Vinylidene chloride manufacture

Diofan n Dispersion of copolymers of vinylidene chloride. Manufactured by BASF, Germany. 

Expandable VDC copolymer microspheres are prepared by a microsuspension process (191). The expanded microspheres are used in reinforced polyesters, blocking multipair cable, and in composites for furniture, marble, and marine appHcations (192—195). Vinylidene chloride copolymer microspheres are also used in printing inks and paper manufacture (196). 

Ninety-six percent of the EDC produced in the United States is converted to vinyl chloride for the production of poly(vinyl chloride) (PVC) (1) (see Vinyl polymers). Chloroform and carbon tetrachloride are used as chemical intermediates in the manufacture of chlorofluorocarbons (CECs). Methjiene chloride, 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene have wide and varied use as solvents. Methyl chloride is used almost exclusively for the manufacture of silicone. Vinylidene chloride is chiefly used to produce poly (vinylidene chloride) copolymers used in household food wraps (see Vinylidene chloride and poly(vinylidene chloride). Chloroben2enes are important chemical intermediates with end use appHcations including disinfectants, thermoplastics, and room deodorants. 

In addition to homopolymers of varying molecular and particle structure, copolymers are also available commercially in which vinyl chloride is the principal monomer. Comonomers used eommercially include vinyl acetate, vinylidene chloride, propylene, acrylonitrile, vinyl isobutyl ether, and maleic, fumaric and acrylic esters. Of these the first three only are of importance to the plastics industry. The main function of introducing comonomer is to reduce the regularity of the polymer structure and thus lower the interchain forces. The polymers may therefore be proeessed at much lower temperatures and are useful in the manufacture of gramophone records and flooring compositions. 

By copolymerising the vinylidene chloride with about 10-15% of vinyl chloride, processable polymers may be obtained which are used in the manufacture of filaments and films. These copolymers have been marketed by the Dow Company since 1940 under the trade name Saran. Vinylidene chloride-acrylonitrile copolymers for use as coatings of low moisture permeability are also marketed (Saran, Viclan). Vinylidene chloride-vinyl chloride copolymers in which the vinylidene chloride is the minor component (2-20%) were mentioned in Chapter 12. 

Trichloroethane may enter the atmosphere from its use in the manufacture of vinylidene chloride and its use as a solvent. It may also be discharged in wastewater associated with these uses and in leachates and volatile emissions from landfills. It has been detected at low levels in groundwater, drinking-water, wastewater, ambient water and ambient air (United States National Library of Medicine, 1997). 

Trichloroethane is used in the manufacture of vinylidene chloride. It has been... 

Vinyl chloride has gained worldwide importance because of its industrial use as the precursor to PVC. It is also used in a wide variety of copolymers. The inherent flame-retardant properties, wide range of plasticized compounds, and low cost of polymers from vinyl chloride have made it a significant industrial chemical. About 95% of current vinyl chloride production worldwide ends up in polymer or copolymer applications. Vinyl chloride also serves as a starling material for Uie synthesis of a variety of industrial compounds. The primary nonpolymeric uses of vinyl chloride are in the manufacture of vinylidene chloride and tri- and tetrachloroethylene. 

Manufacture. Vinylidene chloride monomer can be conveniently prepared in the laboratory by the reaction of 1,1,2-trichlorocthanc with aqueous alkali ... 

Ethylene is also used to manufacture perchloroethylene (CC12=CC12), methyl chloroform (CH3CC13), vinylidene chloride (CH2=CC12), and eth-ylamines (e.g., H2NCH2CH2NH2). 

The most common commercial process for the manufacture of vinylidene chloride is the dehydrochlorination of 1,1,2-trichloroethane with lime or caustic in slight excess (2 to 10%). A continuous liquid-phase reaction at 98 to 99°C gives a 90 percent yield of vinylidene. 

Acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, ethyl acetate, and tetrahydrofuran are solvents for vinylidene chloride polymers used in lacquer coatings methyl ethyl ketone and tetrahydrofuran are most extensively employed. Toluene is used as a diluent for either. Lacquers prepared at 10—20 wt % polymer solids in a solvent blend of two parts ketone and one part toluene have a viscosity of 20—1000 mPa-s (=cP). Lacquers can be prepared from polymers of very high vinylidene chloride content in tetrahydrofuran—toluene mixtures and stored at room temperature. Methyl ethyl ketone lacquers must be prepared and maintained at 60—70°C or the lacquer forms a solid gel. It is critical in the manufacture of polymers for a lacquer application to maintain a fairly narrow compositional distribution in the polymer to achieve good dissolution properties. 

For the manufacture of non-crosslinked ionomer polymer mixtures ethylene, butene-1, isobutylene, vinyl chloride, vinylidene chloride, aliphatic carboxylic acids of vinyl esters (C2-C18), aliphatic unsaturated mono and di carboxylic organic acid esters (C3-C8) with mono aliphatic saturated alcohols (C2-C12) and unsaturated aliphatic mono and di carboxylic organic acids (C3-C8) can be used as raw materials. 

Peroxide crosslinked ionomer mixtures made from the abovementioned raw materials may be used in contact with fatty foods under certain limited conditions, according to their raw materials and additives. Vinyl chloride and vinylidene chloride should not be used in materials having either ionic (ionomer) or physical (e.g. through electron beam irradiation) crosslinks. Crosslinked polyethylene can be used for the manufacture of food contact materials, e.g. for drinking water pipes and fittings. The cross-linking can be done using either peroxide or electron beam irradiation. 

Although 1,1-dichloroethylene (vinylidene chloride) is a relatively small-volume product, it provides a way of upgrading the unwanted 1,1,2-trichloroethane by-product from the manufacture of EDC and 1,1,1-trichloroethane. Its major use is as an intermediate for polyvinylidene chloride and its copolymers, which are important barrier materials for food packaging. 

The first two modacrylic fibers ever introduced in the United States were Dynel (by Union Carbide) in 1949 and Verel (by Tennessee Eastman) in 1956. The former was a copolymer of 60 percent vinyl chloride and 40 percent acrylonitrile, and the latter was said to be a 50-50 copolymer of vinylidene chloride and acrylonitrile with perhaps a third component graft-copolymerized onto the primary material to secure dyeability. SEF and its version for wigs, Elura , were introduced by Monsanto Fibers in 1972. A few foreign manufacturers are making modacrylic fibers, but the only modacrylic fiber currently in production in the United States is SEF . 

Direct chlorination of vinyl chloride generates 1,1,2-tnchloroethane [79-00-5] from which vinylidene chloride required for vinylidene polymers is produced. Hydrochlorination of vinylidene chloride produces 1,1,1-trichloroethane [71-55-6], which is a commercially important solvent. Trichloroethylene and perchloroethylene are manufactured by chlorination, hydrochlorination, or oxychlorination reactions involving ethylene. Aromatic solvents or pesticides such as monochlorobenzene, dichlorobenzene, and hexachlorobenzene are produced by reaction of chlorine with benzene. Monochlorobenzene is an intermediate in the manufacture of phenol, insecticide DDT, aniline, and dyes (see Chlorocarbons a>td Chlorohydrocarbons.)... 

Tetrahydrofuran is a solvent used in natural and synthetic polymers and resins such as polyvinyl chloride and vinylidene chloride copolymers. It is also used in the manufacture of lacquers, glues, paints, and inks. 

Vinyl chloride is produced in the following industrial reactions (1) the thermal cracking of 1,2-dichlor-oethane, which is produced by the chlorination and/ or oxychlorination of ethylene and (2) the hydrochlorination of acetylene. The vast majority of vinyl chloride is used for the production of polyvinyl chloride (PVC) and the manufacture of copolymers with monomers such as vinyl acetate or vinylidene chloride. A much smaller proportion of vinyl chloride is used in the production of chlorinated solvents - primarily trichloroethanes. 

Use Manufacture of vinyl chloride vinylidene chloride vinyl acetate acrylates acrylonitrile acetaldehyde per- and trichloroethylene cyclooctatetraene 1,4-butanediol carbon black and welding and cutting metals. 

Manmade Organic Fibers, Except Cellulosic Establishments primarily engaged in manufacturing manmade organic fibers, except cellulosic (including those of regenerated proteins, and of polymers or copolymers of such components as vinyl chloride, vinylidene chloride, linear esters, vinyl alcohols, aery-... 

Figure 3 shows the solubility characteristics of the vinyl acetate copolymers in MEK note the improved solubility over the homopolymers of vinyl chloride. Because these copolymers are still significantly less soluble than the metal adhesion terpolymers, one manufacturer has produced a copolymer not based on vinyl acetate (see Figure 3, high solubility copolymers). This copolymer is described in more detail in Figure 13. Copolymers are also available based on vinyl chloride-trifluorochloro-ethylene and vinyl chloride-vinylidene chloride.

Acetylen Acetylene EINECS 200-816-9 Ethine Ethyne HSDB 166 Narcylen UN1001, An asphyxiant gas intermediate for manufacture of vinyl chloride, vinylidene chloride, vinyl acetate, acrylates, acrylonitrile, acetaldehyde, perchloroethylene trichloroethylene, 1,4-butanediol, carbon black, welding and cutting metals. Colorless gas mp = -81° d = 1,166 g/l (0°, 760 mm), d of gas = 0.90 (air = 1) soluble in H2O (1 1 v/v), soluble in AcOH, EtOH, Et20, CeHe, MezCO LC (rat inh) = 9000 ppm. Air Products Chemicals Inc. BASF Corp. BOC Gases Union Carbide Corp. 

Trichloroethane is a clear, colorless, and nonflammable liquid, with a pleasant odor. It is practically insoluble in water but miscible with ethanol, chloroform, ether and chlorinated solvents. It is mainly used in the manufacturing of vinylidene chloride but may act as a specialty solvent for adhesives, fats, and resins. 

Vinylidene Chloride-Vinyl Chloride VDC/VCM). VDCA CM copolymers are tough, flexible, and durable. As a film, they find significant use in the food packaging industry. They are also manufactured as a fiber used in car upholstery and garden furniture fabrics. 

Biaxial orientation effects are important in the manufacture of films and sheet. Biaxially stretched polypropylene, poly(ethyleneterephthalate) (e.g., Melinex) and poly(vinylidene chloride) (Saran) produced by flat-film extrusion and tentering are strong films of high clarity. In biaxial orientation, molecules are randomly oriented in two dimensions just as fibers would be in a random mat the orientation-induced crystallization produces structures which do not interfere with the light waves. With polyethylene, biaxial orientation often can be achieved in blown-film extrusion. 

Vinylidene chloride-vinyl chloride copolymers are used in the manufacture of filaments. The filaments have high toughness, flexibility, durability, and chemical resistance. They find use in car upholstery, deckchair fabrics, decorative radio grilles, doll hair, filter presses, and other applications. A flame-resisting fiber said to be a 50 50 vinylidene chloride-acrylonitrile copolymer is marketed by Courtaulds with the name Teklan. 

The acrylics and modacrylics are among the most important of the amorphous fibers. They are based on the acrylonitrile unit —CH2CH(CN)— and are usually manufactured as copolymers. When the aaylonitrile content is 85% or higher, the polymer is an acrylic fiber but if this drops to between 35 and 85%, it is known as a modacrylic fiber. Vinyl chloride and vinylidene chloride are the most important comonomers, and the copolymers produce high-bulk yams, which can be subjected to a controlled shrinking process after fabrication. Once shmnk, the fibers are dimensionally stable. 

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