

J. W. Darden, C. A. Triebel, W. A. Van Neste, and J. P. Maes. Monobasic-dibasic acid/salt antifreeze corrosion inhibitor. Patent EP 229440, 1987. 

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