Ozone-depleting solvents

There now exist alternatives or sufficient quantities of controlled substances for almost all applications of ozone-depleting solvents. Exceptions have been noted for certain laboratory and analytical uses and for manufacture of space shuttle rocket motors. HCFCs have not been adopted on a large scale as alternatives to CFC solvents. In the near term, however, they may be needed as the conventional substances in some limited and unique applications. HCFC-141b is not a good replacement for methyl chloroform (1,1,1 -trichloroethane) because its ODP is three times higher. Alternatives for specific uses of ozone-depleting solvents are briefly described below. 

Electronics cleaning - For most uses in the electronics industry, ozone-depleting solvents can be replaced easily and, often, economically. A wide choice of alternatives exists. If technical specifications do not require postsolder cleaning, noclean is the preferred technology. If cleaning is required, the use of water-soluble chemistry has generally proved to be reliable. There are however limitations, whereby water-soluble chemistry is not suitable for all applications. 

Dry cleaning - Several solvents exist to replace the ozone-depleting solvents that have traditionally been used by the dry cleaning industry. Perchloroethylene has been used for more than three decades. Petroleum solvents, while flammable, can be safely used when appropriate safety precautions are taken. They include white spirit, Stoddard solvent, hydrocarbon solvents, isoparaffins, and n-paraffin. A... 

Chlorinated rubber is soluble in aromatic solvents, and paints made from it dry by solvent evaporation alone. In contrast to the vinyls, there is less difficulty in formulating systems that are suitable for brush application. It has excellent resistance to a wide range of chemicals and to water, but as it is extremely brittle it needs to be plasticised. To preserve chemical resistance it is necessary to use inert plasticisers such as chlorinated paraffin wax. Due to the presence of ozone depleting solvents, chlorinated rubber coatings are being phased out and largely replaced by vinyl acrylic coatings which have very similar performance and can be formulated from lower aromatic or aliphatic solvents. 

In addition to the availability issue, short-term price pressure on all regulated solvents is being felt in the form of taxes. Market forces have historically created prices inflated in excess of the newly taxed price. As additional solvents come under increased regulatory scratiny, we may see the hazard excise tax used again, as it has proved successful in speeding the move away from ozone-depleting solvents. 

Table 7.3. Ozone-depleting solvents restricted under the Montreal Protocol.

A variation on this procedure has been developed and constitutes passing fluorine through a dry column of AcOK. The AcOF thus formed was then usually dissolved in a suitable solvent, such as CFC13257. Recently it was discovered that this ozone-depleting solvent can be replaced by acetonitrile with no ill effects on the formation of AcOF nor on its reactions with various n centers258. 

SkyKleen [Solutia], TM for an aviation solvent that is a replacement for chlorinated or ozone depleting solvents such as MEK (methyl ethyl ketone), 1,1,1, trichlorethane, isopropyl alcohol, and acetone. It contains no halogenated materials. 

Annual report a copy of the annual report and the CER were received. As well as presenting the financial statements the annual report contains a business review in which some environmental highlights are reported. These mention certification of several sites to ISO 14001 and the conclusion of a marketing agreement for a low ozone-depleting solvent. There is also a separate section on HS E issues, which includes safety figures, reports on environmental management and describes Elf Atochem s approach to product stewardship. 

Organic solvents Remove adhesive and solder paste residues have a wide-process window can clean at room temperature do not oxidize or corrode metals Solvents and solvent vapors may he flammable high cost may be slow drying limits on VOCs and ozone-depleting solvents (ODSs) require explosion-proof equipment... 

Uses Non-ozone depleting solvent for industrial solvent cleaning, aerosols, adhesives, coatings, inks, electronic applies. 1,1,1-trichloroethane alternative dye intermediate chemical intermediate dielec, fluid Manuf./Distrib. Aldrich Fluka Occidental Sigma Trade Names Oxsol 100... 

Oynasolve XD 22-1 is an experimental solvent that was developed for use in cleaning and degreasing applications. Oynasolve XD 22-1 is a non-chlorinated, non-flammable, non-carcinogenic, non-ozone depleting solvent... 

Table 19.3. List of acceptable replacement chemicals for ozone-depleting solvents ODS) ...

Electrically conductive adhesives, primarily silver-filled epoxies, are finding uses as replacements for solder in surface-mounting components on printed-circuit boards and in flip-chip attachments. There are several driving forces for this application, a major one being the trend to eliminate lead and tin-lead solders because they may be health hazards. Also associated with the use of solder, is the need to eliminate ozone-depleting solvents presently used to clean and remove flux residues. Electrically conductive polymer... 

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